March Will Come in Like a Lion Monday...Cold & Dry Mid-Week...

Sunday, February 28, 2010

SW Louisiana Forecast Discussion...It was a splendid Sunday across the area, and a wonderful weekend for the most part after some early clouds Saturday. This came in the wake of our last wet weather maker on Friday. It will seem like a bad case of deja vu, perhaps worse on Monday. Temperatures on this Sunday afternoon reached the mid 60s...just about normal for the end of February. It was a cold start across the entire realm of the forecast area this morning with minimums in the 30s. Some locations saw a light freeze. There was also some areas of fog this morning with the residual lingering effects from Friday's rain and a night of maximum condensation with clear skies and calm winds. The fog quickly scoured out after sunrise, and skies were cloud-free from that point on. The controlling high pressure from the weekend is heading East down I-10 tonight, and on its heels is our next in the never-ending Pacific parade of storms. This is what will be making its presence felt across the forecast area on Monday as we start March and meteorological Spring.

This highly progressive pattern will result in a quick turnaround with rain chances back in the forecast overnight. Do you remember the scenario that played out Friday? This scenario will be repeated Monday, albeit a bit stronger this time around. The current dry air mass will quickly be displaced overnight as clouds return this evening, and as the strong upper level impulse approaches from the West rain will develop overnight as a term I've discussed a nauseum this winter season comes into play once again, overrunning (isentropic lift). The strong upper level impulse will interact with the ever-present Subtropical Jet Stream to add energy to the mix. This will engender cyclogenesis in the Western Gulf again, and that will result in widespread rain across the area Monday. The low will likely form off the coast of South Texas late tonight into Monday morning, and then trek NE through the coastal waters. The trajectory of the low should keep the forecast area in the cool sector, but the eventual track will be very close to the coast, thus heavier rain is expected during the day Monday. Clouds increase this evening, and then rain should begin to spread into the forecast area after midnight. Rain chances will be in the likely category once rain begins overnight, and be maxed out on Monday.Temperatures will be on the cool side, but will be several degrees warmer than last night. Expect temperatures to range from around 40 well inland to near 50 at the coast.

The upper level low is currently situated near ELP (El Paso, TX). It will quickly slide Eastward through Texas tonight, and be on our doorstep Monday. The ULL and surface low will produce this widespread rainfall event across the area, but they will also generate lift and an unstable air mass over the area. What this means is the potential for some thunderstorms throughout the day on Monday, most likely from around 10a.m. to 4p.m. at which times the instability will be at its greatest. The air at the surface will be cool and stable, but the ULL will produce very cold air aloft (instability). Thus, the threat for elevated thunderstorms exists. Some of the storms could be strong enough to produce small hail or graupel. See the previous post, to learn what grapuel is. All severe weather should remain in the coastal waters in the vicinity of the surface low. The threat for a thunderstorm will be less the further inland you go, but it could certainly happen at any particular location across the area. The heavy rain threat will exist for the entire forecast area as well, but the highest rainfall amounts will be closest to the coast. Average rainfall amounts (QPF) should be 1-2" with isolated amounts near the coast up to 3". A flood watch is not anticipated, though there could be some localized flooding where the heaviest rains occur especially since grounds are still saturated across the area. The atmospheric sounding shows the cool layer of air at the surface, then a layer of warm air generated by the Gulf low exists from about 2,000 to 5,000 feet up, then the extremely cold air exists up above that. This is a classic overrunning situation, but since you have to have the presence of cold air aloft to generate thunderstorms, this is added to the equation this time around. There was a bit of thunder and lightning with the preceding system on Friday, and I believe that'll be the case on Monday as well. Thankfully, the low will track through the Gulf, so there will not be a severe weather threat. Rain will encompass the entire forecast area for the duration of Monday into Monday night as the system slows down a bit because of Gulf cyclogenesis. The Gulf low will only slowly lift NE and be near the Mouth of the Mississippi River Monday night. As I've mentioned the forecast area will remain in the cool sector of this complex storm, and this will add insult to injury temperaturewise. March will still off with below normal temperatures. After morning lows in the 40s, only a modest warm up of 3-5 degrees is expected. Temperatures along the I-10 corridor will likely not get much above 50, and many locations will remain in the 40s. Along the coast, a bit more of a warm up is expected due to their closer proximity of the surface low. Coastal locations could reach close to 60, but this is still on the cool side. The pressure gradient will tighten as well with the surface high to our East and the developing and strengthening surface low in our backyard. Expect NE over 20 mph at times, and this will also add a bite to the chill. This is the same song and dance we've experienced all winter, and the first day of meteorological spring will be a raw, winter day indeed. The old bit of weather folklore..."March Comes in Like a Lion" will come to fruition.

The departure of the low will be a slow process, and there will certainly be wraparound moisture. The ULL will likely pass overhead overnight, and there could very well be a break in the rain as the low pulls to our East. As the ULL moves into and through our vicinity, the leftover moisture will get wrung out, as the pocket of cold air creates the dynamics to cause the additional rainfall. Temperatures will remain on the chilly side, likely falling a few degrees on the backside of the low as weak CAA takes over. There is some cold air bottled up to our North, and some of this will be pulled Southward into the area as the low departs. Rain should continue most of the night Monday, but conditions will begin to improve after midnight. The colder air filtering in would suggest the possibility of a changeover to frozen precipitation overnight into early Tuesday, however, the temperature profile isn't favorable for such an occurrence anywhere in the forecast area. Colder air will be filtering in at the low-levels, but we have to look at the temperature all the way up through the atmosphere. This is the problem. The air will simply be too warm in the lowest levels of the atmosphere from the surface to about 2,000 feet. This is too much of a warm pool of air to support anything frozen. All models indicate that the 0 C line at 850 mb. (a good measure of determining where the rain/snow line will be) will be in the Northern Gulf of Mexico, but at the same time the models clearly show the deep layer of above freezing air. So, no frozen precip is a no-go this time. This could certainly change, but it doesn't appear likely. For that matter, no frozen precip should occur anywhere in the state. Temperatures for Monday night into Tuesday should be on the cold side, and certainly unseasonable for early March. Expect readings to be fairly uniform with mid to upper 30s across the area. Some light rain and/or drizzle may carry over into the early daylight hours of Tuesday, but for the most part the rain should be over with before daybreak. Clouds will linger for a time longer.

A pattern shift follows the departing low. Much better weather will be in store for the rest of the week. It will be more representative of early March, although it will be on the cold side for a few days as CAA continues behind this low. Clouds will clear out Tuesday as drier air filters in at all levels of the atmosphere. It will be cold with highs struggling to reach 50. A tight pressure gradient on the backside of the low will keep it rather breezy across the area as well. Morning wind chills will be in the 20s. Clear skies and lighter winds in place Tuesday night will set the stage for a late season light freeze. Temperatures should range from the upper 20s to near freezing. The immediate coast should avoid a freeze, though certainly the mid 30s seems feasible with the drier and colder air mass in place. High pressure will be in control for the Wednesday through Friday period. A slow moderation is expected in regards to temperatures. Mornings will be cold through Friday with lows in the low to mid 30s on Wednesday night/Thursday morning and mid to upper 30s on Thursday night/Friday morning. Highs for the same time will rebound to the mid to upper 50s on Wednesday, upper 50s to mid 60s Thursday, and mid to upper 60s on Friday. It will be very pleasant each day with limited surface moisture in place resulting in low humidity values. Though temperatures will be moderating for this period, this is still below normal. Finally, for the weekend the moderation will continue. Saturday looks great at this time with temperatures approaching normal. Morning lows should be in the 40s while afternoon highs approach 70 topping out somewhere in the upper 60s. The controlling high should slowly shift Eastward as we get into the weekend, and a return flow will likely commence either late Friday or early Saturday. There is still some uncertainty involving the next weather maker. Timing issues arise. The consistency is there that another system will be on the horizon towards the end of the forecast period. The uncertainties are with the timing and strength of this system. For now, a chance of rain is reflected on Sunday. It is too early to decipher if we'll have any thunderstorms or a severe weather threat, but it certainly looks much warmer next time around. Temperatures could eclipse the 70 degree threshold for highs on Sunday, after a mild morning with a low above 50. This is seasonal for early March. Further fine tuning is expected as we go through this first week of March. The bottom line is that the pattern is shifting, even if it is perhaps only temporary. The El Nino will still be present through the month of March, so I would expect more topsy-turvy weather. A likely transition into severe weather season is expected as well with the active El Nino and an active Southern storm track. March can be a month of great variability as we see the evidence of the changing seasons. March is often one of the driest months of the year across our part of the world, but who knows if it will be in 2010 with the present El Nino.


Preliminary Numbers & Zone Forecast:


LCH  45/51  37/48  31/54  60 100 60 0 0 0
LFT   44/53  37/47  30/54  40 100 70 0 0 0
BPT   47/52  38/49  32/54  60 100 40 0 0 0
AEX  40/45  35/45  28/51  30 100 60 0 0 0
POE  40/45  35/45  28/51  40 100 50 0 0 0
ARA  44/55  37/47  31/54  40 100 70 0 0 0


Tonight...Mostly Cloudy and Not as Cold with rain developing towards morning. Low 45. East wind around 10 mph. Chance of rain 60% after midnight.

Monday...Cloudy, Cold, & Windy with widespread rain and a few thunderstorms likely.Some small hail possible. Rain heavy at times. 1-2" of rainfall expected. High 51. Temperatures falling in the afternoon. NE wind 15-25 mph and gusty. Chance of rain 100%. Wind chill readings 35-45.

Monday Night...Cloudy and Windy with rain likely before midnight. Rain tapering off after midnight. Colder. Low 37. NNW wind 15-25 mph and gusty. Chance of rain 60%. Wind chill 25-30.

Tuesday...Cloudy early. Decreasing Cloudiness through the day. Becoming Sunny in the afternoon. Cold. High 48. Continued windy with NNW winds 15-20 mph and gusty. Wind chill 25-40.

Tuesday Night...Clear and Cold. Low 31. NW wind 10-15 mph. Wind chill 25-30.

Wednesday...Sunny and Warmer. High 54. North wind 10 mph.


Drew's 7 Day Outlook


Monday
3-1-10

Low: 45
High: 51
Precip: 100%
Wind: NE 15-25
W.C.: 35-45


Tuesday
3-2-10

Low: 37
High: 48
Precip: 0%
Wind: NNW 15-20
W.C.: 25-40


Wednesday
3-3-10

Low: 31
High: 54
Wind: N 10
Precip: 0%
W.C.: 25-30


Thursday
3-4-10

Low: 36
High: 62
Precip: 0%
Wind: N 5-10


Friday
3-5-10

Low: 39
High: 65
Precip: 0%
Wind: NE 5-10


Saturday
3-6-10

Low: 45
High: 68
Precip: 0%
Wind: SE 5-10


Sunday
3-7-10

Low: 50
High: 72
Precip: 20%
Wind: SSE 10-15


...Marine Forecast...

* Small Craft Advisory in effect through Tuesday afternoon. *

Tonight...Southeast winds 15 to 20 knots in the evening increasing to around 20 knots after midnight. Seas 1 to 3 feet. Rain likely after midnight.

Monday...Southeast winds around 20 knots becoming east 20 to 25 knots in the afternoon. Seas 3 to 5 feet. Rain and scattered thunderstorms.

Monday Night...North winds 20 to 30 knots. Seas 3 to 4 feet. A chance of rain.

Tuesday...North winds 15 to 25 knots becoming 15 to 20 knots in the afternoon. Seas 2 to 4 feet subsiding to 1 to 3 feet in the afternoon.

Tuesday Night...North winds 15 to 20 knots decreasing to 5 to 10 knots after midnight. Seas 1 to 3 feet subsiding to 1 foot after midnight.

Wednesday...Southeast winds 5 to 10 knots. Seas 2 feet or less.


...Tide Data...

Monday Tides @ Calcasieu Pass

Low:  9:20a.m.     9:17p.m.
High:  1:53a.m.     2:40p.m.
 

...Toledo Bend Pool Level...

   171.66'


...Lake Charles Climate Summary...

Sunday, February 28, 2010

Low:               37
Normal Low:  47
Record Low:  26-1913
High:              65
Normal High: 68
Record High: 85-1932

Precipitation
Today:                             0.00"
Month to Date:                4.33"
Normal Month to Date:   3.28"
Year to Date:                  7.68"
Normal Year to Date:     8.80"
Record:                          1.44"-1995


Sunrise Monday:    6:39a.m.
Sunset Monday:     6:12p.m.


...Lunar Table...

Full Moon- Tonight February 28

Last Quarter- Sunday March 7

New Moon- Monday March 15

First Quarter- Tuesday March 23


This Date in Weather History...February 28, 1987: March often comes in like a lion, but in 1987 February rolled out with a fury! Severe thunderstorms occurred across the Gulf Coast in response to a strong Pacific storm. At mid-morning on this Saturday a violent tornado touched down near Moselle, MS. It would grow to a width of two miles as it passed very near Laurel, MS. This long-track F4 tornado traveled a distance of 40 miles, killed 6 people, injured 330 others, and inflicting $28.5 million in damage. An elementary school was nearly completely destroyed, but thankfully it was a Saturday, so no one was there. The tornado swept homes right off their foundations, & tossed 18-wheelers around like play toys. Strong straight line winds over 70 mph caused damage at Jonesboro, AR and Carbondale, IL.


Good night and God bless!
-DM-

Wet Friday...Dry & Cool Weekend...March Comes In Like a Lion Monday...

Thursday, February 25, 2010

SW Louisiana Forecast Discussion...The weather has been quite nice, a little cold, but overall nice since our latest snow disappointment Tuesday night. This will be changing in a big way to close out the last work week in February. Today started out on the cold side with a cold dome of high pressure in place. This resulted in an area wide freeze to start the day with temperatures in the mid 20s to lower 30s. It was a terrific Thursday with mostly sunny skies and pleasantly cool temperatures for afternoon highs in the mid 50s. A southerly flow commenced across the area as the large controlling high shifted Eastward during the day. Low level moisture is slowly increasing tonight, and the cloud cover isn't far behind now as our next unwelcome visitor hangs in the balance. The lower levels will continue to moisten up tonight and the clouds will increase from W to E overnight. It will be a good 10-15 degrees warmer across the forecast area overnight with mid 30s to lower 40s expected.

The last Friday of February will be one of the wettest days of the month. The strong El Nino system is visible on satellite imagery tonight. It is cutting through NW Texas in the vicinity of Amarillo. It is in the form of a potent short wave (disturbance) that is coming out of the Rockies. The active Subtropical Jet Stream will come into play as well, and as this energy dives SE towards the forecast area Friday, it will help to engender a surface low over the NW Gulf of Mexico. Warm air will surge up and over the cool air at the surface (overrunning), and as this isentropic ascent increases Friday morning, areas of light rain will break out across the forecast area. This should occur in the mid-late morning hours. The best chances for rain will come during the afternoon hours Friday as the low forms off the coast of SE Texas, and traverses the Northern Gulf waters through the afternoon. This will send additional surges of moisture Northward across the forecast area, and rainfall will increase in areal coverage and intensity. Rain could be heavy at times Friday afternoon. Greater instability and Jet energy will move in at this time as well. There will be plenty of cold air aloft generated by the upper level low, and this is what leads to the instability in the atmosphere. The increased amounts of instability could lead to a few thunderstorms during the afternoon or evening Friday. The track of the surface low will preclude any severe weather across the area, however, there will likely be some elevated convection due to the instability values in place. Thus, the possibility of some thunder during the afternoon. With plenty of cold air aloft I wouldn't rule out the possibility of some small hail or what is known as graupel. Graupel is basically a supercooled water droplet. It often takes on the appearance of a small hail stone or a snow grain, but it is more in the ice family. Temperatures will remain on the cool side with highs struggling to reach 50 with the rain. No frozen precipitation is expected. Rain will be in the likely category, nearly maxing out. Rainfall totals will likely be on the average of 1" or so, but some areas especially those closer to the coast could stand to see 2". The QPF chart displaying expected rainfall follows. The surface low will not only help bring rain to the area, but it will also help to stiffen the pressure gradient across the realm of the forecast area. Thus, some gusty winds are expected up to 20 mph at times. The low will slowly move Eastward in tandem with the departing ULL Friday night, and some colder air will filter into the region on its backside. Rainfall will gradually end from west to east, as a cold front is pulled through the area behind the surface low. Some moisture could linger keeping a chance for some showers in the forecast through early Saturday. No frozen precipitation is expected at this time, but models do insist that temperatures aloft will be cold enough for sleet/snow by Friday night, however, surface temperatures will be too warm to support any frozen precipitation. I will keep an eye on the model trends, but for now all precip should remain liquid in this forecast area. The Northern half of the state could see a changeover to snow late Friday through early Saturday, but even this is a marginal prospect right now. Temperatures will cool into the mid to upper 30s by Saturday morning. Conditions will drastically improve just in time for the weekend, and the majority of the weekend is shaping up nicely.

Clouds hang around for a short time Saturday morning with wrap-around moisture in place and a temperatures inversion from 925-850 mb., however, this will quickly change as the drier air lagging behind in the boundary layer finally catches up, skies will clear and become sunny by noon Saturday as a renewed area of high pressure in the wake of the Gulf low builds down into the region from the NW. It will remain on the cool side with a high only reaching the lower 50s. Sunny skies are expected for Saturday afternoon with benign weather in place with no rain expected through Sunday. Chilly weather is in store for Saturday night with high pressure right overhead. The clear skies and calm winds will provide for maximum radiational cooling, and while temperatures will be below normal, they should remain above freezing with readings in the mid 30s on average. The coldest locations of the forecast area will likely see a light freeze heading into Sunday morning. Sunday looks to be a great day to close out the month of February. There will be lots of sunshine, and it should be pleasantly mild with a high around 60. The controlling high in place for the weekend will slide Eastward into Dixie Sunday afternoon, thus establishing a return flow ahead of an even strong Pacific storm system. The weekend is going to be a sandwich....so I hope you're hungry!!! Eat up the pretty weather!

The specifics of this next event will come over the weekend, as we put the Friday system behind us. However, it is certain that we'll be facing another El Nino system and wet weather maker on Monday. The saying "March comes in like a lion" will come to fruition in 2010. The persistent Pacific parade of storms will simply just not give up its fight. A largely amplified trough digging through the Rockies will help to carve out another short wave. This wave will move into range Monday, and the active Subtropical Jet Stream will lead to Gulf cyclogenesis one more time. Rain will overspread the area once again as overrunning conditions intensify. Rain could be heavy at times once again, and I wouldn't rule out some thunder as well with plenty of instability in place. The surface low should once again remain offshore, keeping the forecast area in the cool sector. The surface low will move East, and be deepening (strengthening) at the same time, and this will in turn increase the pressure gradient over the area once again. Winds will be a factor as well. There will once again be lots of cold air present aloft, and models once again insist that there will be a changeover to frozen precip on the backside of the system. However, surface temperatures once again look to be too warm to support this idea, so this is once again left absent from the forecast at this time. Once again, this is something that I will closely be monitoring trends for. It is a tough task when forecasting winter weather, as you found out earlier this week. It certainly does look like Monday will be a day with falling temperatures. Temperatures could very well be confused for the Sunday night/Monday period as it is possible temperatures will rise overnight Sunday with the developing low and associated weak WAA, and then as the low goes by and CAA is established once again Monday afternoon temperatures will fall. This is reflected in the forecast at this time. Best guess is that temperatures will be near 50 in the morning, and fall to near 40 by evening. Rain chances will once again be very close to maxing out if not totally. It could rain all day on Monday as there will be overrunning rains ahead of the low, and wrap around rains behind it. The rain chances will begin as early as late Sunday night with the onset of the overrunning, and continue into Monday night as the post-low moisture hangs around with the colder Canadian filtering in. Look for blog entries over the weekend on this second system. The 5 day total rainfall accumulation map is included below.As of right now 1-2" of rainfall looks likely for Monday.

Timing uncertainties exist with the Monday system. Moisture could hover into early Tuesday, but this is not currently reflected. Either way, conditions improve greatly for Tuesday. High pressure builds in and takes control of the weather in the wake of the Monday storm. I should note that both the Friday and Monday storm will take the corner and go on to be big snowstorms for the East coast after they affect our region. The system that affected us this past Tuesday is dumping on them tonight. The stretch of below normal weather will continue for Tuesday as the colder Canadian resides over the area. Skies should be clear, and there will be plenty of sunshine with conditions on the cool side. Highs should reach the low to mid 50s. The remainder of the forecast period looks quiet with the high pressure continuing to dominate. A late season freeze could make a visit to the area on Wednesday with the core of the high over the area. Winter just doesn't want to loosen its grip. Light winds and sunny skies will result in a fast warm up Wednesday. This will also be a return flow off the Gulf as the high slides Eastward late in the day. The atmosphere will very remain dry at this time, so it is likely that it won't be a noticeable moisture at first. Highs will be closer to 60. Thursday remains dry, but low-level moisture increases. Temperature modification continues in earnest as well. Some clouds will dot the landscape Thursday, but after morning lows near 40, highs should be well up into the 60s. Could it actually transition to Spring that fast? While the temperatures will begin to reflect the changing of the seasons, and that yes, we are heading to spring, the active El Nino pattern will not fade away just yet. Another El Nino type system looms just beyond the forecast period. Temperatures approach 70 around this time, but this could also set the stage for some big storms in the day 8-9 time frame. It is also possible that we will transition right into severe weather threats from the frozen precip threats that we've had of late. Stay tuned as there are no dull moments in the world of weather anytime soon..


Preliminary Numbers & Zone Forecast:

LCH  40/53  38/52  35/58  20 90 30 0 0 0
LFT   41/53  38/51  36/59  10 90 30 0 0 0
BPT   43/54  39/53  37/60  30 90 30 0 0 0
AEX  36/48  35/50  31/55  20 80 30 0 0 0
POE  36/48  35/50  32/56  20 70 30 0 0 0
ARA  42/55  40/53  36/58  20 90 40 0 0 0


Tonight...Becoming Cloudy and Not as Cold with a 20% chance of showers towards morning. Low 40. SE wind 5-10 mph.

Friday...Cloudy with rain likely by afternoon. Rain could be heavy at times with embedded thunderstorms in the afternoon. Rain could contain small hail or graupel in the afternoon. High 51. NE 10-20 mph. Chance of rain 90%.

Friday Night...Cloudy with a 30% chance of rain. Ending late. Low 38. NNW wind 10-15 mph.

Saturday...Becoming Mostly Sunny and Cool. High 52. North wind 10-15 mph.

Saturday Night...Clear and Cold. Low 35. Light North wind.

Sunday...Sunny. High 58. NE wind becoming SE 5-10 mph.


Friday 2/26/10 Daily Planner

7a.m.

Weather: Cloudy
Temp: 40
Precip: 20%
Wind: NE 12

Noon

Weather: Rain
Temp: 48
Precip: 60%
Wind: NE 17

5p.m.

Weather: Rain
Temp: 51
Precip: 90%
Wind: NE 14


Drew's 7 Day Outlook


Friday
2-26-10

Low: 40
High: 53
Precip: 90%
Wind: NE 10-20


Saturday

2-27-10

Low: 38
High: 52
Precip: 0%
Wind: N 10-15


Sunday
2-28-10

Low: 35
High: 58
Precip: 0%
Wind: NE/SE 5-10


Monday
3-1-10

 

Low: 52

High: 41

Precip: 70%

Wind: NNE/NNW 20-25

W.C.: 30s PM

Tuesday

3-2-10

 

Low: 36

High: 53

Precip: 0%

Wind: N 10-15

W.C.: 25-35

Wednesday

3-3-10

 

Low: 32

High: 58

Precip: 0%

Wind: NE/SE 10

 W.C.: 25-40

Thursday

3-4-10

 

Low: 39

High: 63

Precip: 0%

Wind: SSE 10-15

...Marine Forecast...

Tonight...Southeast winds 10 to 15 knots. Seas 2 to 3 feet.

Friday...Southeast winds 10 to 15 knots becoming southwest 15 to 20 knots in the afternoon. Seas 3 to 4 feet. Rain likely.

Friday Night...Northwest winds 15 to 25 knots becoming north 20 to 25 knots after midnight. Seas 3 to 4 feet building to 3 to 5 feet after midnight. A chance of rain.

Saturday...North winds 15 to 25 knots decreasing to 10 to 15 knots in the afternoon. Seas 3 to 5 feet subsiding to 2 to 3 feet in the afternoon.

Saturday Night...Northwest winds around 10 knots becoming north after midnight. Seas 2 feet.

Sunday...East winds 10 to 15 knots. Seas 3 to 5 feet. A chance of rain.


Good night and God bless!
-DM-

Late Season Winter Storm On Track...Quickly Improving Wednesday...Active Pattern Continues...

Tuesday, February 23, 2010

Late Season Snow Still on Tap Overnight...

SW Louisiana Forecast Discussion...The much advertised short wave and upper level trough is affecting the region right on schedule tonight. Precipitation is predominantly rain at this time, but the changeover has occurred across the extreme NW portion of the forecast area with snow being reported from around Leesville-Fort Polk, but into East Texas. Temperatures will continue to fall, and reach the 30s area wide by midnight. The threat for precipitation will continue through the early morning hours of Wednesday, but as the cold core upper level low currently over Central Texas drops ESE into the forecast area, precipitation will be in the form of snow. The rain over the area at present is being caused by upper level forcing generated by the advancing short wave. The upper level low is the driving force behind this system, and is what will produce the snow across the area. There will be a break in the precipitation as the initial short wave heads off to the East quickly. The snow will spread into the area between midnight and 2a.m. and exit the region around sunrise Wednesday.While snowfall amounts will be generally an inch or less, the same can be said for rainfall totals due to the light nature of the precip, and the quick motion. One problem that has prevented much frozen precip so far is that the precip has outrun the colder air. That's why I always use the disclaimer...you just never know what you're going to get with frozen precip events in SW Louisiana, and this has been no exception.

The winter weather advisories remain in effect for all of SW Louisiana, and the only area still under a Winter Storm Warning remains over upper SE Texas. Accumulations for the entire area should be limited due to temperatures at the surface remaining above freezing for the majority of the area. The areas which have already changed over and those in the Winter Storm Warning area will likely reach freezing overnight, and there could be some icy travel up that way. Accumulations in this area could exceed 2", but average accumulations for the rest of the forecast area should be an inch or less. It won't take much snow to make this a historical event across SW Louisiana. Any accumulation of more than a trace would result in the latest accumulating snowfall in history for Lake Charles. This would break the record by one day...February 23, 1968 is the current record. 0.3" of snow fell on that late February day back in 1968. This would also be the third snowfall event of the season across the forecast area, and this is almost unprecedented.

The upper level low is currently over Central Texas and continues to dive SE towards the Bryan-College Station and Houston areas. Moisture amounts aren't overly impressive with the ULL, but it is generating its own moisture, and will likely feed off the Gulf as it approaches Houston in the next few hours, to produce a little more coverage of snow that what is currently ongoing. As the snow falls from the upper levels of the atmosphere, it will help pull down the colder air associated with the upper level low to the surface. This is a process known as dynamic cooling. It is the dynamic cooling that causes the snow to reach the ground. Temperatures at the surface don't have to be below freezing for snow to fall, if you remember my diagram of the atmosphere from last night. That is the case we have tonight. The snow will fall, but the majority of it will melt on contact. The minor accumulations will occur mainly on grassy and elevated surfaces, and all snow will melt very quickly once the precip ends after sunrise Wednesday. The most likely time frame for snow in the Lake Charles area will be between 1 and 6a.m. Snowflakes will likely be seen all the way down to the coast at some point early Wednesday morning, but with warmer air hugging the coastal areas a rain/snow mix may be the mode of precipitation with no accumulation. Unlike, the last event across the area, all accumulations will be light, and no one should see snowfall approaching 4-5" that occurred in parts of the area last time. Precipitation chances are in the likely category especially for the rain that is ongoing, but the chances of snow will be fairly high as well as this upper level comes across. This will be very similar to the event of December 11, 2008, although snow amounts will likely be more uniform this time around. There could be just as much snow in Lake Charles as there will be in Alexandria, or there could be more in Lake Charles than there will be in Alexandria, or vice versa....there's really no skill in pinpointing who exactly will get the heavier amounts with this type of set up. The upper level low supports some convective banding somewhere in the forecast area, and where this occurs amounts could exceed 1". It is just a wait and see deal at this point. Models are irrelevant at this point, although they do get credit because they depicted this chance of snow as early as about a week ago, especially the GFS. If you want to see the snow you will have to either stay up late, or get up early, because as quickly as it comes in, it will be gone. Conditions will drastically improve on Wednesday with high pressure moving in behind the departing snow. The morning low will be in the low to mid 30s across the area with the early morning snow, but with the sun quickly appearing by noon, temperatures should warm up close to 50. Brisk Northerly winds will be an issue as well with a strong pressure gradient in place in response to the advancing ULL coming across Texas, and the strong Mid West high that will be settling Southward on Wednesday. The Winter Weather Advisory is in effect for the entire area with the exception of the coastal parishes and lower Acadiana until 9a.m. (15Z) Wednesday. The counties in upper SE Texas will remain under the Winter Storm Warning until the same expiration time.

The snow is all gone Wednesday after sunrise, and the aforementioned quick improvement will be noted. The period of benign weather will be short-lived, however. Wednesday should turn out to be quite a beautiful late February day, albeit on the cool side. Highs will reach the upper 40s for much of the area, but some lower 50s are possible as well in places where the sun comes out sooner. This will quickly melt any snow that does happen to accumulate quickly, and it will be a fast, fading memory before noon. A cold night is in store Wednesday night as the Canadian high settles in right over the forecast area. This will provide for a night of maximum radiational cooling, and set the stage for an area wide freeze. Under clear skies and calm winds, temperatures will fall into the upper 20s to lower 30s. The coast should avoid a freeze, but it'll still be plenty cold with readings in the mid 30s by Thursday morning. Thursday will be a quiet weather day with plenty of sunshine to start the day, but clouds will be on the increase late in the day as our next El Nino storm system approaches. The controlling high will slide into Dixie early Thursday, and the anti-cyclonic flow will result in a return flow off the Gulf by the afternoon. This will increase low-level moisture in response to the continued fast flow at the surface with the next short wave over the Desert SW. The advanced guard of cloud cover out ahead of this system will move into the region late Thursday and Thursday night, but this period should remain dry. A warming trend will result as well with highs reaching the upper 50s. No threat of freezing temperatures Thursday night in response to the increased cloud cover and moist low-level flow. Lows should be in the mid 40s. This next disturbance will be weaker than its predecessor, and a bit moisture starved despite the low-level return flow. However, there will be enough lift and forcing to generate some showers on Friday. It doesn't appear that there will be a threat for a changeover to snow on the backside of this system in the forecast area , although Northern portions of the state could see some snow with this event.  This doesn't look like a major rain event, and it should also move through fairly quickly. This should set the stage for a fairly nice weekend.

A renewed area of high pressure follows the Friday short wave just in time for the weekend. It will remain on the cool side as drier air filters into the region Friday night. Lows should be in the mid to upper 30s. Saturday looks beautiful with lots of sunshine, low humidity, and pleasantly cool temperatures for late February. Maximums should remain below normal in the mid 50s. Dry weather continues for Saturday night into Sunday, the timing was just right! Saturday night's low will be similar to that of Friday night's. Sunday will be another day of fast transition as a return flow off the Gulf is established once again. This is ahead of a more vigorous system which is in the offing for Monday. Clouds increase after church Sunday, and I wouldn't rule out a shower or two Sunday night. Some modification occurs with highs reaching the upper 50s at best. A much stronger system moves into the region for Monday, and it looks like March will come in like a lion in 2010. A potent Pacific trough will be digging into the Rockies, and this will carve out more short waves that will be embedded in the Jet Stream. The active Subtropcial Jet will come into play, and help to energize the system further. The Jet Stream energy will engender a surface low in the Western Gulf Monday. Have we heard that before this winter? Widespread rain is expected, and it could be heavy at times. No severe weather is anticipated, but locally heavy rainfall could lead to some flooding. There will be plenty of lift and forcing could be maximized as well. Upper level dynamics could generate some elevated convection, and a few rumbles of thunder are possible. There is still some uncertainty in regards to the evolution of this system, but we'll focus on it over the weekend. Rain appears likely for most of the day Monday with rain ending Monday night as the low pushes further East through the Gulf. There is somewhat of an increasing likelihood of frozen precip on the backside of this low as colder air will be looming up North. As the low pushes on by, it will pull down this colder air. Models indicate that there will be a good deal of post-frontal precip, and some of this could changeover to sleet/snow before the precip ends late Monday night or early Tuesday. For now, this possibility will continue to be watched, but it will not be included in any forecast. At this point, rain seems inevitable for Monday, and I believe rain chances will max out by week's end. Rainfall totals Monday could exceed 2", but for now I'll say 1-2" is expected. A colder and drier air mass takes over Tuesday behind this latest system, and  temperatures will remain below normal for early March with lows in the 30s and highs in the low to mid 50s. The active pattern should continue through the first half of March, but a progression towards Spring should occur before too long. 


Preliminary Numbers & Zone Forecast:


LCH  35/50  30/56  40/55  80 30 0 0 0 60
LFT   36/51  29/55  39/55  80 30 0 0 0 50
BPT  34/52   31/57  42/55  70 20 0 0 0 60
AEX  33/48  27/53  37/50  90 30 0 0 0 60
POE  33/49  28/53  38/51  70 20 0 0 0 60
ARA  38/51  30/57  41/55  80 30 0 0 0 40


*Winter Weather Advisory in effect until 9a.m. Wednesday.*

Tonight...Cloudy, Cold, & Windy with rain likely before midnight, transitioning to all snow after midnight. Light snow accumulations possible up to 1". Low 35. NNW wind 15-20 mph and gusty. Chance of precipitation 80%. Wind chill in the 20s.

Wednesday...Cloudy with a 30% chance of snow ending by 8a.m., then quickly clearing with skies becoming Sunny by noon. High 50. NNW wind 10-15 mph.

Wednesday Night...Clear and Cold. Low 30. Light North wind.

Thursday...Mostly Sunny. High 56. NE wind 5-10 mph in the morning, becoming SE in the afternoon.

Thursday Night..Becoming Mostly Cloudy & Not as Cold. Low 40. SE wind 5-10 mph.

Friday...Cloudy with rain likely. High 55. SE wind 10-15 mph becoming NNW at 15-20 mph and gusty in the afternoon. Chance of rain 60%.


Wednesday 2/24/10 Daily Planner

7a.m.

Weather: Snow Ending
Temp: 35
Precip: 30%
Wind: NNW 12
W.C.: 27

Noon

Weather: Sunny
Temp: 46
Precip: 0%
Wind: North 10
W.C.: 42

5p.m.

Weather: Sunny
Temp: 49
Precip: 0%
Wind: N 6


Drew's 7 Day Outlook


Wednesday
2-24-10

 

Low: 35
High: 50

Precip: 30% AM 

Snow Ending by 8a.m.

Wind: NNW 10-15

W.C.: 25-40

Thursday

2-25-10

Low: 30

High: 56

Precip: 0%

Wind: NE/SE 5-10

W.C.: 20-35

Friday

2-26-10

Low: 40

High: 54

Precip: 60%

Wind: SE/NNW 15-20

Saturday

2-27-10

Low: 38

High: 54

Precip: 0%

Wind: NNW 5-10

Sunday

2-28-10

Low: 38

High: 58

Precip: 20% after dark

Wind: SE 15-20

Monday

3-1-10

 

Low: 42

High: 50

Precip: 70%

Wind: SSE 15-20/NNW 20

Tuesday

3-2-10

Low: 35

High: 45

Precip: 20%

Wind: NNW 15-20

W.C.: 25-35

...Marine Forecast...

*Small Craft Advisory.*

Tonight...North winds 20 knots. Seas 5 to 6 feet. Rain likely.

Wednesday...North winds 20 knots. Seas 4 to 5 feet subsiding to 3 to 4 feet in the afternoon. A slight chance of rain in the morning.

Wednesday Night...North winds 10 to 15 knots. Seas 2 to 3 feet subsiding to 1 to 2 feet after midnight.

Thursday...East winds 5 to 10 knots becoming southeast 10 to 15 knots in the afternoon. Seas 1 to 3 feet.

Thursday Night...South winds 10 to 15 knots. Seas 2 to 3 feet.

Friday...North winds 15 to 25 knots. Seas 4 to 6 feet. A chance of showers.


Good night and God blesss!
-DM-

Winter Storm Morning Update...

Tuesday, February 23, 2010

Good morning! Please scroll down for a complete discussion on the impinging winter storm. Just a couple of quick notes this morning.

-No change to the Winter Storm Warning or Winter Weather Advisory.

-No change in the timing of this event. Currently, rain is encroaching on the Houston area. Snow covers much of Texas along the I-35 corridor. It's snowing in San Antonio, Austin, Waco, and into parts of the DFW Metroplex. Look for rain to move into the forecast area after lunch, and a transition to snow to begin by mid-late afternoon from NW to SE. The transition should reach I-10 after sunset, and precip will become all snow by midnight for just about the entire area.

-No more model watching, time to look downstream at radar, and look out the window.

-Temperatures are holding in the low to mid 40s at this hour, but will drop at the onset of the precip into the mid to upper 30s.

-Still expecting up to an inch of snow here in Lake Charles. Some areas North of U.S. 190 could see amounts exceeding 2", and some icing problems first thing Wednesday morning.

-All snow melts in the morning hours on Wednesday.


Watch the snow move our way:


Radar Data


Remember, if you take some pictures, I want to see them. I'll display them on the blog, and give you the proper accolades. Send your pics to me via e-mail at BestWxMan1980@yahoo.com. Please indicate the location of your picture, and a snow amount if you can.


That's it for now. More later!

-DM-

Late Season Winter Storm Tuesday into Wednesday...

Monday, February 22, 2010

Late Season Winter Storm to Bring Accumulating Snow to Much of the Forecast Area Tuesday Night...

Get your cameras out, I want your snow pictures! If you get snow, and can get some good pictures please feel free to send them to me at BestWxMan1980@yahoo.com

SW Louisiana Forecast Discussion...The following discussion may get a bit technical at times, but I feel it is prudent to do so to justify forecast reasoning ahead of this snow event. Again, I use my usual disclaimer when it comes to forecasting snow.."Some will be disappointed, and some will be ecstatic" with what transpires. There's little skill in specifying who is going to get the most snow, and the following forecast and logic behind it can change at the last minute, so without further adieu...

Did you enjoy the free preview of spring this weekend? I hope so because it is going away in a hurry this Monday night. We will quickly be zapped back into the reality of late winter. It was a breezy and cooler day today in the wake of a Pacific front which came through last night. This front brought widely scattered showers and thunderstorms to the area Sunday afternoon and evening. Most of the area came through virtually unscathed, but one severe thunderstorm in St. Mary Parish near Franklin caused destructive hail to the size of tennis balls. The taste of spring across the area this weekend resulted in temperatures reaching the 70s area wide on Sunday. Today was a bit cooler with a sun and cloud mix. Monday maximums reached the mid 60s along I-10. It was much cooler across the Northern half of the forecast area where colder air was filtering in. This was as a result of a secondary, stronger cold front with Arctic origination. This boundary was slow to ooze through the remainder of the forecast area, but it has since done so. As a result temperatures are steadily falling tonight, and many areas are already in the 40s. A low stratus deck envelops the area at this time, and this will continue as a temperature inversion remains in place across the area. Surface CAA will continue resulting in a continued decrease in temps overnight. By morning, expect temperatures to range from the upper 30s to mid 40s across the forecast area with overcast conditions. Boundary layer moisture is at a minimum tonight, so no rainfall is expected. However, the dry stint will be short-lived as our next weather maker is already on the map. This will be heading our way Tuesday afternoon through Wednesday morning, and this is where the fun ensues...

This next weather system, a potent upper level low and associated trough of low pressure is located over the Desert SW stretching into West Texas tonight. It will trek ESEward overnight and approach the area Tuesday. This is a very similar system to many of its predecessors this winter. The big difference this time is the ample amounts of cold air in the atmosphere that will be transported downward as the lift associated with the aforementioned feature. The lift will generate precipitation across the forecast area with commencement expected between 18Z and 22Z (noon-4p.m.) The precipitation will overspread the area from W to E as the potent upper air system dives SE. The Arctic air will be trickling into the region during the day Tuesday with temperatures struggling to warm up much. Initial light rain and/or drizzle is possible Tuesday morning, but the more significant rainfall will hold off until afternoon when isentropic lift increases. Temperatures will be in the low to mid 40s in the morning, but once the precip begins in the afternoon, temperatures will drop back into the upper 30s. Dry and colder air is filtering into the area tonight, and this will continue with dew points continuing to drop into the 30s overnight. The drier air at the surface and in the boundary layer will slowly erode, and some evaporative cooling will occur. This evaporative cooling is what will help to moisten the lowest levels of the atmosphere, and by late afternoon the entire atmospheric column should be sufficiently moist to support precipitation reaching the ground. It is certain that precip will begin as rain across the forecast area, but now I'll get to the uncertainty. Snow will be ongoing across a large portion of Texas by Tuesday afternoon as temperatures continue to drop across this area with the SE advancing disturbance. The light rain over the forecast area will begin to transition to snow after 5p.m. from NW to SE across the forecast area. There will be a rain/snow mix for several hours from late afternoon through the evening before a complete transition to snow occurs closer to midnight for just about the entire area. All but the immediate coast and portions of Lower Acadiana will see a complete transition as the potent upper level low makes its way into the forecast area. I will give a specific time line for Lake Charles momentarily. A series of graphics follows to help illustrate the situation.

First, here's a look at model data from the NAM and GFS just as I did back in December.

This is the 00Z Tuesday run of the GFS model valid from 00Z Wednesday (6p.m. Tuesday). It depicts snow across the entire forecast area. The 0 C isotherm runs from near Birmingham, AL to Baton Rouge to offshore of Sabine Pass. If this is right then the complete changeover will occur a bit sooner than I currently expect it to. I do believe this run of the GFS is a bit fast, so we'll look at the NAM in just a minute.

Now, here's the GFS on the same model run 6 hours later. Remember, these images come in 6 hour intervals.

If this run is correct, it will be snowing at Midnight Wednesday all the way to the coast with snow tapering off back over the East Texas Lakes Area. This run seems a bit fast with the end of the precip, but I am mainly using this to show what sort of time line we can expect for snow in the Lake Area.


Now, let's switch gears and look at the NAM.

Determining which model has the timing of the precip correct is a tough call. The NAM is a bit slower and wetter than the GFS on this run, and who knows they could be flip-flopped on the next run. Again, the main reason for showing this is to throw out all possibilities in regards to the snow potential. This look shows the 0 C isotherm running from near Baton Rouge to offshore the Texas coast. On this run, snow would be falling at midnight Wednesday along and W of this line. This would mean that all of the forecast area will have switched over to snow.

6 hours later, the NAM shows snow continuing across the forecast area. At this time, snow is tapering off over the Lakes Area of SE Texas. The timing of the precip on the NAM seems more reasonable. The total QPF for the NAM and the GFS seems fairly close. In forecasting snow, you have to remember that the models depict precip values in the liquid equivalent. The conversion rate for snow varies depending on location, and generally along the Gulf coast is 10:1....that means 1" of rain equals 10" of snow. So, based on the depicted QPF amounts total accumulations between 1-2" are possible. Although, accumulations will be largely limited across the forecast area based on the following parameters: warm soil temperatures, relatively warm surface temperatures for much of the event. Surface temperatures in the 40s on Tuesday afternoon with rain will drop into the 30s, but as the atmospheric column moistens up the temperature will level off in the mid 30s, and only slowly fall closer to freezing as the heavier snow falls. Also, the soil temperatures are well above freezing, therefore, most of the snow that falls will melt shortly after it makes contact with the ground. These factors should preclude significant accumulations across the area, but 1-3" of snow will be possible across the forecast area. The highest totals based on the current model trends should be across the Northern half of the forecast area, with up to an inch possible for the Lake Charles area. Along the coast, snow will likely fall but accumulations should be just a bit more than a dusting.

Perhaps the most important tool to use as a meteorologist when forecasting snow is an atmospheric sounding. The sounding is a graphical representation of the atmospheric profile. It depicts temperatures and dew points at all levels of the atmosphere. This is the forecast sounding for LCH at 6p.m. Tuesday. Here's a few pointers to help you better understand how this diagram works. The bottom row of numbers represents the temperature in C. The 2 curved lines on the graph represent temperature and dew point. Dew point is on the left, and temperature is on the right (C). The numbers on the left hand side of the graph are the levels of the atmosphere. 100 mb. is the top of the atmosphere, while 1000 mb. is near the surface. Also, the closer together the lines are, the more moist the atmospheric profile is.

Nearly the entire air column is below freezing. The exception is the temperature from around 800 mb. to the surface. This would indicate that a rain/snow mix is likely at this time, with rain still the most likely p-type as snow falls into this above freezing layer, but melts before reaching the surface.

Fast forwarding 6 hours...at midnight Wednesday...the sounding is indicative of a snow profile. Nearly the entire atmospheric profile is below freezing. Only a small portion of the atmosphere from the surface to about 950 mb. is above freezing. This leaves very little time for the snow to melt on its way to the surface, therefore most of the precip at this time would be in the form of snow.

Let's take it out a bit further, even though precip could be over by this time...it's a tough call. For now, I believe precip will continue after daylight Wednesday. So, based on that here's the projected atmospheric profile at 6a.m. Wednesday at Lake Charles.

It is very similar the profile at 6Z except some drier air is beginning to set in at the lower levels as depicted by the spread between the dew point and temperature line. Temperatures are just above freezing at the surface, but any precip at this time would be in the form of snow.

I'll take another look at sounding data tomorrow morning, but it is getting down to time now where it's just a matter of looking out the window, and not relying on models to see what will transpire. When forecasting snow, things can change right up to the last minute, and I would expect further revisions to the accumulation forecast and possibly further revisions to the watches and warnings already set forth by the National Weather Service. Based on the data above, the National Weather Service in Lake Charles has issued the following:

*A Winter Storm Warning is in effect from 6p.m. Tuesday until 9a.m. Wednesday for Vernon, Rapides, and Avoyelles Parishes in Louisiana, and Tyler, Jasper, and Newton Counties in SE Texas.

*A Winter Weather Advisory is in effect south of this area for the same time frameand includes a large portion of the forecast area. In SE Texas, it includes Jefferson, Hardin, and Orange Counties, and in SW Louisiana it includes Beauregard, Allen, Evangeline, St. Landry, St. Martin, Lafayette, Acadia, Jefferson Davis, and Calcasieu Parishes.

What is the difference in these? A Winter Storm Warning means that significant amounts of snow, sleet, or ice are occurring (in this case, snow) or will occur. Travel will likely become treacherous. Generally, a Winter Storm Warning is issued when 2" or more of snow is expected. A Winter Weather Advisory means that periods of snow, sleet, or ice will occur and cause travel difficulties, slippery roads, and limited visibilities. Use caution when driving. A Winter Weather Advisory is typically issued when snow amounts are forecasted to be less than 2". This criteria varies depending on location.

These warnings/advisories encompasses nearly the entire forecast area. The only parishes not included in any sort of winter weather advisory or winter storm warning is Cameron and Vermilion Parishes. Though, even these areas will see some snow. Little to no accumulation is expected in these areas as the precip should predominantly be a rain/snow mix for the duration of the event. 

As I stated earlier, rain is the likely p-type for the afternoon hours on Tuesday. It should mostly be light with total amounts of a quarter inch or less. Snow will start mixing in across the Northern half of the forecast area after 4p.m. The same holds true for SE Texas. Snow should start to mix in with the rain in Lake Charles after sunset, and it may take a few more hours for the complete transition to all snow to occur. However, there is the possibility that the air could be a couple of degrees colder than forecast, and if so the transition would occur sooner. By the same token, if the temperature is a couple of degrees warmer, than the transition would take longer. There's a really fine line in determining this, and there's very little skill in pinpointing exactly when the changeover will occur. All model data suggests that snow will occur in SW Louisiana, and I see no reason to believe otherwise. Snow should fall much of the night Tuesday night through the early morning hours of Wednesday before ending between sunrise and mid-morning across the area. Here is my official time line for the city of Lake Charles. It'll be a 24 hour time line from noon Tuesday to noon Wednesday for purposes of this event. Precip type and temperatures are indicated in this time line.

Noon

Light Rain/Drizzle- 42

4p.m.

Light Rain- 39


8p.m.

Rain/Snow Mix- 37

Midnight Wednesday

Snow- 35

4a.m. Wednesday

Snow- 34

8a.m. Wednesday

Snow Ending- 35

Noon

Sunny- 43

*While not indicated here, a transition period may begin the 4p.m. and 8p.m. window at Lake Charles. If transition occurs a little later, it could be between 8p.m. and midnight, but it is likely to be all snow by midnight. This is the way I see things at the moment. I will update this in the morning once we see how the system is progressing over Texas.

Precipitation amounts should be light, but there has been some hint at a surface reflection forming over the Gulf as the potent system moves into SE Texas. This solution is discounted for now, as models have been inconsistent with this idea, but if this were to occur then precip would likely be enhanced across the forecast area. Rainfall amounts will be light as I've previously stated, and while significant by SW Louisiana standards, the actual snow amounts will be light as well basically because of reasons stated above. Snow will potentially be heavy at times. The set up favors convective banding (deformation zone) as most snow events typically do, and wherever this deformation zone sets up is where the heaviest snow will likely occur. At this time, this looks to be in the Winter Storm Warning area, but other heavier bands could possibly set up further South, it just remains to be seen. I say it every time we have the potential for snow in SW Louisiana, but it really is a situation where we won't know who is going to get the heaviest snow until the snow bands materialize. Precip chances will be minimal in the morning hours on Tuesday, but will quickly leap into the likely category by the evening. Precip chances will max out overnight Tuesday through early Wednesday before the system pushes East during the morning hours Wednesday. A chance of snow is maintained until mid-morning Wednesday, but conditions will rapidly improve as the potent upper level system pulls away on Wednesday with sunshine returning by the afternoon hours. Temperatures will be challenging as well. Tuesday temperatures will likely be confused with falling temperatures with the onset of the rain in the afternoon. Temperatures will approach freezing during the snow Tuesday night/Wednesday morning, and be below freezing North of I-10. This is where the difficulty comes into play. The surface temperatures North of I-10 will likely lead to some ice formation on bridges and elevated roadways, which will make for difficult travel Wednesday morning. Any snow that melts while temperatures are above freezing will re-freeze towards sunrise creating black ice. Some snow could stick to the roads and bridges if temperatures cool off quicker than expected in these areas, and make Wednesday morning travel quite dangerous. Further south, along I-10 not many travel problems are expected, though there could be some icing on elevated surfaces, however, temperatures are forecast to bottom out right at or just above freezing, thus limiting icing potential in these areas. Depending on how long the moisture hangs over the area, SW Louisiana could wake up to a world of white on Wednesday with some snow on the ground, and snow still falling for a little while longer. However, as stated previously, the snow will quickly end after sunrise Wednesday, and skies will clear rapidly behind the snow. All snow will melt away by noon Wednesday. The sun comes out, but it will remain cold with highs in the mid to upper 40s. A brisk North wind will be present as well, not only for the winter storm but into Wednesday. A wind chill factor in the 20s will be present during the precipitation, so bundle up if you head out to play in the snow. The clear skies, and continued CAA will set the stage for another cold night on Wednesday night into Thursday morning with an area wide freeze. Temperatures will range from the upper 20s to lower 30s across the forecast area.

I need to be brief with the rest of this discussion, because all focus is on the winter storm. Here goes...the active pattern that we are accustomed to this winter will continue as we head into March. Thursday should be a nice day after a cold start. Lots of sunshine is expected with high pressure overhead. Temperatures should easily top the 50 degree mark, and probably end up near 55. Unfortunately, the nice weather doesn't last long as we'll have another El Nino type system in the offing for Friday into Saturday. The timing of this second system is still a bit uncertain, but we'll hone in on that come Wednesday. Models depict a Gulf low forming, so this could enhance the expected cold rain across the area. Rain should begin late day Friday, and be in the likely category for Friday night into Saturday morning. Rain should be the predominant p-type, and probably the only p-type with this event for this area, however, a snow event could occur up across North Louisiana. There is a chance of some frozen precip on the backside of this system across our neck of the woods, but again, I'll re-evaluate that later. Conditions improve quickly again Saturday, but it remains cold with highs in he 40s and 50s and lows in the 30s, and we'll stay dry with not a whole lot of sunshine into Sunday, before another Gulf low forms in response to yet another potent Pacific short wave. This one could usher in March like a lion on Monday. It, too, may provide a chance for some frozen precip on its backside late Sunday into Monday. Insult will be added to injury during this time, as the cold temperatures remain in place. We don't anymore rain either, in what has been an incredibly wet winter. As we get into March next week, you would figure Spring isn't too far way, but in this pattern all bets are off. I certainly believe the wet pattern will continue for March, but Spring should make a more permanent appearance before too long. This has been an incredible winter. Multiple frozen precipitation events in South Louisiana, who would've guessed that? I can't recall an instance where we've ever had 3 snows in one season, but that is indeed what may happen if it snows tomorrow night into Wednesday. In closing, here's a brief aside...if it snows more a trace at Lake Charles on Wednesday (2/24), it would be the latest accumulating snowfall of more than a trace on record at that location. It's very interesting indeed because we have already established a record for our earliest snowfall on record this season. As it stands right now, the record for latest snowfall is 0.3" on February 23, 1968. There have been many occurrences of trace snow amounts in March, and even in April. Stay tuned for more on this winter storm!


Preliminary Numbers & Zone Forecast:
 
LCH  48/36  33/47  30/54  0 60 100 40 0 0 
LFT   48/37  34/46  31/54  0 40 100 50 0 0
BPT   46/36  33/48  32/55  0 70 100 30 0 0
AEX  43/32  29/44  26/50  0 40 100 40 0 0  
POE  43/32  29/45  26/51  0 50 100 40 0 0
ARA  50/38  35/49  32/55  0 30 100 60 0 0


*Winter Weather Advisory in effect for Jefferson, Orange, & Hardin Counties in SE Texas, & Calcasieu, Beauregard, Jefferson Davis, Allen, Evangeline, Acadia, Lafayette, St. Landry, & St. Martin Parishes in SW Louisiana  from 6p.m. Tuesday until 9a.m. Wednesday.*

*Winter Storm Warning from 6p.m. Tuesday until 9a.m. Wednesday for Tyler, Jasper, and Newton Counties in SE Texas and Vernon, Rapides, and Avoyelles Parishes in Louisiana.*


Tonight...Cloudy and Colder. Low 43. North wind 10-15 mph.

Tuesday...Cloudy, Cold, & Windy with rain developing in the afternoon. Intermittent light rain and/or drizzle in the morning. Rain becoming likely late afternoon. Rain becoming mixed with snow in the evening. No snow accumulation. High 46 with temperatures falling into the 30s in the afternoon. North wind 15-20 mph and gusty. Chance of precipitation 60%.

Tuesday Night...Rain and Snow likely in the evening, then becoming all Snow by midnight. Snow after midnight. Snow accumulations up to 1". Low 33. North wind 15-20 mph and gusty. Chance of precipitation 100%. Wind chill in the 20s.

Wednesday...Cloudy & Cold w/ a chance of snow until mid-morning. No additional snow accumulation expected. Snow totals 1-3" across the forecast area. Snow ending in the morning with skies become Sunny around noon. High 47. North wind 10-15 mph. Chance of snow 40% in the morning.

Wednesday Night...Clear and Cold. Low 30. Light North wind.

Thursday...Sunny and Warmer. High 54. North wind 5-10 mph.


Drew's 7 Day Outlook


Tuesday
2-23-10

 

Low: 36

High: 48 

Precip: 60% PM

Mostly Rain until after Sunset

Wind: N 15-20

W.C.: 30s

Wednesday

2-24-10

Low: 33
High: 47
Precip: 40% AM Snow
Wind: N 10-15
W.C.: 25-40


Thursday
2-25-10

Low: 30
High: 54
Precip: 0%
Wind: N 5-10
W.C.: 25-40


Friday
2-26-10

Low: 37
High: 52
Precip: 60%
Wind: NE 10-15
W.C.: 40s


Saturday
2-27-10

 

Low: 38

High: 46

Precip: 40% AM

Wind: NNW 15-20

W.C.: 30s

Sunday

2-28-10

 

Low: 42

High: 54

Precip: 30% PM

Wind: NE 10-15

W.C.: 40s

Monday

3-1-10

 

Low: 43

High: 51

Precip: 70%

Wind: SE/NNW 15-20

W.C: 40s

...Marine Forecast...

Tonight...Northeast winds 10 to 15 knots. Seas 2 to 3 feet.

Tuesday...Northeast winds 10 to 15 knots. Seas 2 to 3 feet. A slight chance of rain in the afternoon.

Tuesday Night...North winds 15 to 20 knots. Seas 3 to 5 feet building to 4 to 6 feet after midnight. Rain likely in the evening... Then a chance of rain after midnight.

Wednesday...North winds 15 to 20 knots. Seas 4 to 6 feet subsiding to 4 to 5 feet in the afternoon. A chance of rain in the morning.

Wednesday Night...North winds 10 to 15 knots. Seas 3 to 5 feet subsiding to 2 to 4 feet after midnight.

Thursday...Southeast winds 5 to 10 knots. Seas 2 to 4 feet.

Good night and God bless!

-DM-