There is no video blog today. The blog is in severe weather mode. The video blog will return tomorrow.
...Severe Weather Threat Tuesday Morning Before the Big Time Arctic Blast Arrives...Frozen Precip Chances Increasing for the End of the Week...
I apologize in advance for the length of the following discussion, but there is much to examine and explain.
SW Louisiana Forecast Discussion...This forecast features something for everybody. This Monday was for all intents and purposes the proverbial calm before the storm. It wasn't a half bad day after the morning fog dissipated. We even saw a little bit sunshine at least for the morning hours. Clouds quickly impeded the sun this afternoon as the vigorous system encroaches. Temperatures were on the mild side with afternoon highs reaching the upper 60s for most locations. Not much in the way of rainfall occurred, but a few very small showers were noted in the mid-late afternoon hours. An onshore flow was present across the area as the system really gets cranked up. The calmness will exist through much of the night, but certain parameters will slowly be coming together as we head into Tuesday morning such that a severe weather threat will unfold. More on that in a moment. Enjoy the mild weather tonight, because that will become a fast fading memory in a matter of hours. Overnight temperatures will hold generally in the lower 60s. A very moist, and stagnant air mass is currently in place, and with plenty of low level moisture in place and a strong marine influence areas of fog will also be possible. The fog will be densest near the coast. The fog will scour out towards sunrise as the rain develops, and surface winds increase to create sufficient atmospheric mixing. Showers will begin to break out after midnight as lifting and forcing increase in advance of the very powerful late winter storm. It will become a wet start to the month of February. Activity should be scattered in nature at first in the pre-dawn hours. The front itself is currently moving through North Texas. Tuesday will start off wet for sure.
Rain chances will be maxed out at 100% for Tuesday with rain becoming widespread ahead of the front during the morning hours. The shear magnitude of this potent storm which is embedded in the Polar Jet will generate surface cyclogensis in Texas later tonight into Tuesday morning. This low pressure will be the one that becomes the driving force behind the weather across much of the nation on Tuesday. We will be in the warm sector of this storm, thus we will have to contend with our first severe weather event of the new year. Forcing and pre-frontal convergence will continue to increase rather dramatically Tuesday morning, and rains will become widespread. The best chance for thunderstorms will come between mid-morning and mid-afternoon basically along and ahead of the strong Arctic front. The surface low and a strengthening low-level Jet will provide the focus for severe weather. Some parameters will be lacking, but this is a very dynamic system with a ton of energy needed to be displaced, so that's another reason for the aforementioned severe threat. The main inhibiting factor will be instability itself. This isn't a classic set up for severe weather like we would experience in the spring time, but the synoptic scale set up favors low-topped wind damaging thunderstorms. Large hail is also in the equation given the amount of cold air aloft that this system will have to work with. Given the veering of the winds, vorticity will be present as well to provide an additional threat for isolated tornadoes. The greatest tornado threat should materialize over Acadiana and into SE Louisiana where they will have a longer duration in the warm sector, thus allowing the effects of convective heating to take place. The entire forecast area is highlighted by the Storm Prediction Center for a slight risk of severe weather. I wouldn't be surprised if a severe thunderstorm or tornado watch was issued for the area Tuesday morning. It will be a good idea to set your NOAA Weather Radio to alert mode. Also, you will want to have a plan of action in place at work or school tomorrow just in case severe weather should occur. The graphical representation from the Storm Prediction Center follows.
As shower and thunderstorm activity transitions from scattered to widespread during the morning hours, the severe threat will unfold. The set up favors the evolution of a fast-moving squall line of thunderstorms just ahead of the front. This line will congeal over SE Texas, and quickly race SE through our forecast area. The main threat from this line will be damaging winds due to the speed of the line itself, and the extremely fast Jet Stream overhead. The squall line should be rather narrow, and the severe weather threat will unfold rather quickly. It will end with the passage of the front. Timing of the roughest weather should be between 10a.m. and 2p.m. across the forecast area. The front will race across the forecast area, and enter the forecast area in the late morning hours, and be in the offshore waters by mid-afternoon. If you have travel plans further North of our area, you may want to call ahead because the weather will be absolutely awful across a large stretch of our great nation. A nasty ice storm will develop from near the Dallas area into parts of the Mid West and into New England. North of that, a nasty snow storm will unfold. Blizzard warnings are in effect from the Red River Valley in Oklahoma including the Oklahoma City and Tulsa areas all the way up through Chicago and towards South Bend, Indiana. 1-3' of snow will occur in a wide swath. We won't have to contend with any of that, but some snow may fall on the backside of this system as close as portions of East Texas and maybe into the Shreveport area.
Back home, high temperatures will occur early in the day likely by noon with readings typically between 62-66 across the forecast area ahead of the major Arctic front. However, temperatures will drop dramatically in its wake tomorrow afternoon. We will likely be in the upper 30s to lower 40s by tomorrow evening's drive home. You will want to bring your winter wraps with you as you head out the door in the morning. Of course, you will want the rain gear in hand as well. Along with the quick severe weather risk, our biggest issue here locally will be the threat for heavy rain. This rain will fall on top of the 1-2" that fell on Sunday. This time average amounts should be closer to 2", but some locations will see upwards of 4" of rain. This could lead to some localized street flooding, but a widespread flood event is not expected since overall we are still in drought conditions overall. We will be getting a head start on rainfall for the month of February, which is a good thing since we will soon be heading into our usual dry season of spring. The severe weather threat will end with frontal passage, and so will this preview of spring. As stated above, temperatures will fall from the 60s ahead of the front to the 30s by tomorrow evening, but it will feel even colder than that because of the wind. It will be windy in the morning as pressure differences increase with the developing storm, but the onshore flow will keep it mild. However, once the front blows on by a strong offshore flow will develop with very strong CAA taking over. Winds on the order of 20-30 mph at times in the afternoon will create wind chills in the 20s and 30s by tomorrow evening. Winter will return with a vengeance! A brief shot of post-frontal rain will be expected, but as the deeper cold air arrives later in the afternoon, the rain will abruptly come to an end. The trajectory of the backside low pressure system will keep the threat of a long duration post-frontal precipitation event from occurring around these parts.
Clouds will hang tough across the region through the overnight hours Tuesday with a few breaks noted after midnight. That won't keep us from experiencing hard freeze conditions. The CAA will lead to this freeze event as temperatures continue to plummet. The winds will be transporting air that will be coming straight off of the ice and snowpack to our North. The massive Arctic high will continue sliding down the base of the Rockies. Overnight temperatures will fall into the 20s area wide, and hard freeze conditions will be experienced all the way to the coast by sunrise Wednesday. Lower 20s are expected for locations further North around Alexandria and Fort Polk, while mid 20s should suffice from Beaumont to Lake Charles. Even Cameron to New Iberia will see upper 20s. The freezing line will drop into the forecast area between 8 and 9p.m. Tuesday night, and reach the I-10 corridor by midnight, and the coast by 2-3 a.m. The winds will also remain a factor as is usual in a strong CAA post-frontal environment. These NNW winds on the order of 20 mph at times will translate into apparent temperatures between 5 and 15 degrees by Wednesday morning. That is brutally cold across our part of the world, and bordering on Wind Chill Advisory territory. A hard freeze warning has already been issued by the National Weather Service in Lake Charles. The period of Tuesday night-Wednesday will be precip free, but it will be very cold and clouds will hang tough with weak overrunning in place. This cold air will be shallow in nature, thus leading to overrunning above the surface. Wednesday will be quiet from the aspect of sensible weather, but the cold air will continue to be the big story. CAA will offset daytime heating, so don't expect much warming. Temperatures won't rise above freezing until about lunch time. Daily maximums will only be in the mid to upper 30s at best (guidance is still a wee bit warm for highs). Guidance doesn't take into account the expanse of the snow and ice to our North. The winds will give the air a continued icy chill with Northerly winds around 15-20 mph. Wind chill readings will likely be below 25 all day. Dress accordingly!
For the next part of this discussion I issue a disclaimer...What I am about to say should be taken with a grain of salt, and will likely change multiple times over the next few days. I also reserve the right to completely change this part of the forecast at any time. Now, with that being said, here goes...
The period of Thursday and Friday looks rather interesting to say the least. I touched briefly on this last night. While it is prudent to discuss this, it is also imperative to remain focused on our severe weather threat looming in the short term. Model data is more consistent today with the idea of some late week shenanigans. Overrunning moisture looks to be present, and models indicate Gulf cyclogenesis will occur on Thursday. At the same time, an embedded disturbance in the active Jet Stream will be translating slowly Eastward from the Western states. All of this sets the stage for moisture to overrun the entrenched Arctic air mass. In this set up, precipitation would be likely. Precipitation that falls in the Thursday-Friday time frame would more than likely be in the form of snow. The atmospheric sounding for Lake Charles indicates that the favored p-type during this time would indeed be snow. There could perhaps be some sleet if there is a deep enough layer of warm air present just above the surface. The air mass will be extremely dry, and it will take some evaporative cooling to get much of the precipitation to reach the ground. Thursday itself looks overcast with the idea that light snow may form late in the day as forcing begins to increase with the formation of the Gulf low off the Lower Texas Coast. Thursday will be a very cold day regardless of if there is precip or not with morning lows in the 22-26 range across the forecast area. Temperatures will not make it out of the 30s once again with average highs in the mid to upper 30s yet again. Wind chills will continue to be in the 10s and 20s. Precip may begin to fall, but will likely sublimate (evaporate) before reaching the surface with the dry air in place. A slight chance of snow is mentioned for later in the day. Our snow chances increase Thursday night and especially for Friday as the surface low and upper level feature translate in tandem from West to East towards the forecast area. Forcing continues to increase and convergence may increase especially closer to the coast.
Confidence is increasing that frozen precipitation will occur later this week, and the idea of some snow is exciting. However, let us not get our hopes up just yet. This is SW Louisiana, and we are talking about winter weather that may or may not occur 3-4 days out. There is little skill in forecasting winter weather accurately this far out. Certainly, the consistency of the models can't be ignored, and the pattern is recognized as one that supports snow formation. The cold air will remain entrenched over the area for the Thursday night-Friday time frame. The chance for precip is at 30% for Thursday night and 40% for Friday for now. A hard freeze is to be expected regardless of precipitation once again for this time frame with readings into the low to mid 20s over the area. Trying to forecast any accumulation of snow at this point is near impossible especially with much uncertainty as to whether it will even snow at all. Let us get past Tuesday's event first before we really start honing in on this end of the week episode with more specificity. Snow looks like the likely precip type at this juncture, but I certainly can't rule out an ice event either. All scenarios are possible with respect to winter weather. Again, at this point there is little skill in pinpointing accumulations or even who gets what. Models continue to trend a bit colder and wetter for this time frame, thus the increased forecast confidence that something will happen. Friday could very well be a day where we don't make it back above freezing depending upon the amount of precipitation that occurs. For now, mid 30s will be the target number. The chance for wintry precipitation will carry over into Friday night as the low transpires Eastward, but we should clear out overnight Friday with high pressure remaining in control. The Arctic air will remain in place, and Saturday will be another very cold morning with readings down into the 20s again.
Saturday's forecast can change as well depending on what happens Friday, but for now we'll roll with this. Saturday should begin a warming trend. After the cold start with 20s again, we'll see beaucoup sunshine with high pressure in control. Air mass modification will ensue as CAA ceases, and daytime heating will allow high temperatures to reach levels that might seem rather balmy, the mid to upper 40s. Temperatures will fall into the light freeze category Saturday night with readings between 28 and 32 in this forecast area. Dew points will have increased some, so frost may be an issue for Super Bowl Sunday morning under clear skies. The warming trend will continue for Sunday, and some cloud cover will move in during the afternoon as weak WAA takes over ahead of another developing and deepening trough. The weekend should be precip free. It will still be chilly by South Louisiana standards, but it will feel bearable heading out to church on your Super Bowl Sunday. It looks nice for any Super Bowl parties as well. High temperatures in the 50s to around 60 should easily be amassed. Clouds will continue to increase Sunday night into Monday. Our next cold front looks to arrive during the day on Monday as we close out the first calendar week of February. This front will provide our next chance of rain at the end of the forecast period, but the exact timing of the front and the amount of rain is still to be determined at this time. It also appears as though this front will feature another Arctic tap with another significant drop in temperatures to follow just beyond this forecast period. For Monday, temperatures will be close to seasonal with the aforementioned chance of rain. The overall trend for the first couple weeks of February is for colder weather to continue. Somebody might want to shoot that furry rodent on Wednesday!
Preliminary Numbers & Zone Forecast:
LCH 62/64 25/37 24/37 30 100 10 0 0 20
LFT 61/65 26/38 24/37 30 100 10 0 0 20
BPT 62/63 24/37 25/37 40 100 10 0 0 20
AEX 57/57 22/35 21/36 40 100 10 0 0 20
POE 58/58 22/35 21/36 40 100 10 0 0 20
ARA 63/66 27/39 25/38 30 100 10 0 0 20
*Hard Freeze Watch from late Tuesday night through Wednesday morning. *
*Wind Advisory from noon Tuesday to midnight Wednesday.*
*Dense Fog Advisory for Cameron and Vermilion Parishes.*
Tonight...Cloudy with rain developing after midnight. Areas of fog, most likely near the coast. Mild. Low 60. SSE wind 10-15 mph. Chance of rain 40%.
Tuesday...Cloudy & Windy with showers & thunderstorms likely. Heavy rainfall likely & severe weather possible. Damaging winds & large hail the main threats. An isolated tornado or two possible in the morning. Rain tapering off in the afternoon. Turning Much Colder & Very Windy. High 64 with temperatures falling into the upper 30s by evening. SSW wind 20 mph and gusty in the morning, becoming NNW at 20-30 mph and gusty in the afternoon. Chance of rain 100%. Rainfall totals 2-3". Wind chills readings in the 20s by late afternoon.
Tuesday Night...Mostly Cloudy, Much Colder, & Windy. A Hard Freeze is Likely. Low 25. NNW wind 20-25 mph and gusty. Wind chill values 5-15 by sunrise Wednesday.
Wednesday...Partly Cloudy & Very Cold. High 37. NNW wind 15-20 mph and gusty. Wind chill values 15-25.
Wednesday Night...Partly Cloudy & Very Cold with Another Hard Freeze. Low 24. North wind 10-15 mph. Wind chills in the 10s.
Thursday...Partly Cloudy in the morning, becoming Mostly Cloudy with a 20% chance of light rain, light sleet or light snow late. No accumulation. Continued Very Cold. High 37. North wind 10 mph.
Tuesday 2/1/11 Daily Planner
6a.m.
Weather: Rain
Temp: 62
Rain: 60%
Wind: S 14
9a.m.
Weather: Rain & T-Storms
Temp: 63
Rain: 80%
Wind: SSW 17
Noon
Weather: T-Storms...Cold Front Approaching
Temp: 64
Rain: 100%
Wind: SSW 21
3p.m.
Weather: Rain, Windy, & Temps Dropping
Temp: 45
Rain: 70%
Wind: NNW 25
W.C.: 32
6p.m.
Weather: Cloudy, Cold, & Windy
Temp: 38
Rain: 20%
Wind: NNW 27
W.C.: 14
9p.m.
Weather: Cloudy, Cold, & Windy
Temp: 34
Rain: 10%
Wind: NNW 25
Drew's 7 Day Outlook
Tuesday
2-1-11
Low: 60
High: 64
Falling to 31 by midnight
Rain: 100%
Wind: SSW/NNW 15-30
W.C.: 20s & 30s in the evening
Wednesday
2-2-11
Groundhog Day
Low: 25
High: 37
Precip: 10%
Wind: NNW 15-20
W.C.: 5-20
Thursday
2-3-11
Low: 24
High: 37
Precip: 20%
Wind: N 10-15
W.C.: 10-20
Friday
2-4-11
Low: 26
High: 34
Precip: 40%
Wind: NNE 15-20
W.C.: 10s
Saturday
2-5-11
Low: 25
High: 48
Precip: 0%
Wind: NE 5-10
W.C.: 20-35
Sunday
2-6-11
Super Bowl
Low: 30
High: 57
Rain: 0%
Wind: ESE 5-10
W.C.: 25-40
Monday
2-7-11
Low: 42
High: 56
Rain: 30%
Wind: SSE/NNW 10-20
...Marine Forecast...
*Dense Fog Advisory in effect until 6a.m Tuesday.*
*Small Craft Advisory through Tuesday morning.*
*Gale Watch in effect from Tuesday afternoon through Tuesday night.*
Tonight...Southeast winds 15 to 20 knots. Seas 2 to 3 feet building to 2 to 4 feet after midnight. Areas of fog. Isolated showers late in the evening...then a chance of rain and isolated thunderstorms after midnight.
Tuesday...Southwest winds 15 to 25 knots becoming northwest 20 to 30 knots with higher gusts in the afternoon. Seas 2 to 4 feet building to 3 to 5 feet in the afternoon. Rain in the morning. Isolated thunderstorms until late afternoon. A slight chance of rain in the afternoon.
Tuesday Night...Northwest winds 20 to 25 knots with higher gusts becoming north 15 to 25 knots after midnight. Seas 4 to 6 feet subsiding to 3 to 5 feet after midnight.
Wednesday...North winds 15 to 20 knots. Seas 3 to 5 feet.
Wednesday Night...Northeast winds 15 to 20 knots. Seas 2 to 4 feet.
Thursday...Northeast winds 15 to 20 knots. Seas 2 to 3 feet. A slight chance of rain.
...Tide Data...
Tuesday Tides @ Calcasieu Pass:
Low: 7:35a.m. 8:38p.m.
High: 3:56p.m.
...Toledo Bend Pool Level...
164.40'
...Lake Charles Climate Summary...
Monday, January 31, 2011
Low: 49
Normal Low: 42
Record Low: 19-1949
High: 69
Normal High: 62
Record High: 80-2002
Rainfall
Today: 0.00"
Month to Date: 5.11"
Normal Month to Date: 5.52"
Year to Date: 5.11"
Normal Year to Date: 5.52"
Record: 2.55"- 2005
Sensible Weather Observed:
Fog
One Year Ago (2010)
Low: 35
High: 53
Rain: 0.00"
5 Years Ago (2006)
Low: 37
High: 67
Rain: 0.00"
10 Years Ago (2001)
Low: 50
High: 63
Rain: 0.00"
Sunrise Tuesday: 7:03a.m.
Sunset Tuesday: 5:50p.m.
Hunting Times:
6:33a.m.-6:20p.m.
...Lunar Table...
New Moon- Thursday February 3
First Quarter- Friday February 11
Full Moon- Friday February 18
Last Quarter- Thursday February 24
Have a great Tuesday & God Bless!
-DM-
No comments:
Post a Comment