SW Louisiana Forecast Discussion...Today was another very nice day as advertised with a clear and cold start with morning lows in the upper 30s to lower 40s across the area. It was a pleasantly mild afternoon with highs around 70. Clouds began increasing across the forecast area late this afternoon, as a return flow of Gulf moisture on the back side of a strong Pacific high began affecting the region. This is in advance of our next vigorous El Nino storm system. Benign weather will continue tonight, but low level moisture will continue to increase with morning lows expected to be much warmer than the 3 previous nights. Minimums should be around 50 at sunrise Thursday. I wouldn't rule out some patchy fog as well, but there is enough mixing ahead of the storm system, that the wind should preclude significant fog development. This storm system is clearly evident tonight on satellite imagery. There are several pieces to the pie that will come together to produce a widespread rain event in about 24 hours. Clouds will continue to increase during the day Thursday, and as deeper Gulf moisture arrives ahead of advertised storm a few showers will be possible by the afternoon hours, however, the majority of the rain will hold off until tomorrow night. Mild conditions will continue for one more day with afternoon maximums around 70. This won't be a record by any means, but it is certainly above normal. Wind will also be a factor on Thursday as the pressure gradient tightens in response to the developing storm system.
Showers and thunderstorms will increase in earnest Thursday night as the advancing trough and associated cold front moves into the region. Other factors that will increase lift and moisture across the forecast area is the presence of a surface low in the vicinity of Central Texas, and a upper level low that will hang back over the Desert SW. This is the driving force behind the entire system. This conglomeration of features will work in tandem to overspread rain across the area from west to east Thursday night. Rain will get heavy at times after midnight, and the worst of the weather should come right around sunrise Friday. There should be ample amounts of instability present by this time, such that some thunderstorms will occur. However, the threat for severe weather looks minimal at this point. Dynamics will be in place by early morning Friday as the presence of a strong low-level Jet will be in place. However, instability will be somewhat lacking, and this will more than likely put the kibosh on any severe weather. Wind profiles are decent, and you have to figure with the strong pressure gradient and intense Jet Stream in place that some of the thunderstorms will produce strong winds. This appears to be the only mode of severe weather that will be possible, but even this should be on an isolated basis. The main issue across the area with this system is going to be the heavy rain threat. Not much change in forecast philosophy has occurred since last night. I still expect average rainfall amounts to be from 1-2" across the area with isolated higher amounts. Rain will be widespread beginning Thursday night lasting through much of the day Friday. The heaviest rainfall will occur along and ahead of the boundary, and this will occur from overnight Thursday through about noon Friday. There are timing uncertainties with the front, but it should clear the entire forecast area by noon. I believe a bit faster movement than what is currently projected will be noted. This should bring the cold front through the Lake Charles area around 9a.m. Friday. The heavy rain threat should come to an end shortly thereafter, but the rain will likely continue for much of the day. Mild weather will persist until frontal passage. Friday morning temperatures should be in the mid 50s early, but they will fall steadily throughout the remainder of the day as strong CAA takes over. On the northern edge of this system, a nasty winter storm will occur with lot of ice and snow. This storm will be newsworthy over the next couple of days. While no frozen precipitation is expected here, we will be indirectly affected by the winter storm. Much colder weather will move into SW Louisiana behind the front Friday. This is largely due in part to a strong NNW wind transporting the cold Canadian air over the ice and snowpack to our North. The snow and ice shield should run from parts of North Texas, Oklahoma, Arkansas, Tennessee, Northern Mississippi and points Eastward from there. The air being transported into the area won't have much time for modification, therefore, temperatures should be colder than models forecast. Friday will be a day with confused temperatures. That is, the maximum will occur during the morning ahead of the front. These readings should be in the mid to upper 50s. A sharp temperature difference is expected in the wake of the front. Friday temperatures will fall from the mild 50s in the morning into the low to mid 40s during the afternoon as the CAA strengthens, and the clouds and rain linger. A wind chill will come into play by Friday afternoon with a brisk NNW wind of around 20 mph. Wind chills should be in the 30s. It will certainly snap us back into the reality of winter.
There is much uncertainty at this time as to when the rainfall shuts off. It all hinges on the movement of the upper level low on the back side of the system. Certainly clouds will hang tough for awhile, likely into early Saturday. The question is with precip. Models indicate that we'll get dry slotted here, therefore, ending precip chances Friday night. However, with the upper level low slow to lift out some overrunning is likely to occur, and this would most likely keep light rain or drizzle ongoing through Friday night. At the same time, colder air will continue filtering into the region. Temperatures will fall into the 30s, but there will be the presence of a warm tongue of air in the mid levels of the atmosphere (850-500 mb.) This would keep the precip in a liquid form across the forecast area. The northern portions of the state could see some light sleet and/or snow Friday night, but any significant frozen precipitation should remain north of the state line. I will re-evaluate this tomorrow. It isn't totally out of the question that some light sleet may mix in with the light rain/drizzle Friday night, but this is not reflected at this time. I will keep rain chances in the forecast for Friday night, and a result I temperatures will not be as cold as previously forecast for Saturday morning. It'll certainly still be cold with a morning low in the mid 30s, and with brisk North winds continuing wind chills could be in the upper 10s at times by Saturday morning. The upper level low will finally eject out to the NE Saturday, and the weather will respond in a positive way at that time. Skies will clear Saturday morning, and become Sunny. It will remain on the cold side Saturday with continued CAA expected. Afternoon maximums will be well below normal in the mid 40s. Winds will slacken during the day as strong Arctic high pressure builds in. The brunt of this cold blast should bypass the forecast area, however, it will certainly be cold enough for an area wide freeze on Sunday morning. Clear skies and light winds Saturday night will result in temperatures falling into the mid to upper 20s for Sunday morning. This is a significant freeze, and the first freezing temperatures we will experience since a couple weeks ago. However, this is not a severe freeze, and is a far cry from the cold blast we experienced back on the 8th-11th. It will be a beautiful Sunday yet again, but it will remain rather chilly with highs only near 50. CAA will end by this time as high pressure builds in, and winds become light.
Cold and dry conditions continue for the Sunday Night/Monday morning period with another light freeze expected. Another El Nino storm system will be in the making as we start February, and clouds will increase in response to this beginning Sunday Night and in earnest on Monday. The cool air will remain in place as Western Gulf cyclogenesis takes shape along the old front in the Gulf. This will bring rain chances back into the forecast by Monday afternoon as deeper moisture moves inland over the top of the cool, stable air at the surface. Temperatures will struggle to reach the 50s on Monday. Rain chances could end up in the likely category, but this is not reflected at this time, but a healthy chance of rain is noted (40%). The air mass in place will be stable, so the typical light rain and/or drizzle should be the dominant precip type. The surface low will slowly move NE towards the coast, and the overrunning rains will continue through the forecast period. Disturbances emanating out ahead of an advancing Gulf warm front, and the low will bring rain into the area from time to time for Tuesday and Wednesday. Timing each one of these disturbances is near impossible especially this far out. The bottom line is that the overall pattern will remain unsettled, and there could be rain at any point during the end of this forecast period. Fine tuning will occur as we get into the weekend, and have a better idea on the timing and specifics of this event. Rain chances will remain on the low side for now, but will go up or down depending on how this system evolves. A subtle warm up is depicted for the latter stages of the forecast as the overrunning continues. Beyond the forecast period, a more pronounced warm up should ensue ahead of a much stronger storm that will round the base of a new trough toward the latter half of next week, and bring about another chance for showers and thunderstorms. Colder weather could return to the area in time for Super Bowl weekend. The unsettled pattern looks to continue for much of the first half of February.
Preliminary Numbers & Zone Forecast:
LCH 49/68 56/43 34/45 0 20 80 100 40 0
LFT 48/69 55/44 35/45 0 20 80 100 40 0
BPT 51/70 57/42 36/45 0 30 90 100 30 0
AEX 43/66 51/39 31/42 0 40 90 100 40 0
POE 44/67 52/40 32/43 0 40 90 100 30 0
ARA 47/68 55/44 35/45 0 30 90 100 40 0
Tonight...Becoming Mostly Cloudy. Low 48. SE wind 10 mph.
Thursday...Mostly Cloudy with a 20% chance of rain, mainly afternoon. High 68. SE wind 10-15 mph.
Thursday Night...Cloudy with rain and a few thunderstorms becoming likely. Rainfall heavy at times. Low 56. SE wind 15 mph and gusty. Chance of rain 90%.
Friday..Cloudy with rain and thunderstorms likely in the morning transitioning to light rain and/or drizzle in the afternoon. Rainfall heavy at times during the morning. Turning Colder & Windy. High in the upper 50s in the morning falling into the lower to middle 40s in the afternoon. SSE wind 15-20 mph and gusty, becoming NNW at 20 mph and gusty in the morning. Chance of rain 100%.
Friday Night...Cloudy, Cold, & Windy with a 40% chance of light rain and/or drizzle. Low 34. NNW wind 15-20 mph and gusty. Wind chill readings in the 20s.
Saturday...Becoming Sunny, Breezy, & Cold. High 45. NNW wind 15-20 mph and gusty, subsiding to 10-15 mph in the afternoon. Wind chill readings 20-30.
Drew's 7 Day Outlook for Lake Charles & Vicinity
Thursday
1-28-10
Low: 49
High: 68
Precip: 20%....90% Night
Wind: SE 10-15
Friday
1-29-10
Low: 56
High: 43
Precip: 100%
Wind: SSE/NNW 15-25
Saturday
1-30-10
Low: 34
High: 45
Precip: 0%
Wind: NNW 10-20
W.C.: 20-30
Sunday
1-31-10
Low: 28
High: 48
Precip: 0%
Wind: N 10
Monday
2-1-10
Low: 31
High: 46
Precip: 40% PM
Wind: NE 10-15
Tuesday
2-2-10
Groundhog Day
Low: 38
High: 52
Precip: 60%
Wind: NE 10-15
Wednesday
2-3-10
Low: 44
High: 56
Precip: 40%
Wind: E 10-15
...Marine Forecast...
Tonight...Southeast winds 10 to 15 knots. Seas 3 to 4 feet.
Thursday...East winds 15 to 20 knots. Seas 3 to 4 feet. A slight chance of showers. A slight chance of thunderstorms in the afternoon.
Thursday Night...Southeast winds around 20 knots. Seas 4 to 5 feet. A chance of showers and thunderstorms in the evening...then showers and thunderstorms likely after midnight.
Friday...South winds 15 to 20 knots becoming west in the afternoon. Seas 3 to 5 feet subsiding to 3 to 4 feet in the afternoon. Showers and thunderstorms.
Friday Night...Northwest winds 15 to 25 knots becoming north 20 to 25 knots after midnight. Seas 3 to 5 feet building to 4 to 5 feet after midnight. A slight chance of showers.
Saturday...North winds 15 to 20 knots. Seas 3 to 5 feet.
Good night and God bless!
-DM-
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