*Major Cold Outbreak on Tap for the End of the Week.*
*Blogs Remains in Short Form.*
SW Louisiana Forecast Discussion...No one is going to say we didn't have a winter this year! Another hard freeze is on tap tonight across the entire forecast area as Arctic high pressure is settled directly over Louisiana. A Hard Freeze Warning is in effect for the entire forecast area once again. This morning was the coldest morning so far this season with readings in the low to mid 20s. A freeze occurred all the way to the coast last night, and I expect the same scenario to repeat itself tonight with clear skies and calm winds. It was a beautiful day with sunny skies as the Arctic high dominated. The January sun only managed to warm us up into the low to mid 40s. Temperatures are already approaching freezing at this hour, and will be below freezing for several hours meeting hard freeze criteria once again. Readings will be similar to last night with low to mid 20s for most locations. This is an Arctic air mass in place, but the core of this air mass is off to our E and NE. This will change in a couple days!
The changes begin to take shape on Wednesday. After a cold start to the day with clear skies in place, brief moderation is in store. A return flow will commence Wednesday morning is the current Arctic high shifts to the East. The Gulf will open up as the high nudges Eastward, and WAA will commence. Clouds will increase during the day as well as a surface low develops over the Rio Grande Valley, and an advancing short wave ahead of the mother load of Arctic air also is added to the mix. The Subtropical Jet Stream will become active once again as well. What all this means is that clouds will increase in earnest during the afternoon. Maximum temperatures will reach the upper 40s to mid 50s across the area. I believe the daylight hours will be dry, but a few showers will develop during the evening as the WAA regime intensifies. At this same time, the major Arctic outbreak will be in transit. It has been dislodged from its source region over Southern Canada tonight. It is beginning to spill into Montana and North Dakota tonight, and it will race Southward over the next 24 hours. A deep trough will be digging across the Eastern 2/3 of the country, and this will establish a deep Northerly flow, and this will transport the frigid air straight towards the Gulf Coast. Before this happens though, we will see a round of rain and perhaps a thunderstorm with added instability from all the ingredients mentioned above. While it will warm up for the Wednesday/Wednesday period, it will still be on the cool side, and because of this no severe weather is anticipated. A heavy rain event is not expected either, as this event will be a very quick mover. Arctic fronts typically move much faster than Pacific cold fronts.
The 50s on Wednesday will seem like a heat wave compared to what is to come. Rain chances will be in the likely category overnight Wednesday into the early morning hours of Thursday. Temperatures will not drop much Wednesday night as the brief WAA will be in place. I will undercut guidance which depicts mid 40s for Lake Charles. I believe the current Arctic air mass will not modify as much as shown by the models. Lower 40s for lows seem reasonable for Lake Charles, with mid to upper 30s for northern areas. Rain will be ongoing at this time. Northern parts of Louisiana may see some sleet and/or/freezing rain at times overnight Wednesday, but all rain is forecast here as the temperature profile will be too warm to support anything but rain at that time. I expect rainfall amounts to be less than an inch for the entire area. The brief return flow will last through the overnight hours, but quickly end as the Arctic front slams into the region. The timing of the Arctic front should be early Thursday morning from just before sunrise for Toledo Bend area down towards Houston to between 7-8a.m. for Lake Charles and by 10a.m. for Lafayette. Temperatures will warm up slightly ahead of this front possibly to the mid 40s before the downward spiral begins as CAA spills into the region in earnest behind the font. Rain will continue to be in the likely category at this time.
The cold air will quickly punch into the region behind the front Thursday morning, and there looks to be a period of post-frontal rain as some overrunning occurs. It is at this time that the atmospheric profile gets interesting. As I have alluded to in the previous days, it is matter of will the precip end before the coldest air punches in, but I really believe that the overrunning precipitation will linger longer than models depict at this time. That being said, I'm not really deviating from my forecast philosophy at this point. I will stay the course, and say that rain will change to snow before the precip ends Thursday afternoon. The majority of the precipitation for this event is going to be rain. If it snows, I am talking about a window of a few hours here, and no big deal. There won't be any accumulations. It should just be a matter of seeing it fall. I also expect that the precip ends before the temperature drops below freezing, but in this case we can see snow flurries with temperatures in the 35-38 range. I expect the areas that have the greatest chance of seeing any snow, again I stress no accumulation, will be from the East Texas Lakes Area across Toledo Bend into Central Louisiana. Snow flakes will be possible as far South as Lake Charles and Lafayette. While it is not certain that we'll see any snow, it is certain that it's going to get seriously cold. You can expect falling temperatures for the majority of the day Thursday, and after highs in the 40s early temperatures will fall into the 30s quickly behind the front, before falling below freezing by Thursday evening. Like I said, this air mass will be racing to the SE from Southern Canada. Just think about how fast it must be moving if it's just crossing into Montana tonight, and will be in Louisiana Thursday morning. All precipitation will end by late Thursday afternoon with the super cold air moving, and dry air moving in at all levels putting an end to the overrunning that will occur Thursday.The other big issue on Thursday will be the wind. It will be very windy with a large pressure gradient behind the front. Winds will be out of the NW up to 30 mph at times. This will create very dangerous wind chills possibly below 0 at times.
Any frozen precipitation will be a pretty sight (as long as there's no icy roads), but the main weather issue I continue to stress is the extreme cold that will be ushered in with this front. Skies will clear Thursday evening as the Arctic high begins moving down the Front Range of the Rockies. Temperatures will plummet with a large snow pack to our North, and the North winds transporting this air right into our area. Record lows will be possible at all reporting sites, and in all honesty I still believe the models are too warm for the Friday-Sunday time frame. Friday morning most locations will drop into the upper 10s with mid 10s possible in the coldest locations, and lower 20s along the coast. In Lake Charles proper, it should be around 18 or 19, and the winds will be very gusty creating wind chills between 0 and 10. I mentioned last night the possibility of a NW flow disturbance rounding the base of the sharp trough in the Friday afternoon/evening time frame, and the implications it might have as far as being able to squeeze out some snow flurries. I still believe there may be some sort of disturbance or low that the models don't depict at this point beings that the NW flow is often active, and the Subtropical Jet Stream is more energized than normal in an El Nino year. For now, I will keep Friday sunny and very cold with no more than just some high clouds streaming into the area. Depending on how much cloud cover is present, temperatures may not even reach 30, much less get above freezing. Temperatures by Friday morning will be running near record levels for early January. I will have a table of record lows, my expectant forecast lows for the Friday-Sunday period, and the record low maximum for each date at the conclusion of this discussion.
The weekend will be deceptively nice. It will not be nice at all though temperature wise. Clear skies prevail Friday night as the massive 1052 mb. high continues to drop through the Great Plains. Temperatures will once again drop into the 10s with the exception of the coastal parishes were lower 20s are expected once again. The Friday night/Saturday period looks even colder than the Thursday Night/Friday Morning with readings down as cold as 12-13 in the coldest spots of SW Louisiana. Even Lake Charles will be coming in with 17-18 degrees. Wind chills will continue to be problem as winds won't go calm until later in the day Saturday. Wind chills should be between 5-10 on Saturday. The position of the Arctic high will keep CAA ongoing through the day. Highs will be around 30. I am forecasting that we won't get above freezing for at least these 2 whole days. The evening model runs were interesting in depicting a rather robust short wave (upper level disturbance) coming down in the established NW flow underneath the massive Arctic high. This would occur during the day Saturday, and would likely lead to a chance of some snow flurries for much of the area. This may be the better scenario in this set up for us to see some snow. I should note that snow flurries don't typically accumulate, and also in the this case the air is very dry, and any snow that would fall would likely sublimate (evaporate) before reaching the ground. I will hold off on this idea of adding flurries to the forecast for Saturday for now, but upon re-assessment of the situation tomorrow I will mention also that if there is an embedded short wave rounding the base of the trough, there might be some sort of Gulf low develop as energy from the Subtropical Jet Stream interacts. No more than high clouds are expected on Saturday, but temperatures will again struggle to reach the freezing mark. I once again refer to the Arctic outbreak in February of 1996. This air mass will be parallel to that one. I want to note a bit of climatological information here...the last time the actual temperature was in the 10s at Lake Charles was in February of 1996. We are on track for this to occur this time as well based on the orientation of the Polar Vortex. The Polar Vortex is the driving force of these extremely cold Arctic air masses.
There is some question right now as to which night will be the coldest of this event. I will forecast this to occur on Saturday night/Sunday morning at this time based on the fact that this is when the massive high should make its closest approach to Louisiana. Winds will decouple almost entirely, and temperatures will once again threaten record levels. Mid 10s are likely even for Lake Charles, and lower 10s are expected for Alexandria. Some single digits can't be ruled out in the coldest locations such as Singer and Oakdale. Either way, it is going to be a very cold few days,, and we have the potential to stay below freezing until for the entire weekend, however, at this time I will forecast readings to get above freezing Sunday, but still in the 30s. Finally, on Monday a warm up commences as the Arctic high pushes Eastward in response to shift in the positioning of the Hudson Bay Polar Vortex. It will another very cold morning with temperatures well down into the 20s again. However, as the Gulf opens up temperatures should have no trouble climbing back into the 40s for Monday afternoon with plenty of sunshine.
The end of the forecast period will continue the air mass modification, but I am not warming things up as much as models do. Such a severe intrusion of Arctic air will erode slower than one that is less severe and less dense. On Tuesday, clouds will increase as a onshore flow strengthens, and another cold front looms just to our NW by this time. A chance of rain will be in the offing with this front, but for now I will hold off rain chances until just beyond the forecast period. It will be warmer by then, yes, but not exactly, mild! Low temperatures will be around freezing while afternoon highs reach the low to mid 50s. Another bout of very cold air looks to be in the offing for the middle to latter part of next week, but it shouldn't be near as cold as what we will endure at the end of the week. Rain chances will be present just beyond the forecast period, but anything beyond this point is shear speculation as far as rain chances are concerned. Overall, the cold and dry pattern of early 2010 will continue through mid-month. I'm sure we'll get back into the persistent El Nino pattern.
Here's the bit of historical info I promised I would offer. This table looks at the record low temperatures for Lake Charles for the January 8-10 period, as well the projected low, official record low maximum, and the projected maximum for Friday-Sunday (January 8-10).
Friday January 8
Record Low: 21- 1996 Projected Low: 18
Record Low Maximum: 35- 1968 Projected High: 32
Saturday January 9
Record Low: 22- 1962 Projected Low: 17
Record Low Maximum: 38- 1973 Projected High: 31
Sunday January 10
Record Low: 15- 1962 Projected Low: 15
Record Low Maximum: 24- 1962 Projected High: 35
Stay tuned for more on this extreme cold outbreak!
Preliminary Numbers & Zone Forecast:
LCH 26/51 40/44 18/32 0 20 70 70 0 10
LFT 25/50 39/46 19/31 0 20 70 70 0 10
BPT 29/53 41/43 18/32 0 20 70 70 0 10
AEX 23/48 36/39 16/27 0 20 70 70 0 10
POE 23/49 37/40 17/28 0 20 70 70 0 10
ARA 27/52 43/46 20/33 0 20 70 70 0 10
*Hard Freeze Warning until 8a.m. Wednesday.*
Tonight...Clear and Very Cold. A Hard Freeze with Heavy Frost. Low 26. Calm wind.
Wednesday...Increasing Cloudiness and Warmer with a 20% chance of rain late. High 51. SE wind 10 mph.
Wednesday Night...Cloudy with rain and a few thunderstorms likely especially after midnight. Warmer. Low 40. SSE wind becoming SSW at 10-15 mph. Chance of rain 70%.
Thursday...Cloudy, Very Windy, and Turning Much Colder with rain likely. Rain possibly changing to snow before ending in the afternoon. No snow accumulation expected. Becoming Clear late. High 44 in the morning with temperatures falling to near 30 by evening. SSW wind 10-15 mph becoming NNW and increasing to 20-30 mph and gusty. Chance of precipitation 70%. Wind chills by late afternoon in the 15-25 range.
Thursday Night...Clear, Windy, and Very Cold. Record Cold and Dangerous Wind Chills. Low 18. NNW wind 20-25 mph and gusty. Wind chill 0 to 10.
Friday...Sunny, Windy, and Very Cold. High 32. North wind 10-15 mph. Wind chill 5 to 15.
Drew's 7 Day Outlook for Lake Charles & Vicinity
Wedenesday
1-6-10
Low: 26
High: 51
Precip: 20% Late
Wind: SE 10
W.C.: 20-25 A.M.
Thursday
1-7-10
Low: 40
High: 44
Falling to near 30 by late afternoon
Wind: SSW/NNW 15-30
W.C.: 10-25 P.M.
Friday
1-8-10
Low: 18
High: 32
Precip: 10%
Wind: N 10-15
W.C.: 0-15
Saturday
1-9-10
Low: 17
High: 31
Precip: 10%
Wind: N 10
W.C.: 5-15
Sunday
1-10-10
Low: 15
High: 35
Precip: 0%
Wind: NE 5-10
W.C.: 10-20
Monday
1-11-10
Low: 23
High: 45
Precip: 0%
Wind: SE 10
W.C.: 15-25
Tuesday
1-12-10
..Marine Forecast...
Tonight...Northeast winds 5 to 10 knots. Seas 1 foot.
Wednesday...East winds 10 to 15 knots becoming southeast 15 to 20 knots in the afternoon. Seas 1 to 2 feet building to 1 to 3 feet in the afternoon.
Wednesday Night...Southeast winds 15 to 20 knots becoming south after midnight. Seas 2 to 4 feet. A slight chance of showers in the evening...then rain likely and isolated thunderstorms after midnight.
Thursday...West winds 20 to 30 knots and gusty becoming north in the afternoon. Seas 3 to 5 feet. Numerous showers and isolated thunderstorms in the morning...then a chance of rain in the afternoon.
Thursday Night...North winds 20 to 25 knots. Seas 3 to 4 feet.
Friday...North winds 15 to 25 knots. Seas 3 to 4 feet.
Good night and God bless!
-DM-
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