Friday, January 8, 2010

The Arctic Blast is Here...Make Like a Bear and Hibernate...

Thursday, January 7, 2010

SW Louisiana Forecast Discussion...The coldest weather in 14 years is here! The Arctic front blew through right on schedule this morning with periods of rain. All of the rain ended by noon as the drier air behind the boundary filtered in. Clouds remained in place for the rest of the day as very strong CAA took affect. High temperatures were realized this morning while WAA persisted ahead of the powerful front. Highs reached the lower 50s, but temperatures have been on the downward spiral since then, and have just about dropped below freezing at all locations as of this writing. Rainfall totals this morning were right on target with values an inch or less. Rainfall ended long before the coldest air moved in, and there were no reports of frozen precipitation anywhere in the forecast area, or in the state for that matter. Skies have tried to clear across the area, but are having a hard time doing so as an active Subtropical Jet Stream remains just offshore. This is streaming high clouds across the area, and this should persist through the night. However, this will not really negate the cooling process much with such a strong Arctic air mass in place. Winds are an issue as well in the wake of the boundary. NNW winds over 20 mph at times can be expected through the night. This will lead to very dangerous wind chills approaching 0 at times by morning. A wind chill advisory is in effect for the entire area, along with a hard freeze warning. Overall, the high clouds will come and go overnight, so we'll call it Partly Cloudy. Hard freeze conditions will be prolonged across the area, and this is just the beginning. It's going feel more like we're in the Mid West somewhere, rather than SW Louisiana. Also of note on satellite imagery this evening is a short wave over West Texas ad East New Mexico. Models did a poor job of depicting this. Downstream there is some snow showing up on radar associated with this feature between Lubbock, TX and Hobbs, NM. However, most of it is not reaching the ground due to very dry air in the lowest levels of the atmosphere. This will play a factor into our weather on Friday. The strong CAA will continue through the night as the Arctic high drives down the front range of the Rockies. By morning, temperatures will be near record levels ranging from the upper 10s to lower 20s across the area. This is when wind chills will be at their worst as well as the strong winds continue. Another issue that we could contend with overnight is the possibility of black ice. Any leftover standing water from today's rain will ice over tonight as temperatures continue to drop. However, a serious icing problem is not expected because much of the water from the morning rains sublimated (evaporated) this afternoon as the drier and colder air moved in.

On Friday, the forecast becomes a bit tricky. The consensus from the forecast models is sunshine, however, one can't ignore the presence of the Subtropical Jet Stream nor the upper level disturbance emanating the periphery of the deep trough. The upper level disturbance could fizzle out as it moves Eastward in the incredibly dry air, or it could strengthen a bit as it interacts with the Subtropical Jet streaming over the Gulf. I believe that the Subtropical Jet will keep clouds moving across the region, and a forecast of Sunny will not come to fruition. The upper level disturbance could produce some returns on radar Friday afternoon, but most likely anything that shows up will be elevated and not likely reach the ground. Snow may fall from the clouds overhead, but sublimate before reaching the ground. We'll see how this evolves. When models don't initialize a system, your forecasting methods change a bit. On Friday, it may be a matter of just looking out the window! For now, I will not forecast any snow, not even a flurry. Certainly the cloud cover will factor into the forecast, and temperatures will struggle with CAA continuing. Model guidance is too warm with the expected continued CAA and forecasted cloud cover. After a morning start with temperatures in the upper 10s to lower 20s, temperatures will struggle to make it to freezing. Much of the area will remain below freezing throughout the day, and those areas which do get above freezing won't be for very long. Wind chills will range from the single digits in the morning, to the mid 10s in the afternoon. I will word the sky condition as Partly to Mostly Cloudy for now, but I will update things tomorrow depending on how things evolve with all the said factors involved. It is strange, but the actual best chance of seeing any snow across the area for the next few days will be over the Gulf of Mexico.

The coldest weather yet arrives Friday night as a secondary surge of Arctic air moves in behind the weak upper level disturbance. The high clouds from the Subtropical Jet Stream should also be further suppressed into the Gulf by Friday night as the strong Arctic high pressure moves closer to the area. 10s are expected for most areas with the exception of the coast where lower 20s will occur. Hard freezes will occur all the way to the coast. This will be the coldest temperatures since February 2-5, 1996. The last time it was this cold I was a Freshman in High School. Record lows will likely be shattered for Saturday morning. A record low maximum will most likely also be set on Friday with the temperature struggling to get to freezing. No precipitation is forecast, and it should be dry for this entire Arctic outbreak. The extreme cold will likely result in some busted pipes over the course of the weekend, so please make sure you are prepared. Other problems can arise from weather this cold, that's why it's essential to have already completed all the necessary precautions. Saturday starts with record cold with temperatures possibly as cold as the mid 10s even in Lake Charles. Full sunshine is expected Saturday, but the sun will do little to offset the extremely cold temperatures. Maximums will briefly warm to above freezing for the Southern half of the area, while many areas across the Northern portions of the area should continue the subfreezing temperatures. I am undercutting guidance once again especially with the core of the Arctic high moving into the Red River Valley by Saturday afternoon continuing the NW flow. There is still some question as to which night will end up being the coldest....Friday night or Saturday night? I am leaning towards Saturday night at this time since winds will be very light or calm at this time as the Arctic high settles right over Louisiana. Record lows could be threaten in parts of the area once again with an average temperature in the mid 10s. However, the coldest locations could see lower 10s while temperatures right around 20 are expected at the coast. Sunday will continue to be cold, but a modest modification is in store for the afternoon. Everyone should get above freezing with temperatures in the upper 30s to lower 40s for maximums. It should be another crystal clear day with a bone dry atmosphere in place.

Air mass modification will be slow at best; slower than models indicate. Another hard freeze is on tap for Sunday night/Monday morning, though 10s are not expected as the core of the Arctic high will be oriented to our East. Low to mid 20s are a good call for Sunday night with very light winds and clear skies. The dry, unseasonably cold weather continues to start the new work week. High pressure will loosen its grip, but still be in control with another sunny day expected. Afternoon highs will continue to moderate with readings in the mid 40s to lower 50s across the forecast area. A transition begins on Tuesday as a more pronounced Southerly flow returns, bringing back Gulf moisture to the area. I still think models are too warm at this time, and I will continue to undercut. However, that being said I don't expect a hard freeze for anyone to start the day on Tuesday. A light freeze and very frosty morning is expected with readings in the upper 20s to mid 30s depending on your proximity to the Gulf of Mexico. Clouds will increase during the day Tuesday as the Southerly flow intensifies ahead of our next cold front. This cold front will be diving out of the Rockies, and another trough will be carved out across the nation's mid-section. However, this trough will not be as deep as the current one. A dry forecast is maintained for Tuesday at this time, with just an increase in clouds noted.

Rain chances return at the mid-week period as our next cold front approaches. There is also some hint of Gulf cyclogenesis as well, however, models aren't as gung-ho on this idea today. Either way, rain chances are in the forecast for Wednesday as the front moves through increasing convergence across the area. I don't anticipate any severe weather. It's a bit early to determine if we'll see any thunderstorms at all, but as we get closer to this time frame, necessary changes will be assessed. The end of the forecast period is a bit "cloudy". Pun intended here as what lies ahead for this period remains to be seen. Models diverge on solutions for the latter half of next week. It is possible that we'll clear out quickly behind the mid-week front with another cool down, but not an Arctic blast. While it's also possible that an overrunning pattern will develop, keeping clouds and off and on rain in place with unseasonably cool temperatures. The idea of a second Gulf low along the front at week's end is still on the table as well. I will blend things for now, and keep clouds around for day 7, but reflect cooler temperatures and limited rain chances. Models warm us into the 60s for the second half of next week, I am a bit skeptical of this, and am not ready to buy into this just yet as I believe much of this is attributed to climatology errors. I will say that the second half of January looks warmer than the first half, although the cold weather won't be over with once we modify next week. What we are experiencing this weekend could easily be the coldest temperatures we'll see all winter. Again, that doesn't mean winter is over. More hard freezes will occur down the road, but this air mass takes the cake. Stay warm and stay tuned!


Preliminary Numbers & Zone Forecast:

LCH   23/32   18/34   16/40   0 10 10 0 0 0
LFT    24/33   17/33   15/39   0 10 10 0 0 0
BPT    22/31   19/34   17/41   0 10 10 0 0 0
AEX   18/30   15/31   14/37   0 10 10 0 0 0
POE   19/30   16/31   15/38   0 10 10 0 0 0
ARA   25/35   20/35   18/41   0 10 10 0 0 0


*Hard Freeze Warning in effect until Noon Friday.*

*Wind Chill Advisory in effect until 10a.m. Friday.*

Tonight...Clear early becoming Partly Cloudy. Windy and Very Cold. Low 23. NNW wind 15-20 mph & gusty. Wind chill readings 5-15 by sunrise.

Friday...Partly to Mostly Cloudy, Windy, & Very Cold. High 32. NNW wind 10-15 mph. Wind chill readings 10-15.

Friday Night...Clear and Very Cold. Record Lows. Low 18. North wind 10 mph. Wind chill 5-15.

Saturday...Sunny and Continued Very Cold. High 35. North wind 5-10 mph. Wind chill 15-25.

Saturday Night...Clear and Very Cold. Near Record Cold. Low 16. Light North wind. Wind chill 10-15.

Sunday...Sunny and Cold. High 40. NE wind 5-10 mph.


Drew's 7 Day Outlook for Lake Charles & Vicinity

Friday
1-8-10








Low: 23
High: 32
Precip: 10%
Wind: NNW 15-20
W.C.: 5-15


Saturday
1-9-10








Low: 18
High: 35
Precip: 0%
Wind: N 10-15
W.C.: 15-25


Sunday
1-10-10








Low: 17
High: 40
Precip: 0%
Wind: NE 5-10
W.C.: 15-30


Monday
1-11-10








Low: 23
High: 46
Precip: 0%
Wind: ESE 5-10
W.C.: 20-35


Tuesday
1-12-10


Low: 31
High: 53
Precip: 10%
Wind: SE 10
W.C.: 30-40


Wednesday
1-13-10


Low: 38
High: 55
Precip: 40%
Wind: SSE 10-15


Thursday
1-14-10


Low: 40
High: 45
Precip: 20%
Wind: NNW 10-15
W.C.: 25-30


...Marine Forecast...

*Gale Warning until 6a.m. Friday.*

*Small Craft Advisory from 6a.m. Friday through Friday afternoon.*

*A Low Water Advisory is in effect for coastal lakes and bays due to the Arctic air creating low water levels.* 

Tonight...North winds 25 to 30 knots becoming 20 to 30 knots after midnight. Seas 5 to 7 feet.

Friday...North winds 20 to 25 knots decreasing to 15 to 20 knots in the afternoon. Seas 3 to 5 feet.

Friday Night...North winds 15 to 20 knots. Seas 3 to 5 feet subsiding to 3 to 4 feet after midnight.

Saturday...North winds 15 to 20 knots decreasing to 10 to 15 knots in the afternoon. Seas 2 to 4 feet subsiding to 2 to 3 feet in the afternoon.

Saturday Night...North winds 15 to 20 knots. Seas 3 to 4 feet.

Sunday...Northeast winds 10 to 15 knots. Seas 2 to 4 feet.


Stay warm!
Good night and God bless!
-DM-

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