The blog will be in severe weather mode through Friday when we get this winter storm out of the area. Due to the magnitude and significant ramifications this storm may have on our area, there will still be a video blog, so that I can give you specific details about what to expect. The blog may take on a little bit format for the next couple of days. I will also include a list of the closings and delays for Thursday. I would expect an even longer list of those for Friday.
Click below for the latest edition of the video blog. Be sure to scroll down for the text form of the blog.
....Rare Winter Storm on the Way...Winter Storm Watches & Winter Weather Advisories Issued...Significant Impacts Expected...
SW Louisiana Forecast Discussion...No need to state the obvious, it's cold! It's going to stay cold, and our next round of precipitation will be in the frozen form. That is almost a certainty at this juncture, and I will iron out specifics momentarily. First, today was one of the coldest days in recent memory. Morning lows in the low to mid 20s and bitterly cold wind chills between 5 and 15 degrees were common to start the day. Weak isentropic lift was present throughout the day, and that kept us blanketed with generally mid and high level cloudiness that shielded from our heat source. Temperatures struggled to make it above freezing, but did so for a few hours at the most reaching the mid 30s on average. That was nearly 30 degrees below the average for early February. There were a few scattered snow flurries, but no accumulations occurred because of very dry air in place at the lower levels. Tonight, cloudiness continues to stream in from the SW as overrunning slowly increases. The Subtropical Jet Stream remains very active, and that will come into play with our precipitation event over the next 48 hours. Tonight should generally just be very cold and overcast. Temperatures will fall at a slower rate tonight because of cloud cover. CAA also continues. Temperatures will fall into the mid 20s on average tonight, but some locations will hold in the upper 20s were the thicker clouds are present. Lower 20s are expected further north were some holes in the clouds are present allowing for better radiative processes. The wind chill will also be in play with gusty Northerly winds between 10-15 mph throughout the night. Wind chill readings will be in the 10s again, but not into Wind Chill Advisory criteria. Overrunning (isentropic ascent) will continue to increase overnight, and towards morning light precipitation will be forming.
There is already a stream of precipitation coming from the Gulf of Mexico, but the current trajectory is into SE Louisiana. The precipitation shield will expand on Thursday as Gulf cyclogenesis originates off the coast of Texas. At the same time, an upper level disturbance currently situated over New Mexico and West Texas will be translating Eastward. These features will move into the entrenched Arctic air mass over the area. Now, before I break this down let me use the same disclaimer I have used in the previous days. What I am about to say is subject to change, and further fine tuning will be necessary as the event unfolds. The current precipitation shield streaming into SE Louisiana will expand Westward overnight, and it may begin over Acadiana around sunrise as light sleet or freezing rain. Some snow flurries are possible mainly along and south of I-10 until then. Moisture will increase from the SW and from the East heading through the day Thursday, and I believe that we will begin to see sleet and/or freezing rain here in the Lake Area between 10a.m. and noon. The precip should be light at first, and it will take a little while for the ice to begin sticking because of the dry air in the lower levels. However, going into the afternoon and evening hours accumulations will begin.
An extensive review of the atmospheric profile suggests that there will be a small layer of above freezing air above the surface, thus allowing for falling snow to melt on its way to the ground as the precipitation intensifies and expands in coverage. The low and the upper level disturbance will increase lifting and forcing over the area. Remember here now, that while temperatures will be plenty cold at the surface for now, we have to look up above to determine precip type. That being said, the most likely scenario I see at this point is for all forms of precip depending on where you are in the area. Freezing rain and sleet will be likely in SW Louisiana at the onset of the widespread precipitation Thursday. Acadiana stands the best chance to see a crippling ice storm with significant amounts of freezing rain. For immediate SW Louisiana, sleet looks to be the more dominant precip type. I expect a freezing rain/sleet mixture for much of the day in the Lake Area. However, the column of air cools during the afternoon as precip continues to fall a better chance for a sleet/snow mix will occur. Accumulations of ice should begin by the afternoon hours, and conditions will rapidly deteriorate from there. Many schools have already canceled for the day Thursday, and that's a very good course of action. The drive home will be a very touch and go situation it would appear with ice on many roads and bridges. Temperatures will struggle to get back above freezing on Thursday, and honestly I don't think we'll be above freezing again until Saturday afternoon.
This storm really cranks up Thursday night into Friday. That's when the surface low will make its closest approach to SW Louisiana. This low will remain offshore, but the exact track still remains to be seen. That will also have a say so in p-type during this period. The mixture of sleet/snow/freezing rain will continue into the overnight hours, but as I said I believe it'll mostly be a sleet event for the Lake Area. Snow will mix in during the evening hours, and we may transition into a period of all snow in the pre-dawn hours on Friday as colder air on the backside of the low, and from the advancing upper level feature work into the area. All precipitation will accumulate, and a very significant coating of ice and snow is expected. At this time, accumulations between 1/2 and 1" of a combination of sleet/snow/freezing rain is expected. Further North, snow amounts of 2-3" are to be expected. Now, this is based on the atmospheric profile evaluation. If some of the models are correct this will become a major snow event with nearly a half foot possible along the I-10 corridor. On the other hand, some models suggest a debilitating ice storm. So, this can swing either way. The bottom line is though that we will see a winter storm and we will have repercussions to deal with. Our best chances for snow will come during the morning hours Friday, but ice certainly looks to be the main issue here.
It is hard to say if this will be comparable to the big ice storm we all remember back in 1997, but it is possible that it could of a similar magnitude. However, the big difference with this frozen precipitation event when compared to the ones in recent memory is the fact that we will have been cold for awhile preceding the event. All surface will be cold and below freezing, therefore, ice accretion will likely occur on everything. Now, if the predominant p-type is sleet, then that will help us as far as tree and power line icing goes, and would cut down on the number of power outages across the area. However, substantial freezing rain amounts over 1/4" of an rain will likely lead to significant amounts of down trees and power lines creating numerous power outages. Of course, snow would be pretty and keep our utilities and communications running unless we get a several inches of the typical heavy wet snow that usually falls when it snows here. I would urge everyone to prepare for a significant ice storm. Check all your batteries in your radios and TVs. Have plenty of food and firewood ready to get through the weekend. Whatever falls and sticks to the ground Thursday and Friday will more than likely remain in place through mid-day Saturday when we will get above freezing. So, just because the precip may end on Friday afternoon doesn't mean that the danger is over. Now, here is my accumulation forecast. Snow amounts will generally be less than 1 inch in the Lake Area, with 2-3" amounts up into Central Louisiana stretching back towards Houston. Freezing Rain accumulations will be between 1/10 and 1/2 inch across the area. Closer to 1/2 inch in the Lafayette area, and closer to 1/10 inch in Lake Charles. Sleet accumulations will range from around 1/2 to 1 inch in the Lake Area and the Golden Triangle, with lesser amounts for Lafayette. Lesser sleet amounts will occur further North as well where it should be more snow. Precipitation chances ramp up quickly into the likely category Thursday, and will max out Thursday night into Friday before tapering off Friday afternoon. The entire storm system should push east of the area by Friday night into Saturday, and as it does so wrap-around moisture may produce some additional light snow or snow flurries for a time Friday evening and Friday night. Temperatures will likely stay at or below freezing for the duration of this event, but not get colder than 25 either until we clear out Friday night. The surface low's orientation will keep a stiff NE wind over the area as well creating dangerous wind chills in the 10s and 20s through Friday. Just to give you an idea of the magnitude of this storm, Winter Storm Watches and Warnings are posted all the way to the U.S./Mexico border in South Texas, and nearly the entire state of Louisiana is under a Winter Storm Watch or Winter Weather Advisory.
Before I continue with the rest of the discussion, Here is a run down of the watches/advisories across our area, followed by a precipitation timeline for the Lake Charles area.
*Winter Storm Watch from Thursday afternoon through Friday morning for all parishes along and north of I-10 including Calcasieu, Jeff Davis, Acadia, Lafayette, Allen, Beauregard, Rapides, Vernon, Evangline, St. Landry, and St. Martin & the Golden Triangle of SE Texas including Orange, Jefferson, Hardin, Tyler, Jasper, & Newton Counties.
*Winter Weather Advisory for the same time frame for Cameron, Vermilion, Iberia, & St. Mary Parishes.
Here's the precipitation timeline for Lake Charles & Vicinity. This will take the place of the usual daily planner.
Thursday 2/3/11
6a.m.
Cloudy & Cold. Light Sleet, Freezing Drizzle, or Snow Flurries Possible
Temp: 25
Chance of Precip: 30%
Wind: NNW 15
W.C.: 13
9a.m.
Cloudy & Cold. Sleet/Freezing Rain Spreading From East to West.
Temp: 27
Chance of Precip: 50%
Wind: N 14
W.C.: 17
Noon
Sleet/Freezing Rain Likely. Light Accumulations Beginning.
Temp: 28
Chance of Precip: 60%
Wind: N 14
W.C. 18
3p.m.
Sleet & Freezing Rain Mix. Accumulations Likely. Driving Becoming Very Dangerous.
Temp: 30
Chance of Precip: 70%
Wind: N 20
W.C.: 15
6p.m.
Sleet & Snow Mix. Significant Icing Expected. Travel Discouraged.
Temp: 30
Chance of Precip: 80%
Wind: N 16
W.C.: 17
9p.m.
Snow/Sleet/Freezing Rain Mix. Significant Ice Storm. Stay home.
Temp: 29
Chance of Precip: 100%
Wind: NNE 18
W.C.: 15
Back to the discussion...Conditions improve at least from a precipitation standpoint Friday night, but again all accumulated ice and snow will remain in place with temps remaining below freezing. We will clear out overnight Friday into Saturday as the system pulls away, and Arctic high pressure remains in control. A hard freeze will be expected with temperatures in the lower 20s. I will undercut guidance because guidance doesn't take into account an ice and snowpack. We will begin a warming trend Saturday, and high temperatures will easily climb above freezing. It'll still well below normal with the maximums only reaching the mid 40s, but that will seem warm compared to what we'll be dealing with through Friday. It won't be quite as cold Saturday night into Sunday, and CAA will cease. Super Bowl Sunday will be a beautiful day with plenty of sunshine. A frosty start is expected with lows near 30, but with abundant sunshine we'll see highs getting into the 50s. A return flow of Gulf moisture will begin on Sunday as well as we await another cold front early next week. The developing trough, and advancing high will create a light onshore flow. Moisture return continues for Sunday night, and clouds will increase as the cold front approaches. We should remain dry during this time. Temperatures will continue to modify with lows into the upper 30s to around 40, still below normal for early February.
Our next cold front slides quickly through the region on Monday. Enough moisture return will allow for a chance of showers, but moisture will still be limited since we won't have near as long of a return flow as we did before this latest front. No severe weather is expected this time around with dynamics bypassing the area. Rain chances will be at 30% for a quick shot of rain ahead of the front during the day Monday. We will not be done with the cold weather after the weekend warm up. All indications are that this front on Monday will be just as powerful, if not even stronger than the previous front. It will certainly have Arctic connections, and all of our forecast models show this. Monday's highs will warm up close to 60 before the front comes through and sends us back into the freezer. Temperatures will fall late. A hard freeze is on tap for Monday night, but there is still some question as to how cold it will get and if we'll clear out or not behind this front for Tuesday. Models have been insistent on some post-frontal precipitation with an upper level low on the backside of the front. This could be another frozen precipitation event for the forecast area, but that remains to be seen. There is a high degree of uncertainty at that time, and we'll concern ourselves with that after we get this winter storm out of here. Models show this idea, but some runs say it'll be Monday night into Tuesday and some say it'll be on Wednesday, thus the high level of uncertainty. For now, I will keep clouds and a chance for rain on Monday night and Tuesday with cold temperatures. Skies clear out Tuesday afternoon, and we'll see a very cold night Tuesday night into Wednesday with the potential for some 10s across the area. For now, I'll reflect low to mid 20s, while highs may struggle to reach 40 yet again. Those waiting for spring, may not have to wait very long. Long range prognostications suggest normal to above normal temperatures by the second half of the month. Stay tuned for more on this developing winter storm!
Preliminary Numbers & Zone Forecast:
LCH 25/32 26/32 22/45 10 70 100 80 20 0
BPT 25/31 27/32 23/46 10 70 100 80 20 0
LFT 27/33 27/34 22/44 20 70 100 80 30 0
AEX 21/30 23/29 18/40 10 60 100 70 20 0
POE 21/30 23/29 19/41 10 60 100 70 20 0
ARA 27/34 28/35 23/44 20 70 100 80 20 0
*Winter Storm Watch in effect from Thursday afternoon through Friday morning along and North of I-10.*
*Winter Weather Advisory in effect from Thursday afternoon through Friday morning for the coastal parishes.*
*Hard Freeze Warning is in effect.*
Tonight...Cloudy & Very Cold. Scattered Snow Flurries. Low 25. NNW wind 10-15 mph. Wind chill readings 10-20.
Thursday...Cloudy & Very Cold with an Ice Storm developing. Sleet and Freezing Rain developing in the morning and increasing through the afternoon. A chance of snow as well. Ice accumulations up to 1/10 of an inch. No snow accumulations. High 32. North wind 10-15 mph. Wind chills 15-25. Chance of precipitation 70%.
Thursday Night...Cloudy & Very Cold with a Winter Storm. Sleet, Freezing Rain, & Snow likely. A very significant & dangerous ice storm is likely. Snow accumulations up to an inch. Ice accumulations from 1/4-1/2 an inch. Low 26. NNE wind 15-20 mph and gusty. Wind chill readings in the 10s. Chance of precipitation 100%.
Friday...Cloudy & Very Cold w/ the Winter Storm Continuing. Snow, Sleet, & Freezing Rain likely in the morning before tapering off in the afternoon. Significant icing expected. Ice accumulations between 1/4 and 1/2 an inch. Snow accumulations of 1-2" possible. High 32. NNE wind 15-20 mph and gusty becoming NNW at 15 mph in the afternoon. Chance of precipitation 80%. Wind chill readings in the 10s.
Friday Night...Cloudy with a 20% chance of snow until around midnight. Decreasing Cloudiness, and quickly becoming Clear after midnight. Very Cold. Low 22. North wind 10 mph. Wind chill readings around 15.
Saturday...Sunny & Warmer but still Cold. High 44. NE wind 10 mph.
Drew's 7 Day Outlook
Thursday
2-3-11
Wintry Mix
Low: 25
High: 32
Precip: 70%
Wind: N 10-15
W.C. 13-18
Friday
2-4-11
Low: 26
High: 32
Precip: 80%
Wind: NNE/NNW 15-20
W.C.: 10-15
Saturday
2-5-11
Low: 22
High: 45
Precip: 0%
Wind: N 10
W.C.: 15-30
Sunday
2-6-11
Super Bowl Sunday
Low: 30
High: 55
Rain: 0%
Wind: ESE 5-10
W.C.: 25-40
Monday
2-7-11
Low: 40
High: 60
Rain: 30%
Wind: SSE/NNW 15-30
Tuesday
2-8-11
Low: 27
High: 37
Precip: 40%
Wind: NNW 20-30
W.C.: 5-15
Wednesday
2-9-11
Low: 21
High: 36
Precip: 0%
Wind: N 10-15
W.C.: 15-30
In closing, here is a link to the list of all the closings, cancellations, and delays for Thursday. This is courtesy of KPLC-TV.
Winter Storm Cancellations, Closings, & Delays
That's all for now! Stay tuned for more updates on the winter storm.
Good night, Have a great Thursday, Stay warm, Pray for Snow & God Bless!
-DM-
No comments:
Post a Comment