Texas Winter 2010-2011

[txagwxman]

Canadian has more moisture over Houston Thu/Fri but air aloft appears too "warm" for snow. Euro and GFS are colder (snow) but with less moisture. It's a delicate balance. Looking like coastal sections of Texas may well see a dusting of snow Thu nite/Fri. However, if the GFS/EC are correct, the Portastorm Weather Center may be too far north (inland) for snow, unless the Canadian is correct.

We've always considered the idea of a satellite office on the coast ... perhaps now's the time to open that office in Corpus.

Our forecasters are having some difficulty this morning due to a Magic 8-ball malfunction. When asked if it will snow in Austin this week, the 8-ball is stuck on the "definitely maybe" answer.

Portastorm, this is it.

[HockeyTx82]

U know something is about to unfold when I can't sleep...

Watch out DFW/SPS! 12" SPS, 2-4" in FTW? ICE/SLEET 7AM TUE. Fort Worth/Denton you guys are in trouble!

Watch out CLL/IAH/DWH/GGG/SHV/AUS Thu/FRI. GEM going bonkers over Austin now!

Watch out OK for -5F to -10F temps over the snow cover later this week. Could see 5F temps over ice/snow N. TX.

And the ECMWF has more cold...wth is going on!

What are you seeing for Denton? Are you still seeing it?

[opticsguy]

6 Zulu NAM looks the same or worse. Sleet, freezing rain, and some snow to top it off for DFW. Time to fire up the generator and make sure it works.

[gboudx]

jeff's update.

Dangerous winter weather heading for the state of Texas.

Preparations for an extended period of very cold air should be completed today.

Major winter storm to affect W and N TX tonight and Tuesday into the central plains

Winter precipitation possible across the entire TX coast (including S TX) Thursday and Friday.

Discussion:

Long advertised arctic outbreak is on the move this morning with the very cold air mass now crossing the US border over Montana and North Dakota. Current temperatures are -27 in northern Montana with the leading edge of the arctic front in central Wyoming. Strong blocking along the US west coast with ridging building deep into Alaska will force the -30 to -40 degree air mass over NW Canada southward into the US central plains over the next 24-36 hours. Appears record cold temperatures are on the way to much of the plains along with a major blizzard for the central plains and Great Lakes. Overnight lows forecast to drop into the -5 to -10 range over the Texas panhandle and possibly the lower teens to single digits over N TX. Sub-zero wind chills will be likely as far south as Waco by Wednesday.

Will break the impacts down by time periods to try and help layout an extremely difficult and changeable forecast.

Tuesday:

Powerful arctic boundary will reach the TX panhandle this evening and sweep southward across N TX by sunrise. Shallow but very cold air mass will undercut the warm Gulf surface layer with widespread rainfall/thunderstorms. Temperatures prior to the front will reach the mid-upper 60’s and then fall rapidly into the 30’s behind the front. Rain will change to freezing rain/sleet/snow from NW to SE over N TX during the day on Tuesday while a large blizzard develops from W TX into OK. Travel to W TX and N TX/OK on Tuesday will be extremely dangerous with heavy blowing snow on 40-45mph winds and temperatures in the teens and 20’s.

Tuesday night:

Arctic cold front blasts into the Gulf of Mexico with very strong cold air advection in progress. Winds will howl post front 20-35mph with gust to 40mph driving wind chills into the teens all across coastal Texas and to near zero as far south as Waco. Freezing line will advance to the US 59 corridor by mid evening and then to the coast with mid 20’s for all locations north of a line from Huntsville to Sugar Land to Victoria by Wednesday morning. This will be a damaging advective freeze for sensitive vegetation. Wind advisories may be required for parts of the area.

Wednesday:

Arctic dome deepens toward 900mb with low level moisture likely trapped near the surface keeping skies mostly cloudy. Strong north winds will continue to drive very cold air southward off the snow pack over W and N TX/OK. Will likely see very little warming to maybe freezing NW of a line from Conroe to Hempstead to Victoria. SE of this line highs may reach the mid 30’s. Wind chills will be in the teens. Clouds may clear out some Wednesday night allowing lows for Thursday morning to bottom out in the teens N of HWY 105, low 20’s along the US 59 corridor, and upper 20’s/low 30’s along the coast.

Forecast for Thursday onward is subject to major changes due to high uncertainty when dealing with forecasting winter precipitation in coastal Texas. There will be significant changes over the next few days to what is described below, it is the best prediction at this time with the model data available.

Thursday:

Upper level energy over the northern Rockies currently dives SSW into the SW US and then begins to move eastward toward TX. Arctic dome deepens toward 850-700mb (5,000-20,000 ft deep) with the center of the arctic high over western OK/KS. GFS is the fastest with this trough ejecting over TX while the ECMWF and CMC are the slowest. The CMC is by far the wettest with the GFS and ECMWF drier. Expect weak isentropic lift to begin midday Thursday thickening the mid level cloud deck. Soundings for CRP and VCT by Thursday evening show a saturated mid to low level profile completely below freezing, but all sounding sites show a very dry sub-cloud layer near the surface. Expect lifting processes and frontogenic forcing to develop meso scale banding of precipitation by Thursday afternoon/evening. Initial precipitation will likely evaporate before reaching the ground helping to moisten the near surface layer. Then once the dry layer is removed, precipitation will start to reach the ground. With the point forecast soundings showing a sub-freezing layer through the entire column for nearly all sites by Thursday afternoon/evening P-type will be snow, except maybe a period of IP (sleet) right along the coast. Expect highs near freezing along and N of I-10 and in the mid 30’s south of I-10

Thursday night:

Upper level trough moves toward/across Texas depending on which model you follow (GFS is the fastest with the ECMWF the slower and the GFS ensembles nearly splitting the difference). The faster GFS produces a quick shot of snow while the slower ECMWF and CMC would produce impressive snowfall totals across all of coastal Texas. Slower solution would allow greater time for the air mass to moisten and a longer period of meso scale snow banding to develop with higher snowfall rates. Surface layer will be in the mid to upper 20’s so what falls will accumulate and after days of sub-freezing temperatures the ground is going to be very cold. GFS shows best snowfall accumulation along a line from Victoria to W of Corpus Christi to McAllen on the order of 2-4 inches in this area. Still too early to be certain on any kind of accumulations as there are questions with moisture quality and how far inland the deeper moisture penetrates. This potential event has similarities to both the Dec 04 snowstorm and the snow event in Dec 1989 with the position of the upper and surface features. I am a little concerned about the amount of moisture available (usually it is the other way around, we do not have the cold air), but the models have been trending wetter with more QPF with each run adding confidence that something will fall later this week.

Friday:

Winter weather event will likely be ongoing Thursday night-Friday with potential for snow and some accumulations. Will go well below GFS guidance on highs and keep temperatures at or below freezing given falling precipitation, clouds, and possible snow accumulations for all areas including the coastal areas. Precipitation should gradually end from west to east Friday as the upper level trough moves over E TX and into LA allowing lift to decrease. Should the slower ECMWF and CMC models verify the best chances for snow will be on Friday and Friday night.

Preparations:

Residents across Texas should take the last warm day today to make the needed preparations for an extended period of cold weather. Protect/shelter sensitive tropical vegetation, hours of sub-freezing temperatures will damage or kill unprotected sensitive plants. Advective nature of the freeze with strong north winds will reduce the “greenhouse effect” of wrapping plants, so make sure coverings are strongly fastened with multiple layers.

Wrap exposed outside pipes and disconnect all water hoses from exterior wall connects. Turn off sprinkler systems and cover back flow preventer pipes which suffered greatly in the freeze last January. It might be a good idea to shut off the water supply to the entire sprinkler system to prevent freezing and bursting of the back flow pipes. Interior pipes should be fine with this event, but to be on the safe side open exterior facing cabinets to allow house warmth against the interior plumbing.

Pets and livestock should be sheltered is possible. Hours of sub-freezing temperatures and wind chills ranging from the single digits to teens will produce highly uncomfortable conditions for animals exposed for long periods of time.

Travel:

Dangerous/life threatening conditions will be developing over portions of W TX into the central plains tonight/Tuesday with full scale blizzard conditions as far south as southern OK. Surface travel is strongly discouraged in this region as significant snowfall and strong north winds of 30-40mph will blow and drift snow likely closing interstates and stranding vehicles. Temperatures over parts of OK and the TX panhandle will fall below zero with wind chills as low as -35 degrees making exposure to the outside air extremely dangerous. Aviation travel will likely be heavily impacted on Tuesday as major airports across the Midwest and plains struggle against heavy snow, low visibilities, and very cold air. Both Chicago and DFW will likely have major weather impacts/delays which will ripple into the rest of the system.

[southerngale]

I think AUS/CLL/IAH will see snow Friday, cold air should be in place. If the GEM solution then Austin will get it, while IAH will get rain. But me thinks the ECMWF/GFS solution the right one. Too bad I don't have the UKMET.

No love for the Beaumont area?

[txagwxman]

jeff's update.

Dangerous winter weather heading for the state of Texas.

Preparations for an extended period of very cold air should be completed today.

Major winter storm to affect W and N TX tonight and Tuesday into the central plains

Winter precipitation possible across the entire TX coast (including S TX) Thursday and Friday.

Discussion:

Long advertised arctic outbreak is on the move this morning with the very cold air mass now crossing the US border over Montana and North Dakota. Current temperatures are -27 in northern Montana with the leading edge of the arctic front in central Wyoming. Strong blocking along the US west coast with ridging building deep into Alaska will force the -30 to -40 degree air mass over NW Canada southward into the US central plains over the next 24-36 hours. Appears record cold temperatures are on the way to much of the plains along with a major blizzard for the central plains and Great Lakes. Overnight lows forecast to drop into the -5 to -10 range over the Texas panhandle and possibly the lower teens to single digits over N TX. Sub-zero wind chills will be likely as far south as Waco by Wednesday.

Will break the impacts down by time periods to try and help layout an extremely difficult and changeable forecast.

Tuesday:

Powerful arctic boundary will reach the TX panhandle this evening and sweep southward across N TX by sunrise. Shallow but very cold air mass will undercut the warm Gulf surface layer with widespread rainfall/thunderstorms. Temperatures prior to the front will reach the mid-upper 60’s and then fall rapidly into the 30’s behind the front. Rain will change to freezing rain/sleet/snow from NW to SE over N TX during the day on Tuesday while a large blizzard develops from W TX into OK. Travel to W TX and N TX/OK on Tuesday will be extremely dangerous with heavy blowing snow on 40-45mph winds and temperatures in the teens and 20’s.

Tuesday night:

Arctic cold front blasts into the Gulf of Mexico with very strong cold air advection in progress. Winds will howl post front 20-35mph with gust to 40mph driving wind chills into the teens all across coastal Texas and to near zero as far south as Waco. Freezing line will advance to the US 59 corridor by mid evening and then to the coast with mid 20’s for all locations north of a line from Huntsville to Sugar Land to Victoria by Wednesday morning. This will be a damaging advective freeze for sensitive vegetation. Wind advisories may be required for parts of the area.

Wednesday:

Arctic dome deepens toward 900mb with low level moisture likely trapped near the surface keeping skies mostly cloudy. Strong north winds will continue to drive very cold air southward off the snow pack over W and N TX/OK. Will likely see very little warming to maybe freezing NW of a line from Conroe to Hempstead to Victoria. SE of this line highs may reach the mid 30’s. Wind chills will be in the teens. Clouds may clear out some Wednesday night allowing lows for Thursday morning to bottom out in the teens N of HWY 105, low 20’s along the US 59 corridor, and upper 20’s/low 30’s along the coast.

Forecast for Thursday onward is subject to major changes due to high uncertainty when dealing with forecasting winter precipitation in coastal Texas. There will be significant changes over the next few days to what is described below, it is the best prediction at this time with the model data available.

Thursday:

Upper level energy over the northern Rockies currently dives SSW into the SW US and then begins to move eastward toward TX. Arctic dome deepens toward 850-700mb (5,000-20,000 ft deep) with the center of the arctic high over western OK/KS. GFS is the fastest with this trough ejecting over TX while the ECMWF and CMC are the slowest. The CMC is by far the wettest with the GFS and ECMWF drier. Expect weak isentropic lift to begin midday Thursday thickening the mid level cloud deck. Soundings for CRP and VCT by Thursday evening show a saturated mid to low level profile completely below freezing, but all sounding sites show a very dry sub-cloud layer near the surface. Expect lifting processes and frontogenic forcing to develop meso scale banding of precipitation by Thursday afternoon/evening. Initial precipitation will likely evaporate before reaching the ground helping to moisten the near surface layer. Then once the dry layer is removed, precipitation will start to reach the ground. With the point forecast soundings showing a sub-freezing layer through the entire column for nearly all sites by Thursday afternoon/evening P-type will be snow, except maybe a period of IP (sleet) right along the coast. Expect highs near freezing along and N of I-10 and in the mid 30’s south of I-10

Thursday night:

Upper level trough moves toward/across Texas depending on which model you follow (GFS is the fastest with the ECMWF the slower and the GFS ensembles nearly splitting the difference). The faster GFS produces a quick shot of snow while the slower ECMWF and CMC would produce impressive snowfall totals across all of coastal Texas. Slower solution would allow greater time for the air mass to moisten and a longer period of meso scale snow banding to develop with higher snowfall rates. Surface layer will be in the mid to upper 20’s so what falls will accumulate and after days of sub-freezing temperatures the ground is going to be very cold. GFS shows best snowfall accumulation along a line from Victoria to W of Corpus Christi to McAllen on the order of 2-4 inches in this area. Still too early to be certain on any kind of accumulations as there are questions with moisture quality and how far inland the deeper moisture penetrates. This potential event has similarities to both the Dec 04 snowstorm and the snow event in Dec 1989 with the position of the upper and surface features. I am a little concerned about the amount of moisture available (usually it is the other way around, we do not have the cold air), but the models have been trending wetter with more QPF with each run adding confidence that something will fall later this week.

Friday:

Winter weather event will likely be ongoing Thursday night-Friday with potential for snow and some accumulations. Will go well below GFS guidance on highs and keep temperatures at or below freezing given falling precipitation, clouds, and possible snow accumulations for all areas including the coastal areas. Precipitation should gradually end from west to east Friday as the upper level trough moves over E TX and into LA allowing lift to decrease. Should the slower ECMWF and CMC models verify the best chances for snow will be on Friday and Friday night.

Preparations:

Residents across Texas should take the last warm day today to make the needed preparations for an extended period of cold weather. Protect/shelter sensitive tropical vegetation, hours of sub-freezing temperatures will damage or kill unprotected sensitive plants. Advective nature of the freeze with strong north winds will reduce the “greenhouse effect” of wrapping plants, so make sure coverings are strongly fastened with multiple layers.

Wrap exposed outside pipes and disconnect all water hoses from exterior wall connects. Turn off sprinkler systems and cover back flow preventer pipes which suffered greatly in the freeze last January. It might be a good idea to shut off the water supply to the entire sprinkler system to prevent freezing and bursting of the back flow pipes. Interior pipes should be fine with this event, but to be on the safe side open exterior facing cabinets to allow house warmth against the interior plumbing.

Pets and livestock should be sheltered is possible. Hours of sub-freezing temperatures and wind chills ranging from the single digits to teens will produce highly uncomfortable conditions for animals exposed for long periods of time.

Travel:

Dangerous/life threatening conditions will be developing over portions of W TX into the central plains tonight/Tuesday with full scale blizzard conditions as far south as southern OK. Surface travel is strongly discouraged in this region as significant snowfall and strong north winds of 30-40mph will blow and drift snow likely closing interstates and stranding vehicles. Temperatures over parts of OK and the TX panhandle will fall below zero with wind chills as low as -35 degrees making exposure to the outside air extremely dangerous. Aviation travel will likely be heavily impacted on Tuesday as major airports across the Midwest and plains struggle against heavy snow, low visibilities, and very cold air. Both Chicago and DFW will likely have major weather impacts/delays which will ripple into the rest of the system.

Good gosh --- cliffnotes please!

[txagwxman]

I think AUS/CLL/IAH will see snow Friday, cold air should be in place. If the GEM solution then Austin will get it, while IAH will get rain. But me thinks the ECMWF/GFS solution the right one. Too bad I don't have the UKMET.

No love for the Beaumont area?

eeeh? not sure.

[GRAYSONCO.WX]

12Z NAM coming in!(:

[txagwxman]

2-4" in SPS---NWS on crack?

[GRAYSONCO.WX]

The latest NAM looks to speed the timing of the arctic air, by a tad!

[txagwxman]

The latest NAM looks to speed the timing of the arctic air, by a tad!

Have u seen the HIRESWRF? It is 28F DFW 12z tomorrow.

[LearnedHat]

I try not to ask everybody to dumb this stuff down for my benefit too often BUT . . . is it a consensus that the frozen precip will start before 6 am now? For point of reference, I am in Keller. Everything I can glean from this site over the last 24 hours is that the cold air is expected to move in earlier than before. Also, with the ground warm from the spring like weather, will the cold follow through quickly enough to keep stuff frozen - I assumed that sleet at 32 degrees might not stay around too long because my ground temps are elevated from the extended 70+ temps we've had.

[iorange55]

Now under a winter storm watch. Models continue to speed up the cold air? This may be a pretty significant winter storm.

[Kelarie]

Y'all already probably have this map, but if you don't it is must have. It is a map of the US with weather stations that gives info on temp, wind, etc.

http://www.wrh.noaa.gov/zoa/mwmap3.php?map=usa

[southerngale]

I try not to ask everybody to dumb this stuff down for my benefit too often BUT . . . is it a consensus that the frozen precip will start before 6 am now? For point of reference, I am in Keller. Everything I can glean from this site over the last 24 hours is that the cold air is expected to move in earlier than before. Also, with the ground warm from the spring like weather, will the cold follow through quickly enough to keep stuff frozen - I assumed that sleet at 32 degrees might not stay around too long because my ground temps are elevated from the extended 70+ temps we've had.

Hi. I see you posted your location. Why don't you take a moment and add your location to your profile and then it will show up whenever you post? Just click on User Control Panel in the top right corner, then click on Profile over on the left. Then add your location.

For anyone else who doesn't have their location in their profile, please add it and then we'll know where you are when you're making comments about your local weather or asking questions.

[iorange55]

I try not to ask everybody to dumb this stuff down for my benefit too often BUT . . . is it a consensus that the frozen precip will start before 6 am now? For point of reference, I am in Keller. Everything I can glean from this site over the last 24 hours is that the cold air is expected to move in earlier than before. Also, with the ground warm from the spring like weather, will the cold follow through quickly enough to keep stuff frozen - I assumed that sleet at 32 degrees might not stay around too long because my ground temps are elevated from the extended 70+ temps we've had.

DFW is supposed to reach freezing by 7am or so I'm guessing it'll be a little early than that. I'd say you'll be a freezing by 5am or so. Ground temps being too warm I always feel is just silly. The temperature will be dropping into the 20s during the event so anything that falls should have no problem sticking. Maybe in the first part of the changeover, but after that it's going to sticking like glue.

[funster]

Looks like we could see many types of wintry precip ending with snow. I wonder if there will be any thundersleet? Would prefer all snow (the non wet kind so we don't have power outages) but obv I don't get to decide what comes down.

[vbhoutex]

Y'all already probably have this map, but if you don't it is must have. It is a map of the US with weather stations that gives info on temp, wind, etc.

http://www.wrh.noaa.gov/zoa/mwmap3.php?map=usa

I didn't have it. GREAT map to have!! Thanks!!!
It is very easy to follow the cold on that map. It appears to me that the cold is advancing faster than originally expected. Would not be surprised if it arrives at least a few to several hours earlier than currently progged. Make sure you get your preparations completed TODAY in all areas of TX.

[Portastorm]

Canadian has more moisture over Houston Thu/Fri but air aloft appears too "warm" for snow. Euro and GFS are colder (snow) but with less moisture. It's a delicate balance. Looking like coastal sections of Texas may well see a dusting of snow Thu nite/Fri. However, if the GFS/EC are correct, the Portastorm Weather Center may be too far north (inland) for snow, unless the Canadian is correct.

We've always considered the idea of a satellite office on the coast ... perhaps now's the time to open that office in Corpus.

Our forecasters are having some difficulty this morning due to a Magic 8-ball malfunction. When asked if it will snow in Austin this week, the 8-ball is stuck on the "definitely maybe" answer.

Portastorm, this is it.

What is "it"? I wish I could believe in the Canadian but c'mon txagwxman, you and I both know it is the fourth best scoring model at 5 and 6 days out right now. The Ukie has given the Euro a run for its money and they're basically tied for first.

It's not time yet for me to lace up the kicking shoes even though Lucy is beckoning!

[TeamPlayersBlue]

I think AUS/CLL/IAH will see snow Friday, cold air should be in place. If the GEM solution then Austin will get it, while IAH will get rain. But me thinks the ECMWF/GFS solution the right one. Too bad I don't have the UKMET.

I agree, if i remember correctly, whenever the mets are confident in an event happening this far in advance it usually happens. Normally moisture is a problem too but the moisture is ALWAYS there. They had a 20% chance of snow for SE Tx for the 2004 xmas event too remember. The bullseye in that event was near Victoria i think. We will see guys, this is our best bet..... slower the better