SE TX/SW LA Winter WX - 2011-2012

[Extremeweatherguy]

Wow, it looks like it is going to be a fun day tomorrow in and around Houston! I am really getting tempted to take a drive south to see this amazing event unfold.

[PTrackerLA]

Man that snowfall model doesn't look too good for Louisiana. Sure hints at a very late changeover to snow given all the QPF on the models, let's hope it's wrong and we see another border to border coating of snow!

[wxman57]

Man that snowfall model doesn't look too good for Louisiana. Sure hints at a very late changeover to snow given all the QPF on the models, let's hope it's wrong and we see another border to border coating of snow!

That's the latest GFS forecast on that graphic. NAM is drier.

[Tireman4]

Wow, it looks like it is going to be a fun day tomorrow in and around Houston! I am really getting tempted to take a drive south to see this amazing event unfold.

Well come on down EWG. You will love it.

[JenBayles]

Dumb question since I don't understand all the dynamics in play here. Is there any chance this could turn out to be more of an icing/ sleet event than snow? I'm worried about trees and power lines in addition to getting Mom back from the hospital late afternoon tomorrow.

My transportation choices are a Cadillac with somewhat worn tires or our pickup truck with new tires and a full load of wood in the back. I'm more worried about inexperienced drivers than my own skills since I learned how to drive in this kind of mess.

[jeff]

Dumb question since I don't understand all the dynamics in play here. Is there any chance this could turn out to be more of an icing/ sleet event than snow? I'm worried about trees and power lines in addition to getting Mom back from the hospital late afternoon tomorrow.

My transportation choices are a Cadillac with somewhat worn tires or our pickup truck with new tires and a full load of wood in the back. I'm more worried about inexperienced drivers than my own skills since I learned how to drive in this kind of mess.

No...profiles strongly support snow...only the near surface layers will be at or above freezing not the other way around from ZR/IP. Suspect given upstream dewpoints over NC TX that even the near surface layers will not be above freezing for long.

[jeff]

Dumb question since I don't understand all the dynamics in play here. Is there any chance this could turn out to be more of an icing/ sleet event than snow? I'm worried about trees and power lines in addition to getting Mom back from the hospital late afternoon tomorrow.

My transportation choices are a Cadillac with somewhat worn tires or our pickup truck with new tires and a full load of wood in the back. I'm more worried about inexperienced drivers than my own skills since I learned how to drive in this kind of mess.

I would try and be off the roads by early afternoon...1-2 hours after the onset of snow at your destination.

[srainhoutx]

Jeff, I'll post your afternoon Update...

Winter Storm Event likely Friday with historic accumulating snowfall over SE TX.

Winter Storm Watch will be in effect from 600am Friday morning to midnight Friday…watch will likely be upgraded to a warning later tonight or early Friday.

Discussion:

Arctic boundary slicing through C TX moving toward the coast with temperatures falling into the lower 40’s and upper 30’s north of this boundary. Powerful trough/short wave over New Mexico is rounding toward W TX with snow breaking out and being reported now at Lubbock. Impressive isentropic lift and jet dynamics come to bear on the region after daybreak Friday. Visible images show rapid N expansion of S TX moisture/cloud shield suggesting the GFS may in fact be getting ready to nail this event from Monday. Things appear to be coming together just as the GFS has been suggesting. With this in mind will go ahead and bump up to 70% chance of snow for Friday in line with the GFS output and mirror accumulations close to this model…especially since the 18Z NAM is falling in line with this thinking and the other drier models have swung toward the wetter solutions. Event is starting to look very similar to the Great 2004 Christmas snowstorm…although totals do not look as likely as in 2004.

This is one of the most highly forecast snow events I have ever seen with some near excellent model agreement…with that in mind a few things could still go wrong and prevent the accumulation totals below. I am glad we only deal with this now once every year!

Accumulation:

Will leave these unchanged from the previous thinking…will probably tinker some late tonight or early Friday.

Austin to College Station to Huntsville:

Will be lowering totals in this region as focus is shifting southward. A dusting to 2” is possible starting early Friday morning.

Columbus to Conroe to Lake Livingston:

This area should be on the north side of the heavier snow band with accumulations of 1-3 inches possible. Should see onset of snow by early to mid morning with accumulations by late morning as temperatures fall to freezing.

US 59 from Victoria to Liberty Co including metro Houston:

Accumulations in the 2-4” range across this area including metro Houston with some areas possibly picking up 6”. Will onset snow between 1000am and noon Friday and continue into early evening. May need to add moderate and heavy snow with visibilities tanking to below 1/4th of a mile at times in heavy snow bands. Could see up to 1” per hour of accumulation. Given the possible increased snowfall rates…not only bridges, but surface streets may become issues by Friday afternoon as surface temperatures fall to and below freezing.

Coastal Counties:

Will need to add accumulation to the coastal counties given the latest data with 1-2” likely including the beaches. Will see snow onset before noon in the Victoria area and spread NE up the coast by early afternoon. May need to go even higher on the accumulation in this region if the models continue to trend southward.

Actions:

Same as the earlier e-mail.

I have had several questions regarding timing and road impacts. Best I can tell is onset of SN over Montgomery/Waller Counties in the 900-1100am then Fort Bend/N and W Harris 1000am-noon and the rest of Harris, Brazoria/Galveston noon-200pm. Initial SN will melt on impact until air temp reaches freezing or snowfall rates exceed melting rates. Once SN begins to fall expect about 1-2 hours before bridges/overpasses ice/glaze over. Remember this is snow falling at your destination not your location.

Travel will become increasingly hazardous Friday afternoon as snowfall rates increase in heavy banding. May see a period of heavy snow with visibilities down to 1/4 or less or a mile in meso scale snow bands. Quick accumulations even of surface streets will be likely under the heavy snow bands.

Freezing Temperatures:

May need to go lower on overnight lows Saturday morning given expected snow cover on the ground. Could see lower 20’s in a few locations N/W and mid 20’s into several locations…even as far S as VCT. Will see little warming Saturday as sun light goes into snow melt instead of low level warming.

Request:

I rarely have request of folks, but am asking for you help as this event unfolds on Friday. There is a general lack of good surface data W, SW, and NW or in the area from College Station to Victoria. Any persons that could provide P-type information and intensities it would be greatly appreciated.

Next update will be Friday morning unless there are significant changes this evening.

[Tireman4]

This situation is getting more serious by the hour. I am trying to tell my brother in law to cancel our Dallas trip that we are making. I really dont want to drive in this mess.

[PTrackerLA]

Not sure what to think of this event, latest GFS looks even warmer for southern LA. Lake Charles says just a winter weather advisory is more likely as accumulations will be less than an inch. Guess we'll just wait and see what falls out of the sky tomorrow night!

[Stormcenter]

Historically when they (NWS) predict something like this it never pans out
so I'm not holding my breath. We shall see.

Not sure what to think of this event, latest GFS looks even warmer for southern LA. Lake Charles says just a winter weather advisory is more likely as accumulations will be less than an inch. Guess we'll just wait and see what falls out of the sky tomorrow night!

[srainhoutx]

Just an FYI, San Angelo in afternoon AFD states the NAM is under estimating QPF. Just something to think about re guidance.

[CYCLONE MIKE]

Just got home from work and trying to catch up on things. If anyone could answer, what has changed so that south LA looks not to get hit to bad by this? Houston looks to be getting colder with more snow while LA temps stay steady with less snow. I did find this bit of info though that says things could change though...

DUE TO THE UNCERTAINTIES SHOWN IN THE LATEST SUITE OF COMPUTER
MODELS WILL NOT UPGRADE INHERITED WINTER WEATHER WATCH ATTM.
ACCUMULATIONS RIGHT NOW LOOK TO REMAIN BELOW WARNING CRITERIA AND
WOULD EXPECT A WINTER WEATHER ADVISORY TO BE ISSUED LATER TONIGHT.
HOWEVER WOULD NOT BE SURPRISED EITHER IF THE NEXT SUITE COMES INTO
BETTER AGREEMENT ON LOCATION AND AMOUNTS WHICH WOULD PUSH OUR
EXPECTED ACCUMULATIONS ABOVE THE TWO-INCH THRESHOLD.

[JenBayles]

Dumb question since I don't understand all the dynamics in play here. Is there any chance this could turn out to be more of an icing/ sleet event than snow? I'm worried about trees and power lines in addition to getting Mom back from the hospital late afternoon tomorrow.

My transportation choices are a Cadillac with somewhat worn tires or our pickup truck with new tires and a full load of wood in the back. I'm more worried about inexperienced drivers than my own skills since I learned how to drive in this kind of mess.

No...profiles strongly support snow...only the near surface layers will be at or above freezing not the other way around from ZR/IP. Suspect given upstream dewpoints over NC TX that even the near surface layers will not be above freezing for long.

Many thanks for the reply Jeff - and for your participation as always here at S2K.

[gboudx]

Not sure what to think of this event, latest GFS looks even warmer for southern LA. Lake Charles says just a winter weather advisory is more likely as accumulations will be less than an inch. Guess we'll just wait and see what falls out of the sky tomorrow night!

This is your best bet. You can have the shoes and football ready by the door. Have Lucy on call.

[southerngale]

I don't believe I've ever seen this high of a chance of snow. This is from KFDM in Beaumont.



And while I have the utmost respect for the guys at KFDM, particularly Greg Bostwick, it's still hard to believe... the chance of measurable snow 2 years in a row, exactly 1 week shy of a year ago. Unreal.

[hurrican19]

Here's to hoping my friends in Austin gets more than projected now! They get the shaft again, lol.

[Sean in New Orleans]

We'll wait and see....it's never snowed in SE Louisiana this early and there is disuccsion of 1 to 2 inches in the western suburbs of New Orleans. I like snow, but, this go around, I actually hope we have none in the city. I am supposed to build a playground with Kaboom on Saturday morning in Lakeview, and I'd rather not in sleet or snow. If it happens, it happens, but, is sure is early in the year for this type of talk.

[PTrackerLA]

00z NAM does indeed look colder and implies a changeover to all snow for all but extreme SE LA, could even be heavy near New Orleans given the QPF. Looks like snow could begin before 5pm in the Lafayette area and continue for much of the night, amazing for December 4th!

[sphelps8681]

live in Lumberton which is North of Beaumont. When should we expect conditions to start becoming bad. I work for the school district and was wondering if road travel might become bad before school is out at 3:45.

Any input would be greatful.

Thanks