Texas Winter 2010-2011

[wall_cloud]

I think I kind of get that now after researching baroclinic zones. So, correct me if I'm wrong but, the system is essentially following a temperature gradient, for example 550 or so thickness layer, meaning that no matter where the storm goes along the baroclinic zone, the weather will be mainly constant, rain, then moisture being scoured as the cold, drier air intrudes.

You can't think of the different atmospheric features as being separate entities. There is a cause and effect for everything going on at any particular time. In this instance, it appears that the shortwave is riding along the low level baroclinic zone. This is generally to be expected as waves in the atmosphere tend to travel with the general flow of the jet stream. This jet usually forms above low level thermal gradients through the thermal wind relationship. This is highly simplified, of course.

[Portastorm]

Looking at temps in the "source region" this morning at 6 am shows nothing too dramatic (yet).

[srainhoutx]

With the Arctic air mass still to the way N of the US/Canadian border, I thought I'd post some 24 hour temps changes across the CONUS and parts of Canada...

[srainhoutx]

I also wanted to remind our Central and SE TX folks that we do have a Slight Risk of Severe Storms from the SPC concerning tonight into tomorrow. In fact HGX is mentioning 2-3 inches of heavy rainfall as well.

[txagwxman]

6z colder...16F DFW next week, 22F IAH.

ECMWF still not on the colder bandwagon yet.

[srainhoutx]

I suspect the Euro will trend down regarding those temps. With all the snowcover that will likely fall across the Central/Southern Plains, that cold N wind will feel mighty chilly, IMO...

[txagwxman]

I also wanted to remind our Central and SE TX folks that we do have a Slight Risk of Severe Storms from the SPC concerning tonight into tomorrow. In fact HGX is mentioning 2-3 inches of heavy rainfall as well.

Houston marathon is going to be a wash out!

[srainhoutx]

I also wanted to remind our Central and SE TX folks that we do have a Slight Risk of Severe Storms from the SPC concerning tonight into tomorrow. In fact HGX is mentioning 2-3 inches of heavy rainfall as well.

Houston marathon is going to be a wash out!

Yeah. We've had wxman57 and Jeff talking about that in the local forum. It's looking mighty damp, but at least not cold.

[wxman57]

Overnight GFS at least sees the cold air for a change. But don't get your hopes up for any frozen precip in southeast parts of the state. This just isn't the pattern for snow in Houston or Beaumont. The precipitation will fall with temperatures well above freezing on Tuesday. There is a chance that the Arctic air will slip south more quickly than the models are indicating, but this may mean freezing rain to our north and, not snow across coastal counties.

[txagwxman]

I also wanted to remind our Central and SE TX folks that we do have a Slight Risk of Severe Storms from the SPC concerning tonight into tomorrow. In fact HGX is mentioning 2-3 inches of heavy rainfall as well.

Houston marathon is going to be a wash out!

Yeah. We've had wxman57 and Jeff talking about that in the local forum. It's looking mighty damp, but at least not cold.

ECMWF dumping 1"+...gfs not so much.

[txagwxman]

6z colder and faster than the 00z and the 18z.

[wxman57]

ECMWF dumping 1"+...gfs not so much.

I did notice on the meteogram above that yesterday's 12Z GFS dropped about 0.1" of rain from 6am-noon. The 6Z run has about .25" with the heavy rain peak a bit closer to 6am. It would take just a few hours delay in the rain to make for a very bad start to the marathon. Each year the wife and I discuss biking out to the start and cheering friends along the route. And each year it's either too cold or too rainy (or both). I think they should move the marathon to July and start it about noon for our convenience.

[txagwxman]

ECMWF dumping 1"+...gfs not so much.

I did notice on the meteogram above that yesterday's 12Z GFS dropped about 0.1" of rain from 6am-noon. The 6Z run has about .25" with the heavy rain peak a bit closer to 6am. It would take just a few hours delay in the rain to make for a very bad start to the marathon. Each year the wife and I discuss biking out to the start and cheering friends along the route. And each year it's either too cold or too rainy (or both). I think they should move the marathon to July and start it about noon for our convenience.

They should have it in late October!

[Portastorm]

12z NAM still has a 1052mb high coming down into Montana by 72-84 hours. Right spot to funnel down into Texas but the upper-level energy story is not a happy one if you want wintry precip. Per this model, looks like only hope would be for north Texas if the cold air slips down faster than progged.

That seems to be the story for early week.

[txagwxman]

12z NAM still has a 1052mb high coming down into Montana by 72-84 hours. Right spot to funnel down into Texas but the upper-level energy story is not a happy one if you want wintry precip. Per this model, looks like only hope would be for north Texas if the cold air slips down faster than progged.

That seems to be the story for early week.

NAM is very close for DFW tue...Sherman/SPS and OKC will get it...OKC/TUL could get a 6"+.

DFW will probably be near 32F by 9AM and get some freezing rain/sleet before precip end around noon.

[Ntxw]

NAM has been trending colder and colder each run and shifting the fight zone each time! I say given inflation, at this rate we'd have the baroclinic ending up in Houston! Ok maybe not Houston, but NAM isn't killing off the southern stream wave, in fact, it's strengthening it over Texas. Cold air movement just can't be emphasized enough.

[Portastorm]

NAM has been trending colder and colder each run and shifting the fight zone each time! I say given inflation, at this rate we'd have the baroclinic ending up in Houston! Ok maybe not Houston, but NAM isn't killing off the southern stream wave, in fact, it's strengthening it over Texas. Cold air movement just can't be emphasized enough.

The upper-air data work being done in the Pacific over the next 24 hours will be invaluable for those model runs tomorrow. Seems like by the 12z runs tomorrow, we should have a good idea about the Monday-Tuesday activity. But I'm also hearing from wise weather sources that convection is increasing in the Pacific and that our friend, the MJO, may have some "surprises" in store next week.

Gonna be fun to watch how this plays out.

[Ntxw]

Starting to get a gut feeling about this one. I don't know if that's good or bad lol.

I call for a PWC briefing to calm down the masses to prevent the ICU Portastorm

[DentonGal]

Local DFW mets are calling for 60% chance of freezing rain/sleet Tuesday. Sure thought our chances were slim to none for frozen precip.

[wxman57]

NAM has been trending colder and colder each run and shifting the fight zone each time! I say given inflation, at this rate we'd have the baroclinic ending up in Houston! Ok maybe not Houston, but NAM isn't killing off the southern stream wave, in fact, it's strengthening it over Texas. Cold air movement just can't be emphasized enough.

It may all depend on whether the models are correct in developing that lee-side low and holding the cold air back on Tuesday morning. If they're wrong, and that's happened often in the past, then the cold air races south and no low forms. The upper-air disturbance moves over a shallow sub-freezing layer and we have an ice storm across central and north TX. We probably really won't be able to tell if this scenario will play out until late Monday.