Texas winter wx thread (2009-2010)

[snow and ice]

Long Range Ensembles look cold and wintry for the southern plains and Texas from 240hrs forward.

Long Range Ensembles:
http://www.meteo.psu.edu/~gadomski/ENSH ... pmref.html

[srainhoutx]

A quick look at the 12Z OP GFS sure looks interesting just beyond Thanksgiving. Things are trending to some much cooler air for those that like cold weather.

[Portastorm]

A quick look at the 12Z OP GFS sure looks interesting just beyond Thanksgiving. Things are trending to some much cooler air for those that like cold weather.

Based on that 12z run, Austin would have about a half inch of precip with temps hovering in the low 30s during the Dec. 3-4 time frame. Wow ... that would be most interesting!

[Portastorm]

Today's 0z run of the GFS continues to advertise a much colder pattern impacting the Southern Plains and Texas beginning late Thanksgiving weekend and continuing throughout the following week.

Pretty much from 204 hrs through 384 hrs, you'll see the impact.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fpc.shtml

[vbhoutex]

Looks more and more interesting the further out you go(not a surprise). Texas wise it will definitely cool us all down, but the brunt looks to go East of us. Am I missing something? About 372 hours it appears SE TX could be in for some of our coldest so far, but without any precip. at those low temps.

[srainhoutx]

Almost all the guidance is locking into a solution that will bring our first tastes of cold air into North America and TX as well as our area. You may ask, how do we know a pattern change is coming? We have to look to several factors. I'll keep it simple and hopefully easy to understand. Cold air has been building across W Siberia and China as well as record breaking temps in AK for the past month. Due to a strong and stormy Polar Jet pattern across the Northern Pacific Region, multiple areas of strong Upper Low Pressure systems have been locked N of the Polar Jet and not allowing any Arctic Air to make intrusions into N America. Areas in the Canadian Provinces have actually been very warm for this time of year due to this pattern. Beginning next week things begin to change. A High Pressure Ridge will build into the Gulf Of Alaska Area and ridging in the Greenland Region will also set up. This will allow a very persistent trough to develop across Central N America. For the past month, we have seen a very zonal flow across the US, with cut of Upper Lows diving into the SW. As the High Pressure ridge develops in the Northern Pacific, the Arctic Air that has been building will be dislodged and will spill across the Arctic Regions into North America (Cross Polar Flow). Storm systems will ride up and over the ridge to our far NW and spill into the Great Plains and trailing Arctic High Pressure Ridges will progressively become stronger with each passing storm. As we have seen so far this Fall Season, we have an active pattern with the Sub Tropical Jet. This is very typical in El Nino years in our area and also affects the southern Half of the US. There are some indications that this El Nino Pattern maybe a tad stronger than previously thought. We shall see. It is my thought that we will see a progressive pattern set up with increasing Arctic Intrusions and a lot of activity along the Sub Tropical Jet giving many over running events and Coastal Low development throughout the Winter. I do not expect extreme cold, but cold enough to give many across TX the chance to see wintry precip chances that will be repeated throughout the season. Sorry for the long post, but I wanted to get the ball rolling for a lively discussion and hope many will chime in.

[snow and ice]

Today's 0z run of the GFS continues to advertise a much colder pattern impacting the Southern Plains and Texas beginning late Thanksgiving weekend and continuing throughout the following week.

Pretty much from 204 hrs through 384 hrs, you'll see the impact.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fpc.shtml

The 6z GFS from about 192 hrs on has a good handle on how the general pattern(with emphasis on general) is shaping up for the first two weeks of December. First of all, a big chunk of -40f air is going to dislodge from Alaska down into Canada and the lower 48. Meanwhile, the subtropical jet will become more active during this time. As shown on the 6z run, a major winter storm will form in the GOM sometime around the first week of December. This will become a repetitive pattern for at least the first two weeks of December as you see the pattern reloading at the end of the 6z run.

As for what this means for Texas, it's still too early to tell. However, this is the type of pattern(GOM low and arctic air to the north) where Texas gets major winter storms, and I'm not talking about overrunning situations, or where someone gets lucky and gets winter precip if they happen to be under the path of an upper level low.

[snow and ice]

"I do not expect extreme cold, but cold enough to give many across TX the chance to see wintry precip chances that will be repeated throughout the season."

Generally, when we see extremely cold, that means a Northwest Flow a loft and dry air at all levels of the atmosphere. All you need for a good winter storm in Texas,(for the northern 2/3rds of the state) is a GOM low and and a cold air mass with low dewpoints. Even if temps are in the mid to upper 30's at the onset of the precipitation, they will drop below freezing if the dewpoints are sufficiently low when the precipitation begins.

[srainhoutx]

"I do not expect extreme cold, but cold enough to give many across TX the chance to see wintry precip chances that will be repeated throughout the season."

Generally, when we see extremely cold, that means a Northwest Flow a loft and dry air at all levels of the atmosphere. All you need for a good winter storm in Texas,(for the northern 2/3rds of the state) is a GOM low and and a cold air mass with low dewpoints. Even if temps are in the mid to upper 30's at the onset of the precipitation, they will drop below freezing if the dewpoints are sufficiently low when the precipitation begins.

No doubt. The one thing that has been persistent is the Cold Core Upper Lows. It's likely that these type systems will continue and therein lies that chance to bring DP's down and cools the atmosphere enough to offer the wintry precip. Rememeber last December along the I-10 corridor.

Edit/Spelling

[wxgirl69]

sounds fantastic!!!! I love the cold weather. Hope things play out..

[mysterymachinebl]

sounds fantastic!!!! I love the cold weather. Hope things play out..

Me too! I am looking forward to the coming changes, and hopefully some wintery weather!

[wxgirl69]

When is this cold supposed to come down? If I am reading things correctly it should start around Dec 1-2.
Please correct me if am wrong. Thanks

[ntxweatherwatcher]

How cold are we talking for North Texas? Any precip with the cold?

[WhiteShirt]

How cold for the upper Texas coast? For this winter, do our chances here look decent for some snow events?

[vbhoutex]

How cold for the upper Texas coast? For this winter, do our chances here look decent for some snow events?

First, this is still a long way out to make exact predictions or even a forecast that I could be held to, but it is obvious that this pattern change is coming. Some indications further out in the model time indicate some possible low to mid 30's for the SE TX area. The point at which I see that does not appear to have any precipitation accompanying it, but being this far out that could easily change. Unless there is a big change in how the models continue to handle this it does appear it will be a cool to cold(for our area) early December. And imo, it does look like we could have "some" winter precipitation events in SE TX(really most of Texas). As anyone who has been here any length of time and follows the weather knows, a lot of things have to all "line up" at the same time(which isn't too often)for us to get winter type precip. The pattern that appears to be setting up is one that can be conducive to these events occurring.

[wxgirl69]

What does - and imo mean? wait!!! I think I got it.
In my opinion...
Am i right?????

[srainhoutx]

What does - and imo mean? wait!!! I think I got it.
In my opinion...
Am i right?????

Yep.

[somethingfunny]

I dunno. Tomorrow is the average date of DFW's first freeze. I was expecting it two weeks ago, looks like we're going to end up being late this season. Doesn't really mean anything of course, just something to think about.

[cheezyWXguy]

I dunno. Tomorrow is the average date of DFW's first freeze. I was expecting it two weeks ago, looks like we're going to end up being late this season. Doesn't really mean anything of course, just something to think about.

I dont think it really means anything. I expect it mid next week with the cold front coming down. The reason we havent seen a freeze yet is because the pattern for the past month has been much more quiet than in october. Nonetheless, starting in less than a week, that pattern is apparently supposed to begin to change. If thats the case, winter weather will be here before we know it.

[Portastorm]

The 0z run of the GFS continues to advertise a much colder airmass over the Southern Plains introducing itself in the 204-240 hr time frame (roughly around Dec. 1st).

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer//gfs/00/gfs_ten204240_l.shtml