Texas Winter 2024-2025

[wxman57]

I plotted all 12Z models. EC is much warmer than 00Z. Canadian is coldest, but only goes out to 240hrs. It has a history of being WAY too cold with Arctic air, at least in Houston. I added EC-AIFS. It's the warmest, by far. Perhaps the AI model won't handle Arctic air very well? Or, maybe winter is just over...

http://www.wxman57.com/images/Models12ZDec29.jpg

Do you remember at what point that you trusted model data for the 2021 outbreak or any previous major outbreaks prior to that?

I know that's a certain window where we wait until we say yep it's coming, but do you genuinely think this one is still on the fence or has potential to truly deliver?

Models didn't really do very well until about 24 hours before the cold air hit. I kept a spreadsheet for every model run. As the cold air arrived, I added in an "observed" line to the model forecasts. I know the Canadian model was much too cold with February 2021 and the Jan. 2024 freezes.

[Ralph's Weather]

We bottomed out at -8 in 2/21. As far as I recall that beat all models coldest predictions. Some runs occasionally hinted at sub 0 but none below -5. Euro was far and away the worst but no model was cold enough.

[fendie]

Nice wind shift for Dallas on the GFS out of the north around noon on Sunday, Jan 5th. Look at those freezing temps dropping from 700 mb to the surface. Wonder what that mysterious blue precip is on the morning of Tuesday the 7th? Meteograms can be fantastical!

[Brent]

We bottomed out at -8 in 2/21. As far as I recall that beat all models coldest predictions. Some runs occasionally hinted at sub 0 but none below -5. Euro was far and away the worst but no model was cold enough.

Yeah I was in DFW then but I seem to remember the airport going below zero was not well forecast

And of course the Euro had famously been slow to show the cold air in the days before. It's actually been weird here to see it in the long range

Also in January this year during that short lived spell we were way colder than forecast one day

[Texas Snowman]

 https://x.com/txstormchasers/status/1873456132246606099

[Cpv17]

We bottomed out at -8 in 2/21. As far as I recall that beat all models coldest predictions. Some runs occasionally hinted at sub 0 but none below -5. Euro was far and away the worst but no model was cold enough.

The coldest it got here was 14°F. Amazing I’m just 4 hours south of you and you were 22° colder than me.

[Ralph's Weather]

We bottomed out at -8 in 2/21. As far as I recall that beat all models coldest predictions. Some runs occasionally hinted at sub 0 but none below -5. Euro was far and away the worst but no model was cold enough.

The coldest it got here was 14°F. Amazing I’m just 4 hours south of you and you were 22° colder than me.

A foot of snow on the ground and ideal radiational cooling did it.

[orangeblood]

Euro AI consistently showing a Major Winter Storm/NW gulf coastal low bombing out just south of Houston week 2

[Ntxw]

Crazy to think that weekend storm is no sure fire for Chicago to Detroit, they're getting robbed to the south. Brent is just a few degrees latitude dip from stealing it.

[Throckmorton]

Some EC–AIFS temperature forecasts for Austin and a few areas of Oklahoma and north Texas for Jan. 10th at 6 pm and 6 am CST (12/29, 12Z run):

49–27...Amarillo
46–24...Austin Camp Mabry
38–23...Dallas
34–21...Oklahoma City
27–13...Tulsa

[Brent]

Crazy to think that weekend storm is no sure fire for Chicago to Detroit, they're getting robbed to the south. Brent is just a few degrees latitude dip from stealing it.

https://i.imgur.com/wouxYBC.gif

There's still some big ensemble members then so we'll see what happens

And Tulsa did mention impactful weather which surprised me this early

[Throckmorton]

Euro AI consistently showing a Major Winter Storm/NW gulf coastal low bombing out just south of Houston week 2

https://images.weatherbell.com/model/ecmwf-aifs-all/scentus/t850_mslp_prcp6hr/1735473600/1736316000-CNIbqXMj1Dw.png

And with surface, 850 mb, and 700 mb temperatures in far north Harris County at or below freezing.

[Throckmorton]

I plotted all 12Z models. EC is much warmer than 00Z. Canadian is coldest, but only goes out to 240hrs. It has a history of being WAY too cold with Arctic air, at least in Houston. I added EC-AIFS. It's the warmest, by far. Perhaps the AI model won't handle Arctic air very well? Or, maybe winter is just over...

http://www.wxman57.com/images/Models12ZDec29.jpg

Do you remember at what point that you trusted model data for the 2021 outbreak or any previous major outbreaks prior to that?

I know that's a certain window where we wait until we say yep it's coming, but do you genuinely think this one is still on the fence or has potential to truly deliver?

Models didn't really do very well until about 24 hours before the cold air hit. I kept a spreadsheet for every model run. As the cold air arrived, I added in an "observed" line to the model forecasts. I know the Canadian model was much too cold with February 2021 and the Jan. 2024 freezes.

For Austin, both GEM and ICON were spot on several days in advance of the event. No other model was close because they did not forecast the snow properly.

[Ntxw]

Baja low on the 18z GFS . TPV lobe over the Great Lakes.

[Throckmorton]

We bottomed out at -8 in 2/21. As far as I recall that beat all models coldest predictions. Some runs occasionally hinted at sub 0 but none below -5. Euro was far and away the worst but no model was cold enough.

Austin Camp Mabry fell to 7°, helped by a 5 inch snow cover.

–1°...Burnet
..1°...Dripping Springs
..2°...Taylor
..3°...New Braunfels
..4°...Austin Great Hills
..4°...Lexington
..4°...Llano
..6°...Austin Bergstrom AP
..7°...Austin Exec. AP
..7°...LaGrange
..9°...San Antonio
11°...Del Rio

[Cpv17]

Baja low on the 18z GFS . TPV lobe over the Great Lakes.

Where do we ideally want the TPV?

[Brent]

Well at least all the snow east of us went away too fixed that problem

[Stratton23]

If its ome thing to take away from that GFS run, look how persistent the blocking pattern is, this run goes out to the 15/16th and we still have a stout - EPO/ AO/ NAO blocking pattern locked in place, this going be a very extended cold period if thats the case

[Ntxw]

Baja low on the 18z GFS . TPV lobe over the Great Lakes.

Where do we ideally want the TPV?

You want it on the southern shores of Hudson Bay with a broad open trough in the intermountain west and plains. The separation allows the cold to spill into that trough. It's what Feb 2021 was. A tight wound up TPV into the US can bring some extreme cold but it's more likely to be east of us since it keeps it in a closer radius.

[Stratton23]

GEFS 18z a touch colder, but like seeing a little bit of a se ridge to make that trough dig more SW