Texas Winter 2024-2025

[Throckmorton]

The 18Z GEFS is about 2 degrees warmer than its 12Z run.

[CaptinCrunch]

This will be another cold system were the NWS will be playing catch-up going as conservative as they are.

[Stratton23]

Im really thinking the dam is going to burst with this one, CMC/ ICON probably have the most realistic handeling on that air not getting locked up and instead send it down the central plains, id say the state is in for a few days of sub freezing highs to maybe low 30’s if i had to guess

[Golfisnteasy7575]

Im really thinking the dam is going to burst with this one, CMC/ ICON probably have the most realistic handeling on that air not getting locked up and instead send it down the central plains, id say the state is in for a few days of sub freezing highs to maybe low 30’s if i had to guess

Coldest air of the season most likely. Just hope we have a few more opportunities at snow and ice

[Throckmorton]

From today's edition of Judah Cohen's "Arctic Oscillation and Polar Vortex Analysis and Forecasts" blog:

This winter has been all about the polar vortex (PV) alternating among strong, a Canadian warming, but most of all a stretched PV. This pattern looks to continue but for how long? Also still watching the battle between high latitude blocking and a strong PV, which has been at a stalemate all winter long. Models are predicting near record strong PV but is it really?

What you see is what you get seems to be the theme of the week in the weather. Overall looks mild for Europe and East Asia but turning much colder in Canada and the US. I don’t see any reason why the weather ride of January 2025 should end as we head into February, but clearly the weather models do with a milder pattern in the Eastern US.

The next stretched PV (sixth of the season) mid–month looks to be sandwiched between two more impressive, stretched PVs this month: one at the beginning and one at the end of the month. In the blog over the past several weeks, I have been focusing on the wave reflection diagnostics and show it again in today’s blog. During wave reflection, wave energy goes up over Asia, bouncing off the stratospheric PV, and then downward over North America. The downward wave energy amplifies the ridge-trough wave over North America and determines the strength or amplitude of the North American wave and the axis or position. Once again, the wave reflection seems to never quit this month, and my diagnostics show wave reflection uninterrupted for the next two weeks. ... [T]he wave reflection for the first event (this week) is more modest compared to the wave reflection for next week. And I believe this is contributing to more impressive cold for the US, including the Eastern US, starting next week.

I will admit to being confused about how to interpret in between stretched PV events six and seven. The sixth event winds down on 17 January, and the seventh event doesn’t seem to get going until around 20 January. This works well with the timing of the cold air into the Eastern US, with the stretched PV about one day ahead of the cold push into the Eastern US but the cold air comes into the Western US a couple of days earlier.

In between the two stretched events is some hybrid looking stretched event / Canadian warming. But no matter how I think about it, I have hard time explaining the timing of the cold air into the Western US around 18 January. But it could simply be that what matters most is the wave reflection or possibly some other forcing such as tropical or even just random weather noise.

...

Heading into the last days of January, the models are in good agreement on a relaxation of the cold pattern in the US, and that makes sense to me as the cold weather associated with stretched PVs when the PV is overall strong is about a week or so and typically not longer. However, one curiosity is that in the PV forecast through two weeks, I still no sign of the PV snapping back to a more circular shape. The models at the end of their runs are suggestive (but it is subtle for now) of maybe some more cold air making it into the Eastern US as January comes to a close. We will have to see if this becomes more significant with time.

Looking ahead into February, I believe that the forecast remains complicated and challenging. There are two major factors that are making the forecast of US temperatures heading into February especially challenging. Both the GFS and European ensembles are predicting a near record strong PV. It is very difficult to get cold in the Eastern US with a PV that strong. Instead, if there is cold, it is much likely to be in the Western US. However, when I look certainly at the operational models and to a lesser extent even the ensembles, that just doesn’t look like a record strong PV.

...

The second complicating factor is the tropical convection. Starting mid-week, tropical convection will be supportive of cold in the Western US and mild in the Eastern US. The models keep predicting the cold to shift into the Western US and for it to turn milder in the Eastern US. It is hard to know if this is real or a model bias.

At least for the foreseeable future, I still think that the PV is supportive of cold in the Eastern US, at least when it stretches. Longer term, I still favor a continuation of the pattern we have seen all winter, stretched PVs that most likely favor cold in the Eastern US and some kind of relaxation, which for the past month has been in the form of one to two Canadian warmings and one circular PV. When I look at the tropospheric pattern in the ensembles, that does not look supportive of a record strong PV. Instead, should at least keep the PV tap dancing and not settle into a nice circular rhythm. Instead, the predicted pattern looks very supportive of stretched PVs with an especially nice-looking wave-2 pattern across the Northern Hemisphere.

https://www.aer.com/science-research/climate-weather/arctic-oscillation/

[Ntxw]

Icon caved at 500mb, still cold.

[Stratton23]

Dry run, yuck, but of course it caved

[orangeblood]

Icon caved at 500mb, still cold.

Having the ICON be the savior is never a good position to be in. Probably going to have to find a system on the back end of this outbreak, front end not looking great

[SnowintheFalls]

Models made the forum screech to a crawl.

[gpsnowman]

Icon caved at 500mb, still cold.

Having the ICON be the savior is never a good position to be in. Probably going to have to find a system on the back end of this outbreak, front end not looking great

Still looking like a multi day below freezing outbreak or some let up on cold? Sorry been busy today. Precip can find a way..... hopefully.

[Ntxw]

GFS has snow for Houston again.

[Stratton23]

Ntxw looks like energy coming from baja on that GFS run

[Ntxw]

Ntxw looks like energy coming from baja on that GFS run

That's a few runs its tried today. While the Baja system is new the S/W from the north provides some of the lift.

[Stratton23]

00z CMC has a winter storm with a coastal low developing

[Stratton23]

GFS with back to back snow storms for se texas , wowza!

[Harp.1]

GFS with back to back snow storms for se texas , wowza!

And me as well!!! I wish this was two days out and I would feel more confident!

[orangeblood]

CMC just a little chilly

[South Texas Storms]

I'm expecting temperatures to be at least 10F warmer than what the Canadian is showing. ICON's temp forecast looks reasonable to me right now for early next week.

[Gotwood]

Has the Canadian ever been right? Stupid temps it’s putting out.

[Throckmorton]

CMC just a little chilly

https://images.weatherbell.com/model/gem-all/tx/t2m_f/1736812800/1737460800-CXaxSNSClP4.png

Jan 13th, 12Z run was similar.