Texas Winter 2020-2021

[mcallum177]

This seems like an exceedingly dangerous forecast for vulnerable populations especially the homeless.

[Ntxw]

FWIW there is a 1064mb (forecast to be upper 1060s) HP currently in the Beaufort Sea (North coast of Alaska and hey wow for once it's a real 1060+ HP that is not in Asia or 384 hr GFS!). The whole thing won't come down but the idea is that a chunk of it will as a 1050s HP. It's one feature to watch as the delivery mechanism to shove it all south.



Amazing again this is not something "it will build a week from now." It's there now.

[Cerlin]

FWIW there is a 1064mb (forecast to be upper 1060s) HP currently in the Beaufort Sea (North coast of Alaska and hey wow for once it's a real 1060+ HP that is not in Asia or 384 hr GFS!). The whole thing won't come down but the idea is that a chunk of it will as a 1050s HP. It's one feature to watch as the delivery mechanism to shove it all south.

https://i.imgur.com/0Ib09XD.gif

Amazing again this is not something "it will build a week from now." It's there now.

So, can it generally be assumed that the higher the pressure that travels south (i.e. if it ends up lowering to 1060 vs 1050), the stronger the arctic airmass?

[Ntxw]

FWIW there is a 1064mb (forecast to be upper 1060s) HP currently in the Beaufort Sea (North coast of Alaska and hey wow for once it's a real 1060+ HP that is not in Asia or 384 hr GFS!). The whole thing won't come down but the idea is that a chunk of it will as a 1050s HP. It's one feature to watch as the delivery mechanism to shove it all south.

https://i.imgur.com/0Ib09XD.gif

Amazing again this is not something "it will build a week from now." It's there now.

So, can it generally be assumed that the higher the pressure that travels south (i.e. if it ends up lowering to 1060 vs 1050), the stronger the arctic airmass?

The Arctic air mass is strong and in place. This question is a little complex. Both matter but generally speaking the stronger the HP the more force it has to push what cold air is in place.

We've had 1050s recently before like Jan 18 and 2017. But what kind of air it is pushing matters too and this one is exceptionally cold in depth and expanse.

[gboudx]

This is from Jeff Lindner and is only the part applicable to the arctic air.

Late Week:

Passage of a disturbance on Wednesday will help to surge the arctic boundary stalled over central TX tomorrow across the region and into the Gulf of Mexico. Global forecast models continue to greatly struggle with the handling of this shallow yet very cold air mass and have had widely varying solutions over the weekend. We are starting to see some weak consensus with the various models and better output form the higher resolution NAM model which shows the front moving across the area on Thursday. Upstream temperatures over the central plains are cold with widespread 10’s and 20’s and this air mass will spread into NC TX by mid week. Incoming surge of cold air on Thursday looks shallow…maybe a few thousand feet thick at the most and with WSW flow over top of this shallow cold layer, clouds will likely remain in the post frontal air mass. Cold air will remain in place through the end of the week and into the weekend. Another disturbance may approach the region on Saturday with showers.

There remains questions as to how cold the incoming air mass will be and at this time some of the extremely cold solutions over the last few days have warmed some while the warmer solutions have cooled. At the moment this does not look like anything historic for the region or any sort of record cold, but sub-freezing temperatures are certainly possible by this weekend. As the arrival of the cold air gets closer will need to watch upstream temperature trends closely for any needed downward adjustments.

[Iceresistance]

6z GFS, 3 snowstorms are lining up.



24-hour Kuchera Ratio snowfall

[Ntxw]

Ryan Maue's tweet of the Jan 1977 event. I find this interesting because we are looking at a similar kind of block over the Davis Strait, except everything is further to the west. El Nino that year +PNA favored east, La Nina neutral -PNA favors west.

 https://twitter.com/RyanMaue/status/1358617405451350017

[Iceresistance]

Morning Observations from the NWS-Norman Area

[Wntrwthrguy]

I apologize if this is a dumb question. How do they have weather models back in 1977?

[gboudx]

I apologize if this is a dumb question. How do they have weather models back in 1977?

Probably they have the data from 1977 and just plug it in into the models to generate the graphical output. That's my guess but I think it's a good one.

[Ntxw]

I apologize if this is a dumb question. How do they have weather models back in 1977?

It is a reconstruction using available data from the time and advancing with modern technology.

[TropicalTundra]

Morning Observations from the NWS-Norman Area

Looks like this arctic air is just north of Abilene on a temperature map. Is this cold air farther ahead than scheduled?

[Iceresistance]

Morning Observations from the NWS-Norman Area

https://s2.gifyu.com/images/Screenshot-2021-02-08-at-8.24.32-AM.png

Looks like this arctic air is just north of Abilene on a temperature map. Is this cold air farther ahead than scheduled?

Yes, it's already 32°F in Town right now.
28°F in OKC
20°F in Enid, OK
15°F in Alva, OK
The Temperatures are dropping fast!

[HockeyTx82]

I apologize if this is a dumb question. How do they have weather models back in 1977?

Keep in mind we also went to the moon in '69 and early 70's. We had technology back then and did everything with slide rulers.

All we have to show for it today is Facebook, Twitter and cat videos on YouTube.

[Ntxw]

12z NAM front crosses North Texas this evening then we hover in the 30s the rest of the week. It slows some in Central Texas, where the boundary stalls makes for a very different forecast down that way. 60s/70s on one side and 40s on the other.

[Iceresistance]

:cold:





12z NAM front crosses North Texas this evening then we hover in the 30s the rest of the week. It slows some in Central Texas, where the boundary stalls makes for a very different forecast down that way. 60s/70s on one side and 40s on the other.

Freezing line south I-44 when those Temperatures were observed, but it's already 32 in town right now!

[Iceresistance]

With the Arctic air already in Oklahoma & Panhandle Texas faster than expected, (I'm under a Winter Weather Advisory until 4 PM CST for Freezing Drizzle)

What will the 12z models react as the events unfold?

[WinterMax]

How many here are thinking, hmm, these darn 12z runs are gonna send this thread down into the low part of the valley of emotions again? Lol

[Ntxw]

:cold:

https://i.imgur.com/UmKtgOX.png

https://i.imgur.com/jYGRzdh.png

12z NAM front crosses North Texas this evening then we hover in the 30s the rest of the week. It slows some in Central Texas, where the boundary stalls makes for a very different forecast down that way. 60s/70s on one side and 40s on the other.

Freezing line south I-44 when those Temperatures were observed, but it's already 32 in town right now!

Yeah regardless of what happens in Texas...Oklahoma has gone under the deep freeze. The state may not go above freezing until later next week. No question now about the cold, only how low can it go.

[Iceresistance]

:cold:

https://i.imgur.com/UmKtgOX.png

https://i.imgur.com/jYGRzdh.png

12z NAM front crosses North Texas this evening then we hover in the 30s the rest of the week. It slows some in Central Texas, where the boundary stalls makes for a very different forecast down that way. 60s/70s on one side and 40s on the other.

Freezing line south I-44 when those Temperatures were observed, but it's already 32 in town right now!

Yeah regardless of what happens in Texas...Oklahoma has gone under the deep freeze. The state may not go above freezing until later next week. No question now about the cold, only how low can it go.

Yeah, ICON has been Aggressive with lows down to -20°F!