Texas Winter 2014-2015

[northjaxpro]

Give it just a little bit more time SeGaBob. I have a decent inclination that the weather across the Deep South is going to become increasingly active within the next 10 days as we enter into 2015. Things are going to get really intriguing with the upcoming pattern shift and the potential of the subtropical jet becoming active. Our Storm2K family out in Texas and into areas of the Deep South potentially will have plenty to discuss by this time next week.

[orangeblood]

Give it just a little bit more time SeGaBob. I have a decent inclination that the weather across the Deep South is going to become increasingly active within the next 10 days as we enter into 2015. Things are going to get really intriguing with the upcoming pattern shift and the potential of the subtropical jet becoming active. Our Storm2K family out in Texas and into areas of the Deep South potentially will have plenty to discuss by this time next week.

Yep, re: Subtropical Jet...pay attention to the system about to cut off from Pacific Jet out toward the Hawaiian Islands, this should be the catalyst that will get the subtropical jet prime for bringing quite a bit of moisture into the lower 48

[northjaxpro]

North and northwest Texas, Tuesday don't sleep on that system. If the models bust the surface temps, it is cold aloft.

You're onto something Ntxw, that system continues to dig further south and west with each model run.

Also, check out the 1058 HP heading into Montana after Christmas on the 12Z GFS

It was fishy from a ways out. Since when is it 50s-60s with a deep cold storm overhead 546dm or less? Surface progs are so bad with low heights. This is why models often bust with cold core low surprises.

Yep! This reminded me of the set up which occured in South Carolina back on November 1. A very strong, deep cold core upper Low swung right over the them and dumped upwards to 5 inches of snow in Lexington, just outside of Columbia, SC. The models underperformed with the strength of that Cold Core Low. These types of systems definitely can spring some surprises, so the system progged to move over North Texas leading into Christmas definitely bears watching IMO.

[wxman57]

Not that I'm in favor of Arctic air here, but if you think back to the mid November event, the models tended to lose the cold air in the 10-15 day time frame and/or shunt it off to the east. Unfortunately, Arctic air rarely does that. It typically plunges straight south lee of the Rockies right through Texas, often hitting Brownsville before reaching Houston. Until this possible event gets within about 5 days of occurring I wouldn't put too much stock in each individual model run.

[Portastorm]

Words of wisdom from one who knows what he's talking about.

[gatorcane]

GFS is showing some extremely cold (and rather impressive) anomalies building across the NW right around the end of the month. Overall the 12Z global model guidance is cold, cold, cold for most of the lower 48 towards the end of this month:

[gatorcane]

and here is the GFS 12Z (6AM CST) temps corresponding to the above. That is some artic airmass

[Ntxw]

North American assault on the Euro by cold air. Double whammy from Pacific and then Atlantic locks it in.

[northjaxpro]

North American assault on the Euro by cold air. Double whammy from Pacific and then Atlantic locks it in.

Yes indeed. Posted the 240 hr EURO over on the Deep South Thread. A classic set-up potentially evolving for Old Man Winter to make his grand return to much of the CONUS by the start of 2015.

[aggiecutter]

12Z GFS builds a glacier from the North Pole to NE Texas:

[gatorcane]

18Z GFS New Year's Day forecast for Texas, most of the state at or below freezing at noon:



Also 18Z GFS throws in some wintry precip too for New Year's Eve:

[SeGaBob]

Give it just a little bit more time SeGaBob. I have a decent inclination that the weather across the Deep South is going to become increasingly active within the next 10 days as we enter into 2015. Things are going to get really intriguing with the upcoming pattern shift and the potential of the subtropical jet becoming active. Our Storm2K family out in Texas and into areas of the Deep South potentially will have plenty to discuss by this time next week.

I hope so... cold weather is exciting to me being as I've only lived long enough to see one decent snow event here. (2010)

[CYCLONE MIKE]

Should have posted the next few pics from that model run. They were even more believable

Going to go out on a limb and say I bet the gulf coast doesn't get anything like that. By tomorrow the cold and or precip will be nothing but a distant memory.

[ronyan]

Should have posted the next few pics from that model run. They were even more believable

Going to go out on a limb and say I bet the gulf coast doesn't get anything like that. By tomorrow the cold and or precip will be nothing but a distant memory.

Pretty sure the cold is coming...what reason do you have to think otherwise?

[perk]

Should have posted the next few pics from that model run. They were even more believable

Going to go out on a limb and say I bet the gulf coast doesn't get anything like that. By tomorrow the cold and or precip will be nothing but a distant memory.

What's your reasoning.

[CYCLONE MIKE]

We will get colder eventually that's a given considering we have been in the 70's for quite a while. Even last week made it into the 80's. What I was talking about regarding the 12 day gfs run was all of LA covered in snow and ice. Just as another poster always says, just like the long range gfs always showing a cat 5 in the gulf.

Also to add on the 13th somebody was posting gfs runs that was showing a snow storm along the gulf coast for the 22nd-23rd. Here we are a week later and the gfs is showing another winter storm for parts of the gulf coast, you guessed it 11-12 days away. That's why I said come tomorrow it will show nothing once again .

[Portastorm]

We will get colder eventually that's a given considering we have been in the 70's for quite a while. Even last week made it into the 80's. What I was talking about regarding the 12 day gfs run was all of LA covered in snow and ice. Just as another poster always says, just like the long range gfs always showing a cat 5 in the gulf.

Also to add on the 13th somebody was posting gfs runs that was showing a snow storm along the gulf coast for the 22nd-23rd. Here we are a week later and the gfs is showing another winter storm for parts of the gulf coast, you guessed it 11-12 days away. That's why I said come tomorrow it will show nothing once again .

Only problem with this is that the European is also suggesting a similar Arctic airmass after Christmas. And many members of the ensemble runs for both models show the major pattern change. And the teleconnections and analog examples also suggest the same. If it was just the GFS, I'd say you might have something. But this is a lot more than just a GFS run or so showing a major winter storm. That being said I also think that some of the more extreme model runs showing parts of Texas and Louisana encased in ice by New Years should be taken lightly (at this point).

[Ntxw]

Any precipitation or storm looks on models should be taken lightly beyond 3 days. They are very small features in a vast atmosphere. Temperature and movement of air is a lot easier to predict than something like snow cover or an individual storm strack.

[ronyan]

This. The cold pattern is coming, but it's impossible to iron out the finer details at this time. But I think the pattern we're going into at the end of the year greatly increases chances for winter weather in the deep south.

[gboudx]

From jeff, includes great discussion of the pattern change and arctic air mass being discussed here.

Changeable weather pattern for the next several days followed by potential significant upper air pattern change between Christmas and New Year’s

After a very wet Friday across SE TX (see rainfall totals below) low clouds have hung in tough all day across the region with a saturated layer trapped below the frontal inversion. Observations have even been bouncing around with drizzle and fog today. Clouds will thicken and lower some tonight and once again on Sunday it will be hard to break out, but forecast soundings are a little more hopeful that by late afternoon a few breaks may transpire as winds turn more SE and possibly breaks the frontal inversion. Temperatures will continue to run on the cool side with lows in the 40’s and highs in the 50’s.

Southerly flow resumes on Monday with temperatures rebounding into the 70’s ahead of a Tuesday morning cold frontal passage. Models have been trending stronger and southward with this system and may need to add a rain chance to the forecast on Tuesday if this trend continues. Strong but short lived shot of cold air will follow the frontal passage with temperatures falling into the 30’s by Wednesday morning and only recovering into the 50’s for highs. Fast flow aloft pushes cold air rapidly eastward on Christmas Day with morning lows in the 30’s rapidly warming to near 70 by afternoon as SW surface winds increase.

Week between Christmas and New Year’s:
The storm system which will cross our area on Tuesday will move NE and rapidly deepen into a powerful mid latitude cyclone over the OH Valley and Great Lakes into SE Canada on Christmas Day. This storm appears to then buckle the upper air pattern over North America resulting in strongly building heights (high pressure) off the US west coast deep into Alaska right after Christmas. A full latitude downstream trough begins to develop in response to the building ridge over Alaska. Heights push 570dm over Alaska between Christmas and New Year’s which is fairly impressive and begins to move very cold air currently over Russia and Siberia into NW Canada. Long range models show the source region for US arctic air outbreaks significantly cooling as the pool of cold air over Russia moves over top the Alaskan ridge and into NW Canada. Forecasted temperatures between -20 and -30 F look possible in this region by the end of next week.

The upper air pattern appears to lock into place around the 28-29th of Dec and the delivery southward of cold arctic air looks to begin shortly after. General upper air pattern is agreed upon by most of the long range model guidance, but they each have their varying degrees of cold air, amount of southward delivery, and amount of upper air amplification. If the pattern is in place to deliver it southward….the arctic air will come southward with almost nothing able to stop it. GFS has been bouncing around with the idea of a monster 1055-1062mb arctic high pressure cell dropping southward into Montana around the 29-30th with a powerful arctic cold front roaring down the front range of the Rockies and off the TX coast on the 31st. Models have been very consistent on a southern branch storm system crossing TX on the 31st-1st, but have been struggling with the amount of cold air. If the arctic intrusion verifies a significant winter storm would be likely on the 31st and the 1st with multiple P-type concerns. If the arctic intrusion does not verify a rain event would be the more likely outcome. Something to keep an eye on over the next few days.