Texas Winter 2014-2015

[somethingfunny]

The snow to our north and west this morning wasn't entirely unanticipated. The PGFS nailed it

As for that band over DFW, we have yet to see... I highly doubt it, but the model has performed well so far.

Sounds like a bunch of bunk to me about any snow with this weekend's system. Maybe some flurries mixing in out by Wichita Falls but nothing sticking, and nothing at all down here in the metro or anywhere southeast of Bowie I would say.

According to the latest GFS P, something more than a trace is moving through DFW on Sunday morning....

http://www.tropicaltidbits.com/analysis ... _wus_9.png

[vbhoutex]

Forecast and temp bust today at the PWC. Currently sitting at 42 and NWS said 46-47 by now. Five degree bust. Hmm ... wonder what happens next week.

I've been tracking the source region....it's Siberian Air currently sitting north of Alaska/Near the Arctic Circle (some -25 to -30 F Deg Vodka Air) poised to rush southeast into NW Canada, straight down into the Plains. With plenty of snow cover all the way down into Colorado/Northern Kansas, I don't see a lot of modification and have a hard time believing the temp model output....BIG bust potential

Euro has a mammoth 1059mb high in Western Canada in about 48hrs and sinks to Montana at 1056mb in 72 yet its trying to hold up the cold air. I smell bust left and right with temperatures, the NAM looks better to me at the surface drilling the dense air mass. Im with wxman57 the front will be down to the Yucatan not stop at Brownsville.

Don't need to add much of anything to these. AS usual the models have lost and will pick up or have picked up on the actual strength of this cold air mass. Our local OCM are al model hugging fiercely and I just sit back and laugh. If there is anything I disagree with in any of the above it is the potential for modification. I think it is there, but this is such a dense air mass I'm not sure the usual modifiers will matter. Not about to call for Winter precip for SE TX this far out, but I won't be fainting if we do get some out of this. The 2nd Arctic plunge possibility really has my interest too.

[Longhornmaniac8]

Forecast and temp bust today at the PWC. Currently sitting at 42 and NWS said 46-47 by now. Five degree bust. Hmm ... wonder what happens next week.

I've been tracking the source region....it's Siberian Air currently sitting north of Alaska/Near the Arctic Circle (some -25 to -30 F Deg Vodka Air) poised to rush southeast into NW Canada, straight down into the Plains. With plenty of snow cover all the way down into Colorado/Northern Kansas, I don't see a lot of modification and have a hard time believing the temp model output....BIG bust potential

Euro has a mammoth 1059mb high in Western Canada in about 48hrs and sinks to Montana at 1056mb in 72 yet its trying to hold up the cold air. I smell bust left and right with temperatures, the NAM looks better to me at the surface drilling the dense air mass. Im with wxman57 the front will be down to the Yucatan not stop at Brownsville.

Don't need to add much of anything to these. AS usual the models have lost and will pick up or have picked up on the actual strength of this cold air mass. Our local OCM are al model hugging fiercely and I just sit back and laugh. If there is anything I disagree with in any of the above it is the potential for modification. I think it is there, but this is such a dense air mass I'm not sure the usual modifiers will matter. Not about to call for Winter precip for SE TX this far out, but I won't be fainting if we do get some out of this. The 2nd Arctic plunge possibility really has my interest too.

Where are you seeing this second Arctic plunge?

[gpsnowman]

For those into weather folklore, the last ten days or so I have seen a big time bird migration south. Large V-flock formations wave after wave. Now, it is not uncommon to see birds fly south for the winter, and I don't think this natural migration is even folklore, but just observing this over the years tells me something is coming. Early November was the last time this was seen and we all know mid November was pretty darn cold. Last year was very noticeable before all the arctic outbreaks we had here in DFW. Maybe I am hallucinating from yearning for snowfall. Craving it. Like my Marlboros. Fingers crossed.

[txprog]

Euro has a mammoth 1059mb high in Western Canada in about 48hrs and sinks to Montana at 1056mb in 72 yet its trying to hold up the cold air. I smell bust left and right with temperatures, the NAM looks better to me at the surface drilling the dense air mass. Im with wxman57 the front will be down to the Yucatan not stop at Brownsville.

I've been tracking the source region....it's Siberian Air currently sitting north of Alaska/Near the Arctic Circle (some -25 to -30 F Deg Vodka Air) poised to rush southeast into NW Canada, straight down into the Plains. With plenty of snow cover all the way down into Colorado/Northern Kansas, I don't see a lot of modification and have a hard time believing the temp model output....BIG bust potential

It will be interesting to watch as this plays out. So-called Arctic air from very cold - nothing extreme but cold nonetheless - source regions on the way, headed down the plains, over a substantial snow pack, model predictions of very strong high pressure, and no forecast or model that I can find even has DFW below freezing for the upcoming period. I have commented on the historical nature of the number of days and weeks at DFW without a freeze, and if the forecast were to hold we will truly enter historical territory. But if, as many are saying, bustorama is certain, why are the local mets being so conservative with the predicted temps? Surely, the expert mets in FW, such as Cavanaugh, are not model huggers. This is not their first rodeo. We shall see.......

[Portastorm]

Very good post there and you raise some credible questions. Cavanaugh is an excellent communicator to be sure. But if you go back to his discussions, you're going to see a lot of references to "guidance." What's "guidance?" That's the suite of computer models and automated grid numbers they look at. These days, NWS forecasters appear to be trained in that way ... not looking too much beyond the models unless they have a lot of local experience. To be honest, I've never examined how well Cavanaugh's forecasts verify or not. If he's as good a forecaster as his AFDs, then he's something special. My point here is that even he is reluctant to throw out any model solution and go with a hunch.

At this point, I don't see why they should deviate much from guidance. The storm which is supposed to cut off is over the far reaches of northwestern North America and barely in range for upper air sampling. By Monday, the models should have a decent grasp of the cutoff low as well as upstream temps and if we're still seeing forecasts of all liquid precip ... it might be time to put away our party favors. Most of the Texas-based NWSFOs are at least mentioning the possibility of wintry precip. They can ramp up their forecasts as needed 24-36 hours out.

[gpsnowman]

Good post txprog. I recently re-read the Christmas Eve 2009 snow posts on Storm2k. A member(can't remember who) posted an excerpt from a NWS Fort Worth discussion just a couple days from the event that read their would be no white Christmas. We all know how that worked out. Blizzard conditions. Playing conservative up until the actual event is the safe way to go. The model mayhem is also an obvious reason why. But it seems to me every winter this happens at least once, an unexpected durable cold spell with unanticipated moisture. Like today for example in Wichita Falls and southwestern Oklahoma. Ok, I am rambling. Hope this pans out for some snow, and I trust the smarter folks on here to give us the latest, conservative or not.
Forecasting winter weather in Texas is not an easy task. Kudos to all of those who keep us updated and informed. It may seem slow and chaotic, but that is why the experts know way more about weather than I do. Thanks.

[somethingfunny]

Cavanaugh did mention in a recent AFD that while he does not believe any of these warm models, he cannot justify forecasting anything colder than the coldest model at his disposal is showing - but also stated that actual temperatures could very well go even colder than that by quite a bit.

Regarding this heavy rain potential, it might actually bust our freezing precip potential, as heavy precip brings down air from higher in the atmospheric column.... this is normally how we "wet bulb" with heavy precip changing from rain into snow as cold air is brought down to the surface by the precipitation, but in this situation we would actually have warmer air above the freezing layer at the surface, wouldn't we? It depends on how deep the cold air is, but this might start as rain, freeze quickly, put down an ice layer, but then revert to plain rain and melt the ice.

That said, FWD posted this:

THE ENERGY OUT
WEST IS STARTING TO SHOW SIGNS OF CLOSING OFF OVER ARIZONA BY
WEDNESDAY...BUT A LEAD SHORTWAVE WILL LIFT NORTHEAST OVER THE AREA
AND INDUCE ISENTROPIC ASCENT OVER THE SHALLOW ARCTIC AIR BY
WEDNESDAY NIGHT INTO THURSDAY WITH MODELS DIFFERING SOMEWHAT ON
ENVIRONMENTAL PROFILES...PRECIP TYPES...AND OVERALL TEMPERATURES.
SO CONFIDENCE ON THE OVERALL EVOLUTION OF ANY WINTER WEATHER
LATER IN THE WEEK REMAINS LOW...BUT APPEARS SOME CHANCE OF A MIX
WILL BE THERE WITH CHILLY CONDITIONS CONTINUING.

That shortwave on New Years Eve/Day is very concerning. This could be a very dangerous situation with sleep-deprived, drunk partygoers driving home on icy roads after midnight.

I'll likely be delivering pizzas up until midnight too.

[Ntxw]

Cold is not the problem. The EPO is working it's magic, the ridge in the Pacific is already building into Alaska. Never question the -EPO the cold will be there, it is tanking. Every guidance has it tanking it will get very cold. I've learned to well to doubt that index as a cold loading feature. The question remains how the system in the west behaves. Backwards S spells trouble in the past.





It is all about timing, if impulses come out then you have trouble. There is another arctic attack behind it, it is rarely seen an ENS suite converge on strong height fields at the range given and the OP have gradually followed by holding the ridge into the Alaskan Peninsula.

[aggiecutter]

It is all about timing, if impulses come out then you have trouble. There is another arctic attack behind it, it is rarely seen an ENS suite converge on strong height fields at the range given and the OP have gradually follow by holding the ridge into the Alaskan Peninsula.

For the event the end of next week, I still think freezing rain is the most likely scenario. I think the shallow dense cold air will get trapped as the moisture returns on Thursday. As you mentioned, the arctic attack that follows the one next week looks quite impressive:

[Kludge]

It is all about timing, if impulses come out then you have trouble. There is another arctic attack behind it, it is rarely seen an ENS suite converge on strong height fields at the range given and the OP have gradually follow by holding the ridge into the Alaskan Peninsula.

For the event the end of next week, I still think freezing rain is the most likely scenario. I think the shallow dense cold air will get trapped as the moisture returns on Thursday. As you mentioned. the arctic attack that follows the one next week, looks quite impressive:

Agreed.

I'm afraid that we're looking at an event comprised of moderate rainfall (1/4 - 3/4") through a shallow ( <5000' ) layer of sub-freezing temperatures.

My thinking is the target area will be between I-20 and I-10, and generally east of I-35.

I would dearly love to be totally wrong on this. Consider this to be a "dreadcast", not a wishcast. I'm going on many years of "gut feel" here.

[ I am NOT a met. See the NWS for official forecasts. ]

[DougNTexas]

My local weatherbug does not show Henderson, Tx getting below 32 degrees in the next 10 days as of today.

[ronyan]

My local weatherbug does not show Henderson, Tx getting below 32 degrees in the next 10 days as of today.

It's likely to be colder given the current pattern, negative EPO and the time of year. The GFS already has temps near 32 in your area with the first Arctic front on the 1st. Seeing as how we think it's warm biased, I wouldn't take that forecast to the bank.

[SouthernMet]

00z PGFS still very bullish on qpf, but the precip moves through a little earlier than recent trends, still shows warming after the onset of precip.

[Ralph's Weather]

It is really starting to look like a potential ice storm for New Year's. I think we are all in agreement that there will not be as much warning ahead of the trough as is shown by the models. Maybe we can get lucky and the cold is deeper than expected. The models do not have a handle on next week's system so I will go with something similar too this coming week until the models come into some kind of agreement.

[orangeblood]

00z PGFS still very bullish on qpf, but the precip moves through a little earlier than recent trends, still shows warming after the onset of precip.

Check out the latest Canadian run...looking much more realistic.

[SouthernMet]

00z PGFS still very bullish on qpf, but the precip moves through a little earlier than recent trends, still shows warming after the onset of precip.

Check out the latest Canadian run...looking much more realistic

Wow... That looks very plausible imo.

Precip starts new years eve night too, which is a bit earlier.

[Portastorm]

I could be wrong orangeblood but I believe that 0z CMC run is the coldest looking run yet from a global model for next week. Will be interesting to see if the others follow suit. The 0z GFS and PGFS were much different from 12z runs.

[TheProfessor]

And if the CMC continues to trend colder with that amount of precip then North and Central Texas could all be in trouble, and the worst part is it could all come in time for the Cowboys game next week.

[orangeblood]

:uarrow:

I could be wrong orangeblood but I believe that 0z CMC run is the coldest looking run yet from a global model for next week. Will be interesting to see if the others follow suit. The 0z GFS and PGFS were much different from 12z runs.

Yep, it's much colder and similar to what the PGFS was showing a few days ago. Showing the two separate events that we've been discussing around here over the past week, one impulse that comes out along the Arctic Boundary on New Years Eve and the other 24-36 hours later. Over an inch QPF from 35 eastward