Texas Winter 2010-2011

[Rgv20]

Edited by wxman57:

The first image below is the GFS ensemble forecast of 500mb (mid level) height anomalies valid Tuesday evening, February 1st. The map shows building high pressure over the Gulf of Alaska and Pacific Northwest and a deepening low over the eastern Hudson Bay region extending all the way southwest to west of Texas.

The suggestion here is that the building ridge will drive very cold air southward out of Canada but that the trof axis will remain west of the cold air next Tue-Wed. This is a setup for snow across the Deep South.



The European version of the same map has an even deeper area of low pressure west of the cold air across the southwestern U.S. next Tuesday evening. The European model is more bullish on southern stream energy with the cold air in place, meaning a greater chance for Deep South snow next week.

[Portastorm]

Hey gang ... when you post model maps, how about a little clarification or description. Put it in context otherwise it is not much help to those here who don't understand. We have a wide variety of weather knowledge here and we should be mindful of all of our members.

Thanks!

[natlib]

30% chance of snow for San Angelo after midnight tonight. Where did this come from? This just goes to show how hard winter weather is to forecast.

[benrayrog]

:uarrow:

Hey gang ... when you post model maps, how about a little clarification or description. Put it in context otherwise it is not much help to those here who don't understand. We have a wide variety of weather knowledge here and we should be mindful of all of our members.

Thanks!

Thanks, Portastorm. That is a great suggestion and would be a great help to some of us.!

[southerngale]

Yeah. Most people are just reading these threads and not commenting. To the majority of people, the model maps mean nothing without an explanation. We were all at that level at one point. A brief (or long) explanation can really help others learn.

As for that 30% chance of snow for San Angelo, I saw the NWS forecaster for that area mention yesterday that the forecast could change and snow was possible, or something to that effect. Hope you get some!!

[Mr. Weather]

is SE Texas chances for getting some wintry weather around the 1st of February getting better or worse j/w thanks

[MSUDawg]

Thanks Porta, the graphics sure are purty but I don't have a clue what 5% of it means as of now.
Like the model rgv just posted, I know from the labeling it is 500mb "anamolies" but I have no idea on when
or what exactly it is showing besides the "high" pressure over the western coast and "low" pressure over the heartland in the shape of a musical 16th note.

It just confuses me that shows a low pressure when everything else talks about high pressure with all this cold.

someone hand the "weather for idiots" book please.

[wxman57]

:uarrow:

Hey gang ... when you post model maps, how about a little clarification or description. Put it in context otherwise it is not much help to those here who don't understand. We have a wide variety of weather knowledge here and we should be mindful of all of our members.

Thanks!

I edited the post above to add a discussion of what I see there.

[utweather]

Kansas City

OF GRAVER CONCERN HOWEVER IS THE LOOMING PROSPECT OF THE COLDEST AIR
OF THE WINTER SEASON SLATED TO ARRIVE FOR THE END OF THE MONTH.
THERE IS INCREASING CONSENSUS AMONG THE MEDIUM RANGE MODEL SUITE
THAT THE DUAL CORED ALEUTIAN VORTEX WILL UNDERGO ADDITIONAL
INTENSIFICATION OVER THE NEXT SEVERAL DAYS AS AMPLE UPSTREAM
ENERGY ARRIVES ACROSS THE NORTHERN PACIFIC. A FORCED DOWNSTREAM
SHORTWAVE RIDGE WILL ALIGN ITSELF ALONG THE PACIFIC COASTLINE AND
THROUGH THE STATE OF ALASKA...PHASING WITH THE PRE-EXISTING RIDGING
ALONG THE US PACIFIC COASTLINE. THE PROSPECTS OF A SINGLE RIDGE AXIS
EXTENDING FROM CALIFORNIA INTO THE ARCTIC CIRCLE DOES NOT BODE WELL
FOR US...ESPECIALLY AS THE POLAR VORTEX SLOWLY MIGRATES BACK
SOUTHWARD TOWARD HUDSON BAY. THIS TELECONNECTION WOULD SPELL A
DIRECT CROSS-POLAR FLOW FROM THE HEART OF EASTERN ALASKA/WESTERN
CANADA...DISLODGING THE FRIGID AIRMASS ALONG THE FRONT RANGE AND
INTO THE CENTRAL US BY THE WEEKEND WHICH MODELS REALIZE AS A
SPRAWLING SURFACE RIDGE OF 1045 TO 1050+ MB.

Music to my ears:-)

[Tireman4]

:uarrow:

Hey gang ... when you post model maps, how about a little clarification or description. Put it in context otherwise it is not much help to those here who don't understand. We have a wide variety of weather knowledge here and we should be mindful of all of our members.

Thanks!

I edited the post above to add a discussion of what I see there.

Thank you Wxman57. We appreciate it.

[srainhoutx]

Impact Weather has an update for those that are interested...

http://www.youtube.com/impactweather

[Ivanhater]

Thanks for the video link, srain.

Wxman57: If you don't mind, could you head over to the deep south thread and give us an update or 2 when warranted?

[txagwxman]

And all those cold GFS fans for the last few days can say goodbye to the ice storm.

GFS totally backs off.

How is that for nutz?

[wxman22]

Seems the GFS is struggling with what it wants to do with the cold air, while it still shows the storm system the cold air never really penetrates into the state. Im not really buying that right now.

[PTrackerLA]

Yep GFS has backed way off, shows at best a chilly rain early next week now for the deep south.

[perk]

And all those cold GFS fans for the last few days can say goodbye to the ice storm.

GFS totally backs off.

How is that for nutz?

So what should we take from the GFS knowing that the Euro and the Canadian has a totally different scenario.

[Rgv20]

GFS has practically the same set up at the 500mb level as past runs but as stated above it cant decide what to do with the cold air. Understandable because its 7 to 10 days away.

[somethingfunny]

Yep GFS has backed way off, shows at best a chilly rain early next week now for the deep south.

It always seems to do that around this time frame, only to begin trending back around 72 hours and then show a full fledged storm again by 24 hours. As some others have said, the really memorable storms tend to be depicted with a relatively high amount of consistency and agreement by the long range models, only to disappear at mid-range and then reappear at the short range.

Or it could just be cold rain or dry face slicing windchills. Patience, grasshopper.

[somethingfunny]

30% chance of snow for San Angelo after midnight tonight. Where did this come from? This just goes to show how hard winter weather is to forecast.

Hehe....I wonder if a certain member of this board who works the overnight shift at the San Angelo NWS office had anything to do with making that decision. I would love to hear his reasoning, and his thoughts on DFW's chances over the next 24 hour period.

[Ivanhater]

Could we really expect the GFS to show a snow storm for the Deep south every run, every day, for 2 weeks straight? It just is not going to happen. As others have said, look at the 500 mb setup and it still looks on track. Also the ensemble mean is still showing a great set-up.