Texas Winter 2012-2013

[weatherdude1108]

:uarrow:

DGEX ... ppfffttt!

C'mon man, the mets at the PWC are going to need more than that to raise their glasses of Grey Goose. Next thing I know, you'll pull out some HRRR runs!

More seriously, I like seeing some of our "lurkers" posting in the thread. We welcome you and encourage you to post often and share your thoughts/insights/questions, whatever. As Ntxw has said so well, there will be plenty to talk about in the days and weeks ahead thanks to Mr. PNA turning positive.

Come on down Mr. Positive PNA!!!

I feel like Bob Barker on "THE PRICE IS RIGHT."

[Cuda17]

Out of the DFW office:



Special Weather Statement

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
325 PM CST FRI DEC 21 2012

TXZ091>095-100>107-116>123-220400-
MONTAGUE-COOKE-GRAYSON-FANNIN-LAMAR-YOUNG-JACK-WISE-DENTON-COLLIN-
HUNT-DELTA-HOPKINS-PALO PINTO-PARKER-TARRANT-DALLAS-ROCKWALL-
KAUFMAN-VAN ZANDT-RAINS-
325 PM CST FRI DEC 21 2012

...WINTER WEATHER OUTLOOK FOR DECEMBER 25TH...

A STRONG STORM SYSTEM IS EXPECTED TO MOVE OVER NORTH TEXAS ON
CHRISTMAS DAY. WHILE THIS SYSTEM HAS BEEN FORECAST TO AFFECT THE
REGION FOR SEVERAL DAYS...CONFIDENCE IS INCREASING THAT WINTRY
PRECIPITATION ASSOCIATED WITH THIS SYSTEM WILL FALL OVER PORTIONS
OF NORTH TEXAS ON CHRISTMAS DAY. BASED ON THE LATEST FORECAST
MODELS...THE TRACK OF THIS SYSTEM WILL MOVE OVER THE INTERSTATE 20
CORRIDOR. ASSUMING THIS TRACK VERIFIES...THIS WOULD SUPPORT A
CHANGE OVER FROM RAIN TO SNOW WITH SOME SNOW ACCUMULATIONS FOR
LOCATIONS GENERALLY ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR
DURING THE AFTERNOON AND EVENING HOURS ON CHRISTMAS DAY. JUST
SOUTH OF THE INTERSTATE 20 CORRIDOR...A MIX OF RAIN AND SNOW WILL
BE POSSIBLE WITH LITTLE TO NO SNOW ACCUMULATIONS POSSIBLE.

AT THIS TIME SNOWFALL IS EXPECTED TO BE BRIEF...AND MAY ONLY
PERSIST FOR A FEW HOURS. CURRENTLY OUR FORECAST CALLS FOR LESS
THAN 1 INCH OF SNOWFALL FOR LOCATIONS ALONG AND NORTH OF THE
INTERSTATE 20 CORRIDOR. AS THE CHANGE OVER TO SNOW
OCCURS...NORTHWEST WINDS ARE EXPECTED TO INCREASE IN INTENSITY TO
20 MPH GUSTING TO 30 MPH. ANY SNOW ACCUMULATION WILL BLOW AROUND
IN THESE WINDS...WHICH MAY REDUCE VISIBILITY IF TRAVELING AFTER
SUNSET ON CHRISTMAS DAY.

AS OF THIS AFTERNOON...THIS UPPER LEVEL STORM SYSTEM REMAINS OVER
THE OPEN WATERS OF THE NORTH PACIFIC OCEAN. THERE REMAINS A GREAT
DEAL OF UNCERTAINTY REGARDING THE EXACT TRACK AND ANY ASSOCIATED
WINTRY PRECIPITATION FALLING OVER NORTH TEXAS ON CHRISTMAS DAY AT
THIS TIME.

A MORE NORTHERLY TRACK TO THIS SYSTEM WILL LIKELY RESULT IN LITTLE
TO NO WINTRY PRECIPITATION OVER NORTH TEXAS ON CHRISTMAS DAY.

A MORE SOUTHERLY TRACK TO THIS SYSTEM COULD RESULT IN A CHANGE IN
THE AREAL COVERAGE AND POSSIBLE INCREASE IN SNOW ACCUMULATIONS
ACROSS NORTH TEXAS ON CHRISTMAS DAY.

BOTTOM LINE...WINTRY PRECIPITATION IS LOOKING MORE LIKELY ALONG
AND NORTH OF THE INTERSTATE 20 CORRIDOR FOR THE AFTERNOON AND
EVENING HOURS OF CHRISTMAS DAY. CHECK BACK FOR THE LATEST FORECAST
UPDATES IN THE COMING DAYS AS THESE DETAILS ARE VERY LIKELY TO
CHANGE IN FUTURE FORECASTS.

$$

CAVANAUGH

[Ntxw]

I think we are starting to get a convergence of the models today. Details such as exact frontal location and who sees how much of what is still up in the air, but the overall consensus is for the shortwave to travel west to east across Texas between the Red River and I-20. Surface low should generate in the middle Texas coast. This will likely give SE Texas a wet Christmas and North/Northeast Texas/Oklahoma should at least see flurries/snow that afternoon/evening.

Right now the best guess precip band for accumulations looks to set up over SE Oklahoma and Arkansas.

[dhweather]

This system still hasn't entered the CONUS and we all watch in awe.

[Ntxw]

Here is the forecast from FWD on Christmas. Should be interesting if we do see any snow, tight gradient.

******
Christmas Day: A chance of rain and snow. Partly sunny, with a high near 43. North northeast wind 10 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 30%.

Tuesday Night: Areas of blowing snow and a slight chance of snow. Mostly cloudy, with a low around 28. North northwest wind 15 to 20 mph, with gusts as high as 25 mph. Chance of precipitation is 20%.

[e2drummer]

More seriously, I like seeing some of our "lurkers" posting in the thread. We welcome you and encourage you to post often and share your thoughts/insights/questions, whatever.

I guess I'll stop lurking and post. I've been a lurker here since the 2004 hurricane season under a different poster name, but in all that time, I only had around 10 posts. I mainly read this board during hurricane season and before possible winter storms for Texas, so I'm not quite the prolific poster some of you others are. I do have a minor in Meteorology, but I've focused mainly on air pollution and chemistry, so I'm not as much help with much of the severe weather forecasting that goes on here.

With regards to this possible Christmas storm, I'm optimistic that the set up is there for North Texas to get snow, but know that up until the event, anything can happen. Snow forecasts in Texas are notoriously unreliable, as I have witnessed many big storms turn to into duds and vis-versa. Even though I know many of the models at this point are somewhat unreliable, I still enjoy getting on here and seeing posters torture themselves over every model run.

[aggiecutter]

EURO snowfall projections through next Thursday via HM at Accuweather:
http://ow.ly/i/1hAk6/original

[iorange55]

More seriously, I like seeing some of our "lurkers" posting in the thread. We welcome you and encourage you to post often and share your thoughts/insights/questions, whatever.

I guess I'll stop lurking and post. I've been a lurker here since the 2004 hurricane season under a different poster name, but in all that time, I only had around 10 posts. I mainly read this board during hurricane season and before possible winter storms for Texas, so I'm not quite the prolific poster some of you others are. I do have a minor in Meteorology, but I've focused mainly on air pollution and chemistry, so I'm not as much help with much of the severe weather forecasting that goes on here.

With regards to this possible Christmas storm, I'm optimistic that the set up is there for North Texas to get snow, but know that up until the event, anything can happen. Snow forecasts in Texas are notoriously unreliable, as I have witnessed many big storms turn to into duds and vis-versa. Even though I know many of the models at this point are somewhat unreliable, I still enjoy getting on here and seeing posters torture themselves over every model run.

Welcome to the board, and go rangers!

[gboudx]

I hope u guys in NTX enjoy the winter weather. We'll miss it this time around but hopefully get in on the action for NYE.

[BrokenGlassRepublicn]

Crickets. Shouldn't the 0z models be rolling out about now?

[Dallasaggie01]

From DFW NWS. Anyone remember where the baroclinic set up in 2009? This feels like a similar set up, with areas south of the metroplex being the rain/snow line.

000
FXUS64 KFWD 212319
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
519 PM CST FRI DEC 21 2012
...

.LONG TERM/CHRISTMAS EVE/DAY AND THE REMAINDER OF THE WEEK/...

BIG CHANGES ARE IN STORE AS WE HEAD INTO CHRISTMAS EVE...AS
PREVIOUS DISCUSSIONS HAVE ALREADY ELOQUENTLY NOTED. THE FIRST PUSH
OF SHALLOW COLD AIR WILL BE ONNLY BE 2000-3000 FT IN DEPTH...BUT
HAVE ENOUGH CAA AND DENSITY TO IT TO DROP LOWS DOWN INTO THE
30S/40S WITH HIGHS ONLY RISING INTO THE 50S. MEANWHILE...OUR UPPER
LOW OFF THE COAST OF VANCOUVER ISLAND WILL CONTINUE TO ORGANIZE AS
IT MOVES EAST INTO THE GREAT BASIN AND PACIFIC NORTHWEST. THIS
ENERGY BEGINS TO SPLIT BY CHRISTMAS EVEN NIGHT OVER THE CENTRAL
ROCKIES IN WHAT WILL EVOLVE INTO WHAT WE CALL SPLIT-FLOW...OR FOR
WINTER WEATHER PURPOSES...A DETACHED UPPER TROUGH PATTERN OF WHICH
THE SOUTHERN PIECE OF ENERGY IS WHAT WE WILL FOCUS ON.

WE EXPECT THE COOLER SHALLOW AIRMASS TO MAINTAIN OVER THE AREA
WITH THE LOW LEVEL BAROCLINIC ZONE DRAPED ACROSS THE PERMIAN
BASIN...HILL COUNTRY...AND CENTRAL TEXAS MONDAY NIGHT...AS
SHORTWAVE ENERGY BEGINS TO EXIT OUT OVER THE WESTERN HIGH PLAINS.
THIS IS WHERE THE MODELS DIVERGE ON NOT ONLY THE MID LEVEL
SHORTWAVE ENERGY...STRENGTH...AND TRACK...BUT ALSO THE LOCATION OF
THE AFOREMENTIONED LOW LEVEL BAROCLINIC ZONE. IN PAST EXPERIENCE
WITH THIS PATTERN...WE FIND THE SOLUTION OF THE GFS HAVING THE
FRONT RESPOND BACK NORTH AS A WARM FRONT IN RESPONSE TO THE MID
LEVEL HEIGHT FALLS TO BE A TAD EXTREME. CONSIDERING THE DENSER
PROPERTIES OF THE SHALLOW COLD AIRMASS ALREADY IN PLACE...WE FEEL
THAT THE PROGRESSIVE OPEN SHORTWAVE TROUGH WILL DROP FURTHER SOUTH
LIKE THE ECMWF/NAM SOLUTIONS WITH THE BAROCLINIC ZONE REMAINING NEAR
OUR SOUTHERN COUNTIES...EVENTUALLY REINFORCING A DEEPER AND COLDER
POLAR AIRMASS INTO THE AREA BY CHRISTMAS AFTERNOON AND EVENING.
THE CANADIAN IS IN BETWEEN...BUT SEEMS TO BE STRUGGLING WITH LOW
LEVEL RESOLUTION OF THE AIRMASS...THOUGH IT IS THE MOST ROBUST
WITH QPF AMOUNTS.

THE ONE BIG UNCERTAINTY THAT REMAINS IS MOISTURE AVAILABILITY AND
DEPTH. AT THIS TIME...ANY WAA AND MID LEVEL TROWAL POSSIBILITIES
WILL HAVE SHIFTED EAST WITH NO ISENTROPIC UPGLIDE INVOLVED...BUT
PRECIPITATION BASED MORE ON MID LEVEL FRONTOGENETICAL FORCING AND
LARGE-SCALE ASCENT. AS FOR PRECIPITATION TYPE...WE ARE LEANING
WITH A RAPID TRANSITION CHRISTMAS AFTERNOON FROM A COLD LIGHT RAIN
TO CHANCE OF ALL LIGHT SNOW NORTH OF A COMANCHE...CLEBURNE...CANTON
LINE BY CHRISTMAS EVENING...AS THE COLD AIR RAPIDLY DEEPENS WITH
THE FULL COLUMN FALLING BELOW FREEZING. THE STRONG CAA AND TIGHT
PRESSURE GRADIENT WILL RESULT IN GUSTY NORTH WINDS 15-30 MPH...
WHICH MAY ALSO RESULT IN AREAS OF BLOWING SNOW AS WELL ACROSS OUR
NORTHERN COUNTIES. AS FOR AREAS FURTHER SOUTH...IT DOES APPEAR A
DRY-SLOT ASSOCIATED WITH THE UPPER JET ROTATING THROUGH THE BASE
OF THE SYSTEM WILL KEEP AREAS FURTHER SOUTH DRY WHEN THE MUCH
COLDER AIR ARRIVES...OUTSIDE OF OUR FAR EASTERN COUNTIES. THE
SYSTEM WILL PROGRESSIVELY MOVE EAST TOWARD THE TN/OH VALLEYS AFTER
MIDNIGHT WEDNESDAY MORNING WITH ONLY WRAP-AROUND LIGHT SNOW
OCCURRING ACROSS AREAS NEAR PARIS AND SULPHUR SPRINGS. AS FOR ANY
AMOUNTS OF SNOW...THE CONFIDENCE ON MOISTURE AVAILABILITY IS STILL
TOO MUCH IN QUESTION TO PROCLAIM ANY VALUES WITH CERTAINTY. WE
WILL CONTINUE TO FINE TUNE STORM TRACK AND PLACEMENT OF THE COLDER
AIR THROUGHOUT THE WEEKEND WHEN HOPEFULLY BETTER UPPER-AIR
SAMPLING WITH THIS SYSTEM OCCURS WITH MORE ACCURATE PROJECTIONS OF
REALITY.

IT WILL CONTINUE TO BE BRISK AND CHILLY ON WEDNESDAY IN WAKE OF
OUR SYSTEM AND HAVE MAINTAINED A COLDER THAN MOS GUIDANCE FORECAST
WITH SOME CAA PERSISTING THROUGH THE DAY. WE WILL SEE A NICE
MODIFICATION OF TEMPERATURES BY THURS/FRI AS ANOTHER UPPER RIDGE
ARRIVES OVERHEAD WITH EVENTUAL RETURN TO SOUTHEAST WINDS AROUND 10
MPH. A FAIRLY DYNAMIC SYSTEM ARRIVES ON FRIDAY...BUT HAVE ONLY
INTRODUCED SLIGHT CHANCES FOR SHOWERS WITH LOW LEVELS STILL
RELATIVELY DRY. CANNOT RULE OUT ELEVATED THUNDER IN THIS
INSTANCE...BUT WE ARE TALKING DAY 7 AND THIS WILL BE ADDRESSED
THROUGH THE WEEK."

[TrekkerCC]

Crickets. Shouldn't the 0z models be rolling out about now?

Hey! Yes, it is about that time again. NAM is currently running and the complete run should be out in a hour. The GFS comes starts rolling out at ~10:30pm or so, and the EURO coming in at around ~12:30am or so. Remember, the NAM is only in the extended ranges at the moment in terms of the Christmas Day forecast (it runs to 84 hours, but it is useful to about 48 hours, generally).

-TrekkerCC

[CYCLONE MIKE]

It's kind of funny watching You guys talking about snow for Christmas and our weather office is starting to get worried about a severe weather outbreak for us over here in se la. Although would love to be able to join in and talk about the prospects of winter Wx around here, just don't see it happening anytime soon.

[KatDaddy]

Oh no its Trekker! Its looking more and more possible I will see some snow up here in NTX. Still many days out.

[TrekkerCC]

It's kind of funny watching You guys talking about snow for Christmas and our weather office is starting to get worried about a severe weather outbreak for us over here in se la. Although would love to be able to join in and talk about the prospects of winter Wx around here, just don't see it happening anytime soon.

Well, keep your hopes up! Snow in SE Louisiana is a rare phenomena, but it can happen. SE Louisiana had a heavy snow event in December 2008. And in 1899, the great arctic outbreak, you had pretty chilly temperatures all the way to the gulf coast!

[Ntxw]

NAM goes out to 84 which is Christmas. Take this with a grain of salt because it's not very good beyond 48 hours. It is very wet for the eastern part of the state and is warmer than the other models. However looking at the surface data it has low level cold air along the Red River so it may be slow with the front. As we get nearer to the date, NAM will be useful for seeing how mesoscale features come into play for convection.

[Turtle]

Here is a graphic from Accuweather about the Christmas snowfall possibility.

[iorange55]

Just got back in from going to a Christmas light show with some friends and family.

Back just in time for 0z GFS! I don't expect it to be much different than previous runs, though.

[Ntxw]

GFS is a little more south and much wetter, I like this trend.

[iorange55]

GFS is a little more south and much wetter, I like this trend.

Yeah, all it took was me saying that I didn't expect any changes!

It's considerably wetter, we just need to work on driving that cold air down...which shouldn't be an issue.