Texas winter wx thread (2009-2010)

[Weatherdude20]

Any moisture gonna be around North Texas Thursday morning?

NWS in Fort Worth expects temps in mid to upper 20's...

[srainhoutx]

As you know, I am always looking at trends. Guidance has been struggling with many factors. Today, forecaster Kocin of the HPC offered some "hints" of what maybe ahead in the Alaska Final Extened Disco...

ALASKA EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
154 PM EST SUN DEC 06 2009

VALID 12Z THU DEC 10 2009 - 12Z MON DEC 14 2009

SOME HUGE CHANGES AGAIN IN STORE FOR THE STATE AS THE HIGH
AMPLITUDE UPPER RIDGE RETROGRADES WESTWARD...ALLOWING AN EQUALLY
ANOMALOUS UPPER LOW/POLAR HIGH ALSO TO BACK IN TOWARDS ALASKA FROM
THE NORTHEAST. HOWEVER...THE 12Z EUROPEAN DOES NOT ADHERE TO THIS
SCENARIO.

WHILE VERY MILD CONDITIONS PERSIST OVER MUCH OF SOUTHERN AND
WESTERN ALASKA INTO THURSDAY/DAY 4...EQUALLY VERY COLD CONDITIONS
APPEAR TO DROP SOUTH AND WESTWARD INTO THE STATE INTO NEXT
WEEKEND/DAYS 5 THRU 7/FRIDAY THRU SUNDAY...AS THE COLDEST AIR OF
THE SEASON IS CENTERED JUST EAST OF NORTHEAST ALASKA ON
SATURDAY/DAY 6.

THE OVERNIGHT OPERATIONAL EUROPEAN AND GFS RUNS ARE RELATIVELY
SIMILAR WITH THIS SOLUTION THROUGH DAY 6/SATURDAY. EVEN THE
OVERNIGHT ENSEMBLE MEANS ALSO CONVERGE ON THIS SOLUTION AS WELL.

MEANWHILE...AS THE UPPER RIDGE MOVES WESTWARD BUT RETAINS ITS
DOMINANCE AS A LARGE SCALE FLOW FEATURE...UPPER TROUGHS CONTINUE
TO UNDERCUT THE RIDGE...AS A NEW TROUGH MOVING EASTWARD OFF OF
NORTHEAST ASIA CARVES OUT A LARGE UPPER LOW SOUTH OF THE ALEUTIANS
BY DAY 6/SATURDAY. UNLIKE THE PREVIOUS CYCLONES...THIS ONE DOES
NOT APPEAR TO DEEPEN AS MUCH AS PREVIOUS SYSTEMS.

FOLLOWING DAY 6...THE ENSEMBLE MEANS CONTINUE TO RETROGRADE THE
UPPER HIGH OVER NORTHEAST SIBERIA WHILE THE MEANS ALSO SHOW THAT A
CUTOFF LOW FORMS OVER ALASKA LATE IN THE PERIOD AS COLD AIR
ENVELOPS MUCH OF THE STATE. IT IS QUITE A SPECTACULAR CHANGE.
THE 12Z GFS DID HAVE MANY SIGNIFICANT CHANGES WITH PREVIOUS
RUNS...BUT WAS SLIGHTLY FARTHER NORTH WITH LOW PRESSURE OVER THE
WESTERN BERING SEA EARLY ON DAY 4/THURSDAY...SO STUCK WITH THE 6Z
GFS MORE AS A COMPONENT OF THE BLEND EARLY IN THE FORECAST. THERE
WERE ALSO FEW MAJOR CHANGES WITH THE 12Z CANADIAN AND UKMET.
THEREFORE...THE MANAUAL ANALYSES WERE DERIVED FROM A BLEND OF
MOSTLY THE 06Z GFS AND THE 00Z EUROPEAN...WITH A COMBINATION OF
THE 00Z EUROPEAN/NAEFS ENSEMBLE MEANS. AT NO TIME DID THE
FORECAST INCLUDE MORE THAN A 50 PERCENT CONTRIBUTION OF THE
ENSEMBLE MEANS.

THE 12Z EUROPEAN PRESENTS AN INTERESTING DEPARTURE FROM WHAT HAD
APPEARED TO BE A PRETTY UNIFIED SET OF FORECASTS. THE 12Z RUN IS
NOT AS GUNG HO WITH THE RETROGRESSION OF THE VERY COLD AIR/UPPER
LOW INTO ALASKA THRU DAY 6/SATURDAY...KEEPING THE COLDEST AIR
MOSTLY EAST OF THE STATE. THIS FORECAST IS CLEARLY A LARGE CHANGE
FROM CONTINUITY BUT WILL BE MONITORED TO SEE IF THIS IS EITHER AN
OUTLIER OR A REAL CHANGE TO THE FORECAST.

KOCIN

The $64,000 question to me is this feature and a reloading of Polar Air in that region and does it suggest an Arctic Intrusion into TX in time? We shall see.

[Portastorm]

I thought Larry Cosgrove had some very interesting comments in his weather blog from last night. Here is one excerpt that I think we should keep in mind about how the subtropical jet sets up in this El Nino and about source regions of Polar and/or Arctic air.

*******************
But once again, this is not "your usual El Nino". The placement of the subtropical jet stream and moisture fetch has consistently been through central and even southern Mexico, then across Florida to the Grand Banks. The teleconnection on that windfield, combined with the tendency since October for strong -AO blocking, strongly favors a ridge West, trough East alignment (+PNA). Indeed, California has been largely missing out on major precipitation events, at least the kind that creates deluges and mudslides in the southern half of the Golden State. If a cAk vortex does develop in the evolving pattern, it would be over ON and QB, with frequent deviations into New England and below Newfoundland. This makes the predictions for middle and late December quite critical. All it will take is one deep, slow-moving storm to set up a jet stream configuration that provides bursts of intense cold to the right of 110 W Longitude through much of January and February.

By the way, most of the cold air in a -AO based alignment forms over Alaska and northern Canada, and NOT from Siberia. It is a common misconception that in order for the lower 48 states to see extreme cold of the tundra variety, a cross-polar flow must be established first. The truth is, 90 percent of the cold values that enter the U.S. have origins in AK, YT, NT, and NU AR.

[amawea]

That's some very good stuff you Posted by Larry Portastorm.

[srainhoutx]

Look what the Long Range "La La Land" GFS spit out last night...

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 84_l.shtml

[rhoby13]

Dun, dun, dunnnnnnn. We shall see.....

[Portastorm]

Would that be Mr. Polar Vortex taking a Christmas-time vacation over the Great Lakes?!

[natlib]

San Angelo weather guys missed it today.......Yesterday the forecast was sunny with a high in the low 60's. Today....freezing drizzle this morning with a high of 38.

Tomorrow? Sunny high of 70.

WHAT!!????

[snow and ice]

I just talked to Bono of U2. He said " No Snow on the Horizon".

[Extremeweatherguy]

San Angelo weather guys missed it today.......Yesterday the forecast was sunny with a high in the low 60's. Today....freezing drizzle this morning with a high of 38.

Tomorrow? Sunny high of 70.

WHAT!!????

Yeah, that is funny. You don't often see a forecast for "freezing drizzle before 10am" followed by the words "clearing, with a high near 69." When I think of 70-degree days, winter precipitation is not the first thing that comes to my mind. lol

Tuesday: Areas of freezing drizzle before 10am. Areas of fog before 10am. Otherwise, cloudy through mid morning, then gradual clearing, with a high near 69. Windy, with a south southeast wind 5 to 10 mph becoming southwest between 25 and 30 mph. Winds could gust as high as 40 mph.

[srainhoutx]

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN ANGELO TX
331 PM CST MON DEC 7 2009

...FREEZING DRIZZLE IS POSSIBLE ACROSS THE BIG COUNTRY AND THE
NORTHERN PORTIONS OF THE CONCHO VALLEY AND HEARTLAND THROUGH
TUESDAY MORNING...

.AREAS OF FREEZING DRIZZLE HAVE DEVELOPED ACROSS THE BIG COUNTRY
AND NORTHERN PORTIONS OF THE CONCHO VALLEY AND HEARTLAND TODAY AS
AN ARCTIC COLD FRONT HAS PUSHED SOUTH ACROSS THE AREA. EXPECT THE
FREEZING DRIZZLE TO CONTINUE INTO TUESDAY MORNING AS TEMPERATURES
ARE AT OR BELOW FREEZING AND ARE NOT EXPECTED TO WARM ABOVE
FREEZING UNTIL MID MORNING ON TUESDAY.

TXZ049-054-064>066-098-099-113-114-127-128-139-140-081100-
/O.CON.KSJT.ZR.Y.0004.000000T0000Z-091208T1500Z/
FISHER-NOLAN-STERLING-COKE-RUNNELS-HASKELL-THROCKMORTON-JONES-
SHACKELFORD-TAYLOR-CALLAHAN-COLEMAN-BROWN-
INCLUDING THE CITIES OF...ROTAN...ROBY...SWEETWATER...
STERLING CITY...ROBERT LEE...BRONTE...BALLINGER...WINTERS...
HASKELL...THROCKMORTON...WOODSON...STAMFORD...ANSON...HAMLIN...
ALBANY...ABILENE...CLYDE...BAIRD...CROSS PLAINS...COLEMAN...
BROWNWOOD
331 PM CST MON DEC 7 2009

...FREEZING RAIN ADVISORY REMAINS IN EFFECT UNTIL 9 AM CST
TUESDAY...

A FREEZING RAIN ADVISORY REMAINS IN EFFECT UNTIL 9 AM CST
TUESDAY FOR FREEZING DRIZZLE.

AREAS OF FREEZING DRIZZLE HAVE DEVELOPED ACROSS THE BIG COUNTRY...
NORTHERN PORTIONS OF THE HEARTLAND AND CONCHO VALLEY AS AN ARCTIC
COLD FRONT HAS PUSHED SOUTH ACROSS THE AREA BRINGING A MUCH
COLDER AIRMASS TO WEST CENTRAL TEXAS. SURFACE TEMPERATURES REMAIN
AT OR BELOW THE FREEZING AND ARE NOT EXPECTED TO WARM ABOVE THE
FREEZING...MAINLY ALONG AND NORTH OF A STERLING CITY TO COLEMAN
TO BROWNWOOD LINE. DO NOT EXPECT ANY SIGNIFICANT ICE ACCUMULATION
TO OCCUR...BUT LIGHT ACCUMULATION IS POSSIBLE ON ELEVATED
ROADWAYS AND BRIDGES. SEVERAL ACCIDENTS HAVE BEEN REPORTED ALONG
INTERSTATE 20...MAINLY BETWEEN SWEETWATER AND TYE. AREA MOTORISTS
ARE URGED TO USE CAUTION AND PAY ATTENTION TO ROAD CONDITIONS.

[Big O]

Have seen mets on other boards talking about a -AO/-NAO/+PNA pattern taking shape for mid to late December. I have done some research into this pattern and it seems to support a western ridge/eastern trough. The question remains whether the cold remains confined to the eastern 1/3 of the nation or eastern 1/2 of the nation.

In addition, while I believe the mean trough position from mid to late December will be centered over the east, it is quite possible there may be a transitory retrogression of the trough, and it was such a scenario, combined with an upper level low travel with the STJ that led to the Christmas Eve Snowstorm across deep South Texas.

Thoughts and opinions are welcomed.

[wxgirl69]

Have seen mets on other boards talking about a -AO/-NAO/+PNA pattern taking shape for mid to late December. I have done some research into this pattern and it seems to support a western ridge/eastern trough. The question remains whether the cold remains confined to the eastern 1/3 of the nation or eastern 1/2 of the nation.

In addition, while I believe the mean trough position from mid to late December will be centered over the east, it is quite possible there may be a transitory retrogression of the trough, and it was such a scenario, combined with an upper level low travel with the STJ that led to the Christmas Eve Snowstorm across deep South Texas.

Thoughts and opinions are welcomed.

Would this mean we will be seeing some colder air at the end of this month?

[serenata09]

Any chance of anything frozen falling tonight in North Texas? It is COLD outside!

[iorange55]

Any chance of anything frozen falling tonight in North Texas? It is COLD outside!

Not in the Dallas area, I don't think just some mist, and maybe a few showers. Brownwood could see some freezing drizzle though, I think the temps are supposed to slowly rise through the night, though. Then fall after tomorrow with the cold front.

[vbhoutex]

Just took a quick glance at some models. Sure looks like that barbed wire fence along the Red River is going to be broken before Christmas. I know it is a long way out, but if the models verify, it at a minimum looks like even Texans will have a cold Christmas.

[gboudx]

Just took a quick glance at some models. Sure looks like that barbed wire fence along the Red River is going to be broken before Christmas. I know it is a long way out, but if the models verify, it at a minimum looks like even Texans will have a cold Christmas.

From Mr. Cosgrove this evening:

...

While wintertime will be on a temporary retreat locally, the 500MB longwave pattern will be shifting to what can only be described as a more ominous configuration as we approach Christmas. A broad Kelvin wave complex is showing signs of imparting energy not only to the subtropical jet stream, but also to the storm sequence over the northern Pacific Ocean. The vast negative Arctic Oscillation signal that cooled much of the nation this past summer and again in October shows up prominently in computer outlooks covering the period December 19 - 23. And while it is way too early to offer any in-depth speculation on apparent weather in Texas during that time frame, I will say this: overcoats, thermals, and ice scrapers may become popular for sale items in stores later in the month.

[wxgirl69]

Just took a quick glance at some models. Sure looks like that barbed wire fence along the Red River is going to be broken before Christmas. I know it is a long way out, but if the models verify, it at a minimum looks like even Texans will have a cold Christmas.

can I get a whoot whoot!!!

[Texas2Florida]

Yeah you can get a woot woot! and a Yee-Haw also!

[srainhoutx]

Morning e-mail from Jeff...interesting nugget in the last paragraph regarding the Arctic Air buildup over Canada we've seen via guidance...

Dense fog blankets the area this morning with drizzle and light rain scattered.



Surface warm front over the coastal sections will slowly lift northward today with areas south of this boundary warming into the 60’s/70’s and areas north staying locked in the fog and drizzle and temps. in the 50’s. Strong short wave over the SW US will eject into TX tonight bringing a strong polar boundary currently stalled over NW TX through the region Wednesday morning. Will see highs prior to sunrise and then strong cold air advection onset with temps. falling/holing in the upper 50’s under sunny skies on Wednesday. Cold Thursday morning with a freeze likely in most areas, before rapid return flow ahead of the next short wave late Thursday/Friday.



Cloud and rain returns Friday as the next wave induces isentropic lift over the surface cold dome with a repeat of yesterday/today. Coastal surface low once again develops over the NW Gulf and tracks toward Louisiana with strong ENE winds along the upper TX coast. Will need to keep an eye on the tide levels Friday as we may see some overwash over on Bolivar. Otherwise widespread fog, drizzle, and light rain early Friday-early Saturday before the trough passes…only to be followed by another fast moving system by Sunday/Monday…pattern is for fast moving system every 1-2 days with weak cold frontal passages and chances for rainfall.



Models have been showing a massive arctic high building over NW Canada and nosing into Montana early next week…however delivery southward is questionable at this time as the pattern goes zonal…it is hard to have a 1050mb high just north of Montana and not be concerned about such a cold dense air mass undercutting an unfavorable zonal flow aloft and sliding down the front range…will continue to watch…but for now keep the real cold air north and east of TX