Texas winter weather thread - Cold snap next week

[wall_cloud]

It is 75 degrees right now.

I doubt that the ground will support the 1-2 inches of accumulation the NWS is now forcasting. It's been so warm.

But since I am not an expert,,,, how many hours/days of sub-freezing temps will the warm ground need to support accumulating snow?

With elevated surfaces, I know that ground temps are no obstacle. So I am assuming my commute through the I-20/360 Superramp will be AWFUL tomorrow.

a good snowburst will cover the ground and accumulate easily. With the warmer ground, you could get a little melting from below but it would refreeze to form an icy crust under the snow. something worth thinking about anyway.

[Janie2006]

Wow. Easily a 30 degree temperature change (maybe 35 in some cases) across barely 60 miles distance in N Texas right now. The same thing is occuring across central Missouri.

[Johnny]

It looks like the northern portions or Southeast, Texas might not escape without a little winter weather. This isn't written in stone but the possibility does exist.

This is from Jeff.


Tornado Watch issued for N TX and NC TX until 700pm



Winter Storm Watches will need southward adjustment later today.



40 degree temp fall across front over NW TX .



Powerful arctic boundary sweeping southward with Childress at 37 and Dallas at 80. Capping ahead of front is starting to break with numerous thunderstorms developing. Per SPC supercells with tornadoes will be possible given strong shearing profiles before linear MCS develops toward evening and sweeps SE.



Front is well ahead of progged timing and will need to speed up frontal passage by another couple of hours. Latest 12Z model runs suggest colder air making it further south than though this morning and with a slightly stronger upper level storm system in the cold air on Thursday. Fort Worth has upgraded to Winter Storm Warnings with 3-6 inches of snow accumulation possible and Winter Storm Watches will need to be extended southward this afternoon likely to include Waco and possibly as far south as our northern tier counties.



Per 12Z NAM forecast soundings for 24, 30, and 36 hours showing a rapidly deepening cold dome (2,000 ft Thursday AM to 6,000 ft midday to all frozen by evening) over N TX Thursday suggest a sooner changeover to snow and sleet across N TX and this will result in the freezing line pushing southward deeper into our area. Feel rain may change to freezing rain during the mid afternoon from College Station to Huntsville and then mix or even change to sleet and snow by early evening. Very tough timing with this aspect as dry slot from the WSW will be cutting in as the cold air deepens to support the change to frozen precip. A Winter Weather Advisory may be needed for our northern counties.



Will be awaiting the 18Z (noon) guidance runs and see how they handle the ejecting upper trough and cold air given the frontal timing is speeding up.



Jeff Lindner

[Dr. Jonah Rainwater]

The front seems to be moving slower than NWS anticipated this morning:

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
1035 AM CST WED NOV 29 2006

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-292200-

ANDERSON-BELL-BOSQUE-COLLIN-COMANCHE-COOKE-CORYELL-DALLAS-DELTA-
DENTON-EASTLAND-ELLIS-ERATH-FALLS-FANNIN-FREESTONE-GRAYSON-HAMILTON-
HENDERSON-HILL-HOOD-HOPKINS-HUNT-JACK-JOHNSON-KAUFMAN-LAMAR-LAMPASAS-
LEON-LIMESTONE-MCLENNAN-MILAM-MILLS-MONTAGUE-NAVARRO-PALO
PINTO-PARKER-RAINS-ROBERTSON-ROCKWALL-SOMERVELL-STEPHENS-TARRANT-VAN
ZANDT-WISE-YOUNG-
1035 AM CST WED NOV 29 2006

...SIGNIFICANT WEATHER ADVISORY FOR NORTH TEXAS...

LATEST THINKING IS THAT THE ARCTIC FRONT AT THE SURFACE IS MOVING
SOUTHEAST FASTER THAN THE MODELS ARE PROJECTING. THE MODELS DO HAVE
A GOOD HANDLE ON THE UPPER SUPPORT...WHICH MEANS THAT NORTH TEXAS
WILL HAVE THE COLD AIR IN PLACE SOONER THAN PREVIOUSLY EXPECTED AND
BUT WILL STILL HAVE STRONG UPPER SUPPORT FOR PRECIPITATION THROUGH
TOMORROW AFTERNOON. WE ARE EXPECTING THE FRONT TO REACH MONTAGUE
COUNTY JUST AFTER NOON AND REACH THE DFW AIRPORT AREA BY 4 TO 6 PM.
THE FRONT WILL HAVE SWEPT ACROSS ALL OF NORTH TEXAS BY 4 AM THURSDAY
MORNING.

And now:

SHORT TERM FORECAST
NATIONAL WEATHER SERVICE FORT WORTH TX
138 PM CST WED NOV 29 2006

......................

THE ARCTIC FRONT WILL MOVE INTO MONTAGUE...WISE...JACK AND PALO
PINTO COUNTIES BY 300 PM...SENDING TEMPERATURES PLUMMETING SOME 25
DEGREES AND BRINGING GUSTY NORTHERLY WINDS OF 20 TO 25 MPH AS IT
PASSES.

This pushes the arrival of the cold front here in Plano back at least 3 hours....

[Janie2006]

Based on a temperature analysis, the front is between Jacksboro and Ft. Worth. The current temp is 63F in Jacksboro (the low 30s in Wichita Falls) and 77F in Ft Worth. Unless that front slows down significantly, Ft. Worth will experience FROPA before too much longer. It may be that the front is slowing as I type.

[jasons2k]

Some things to note:

You can clearly see the front - from near Lake Possum Kingdom to Ardmore.

ALSO - look at the two Ardmore OK observations - a 30 degree difference between the two airports - a distance of ~10 miles. WOW.

[jasons2k]

In the latest frame Ardmore Downtown dropped from 79F to 52F!!

...next one to watch will be Bridgeport which is currently @ 81F

[jasons2k]

Look out NE Wise County....

[Tireman4]

Wowzers. This is major front. 30-40 degree drops in an hour to hour and a half.

[cctxhurricanewatcher]

And EWG is missing all of this. Where did he go?

[jasons2k]

The squall line is taking shape:

[Extremeweatherguy]

And EWG is missing all of this. Where did he go?

Im here! Don't worry. Just havn't had time to get on lately, but I am back now and this sure does look interesting!

[Extremeweatherguy]

Is it just me, or is this one of the strangest AFDs you have ever seen for Houston?

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
ISSUED BY NATIONAL WEATHER SERVICE LAKE CHARLES LA
242 PM CST WED NOV 29 2006

.SYNOPSIS...
A COLD DOME OF HIGH PRESSURE ACROSS NEVADA WILL BUILD SOUTHEAST INTO
WEST TEXAS, SHOVING A STRONG COLD FRONT THROUGH SOUTHEAST TEXAS
THURSDAY MORNING.

&&

.DISCUSSION...
FOR TONIGHT, STRONG GULF-AIR ADVECTION WILL KEEP THE NOCTURNAL
TEMPERATURES UNSEASONABLY WARM; ACTUAL READINGS WILL BE RUNNING FROM
20 TO 25 DEGREES ABOVE NORMAL, UNDER A POROUS BLANKET OF GULF STRATUS
AND PACIFIC CIRRUS.

FOR THURSDAY, SHOWERS AND THUNDERSTORMS SEEM LIKELY, ORGANIZING
WITH THE APPROACH OF THE COLD FRONT. LONG-LIVED SEVERE WEATHER SEEMS
LESS LIKELY. A FEW LIMITING FACTORS WILL BE IN PLACE.

FIRST, GRAVITATIONAL INSTABILITY WILL BE MODEST, WITH CAPES (AROUND
500 J PER KG) ACCUMULATING AND ALIGNING IN A NARROW PRE-FRONTAL
ZONE. SECOND, MOISTURE WILL BE LIMITED, CONFINED MAINLY TO THE LOWER
TROPOSPHERE; ADVECTING PACIFIC CIRRUS WILL PERSIST NEAR THE
TROPOPAUSE. FINALLY, THE UPPER-LEVEL DYNAMICS IN THE FORM OF QUASI
-GEOSTROPHIC OMEGA WILL BE OUT-OF-PHASE WITH THE FRONTAL LIFT.

THE ONE FAVORABLE FACTOR FOR SEVERE WEATHER WILL BE THE ALIGNMENT OF A
MODEST LOW-LEVEL JET ALONG THE FRONTAL INTERFACE. ITS ATTENDANT
CYCLONIC SHEAR (OR CROSS-STREAM VORTICITY), WHEN TIPPED UPWARD BY
FRONTAL LIFT, WILL ADD SOME SPIN TO THE PRE-FRONTAL STORMS.

WITH THE PASSAGE OF FRONT, LIGHT RAIN IS POSSIBLE, ESPECIALLY ACROSS
THE NORTHERN PORTIONS. THE BASIC INGREDIENTS FOR RAIN WILL BE IN
PLACE; MOISTURE, POTENTIAL SYMMETRIC INSTABILITY, AND LIFT. PASSING
SHORTWAVES (AND ASSOCIATED QUASI-GEOSTROPHIC OMEGAS) WILL LIFT THE
MOIST, SLANTWISE UNSTABLE AIR; RELEASING THE INSTABILITY, AND
PRODUCING RAIN, ALTHOUGH LIGHT AND SHORT-LIVED.

THE BLUE NORTHERS BEHIND THE FRONT WILL BE ON THE STRONG SIDE. A
WIND ADVISORY WILL LIKELY BE REQUIRED.

AS FOR THE TEMPERATURES, THE WARMEST READINGS WILL BE FELT IN THE
EARLY MORNING HOURS, JUST BEFORE PASSAGE OF FRONT.

FOR THURSDAY NIGHT, I FOLLOWED THE WARMER STATISTICAL SOLUTION
GENERATED BY THE GLOBAL MODEL. THE INCOMING CONTINENTAL POLAR AIR
ORIGINATES OVER EASTERN COLORADO, WHICH IS NOT COMPLETELY SNOW
COVERED AT THIS TIME. IN ADDITION, THE NORTHERLY WINDS WILL BE
MIXING-UP THE NOCTURNAL AIR, THUS CANCELLING OUT ISOBARIC (OR
RADIATIONAL) COOLING. NEVERTHELESS, THE OVERNIGHT WILL BE RUNNING
FROM 10 TO 15 DEGREES BELOW NORMAL, DUE MAINLY TO COLD-AIR ADVECTION.

Why is Lake Charles issuing our forecasts?

[Tireman4]

Maybe the HGX guys are getting a late lunch. Maybe they are in the break room drinking a Coca-Cola. Only speculating. Not to quote Arsenio Hall, but it makes one go hummmmm

[Extremeweatherguy]

Has anyone taken a look at the latest forecast for Beaumont?!?! This is a MAJOR change from their much warmer forecasts of recent days. They are now calling for highs in the 40s this Sunday and Monday!

Thursday: Scattered showers and thunderstorms. Cloudy, with a temperature rising to near 71 by noon, then falling to around 61 during the remainder of the day. South wind 10 to 20 mph becoming west. Winds could gust as high as 20 mph. Chance of precipitation is 40%.

Thursday Night: Mostly cloudy during the early evening, then gradual clearing, with a low around 34. Northwest wind between 15 and 20 mph, with gusts as high as 20 mph.

Friday: Sunny, with a high near 51. North wind between 5 and 10 mph.

Friday Night: Mostly clear, with a low around 30. North wind between 5 and 10 mph.

Saturday: Mostly sunny, with a high near 51. Northeast wind between 5 and 10 mph.

Saturday Night: Mostly clear, with a low around 35. North wind around 10 mph.

Sunday: Mostly sunny, with a high near 49. North wind between 10 and 15 mph.

Sunday Night: Mostly clear, with a low around 33.

Monday: Sunny, with a high near 45.

Monday Night: Mostly clear, with a low around 35.

Tuesday: Mostly cloudy, with a high near 56.

[CaptinCrunch]

FIRST, GRAVITATIONAL INSTABILITY WILL BE MODEST, WITH CAPES (AROUND
500 J PER KG) ACCUMULATING AND ALIGNING IN A NARROW PRE-FRONTAL
ZONE. SECOND, MOISTURE WILL BE LIMITED, CONFINED MAINLY TO THE LOWER
TROPOSPHERE; ADVECTING PACIFIC CIRRUS WILL PERSIST NEAR THE
TROPOPAUSE. FINALLY, THE UPPER-LEVEL DYNAMICS IN THE FORM OF QUASI
-GEOSTROPHIC OMEGA WILL BE OUT-OF-PHASE WITH THE FRONTAL LIFT.

THE ONE FAVORABLE FACTOR FOR SEVERE WEATHER WILL BE THE ALIGNMENT OF A
MODEST LOW-LEVEL JET ALONG THE FRONTAL INTERFACE. ITS ATTENDANT
CYCLONIC SHEAR (OR CROSS-STREAM VORTICITY), WHEN TIPPED UPWARD BY
FRONTAL LIFT, WILL ADD SOME SPIN TO THE PRE-FRONTAL STORMS.

Smoke some more before posting....

[JenBayles]

FIRST, GRAVITATIONAL INSTABILITY WILL BE MODEST, WITH CAPES (AROUND
500 J PER KG) ACCUMULATING AND ALIGNING IN A NARROW PRE-FRONTAL
ZONE. SECOND, MOISTURE WILL BE LIMITED, CONFINED MAINLY TO THE LOWER
TROPOSPHERE; ADVECTING PACIFIC CIRRUS WILL PERSIST NEAR THE
TROPOPAUSE. FINALLY, THE UPPER-LEVEL DYNAMICS IN THE FORM OF QUASI
-GEOSTROPHIC OMEGA WILL BE OUT-OF-PHASE WITH THE FRONTAL LIFT.

THE ONE FAVORABLE FACTOR FOR SEVERE WEATHER WILL BE THE ALIGNMENT OF A
MODEST LOW-LEVEL JET ALONG THE FRONTAL INTERFACE. ITS ATTENDANT
CYCLONIC SHEAR (OR CROSS-STREAM VORTICITY), WHEN TIPPED UPWARD BY
FRONTAL LIFT, WILL ADD SOME SPIN TO THE PRE-FRONTAL STORMS.

Smoke some more before posting....

Or better yet, pass it around....

[Tireman4]

Ha. Ha. That was funny. I have to tell you that. Are not the meterologists from Lake Charles, Beaumont and HGX using the same software? To have that wide of a divergence between the three forecasts is either silly or suicidal. Must be drinking the frozen Dr. Pepper again.

[AggieSpirit]

Johnny,

NWS Ft. Worth has NOT upgraded to Winter Storm Warning for DFW (Dallas and Tarrant counties) yet. Denton County and other Northern Sections are however under a Winter Storm Warning.

I think it's very strange to see a Winter Storm Warning and Tornado Watch over the same areas!

[wall_cloud]

the Beaumont forecast comes from LCH anyway, so there are really only two forecasts. the software is the same, but the analysis of the models is not. Just a different decision on what will happen.