2008-09 Texas Winter Weather Thread

[Ed Mahmoud]

GFS and NAM both show several hours of onshore flow before precip starts later tonight, not the recipe for any kind of freezing/frozen near HOU.

[MGC]

Yikes....-NAO usually means cold.....MGC

[Ed Mahmoud]

Not what people think of as "winter weather", but a lot more common than snow...


Thunderstorms.

Looks like one limiter on potential severe weather tomorrow with the front coming mid-morning is a warm nose projected by both the NAM and GFS around 850 mb.

But the GFS especially sees storms with the front, and enough instability for some strong (but probably not severe) storms.

[Portastorm]

Signs of hope for more "winter" in the 12z GFS after 312 hours:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fpc.shtml

[Ed Mahmoud]

Double post from severe thread, and Winter weather mainly in that it occurs in late December...



.................................................................................................................
DFW- Best action should be just across the Red River in Oklahoma, and the likelihood the storms hit around dawn, when the planetary boundary layer may be decoupled, further reduces the tornado risk. But excellent instability (for December) and low level wind fields (for any time of year) means if any discrete cells just ahead of the front can root into the boundary layer, means an isolated tornado or two can't be ruled out, and as the co-location of SPC's 10% tornado risk and 10% significant tornado risk implies just across the River, with such strong low level winds, any tornadoes that do form would likely be strong.
Note total totals, an indication of mid-level (850 to 500 mb) instability from both NAM and GFS near 55, an indication of very strong mid level instability and maybe hail.



GFS



NAM

[Ed Mahmoud]

Thunderstorm and mid 40sF is pozole weather.

[gboudx]

Norman NWS having some fun with the Cowboys from this morning's AFD.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
429 AM CST MON DEC 29 2008

.DISCUSSION...
TEMPERATURES ARE THE MAIN CHALLENGE OVER THE NEXT WEEK. AT TIMES
THEY LOOK GREAT AND AT OTHER TIMES THEY LOOK PRETTY BAD...
ESPECIALLY IN DECEMBER AND EARLY JANUARY (FORECAST TEMPS THAT
IS - NOT THE DALLAS COWBOYS.)
....

[iorange55]

Norman NWS having some fun with the Cowboys from this morning's AFD.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
429 AM CST MON DEC 29 2008

.DISCUSSION...
TEMPERATURES ARE THE MAIN CHALLENGE OVER THE NEXT WEEK. AT TIMES
THEY LOOK GREAT AND AT OTHER TIMES THEY LOOK PRETTY BAD...
ESPECIALLY IN DECEMBER AND EARLY JANUARY (FORECAST TEMPS THAT
IS - NOT THE DALLAS COWBOYS.)
....

Lol that is hilarious.

[cctxhurricanewatcher]

Norman NWS having some fun with the Cowboys from this morning's AFD.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
429 AM CST MON DEC 29 2008

.DISCUSSION...
TEMPERATURES ARE THE MAIN CHALLENGE OVER THE NEXT WEEK. AT TIMES
THEY LOOK GREAT AND AT OTHER TIMES THEY LOOK PRETTY BAD...
ESPECIALLY IN DECEMBER AND EARLY JANUARY (FORECAST TEMPS THAT
IS - NOT THE DALLAS COWBOYS.)
....

They better hope the Choklahoma Sooners come thru for them next week or the jokes will be flowing by the millions from down here.

[Ed Mahmoud]

Its winter, and the SPC has my house inside the 2% tornado w/i 25 miles circle.

Better severe threat morning and early afternoon tomorrow.





*edited by sg to make the image static

[vbhoutex]

Latest from Jeff for our area. We need the rain, but we don't need severe!

Atmosphere getting primed for a round of thunderstorms tonight and Saturday and then again Sunday into Tuesday.

Split flow upper air pattern developing with polar jet to the north and southern stream jet active from the central Pacific to TX. Potent short wave in the southern branch jet currently approaching Baja California will move across TX tonight and Saturday.

At the surface warm moist Gulf air mass has returned to the area with dewpoints in the low to mid 60's. Dense sea fog will continue to plague the coastal locations and inland bays as warm moist air flows atop the cold near shore waters.

Baja short wave spreads strong lift across the area starting late tonight. Expect numerous thunderstorms to develop SW of the area in the region bounded by Del Rio to San Antonio to Matagorda Bay in the 900pm to midnight timeframe and move NE across much of the area early Saturday. Parameters are in place for some strong storms and a few severe storms. Main threats will be wind damage and hail. Will need to keep an eye on this through the afternoon...if storms can root close to the surface a few could become very nasty. Shortwave should progress east of the area by early Saturday afternoon with strong southerly flow resulting in very warm reading especially our SW areas around Victoria and Matagorda Bay where lower 80's will be possible.

Strong cold front arrives Sunday afternoon as long wave trough over the western US phases with southern branch jet. Cold air advection will result in a rapid temp fall Sunday night. It is very cold over AK at the moment with surface temps in the -40 to -50 range...however most of this cold will be shunted eastward with TX getting a glancing blow Monday and Tuesday. Powerful trough ejects across the state Monday and Tuesday. While the 850mb to surface layer will be cold due to the shallow polar ridge in place....tremendous warm air advection above this cold pool will bring a strongly unstable air mass into the region. Surface coastal trough and isentropic upglide increasing above the cold pool will result in showers starting late Sunday night and into Monday.

As trough approaches late Monday expect strong lift to come to bear across unstable elevated warm sector resulting in widespread thunderstorm development. Severe weather will be possible..but limited to mainly hail. Another threat will be the increase chances for heavy rains.

It will be cold at the surface through the period from Sunday night through Tuesday as clouds and rain along with surface cold pool become entrenched. Surface temps. will remain well above freezing and temps. above the surface will be warming with ongoing waa from the south...so an easy all liquid forecast.

Long wave trough should pass east of the area by early Wednesday clearing skies with seasonal Jan. temps. Expect W to WNW flow aloft to maintain lows in the 40's and highs in the 60's into the upcoming weekend of the 10th and 11th.

[severe]

Not snow, but exciting weather nonetheless.
Thanks vbhoutex for the info.

[CaptinCrunch]

another day of almost record heat in NTX, man I sure do miss winter.

[gboudx]

another day of almost record heat in NTX, man I sure do miss winter.

And tomorrow promises to be even warmer.

[srainhoutx]

Midland/Odessa, San Angelo, and Dallas/Ft Worth are mentioning some concern regarding freezing precip tomorrow night into Monday morning. Models vary with the amount of moisture available in the overrunning event, but tomorrow through Monday will feel a lot different than todays near record warmth.

[Portastorm]

I posted something about this in the January thread ... but we're seeing some signs from the modeling that we might have an impressive front next weekend. Take a look at the Euro at 240 hr from the 12z run. Looks pretty cold:

http://www.ecmwf.int/products/forecasts/d/charts/medium/deterministic/msl_uv850_z500!Geopotential%20500%20hPa!240!North%20America!pop!od!oper!public_plots!2009010312!!/

[wxman22]

doesnt that suggest that most of the cold air would plummet straight down into the southern plains,instead of getting shunted of to the east?

[Ed Mahmoud]

New 0Z GFS has barely sub-freezing 2 meter temps on the Northwestern side of the Metroplex (sorry, not Dallas) with precip falling Monday morning, slight chance of an extended holiday break for school children of portions of the Metroplex.

[iorange55]

New 0Z GFS has barely sub-freezing 2 meter temps on the Northwestern side of the Metroplex (sorry, not Dallas) with precip falling Monday morning, slight chance of an extended holiday break for school children of portions of the Metroplex.

It's gonna be close, I kind of get the feeling it's going to be one of those times where they get the temps wrong by a couple degrees and it might be a little worse than they're thinking and worse than the models are showing. It just kind of feels like it, we'll see how it plays out.

[josephtwyman]

the latest shows a warm nose in metroplex and it will increase the moisture after midnite into monday morning, also we are about to go in the coldest part of the season and could be interesting in the next two weeks so please keep a look out!.