Texas winter weather thread - Cold snap next week

[Extremeweatherguy]

Well, the 12z GFS run is out now for the most part ... and it shows little continuity from previous runs, especially with regards to the weekend. I might also add that this particular run has little in common with the 0z run of the Euro. The former looks warm early week in Texas followed by a snowstorm later in the week. The Euro, however, shows a reinforcing cold blast on Monday but is a bit drier.

I'm going to throw out this GFS run as it doesn't match well with its previous runs or the Euro.

yeah that run does not look very "arctic" at all. It doesn't show a strong push down the plains, instead it starts to retreat the cold air to the north way to quick.

Also as EWG said earlier the GFS does not initialize the 1054 high pressure in Canada, instead it keeps it at 1044. I don't know if that is causing some of the problems or does it even matter?

The high today actually has weakened to 1048mb.

http://www.hpc.ncep.noaa.gov/sfc/satsfcnps.gif

[Extremeweatherguy]

The NAM is completely different than the GFS. Here the 18Z run which shows one hell of a powerful front in TX on Thursday:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _072.shtml

It is showing up to a 24C 850mb temperature drop behind the front!

[JenBayles]

Is it just me not paying enough attention, or has HGX gotten warmer yet again for this event?

Thursday: A 50 percent chance of showers and thunderstorms. Cloudy, with a high near 67.

Thursday Night: Mostly clear, with a low around 36.

Friday: Sunny, with a high near 53.

Friday Night: Clear, with a low around 30.

Saturday: Mostly sunny, with a high near 59.

Saturday Night: Mostly cloudy, with a low around 40.

Sunday: Cloudy, with a high near 59.

[Extremeweatherguy]

Though I still think this front will be very cold and exciting. I am beginning to wonder if next week might top it. If we are as stormy as the models and JB is thinking, then a cold, cloudy, windy period may be coming up with multiple threats of winter precip. Could get interesting..

[Extremeweatherguy]

Is it just me not paying enough attention, or has HGX gotten warmer yet again for this event?

Thursday: A 50 percent chance of showers and thunderstorms. Cloudy, with a high near 67.

Thursday Night: Mostly clear, with a low around 36.

Friday: Sunny, with a high near 53.

Friday Night: Clear, with a low around 30.

Saturday: Mostly sunny, with a high near 59.

Saturday Night: Mostly cloudy, with a low around 40.

Sunday: Cloudy, with a high near 59.

No, they havn't. In fact, that forecast is an almost exact copy of the morning (4am) forecast. I wonder if may be they havn't updated it yet? Those could still be the old numbers (especially since the latest AFD is not in yet).

[Extremeweatherguy]

What's the infamous JB saying today about this today?

Johnny (and others), I know you will be shocked by this revelation: JB is saying "winters worst" for southern Plains!

He is bullish on GFS-busting cold temps with potential for wintry precip for the northern half of Texas. He's also saying by mid December, we'll see normal to below to normal followed by a "wild rather than mild" last 10 days of December.

If he's right, then those of us in Texas are in for a very cold, potentially icy next 10-15 days with several possible storms.

I don't know ... like my Charlie Brown analogy ... I'm not so sure that Lucy is going to hold that football down for me. I'm not totally conviced yet.

I pray JB is right on this! I would really enjoy seeing a snowball be made in many parts of TX and to see one of the coldest starts to December in the southern plains in "many a year" (as he is saying on his site will happen). It would give a nice exciting twist to our recent weather pattern.

[cctxhurricanewatcher]

The only thing I hope does not happen with this early cold shot is not allowing enough time for the source regions to recharge for some cold stuff for Christmas. It was bad enough having temps in the 80's for Thanksgiving. If we have above average stuff for Christmas goin into New Year's, I'll scream. Last year's Christmas was warm if you all recall.

[JenBayles]

What you said!

[JenBayles]

So where is the leading edge of this cold air mass now, and how fast is it moving?

[Extremeweatherguy]

Latest NWS forecast is in now:

Thursday: A 50 percent chance of showers and thunderstorms. Cloudy, with a high near 73.

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

Friday: Sunny, with a high near 55.

Friday Night: Clear, with a low around 30.

Saturday: Mostly sunny, with a high near 59.

Saturday Night: Mostly cloudy, with a low around 40.

Sunday: Cloudy, with a high near 58.

And yes it has warmed some for the highs...cooled some for the lows (overall not huge changes though). I think the 55F forecast for Friday is still too warm though, but I guess we will see. I also think the weekend temps. are too high compared to the models.

Next week will likely be more interesting though if JB is correct...

BTW: The forecast for Austin this afternoon is ridiculous. They are calling for a high of 61F on Friday. I highly doubt this airmass is that weak to only be able to knock temps. down to slightly below normal levels.

[Extremeweatherguy]

It is interesting to note that Dallas has lowered their temps (now showing a high of 38F in the city of Thursday)...and Waco now has freezing rain the forecast:

Waco Forecast

Thursday: A 50 percent chance of rain. Cloudy, with a high near 53. Windy, with a northwest wind between 20 and 30 mph, with gusts as high as 40 mph.

Thursday Night: A slight chance of freezing rain. Partly cloudy, with a low around 27. Windy, with a north northwest wind between 15 and 25 mph, with gusts as high as 35 mph. Chance of precipitation is 10%.

Friday: Mostly sunny, with a high near 48. North northwest wind between 10 and 15 mph becoming calm. Winds could gust as high as 20 mph.

Friday Night: Mostly clear, with a low around 29.

Saturday: Partly cloudy, with a high near 54.

Saturday Night: Partly cloudy, with a low around 32.

Sunday: Partly cloudy, with a high near 52.

It is also interesting that the Dallas NWS is going with a faster front scenario.

[Portastorm]

(sigh)

You don't have to tell ME about the odd forecasts coming out of the Austin/San Antonio NWS forecast office! Their forecast of 61 degrees for a high on Friday is laughable.

Meanwhile, NWS Fort Worth is forecasting a high of "near 50" for Lampasas, which is about 25 miles northwest of Austin.

Gggrrrrr ....

[Extremeweatherguy]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
336 PM CST MON NOV 27 2006

.DISCUSSION...LIGHT RAIN SHOWERS CONTINUE TO MOVE ACROSS
EASTERN PORTIONS OF THE CWA THIS AFTERNOON. MSAS SURFACE ANALYSIS
INDICATED A WEAK LOW DEVELOPING ACROSS THE NORTHWEST GULF OF
MEXICO. LOW LEVEL JET THAT WAS DEVELOPING ACROSS WEST CENTRAL
TEXAS HAS SHIFTED INTO OKLAHOMA AND NORTH TX. LOW PRESSURE IS
EXPECTED TO DEVELOP ACROSS THE CENTRAL UNITED STATES TONIGHT AS A
SIGNIFICANT 500MB TROUGH CONTINUES TO MOVE INTO THE WESTERN UNITED
STATES. SCATTERED SHOWERS LIKELY TO CONTINUE TO DEVELOP ACROSS
SOUTHEAST TX TONIGHT INTO TUESDAY AS LOW TO MID LEVEL MOISTURE
CONTINUES TO ADVECT NORTHWARD FROM THE WESTERN GULF OF MEXICO
AND A WEAK SHORTWAVE TROUGH ACROSS WEST TX MOVES EAST TO NORTHEAST.
AS THE TROUGH OVER THE WESTERN U.S. WEDNESDAY MOVES EASTWARD
THURSDAY...THE POLAR/ARCTIC AIRMASS ACROSS WESTERN CANADA WILL
SURGE SOUTHWARD AS A STRONG COLD FRONT MOVES THROUGH SOUTHEAST TX
THURS AFTERNOON. SOME MODELS CONTINUE TO SLOW DOWN THE FRONTAL
PASSAGE BUT THURSDAY HIGHS WILL LIKELY BE EARLY WITH TEMPERATURES
FALLING IN THE AFTERNOON. ALSO...BEST CHANCE OF RAIN CONTINUES TO
BE ALONG AND AHEAD OF THE FRONT LATE WEDNESDAY/EARLY THURSDAY
ACROSS NORTHERN PORTIONS OF THE CWA AND THURS AFTERNOON ACROSS
SOUTHERN PORTIONS OF THE CWA. WILL KEEP A CHANCE OF SHOWERS AND
THUNDERSTORMS WED AFTERNOON EVEN THOUGH THE FRONT WILL BE THE MAIN
FOCUS FOR DEVELOPMENT. FREEZING TEMPERATURES POSSIBLE THURS NIGHT
ACROSS NORTHERN PORTIONS OF THE CWA WHERE COLD AIR ADVECTION AND
CLEARING SKIES ALLOW TEMPERATURES TO FALL LOW ENOUGH. BEST CHANCE
OF WIDESPREAD FREEZING TEMPS CONTINUES TO BE FRI NIGHT WITH CLEAR
SKIES AND CALM WINDS BUT IT APPEARS THE FREEZE WILL BE MOSTLY A
LIGHT ONE. MODELS HAVE BACKED OFF ON A COASTAL TROUGH DEVELOPING
OVER THE WESTERN GULF OF MEXICO OVER THE WEEKEND BUT WILL CONTINUE
RETURN OF CLOUD COVER SUNDAY INTO MONDAY WITH A SLIGHT CHANCE OF
RAIN MONDAY AS RETURN FLOW DEVELOPS TOWARDS THE END OF THE PERIOD.
32

Friday night's freeze a light one? I just do not know who to believe right now. Some mets are calling for mid 20s...some for a light freeze...some for no freezing temps...it is just amazing the amount of confusion that must be going on. Just a few days ago, the Houston NWS was even calling themselves for a "hard freeze" and now this.

I feel like I am in the twilight zone right now! There are too many forecasts floating around out there that I do not know which one to put faith in ATM.

[CaptinCrunch]

Here we GO Winter WX Fans

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
400 PM CST MON NOV 27 2006

.DISCUSSION...
COMPLEX FORECAST WITH A CLASH OF SEASONS OCCURRING OVER THE CWA ON
WEDNESDAY AND THURSDAY. FIRST FORECAST CHALLENGE IS THE CONVECTION
CHANCES AND POTENTIAL FOR SEVERE WEATHER WEDNESDAY AFTERNOON AND
EVENING. THE SECOND FORECAST CHALLENGE IS THE ARCTIC FRONT WHICH
SHOULD BLAST THROUGH ON WEDNESDAY NIGHT AND EARLY THURSDAY
MORNING...WITH FROZEN PRECIPITATION POSSIBLE ACROSS THE NW HALF
OF THE CWA THURSDAY.

FIRST THINGS FIRST. SHORTWAVE SEEN ON WATER VAPOR OVER NORTHERN
MEXICO WILL MOVE ACROSS THE CWA THIS EVENING. DYNAMIC LIFTING WILL
ALLOW LAPSE RATES TO BECOME STEEP ENOUGH FOR SOME ISOLATED
THUNDERSTORMS...AS CONVECTION CONTINUES TO STREAM NORTH WITH THE
LOW LEVEL JET. BEST CHANCES OF RAIN WILL BE OVER THE EASTERN
ZONES...WHERE MOISTURE WILL BE HIGHEST AND LIKELY POPS ARE
FEATURED. THE SHORTWAVE WILL BYPASS THE REGION BY MORNING AND
WESTERLY COMPONENT TO THE LOW LEVEL FLOW SHOULD PUSH THE CHANCES
OF RAIN TO THE EAST OF THE AREA. GENERALLY MOS LOOKS GOOD THROUGH
WEDNESDAY FOR TEMPS AND POPS WITH JUST SOME MINOR CHANGES MADE.

BY WEDNESDAY AFTERNOON AND EVENING...POWERFUL UPPER LEVEL LOW
WHICH IS NOW LOCATED OVER THE PACIFIC NW...WILL BE SWINGING
THROUGH THE 4-CORNERS REGION AND WILL BE THE PRIMARY CULPRIT FOR
THE WILD MID TO LATE WEEK WEATHER. AS SYNOPTIC FORCING OVER-
SPREADS THE AREA WEDNESDAY EVENING...MODEL SOUNDINGS SHOW THE
AIRMASS WILL BECOME INCREASINGLY FAVORABLE FOR ROTATING/SEVERE
STORMS. IT IS UNCLEAR IF THERE WILL BE ANY SURFACE FOCUS FOR
STORMS LATE WEDNESDAY AHEAD OF THE FRONT...BUT GFS IS MOST
AGGRESSIVE WITH THE POPS IN THIS TIME FRAME.

COLD FRONT IS PROGGED BY THE MODELS TO RAPIDLY MOVE THROUGH
THURSDAY MORNING...BUT GIVEN THE ARCTIC NATURE OF THE AIRMASS AND
THE USUAL NUMERICAL MODEL BIAS OF BEING TOO SLOW WITH THESE
EVENTS...WE WILL BUMP THE TIMING UP 6-12 HOURS. WE EXPECT THE
FRONT TO BE BISECTING THE CWA AROUND SUNRISE THURSDAY
MORNING...WITH A 25-30 DEGREE DROP IN TEMPERATURES IN THE FIRST
HOUR BEHIND THE FRONT. THIS MEANS HIGH TEMPS THURSDAY WILL BE
EARLY...WITH TEMPERATURES FALLING INTO THE UPPER 20S AND LOWER 30S
JUST ABOUT AREAWIDE THURSDAY AFTERNOON. THE FORECAST CONFIDENCE
IN SURFACE TEMPS IS FAIRLY HIGH AT THIS POINT...WITH THE MAIN
UNCERTAINTY BEING THE TIMING/EXTENT OF POST FRONTAL PRECIPITATION.

AT THIS TIME...WE ARE STILL 72 HOURS OR SO OUT FROM THIS POSSIBLE
WINTER EVENT. IT IS UNREASONABLE TO EXPECT THE COMPUTER MODELS TO
BE ABLE TO PINPOINT EXACTLY THE TYPE/AMOUNT OF WINTER
PRECIPITATION BECAUSE OF A LACK OF PRECISE AGREEMENT WITH RESPECT
TO THE TIMING/POSITION/STRENGTH OF THE AFOREMENTIONED UPPER LEVEL
LOW. THE MODELS SUGGEST THAT THE MAIN TRACK OF THE LOW WILL BE
ACROSS OKLAHOMA...AND AS LONG AS THIS PANS OUT THE MAIN THREAT OF
SIGNIFICANT SNOW WILL BE TO THE NORTH OF THE CWA. HOWEVER...THE
ARCTIC AIRMASS IS EXPECTED TO LOWER TEMPERATURES BELOW FREEZING
BEFORE THE STRATIFORM POST FRONTAL RAIN ENDS. AT THE LEAST...WE
EXPECT SOME BRIEF/LIGHT FREEZING RAIN OVER THE NW HALF OF THE CWA
BY THURSDAY AFTERNOON. ALONG THE RED RIVER...WHERE THE WARM NOSE
ALOFT WILL BE MUCH WEAKER...A MIX OF SLEET/SNOW/FREEZING RAIN IS
POSSIBLE. ALL OF THE PRECIPITATION SHOULD CLEAR OUT OF THE AREA
THURSDAY EVENING AS COLD LAYER DEEPENS AND DRIES SUBSTANTIALLY.

THE PRECIP TYPE FORECAST IS BASED PRIMARILY ON THE GFS...WHICH
OFFERED A GOOD BLEND OF ALL THE MODELS WITH RESPECT TO THE UPPER
LOW. IF THE VERIFYING SOLUTION LOOKS LIKE THE CANADIAN/ECMWF UPPER
PATTERN...THE AMOUNT/TYPE OF WINTER PRECIP WOULD BE MUCH MORE
SIGNIFICANT THAN FORECAST AT THIS TIME. OBVIOUSLY...THIS SITUATION
BEARS WATCH AND FURTHER REVISION TO THIS FORECAST ARE THE ONLY
GUARANTEE AT THIS POINT.

BRIEFLY...IN THE EXTENDED...COLD AIR REMAINS IN PLACE ACROSS MUCH
OF THE COUNTRY WITH ANOTHER POLAR HIGH MOVING INTO THE REGION
SUNDAY. WINTER IS HERE IT SEEMS.

[Portastorm]

Captin, thanks for posting that ... you just beat me. I encourage EVERYONE in Texas on this board to read the forecast discussion from Fort Worth. It is an excellent discussion that lays out all parameters. They also pick up on next week's cold which the Euro and the 0z and 6z GFS show clearly. The 12z run backed off on that and it looks like many of the NWS Texas forecasters took that run hook, line, and sinker.

Geez ... the NWS Fort Worth guys are putting everyone else to shame IMHO.

[Extremeweatherguy]

If the Houston NWS is correct about 70-73F Thursday morning and the front really does end up as strong as Dallas shows (a 25-30F temp. drop the hour behind it), then that means Houston could go from a mild 70F morning down to a very cold 40F (and wet) afternoon. If Houston is going to get some winter precip. out of this...my bet is on Thursday late afternoon and evening when are temps. could be in the 30s with rain.

BTW: I like the Dallas discussions a lot. They are much more detailed than ours in Houston and are usually more accurate. I think they probably have the best handle on the situation right now.

[Extremeweatherguy]

Captin, thanks for posting that ... you just beat me. I encourage EVERYONE in Texas on this board to read the forecast discussion from Fort Worth. It is an excellent discussion that lays out all parameters. They also pick up on next week's cold which the Euro and the 0z and 6z GFS show clearly. The 12z run backed off on that and it looks like many of the NWS Texas forecasters took that run hook, line, and sinker.

Geez ... the NWS Fort Worth guys are putting everyone else to shame IMHO.

I agree. It almost makes me wish I lived in Dallas so I could enjoy better forecast reliability.

[Extremeweatherguy]

the 18Z GFS STILL shows winter precip. reaching Houston Friday morning. I am really amazed this trend has yet to be mentioned by the Houston NWS (or the Austin NWS).

This whole situation just makes me really upset with our local NWS office. It seems like all they are doing is going with the warmest scenarios, not taking any risks, and just hoping they are right. Hopefully by Thursday morning they will have it all sorted out.

[gboudx]

THE PRECIP TYPE FORECAST IS BASED PRIMARILY ON THE GFS...WHICH
OFFERED A GOOD BLEND OF ALL THE MODELS WITH RESPECT TO THE UPPER
LOW. IF THE VERIFYING SOLUTION LOOKS LIKE THE CANADIAN/ECMWF UPPER
PATTERN...THE AMOUNT/TYPE OF WINTER PRECIP WOULD BE MUCH MORE
SIGNIFICANT THAN FORECAST AT THIS TIME.

So, what does the verifying solution for the Canadian/ECMWF look like that they give this mention? Sounds like a stronger possibility of wintry precip.

[jasons2k]

Who knows. It's still too far away to know what will happen. For now though, this is music to my ears:

BEST CHANCE OF WIDESPREAD FREEZING TEMPS CONTINUES TO BE FRI NIGHT WITH CLEAR SKIES AND CALM WINDS BUT IT APPEARS THE FREEZE WILL BE MOSTLY A LIGHT ONE.