TX winter wx thread: Spring-like pattern

[cheezyWXguy]

Well once again the GFS is out to lunch again...this time on the 0z it looks like the front gets even less far than before, before sloly moving back north...I dont understand how such a strong shallow airmass could be halted so quick and shunted back north.

[vbhoutex]

Well once again the GFS is out to lunch again...this time on the 0z it looks like the front gets even less far than before, before sloly moving back north...I dont understand how such a strong shallow airmass could be halted so quick and shunted back north.

Remember the models, especially the GFS, don't do well with these very shallow very dense cold air masses. We're still several days out. Most indications are that it will make it off the coast by Wednesday, but will have some troulbe doing that initially.

[Extremeweatherguy]

For the Houston area in specific, here is a look at what the 00z GFS shows...

The 0z GFS continues to stall the front and meander it around TX through Wednesday. This may or may not turn out to be right, but either way, it does finally push the front offshore by Wednesday afternoon with cooler air filtering in behind. By Wednesday night we should be much cooler with lows into the 40s and then by Thursday night a secondary surge of chilly air will make things even cooler across the area. In fact, on Friday, the 0z run is showing a morning low in the 30s/40s followed by a high only in the 40s to near 50˚ and then a low near freezing by next Saturday morning. Brr.

BTW - - The 00z run then goes on to push a stronger front through the area the week of the 17th. This front, according to the run, would be capable of more than one freezing morning across SE Texas. Definitely something worth watching.

**This is a repost of one of my posts on another forum**

[Ed Mahmoud]

Well once again the GFS is out to lunch again...this time on the 0z it looks like the front gets even less far than before, before sloly moving back north...I dont understand how such a strong shallow airmass could be halted so quick and shunted back north.

Remember the models, especially the GFS, don't do well with these very shallow very dense cold air masses. We're still several days out. Most indications are that it will make it off the coast by Wednesday, but will have some troulbe doing that initially.

IIRC, the coarser grid scale resolution required of the GFS to get it to run as a global model past 15 days in a reasonable time period means, almost by definition, it has trouble with shallow cold air masses.

[southerngale]

I don't think the Lake Charles NWS sees it making it this far south. Christmas shopping in shorts and flip-flops... it just ain't right!

We might see some records broken. Shall we call this a heat wave?

And whatever does make it this far mid-week, isn't going to drop temperatures all that much... maybe closer to normal though.

---------------------------------------------------------------

Tonight: Patchy dense fog. Otherwise, mostly cloudy, with a low around 64. South wind around 5 mph.

Saturday: A 20 percent chance of showers and thunderstorms after noon. Areas of dense fog before 9am. Otherwise, mostly cloudy, with a high near 84. South wind between 5 and 15 mph, with gusts as high as 20 mph.

Saturday Night: Patchy fog after 9pm. Otherwise, mostly cloudy, with a low around 68. South wind around 10 mph.

Sunday: A 30 percent chance of showers and thunderstorms, mainly after noon. Areas of fog before 9am. Otherwise, mostly cloudy, with a high near 82. South wind between 10 and 15 mph, with gusts as high as 20 mph.

Sunday Night: A 20 percent chance of showers and thunderstorms. Patchy fog. Otherwise, mostly cloudy, with a low around 63. East wind around 5 mph.

Monday: A 20 percent chance of showers and thunderstorms. Areas of fog before 9am. Otherwise, mostly cloudy, with a high near 77. South wind between 5 and 10 mph.

Monday Night: A 20 percent chance of showers and thunderstorms. Patchy fog after midnight. Otherwise, mostly cloudy, with a low around 62. South wind around 10 mph.

Tuesday: A 20 percent chance of showers and thunderstorms. Patchy fog before 8am. Otherwise, mostly cloudy, with a high near 78. South wind between 10 and 15 mph, with gusts as high as 20 mph.

Tuesday Night: Scattered showers and thunderstorms. Mostly cloudy, with a low around 60. South wind between 5 and 10 mph. Chance of precipitation is 50%.

Wednesday: Scattered rain and thunderstorms. Mostly cloudy, with a high near 73. Chance of precipitation is 40%.

Wednesday Night: A 30 percent chance of rain. Mostly cloudy, with a low around 48.

Thursday: Mostly cloudy, with a high near 61.

Thursday Night: Mostly cloudy, with a low around 44.

Friday: Mostly cloudy, with a high near 63.

[jinftl]

If anything....the above normal temps look to be growing in value and coverage at the end of the 2-week forecast:

Compare Days 6-10 across Texas & S.E.


with Days 8-14 for same areas...

[vbhoutex]

That graphic makes sense to me. We are talking the cold being mid to late week this coming wekk and then a warm up would make sense. I just wish it wouldn't warm up llike it is now. Our low this morning in Houston is, depending on where you live in the area, from 65-69 which is higher than what our hign is supposed to be this time of year.

[gboudx]

DFW says the front is way ahead of schedule.

.PREV DISCUSSION... /ISSUED 435 AM CST SAT DEC 8 2007/

DISCUSSION...
TO SAY THAT THE COLD FRONT IS AHEAD OF SCHEDULE MIGHT BE AN UNDER-
STATEMENT...AS THE DENSE BUT VERY SHALLOW LAYER OF COLD AIR IS
ALREADY OOZING SOUTH INTO NORTH TEXAS. THE RUC/NAM FORECASTS ARE
FAR SUPERIOR IN HANDLING THE FRONTAL POSITION AND THE FORECAST
WILL CLOSELY FOLLOW THEIR OUTPUT. FRONT WILL MAKE FASTER PROGRESS
OVER THE WESTERN ZONES AS THE PUSH SOUTH WILL BE AUGMENTED BY COLD
AIR DAMMING AGAINST THE HIGHER TERRAIN OF WEST TEXAS. RUC/NAM
SUGGEST FRONT WILL REACH THE METROPLEX LATE THIS MORNING AND HOLD
STATIONARY FOR A WHILE THIS AFTERNOON BEFORE RESUMING ITS
SOUTHWARD PUSH TONIGHT. BELIEVE IT WILL REACH THE WACO AREA SUNDAY
MORNING AND FINALLY CLEAR THE CWA BY SUNDAY EVENING. OBVIOUSLY
TEMPERATURE FORECASTS FOR THE NEXT 36 HOURS ARE EXTREMELY
DIFFICULT WITH SHARP THERMAL GRADIENT ACROSS THE FRONT. BEHIND THE
FRONT...AS WARM/MOIST AIR OVER-RUNS THE SHALLOW COLD LAYER...
EXPECT AREAS OF FOG/DRIZZLE TO DEVELOP TODAY BUT THE BONA FIDE
CHANCES OF RAIN SHOULD HOLD OFF UNTIL TONIGHT.

LOW LEVEL --700 TO 850 MB-- WINDS INCREASE TO 25-35 KT TONIGHT
AND WILL TRANSPORT MIXING RATIOS OF 8-12 G/KG NORTHWARD OVER THE
COLD DOME. NAM SHOWS STRONG FRONTOGENETIC FORCING BELOW 850
MB...WHICH WILL HELP START THE LIFTING PROCESS OF PARCELS ABOVE
THE FRONTAL INVERSION WITH AMPLE ELEVATED INSTABILITY AVAILABLE
FOR CONVECTION. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP
ALONG AND BEHIND THE FRONT AFTER MIDNIGHT AND CONTINUE TO INCREASE
IN COVERAGE DURING THE DAY SUNDAY. RAINFALL WILL AVERAGE AN INCH
THROUGH SUNDAY NIGHT...AND SPC HAS EVEN INDICATED A LOW THREAT OF
SMALL HAIL.

THE ISENTROPIC LIFT AND FRONTOGENESIS WILL CONTINUE INTO MONDAY
WITH WIDESPREAD RAIN OCCURRING. ELEVATED INSTABILITY WILL DIMINISH
AND HAVE TRENDED TOWARD JUST ISOLATED THUNDERSTORMS. IT WILL
PRIMARILY BE A COLD RAIN OVER NORTH TEXAS MONDAY AND TUESDAY...BUT
SURFACE TEMPERATURES BELOW FREEZING ARE EXPECTED TO INVADE THE FAR
NORTHWESTERN PARTS OF THE CWA. THIS MAY RESULT IN SOME PERIODS OF
FREEZING RAIN...BUT WITH SUCH WARM AIR ALOFT...WE ARE NOT
ANTICIPATING A MAJOR ICE EVENT. SINCE THE COLD ADVECTION WILL BE
FAIRLY WEAK BY MONDAY AND TUESDAY...PERIODS OF MODERATE RAIN WOULD
LIKELY RAISE TEMPERATURES ABOVE FREEZING AS WARMER AIR/WATER ALOFT
IS BROUGHT TO THE SURFACE. AT THIS TIME A LIGHT GLAZE ON TREES AND
POWER LINES APPEARS TO BE THE PRIMARY IMPACT. THIS IS DEPENDENT ON
TEMPS ONLY REACHING THE LOW 30S FOR LOWS MONDAY AND TUESDAY. ALL
BETS ARE OFF IF TEMPS ARE COLDER...WHICH APPEARS UNLIKELY ATTM.

AGAIN...NOT MUCH FAITH IN THE GFS SOLUTION AS IT IS QUICK TO
ERODE/MODIFY THE LEADING EDGE OF THE FRONT. THE NAM FORECAST ONLY
GO OUT THROUGH TUESDAY AND THEREAFTER THE FORECAST CONFIDENCE IS
VERY LOW. BELIEVE THAT THE FRONT WILL WAVER AROUND IN EAST TEXAS
AND HAVE SHOWN SOME WARMING TUESDAY IN THE EASTERN ZONES AS UPPER
LEVEL LOW BEGINS TO APPROACH TEXAS FROM THE WEST. LOW LEVEL FLOW
WILL AGAIN INTENSIFY TUESDAY NIGHT AND WEDNESDAY AND THIS SHOULD
RESULT IN CONTINUED WIDESPREAD RAIN. SOME UPPER LEVEL COOLING WILL
OCCUR AS UPPER TROUGH SWINGS THROUGH WEDNESDAY...BUT CHOSE TO KEEP
TEMPS ABOVE FREEZING AND PRECIP LIQUID. RAIN CHANCES WILL END WED
NIGHT WITH MODERATING TEMPERATURES TOWARD THE END OF THE WEEK.

[Portastorm]

. . . and the Austin/San Antonio NWS forecasters are up to their usual tricks. They insist the front will remain STATIONERY!

"STARTING TOMORROW A FRONTAL SYSTEM WILL SET UP ALONG THE RED RIVER
AND STRETCH INTO WESTERN TEXAS. THIS WILL REMAIN MAINLY STATIONARY
FOR THE EARLY PART OF THE NEW WEEK."

[gboudx]

Yeah, I don't know about that Portastorm. The front is through most of the DFW NW counties and right on the doorstep of Denton. It's passed the Red River counties and supposed to move through the entire area later today. But the DFW folks are using the RUC/NAM for their forecast. Maybe the SA/Aus folks are using the GFS?

[jasons2k]

Almost all the WFOs and the models do prog the front to pull stationary for a period, maybe even retreat north a bit until a secondary surge at mid-week. So SAT is not completely "out to lunch", so to speak. It won't be stationary near the Red River though.

The question is - far south will it go before it pulls stationary?? Regardless, such airmasses end-up being highly modified before the bottom drops-out, so for SE Texas it won't be any big deal. We may not even get a freeze here which would suit me just fine

[Portastorm]

Gboudx -- nah, they didn't mention what modeling they were using in considering their forecast, so hard to say. I know we go through this every winter season but the folks in DFW always seem to be much better about adjusting to real-time developments and throwing modeling out the window when it's apparent that it's not helping. Others hold on to the models like a baby blanket.

Jason -- I think you hit the proverbial nail on the head. How far south will it go before it pulls up stationery! That's the $10,000 question. One thing is certain though ... there will be an amazing baroclinic zone on each side of that front. As it is right now at 8 am Saturday, I'm seeing a 50-degree temperature difference between the Panhandle and what we have here in south central Texas.

[Extremeweatherguy]

Yeah, the GFS is clearly having issues. It didn't have the front reaching it's current location until TOMORROW MORNING! So if this pattern of being 24 hours behind schedule continues, then I wouldn't doubt that this front makes it all the way to Houston and Austin before trying to stall.

[double D]

Lubbock's high of 65 looks very unlikely today as the front came in and dropped them down to 36.

[Ed Mahmoud]

Lubbock's high of 65 looks very unlikely today as the front came in and dropped them down to 36.

Looks like the WRF at 12Z predicts frontal passage in ABI around 6 pm tonight. Of course, temps are already in the 40s with North winds, so even the finer gridded model is having trouble.

[Extremeweatherguy]

Front just passed through Fort Worth. Their temperature fell from 69 to 62 and their dewpoint went from 65 to 55.

[Extremeweatherguy]

Interesting Houston NWS AFD (10:06am)...

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1006 AM CST SAT DEC 8 2007

.DISCUSSION...
INLAND FOG DISPERSED QUITE QUICKLY THIS MORNING AS 5 TO 10 KNOT
SOUTHEAST WINDS EFFICIENTLY SCOURED OUT THE LOWER LEVELS. SEA FOG
BECOMING LESS OF AN ISSUE ALONG THE IMMEDIATE COAST AND OVER GLS
BAY...EXPECTING THIS DECK TO SCATTER OUT...WITH MUCH IMPROVED
VISIBILITIES...BY 17Z PER LATEST SATELLITE TRENDS. AFTER A VERY
MILD AND HUMID START TO THE DAY WITH MORNING MINIMUM`S IN THE
UPPER 60S TO LOWER 70S...STILL EXPECTING AFTERNOON TEMPERATURES TO
FLIRT WITH MAXIMUM RECORDS (SEE BELOW) UNDER A MOSTLY CLOUDY SKY.

RAIN CHANCES WILL INCREASE FROM THE NORTHWEST TOMORROW MORNING AS
THE 12Z NAM COMING IN WITH THE NEXT FRONT MAKING IT TO THE COAST
BY EARLY MONDAY MORNING...MAYBE RETURNING AS A WARM FRONT GOING
INTO TUESDAY? CURRENT SFC ANALYSIS HAS THE FRONT / WIND SHIFT
NEARING THE DFW METROPLEX AT 16Z. (DISCLAIMER) OF COURSE...THE
NEXT 48 TEMPERATURE AND DENSE FOG FORECAST(S) ARE HIGHLY DEPENDENT
UPON THIS FRONT`S SOUTHERN PROGRESSION.

It now seems like there is a chance this could make it all the way to the coast by Monday. If that is the case, then we could be looking at some pretty wild temperature swings Monday and Tuesday as the front drifts around the area and then possibly returns north as a warm front before pushing offshore by Wednesday.

[richtrav]

Hey great news, I hear someone (you know who) over at accuweather has just issued a winter cancel for the southern plains starting in a week or so. Wouldn't it be GREAT if that ugly Thanksgiving drearyfest was the worst of the winter! Hehe, of course I don't believe it - this isn't Key West - but we can only dream. My luck it'll be a repeat of Jan '89 or '33.

[Portastorm]

Hey great news, I hear someone (you know who) over at accuweather has just issued a winter cancel for the southern plains starting in a week or so. Wouldn't it be GREAT if that ugly Thanksgiving drearyfest was the worst of the winter! Hehe, of course I don't believe it - this isn't Key West - but we can only dream. My luck it'll be a repeat of Jan '89 or '33.

Where did "you know who" say that? It's nowhere on his blogs. Was it on the Big Dog?

I'm not aware of "you know who" changing anything as he has said all along that the Southern Plains would experience a warmer- and drier-than normal winter with a few bouts of short-lived Arctic chill. And so far, that's what we have seen.

[southerngale]

We have a Christmas party to attend tomorrow afternoon. I guess with highs in the 80's, the Christmas sweaters we bought will have to stay in the closet. I think we'll go with a beach theme instead.