Texas winter wx thread (2009-2010)

[Big O]

what gfs run was that you posted that shows that it wasnt the one from last night was it.

No. 12Z today (12/21).

[iorange55]

To be fair there is a chance that places like Wichita Falls, tx and around the red river there could be some snow, it's not impossible and will probably happen. But saying that I don't see anywhere near 6-10 inches or even 2-4 inches really. Wichita Falls maybe an inch, or so. Red River maybe a dusting, or just flurries. It's possible for the red river and Wichita Falls area to get some, just not to that extreme, or even close. I don't believe abilene, and places that south in West Texas we'll see any, but further to the north possibly.

[Texas MidCoaster]

Now that snow is out of the picture for us in the Houston area, what types of temperatures can we expect next week? Accuweather has taken them a bit lower but nothing indicating a hard freeze.

[cctxhurricanewatcher]

Just from reading the AFD's from this afternoon, the NWS offices from accross the state are still having issues with the upcoming forecast after Wednesday. Take this snippet from the Corpus NWS AFD.

MEDIUM RANGE MODELS AGREE THE INITIAL DEEP UPPER LOW WILL LIFT OUR
BUT BE IMMEDIATELY REINFORCED BY A S/WV DROPPING DOWN THE EAST SIDE
OF AN UPR RIDGE ACROSS THE PAC NW. THIS RIDGE EXTENDS ALL THE WAY UP
INTO ALASKA AND WILL PROVIDE SEVERAL DAYS OF A HIGHLY AMPLIFIED UPR
PATTERN W/ AS THE DEEP TROUGH PERSISTS OVER THE CEN PLAINS. THIS
WILL ALLOW SOME OF A VERY COLD AIRMASS NOW ACROSS NWRN CANADA / SERN
ALASKA TO SPILL SOUTH INTO THE PLAINS AND THE BIG QUESTION IS HOW
MUCH COLD AIR WILL MAKE IT THIS FAR SOUTH. LAST FEW MODEL RUNS ARE
SHOWING MORE SWRLY FLOW ALOFT W/ A SUBTROPICAL JET JUST NORTH OF THE
REGION. BECAUSE OF THIS THEY ARE BOTTLING UP THE COLD AIR FURTHER
NORTH AND MOS LOW TEMPS HAVE BEEN INCREASING. THAT BEING
SAID...THERE IS PLENTY OF NRLY FETCH ACROSS THE ROCKIES THAT A
SHALLOW COLD AIRMASS NOT HANDLED WELL BY THE MODELS COULD BLEED INTO
THE REGION AND UNCERTAINTY IS VERY HIGH. ALSO...THE SWRLY FLOW ALOFT
IS LEADING TO A BETTER PATTERN FOR CLOUDS AND POSSIBLY SOME LIGHT
RAIN AND HAVE INCREASED POPS SLIGHTLY FOR FRI NIGHT THROUGH SAT
NIGHT TIME FRAME. WILL DEFER CLOSE TO ENSEMBLE MEAN MOS FOR LOW
TEMPS AD ENSEMBLE LOW MEMBERS FOR HIGHS GIVEN THE UNCERTAINTY
FOR...BUT EXPECT MORE ADJUSTMENTS OVER THE NEXT FEW DAYS AS MODELS
GET A BETTER HANDLE ON THE SITUATION.

NWS San Antonio/Austin says this which probably has Portastorm rolling his eyes.

THE EXTENDED FORECAST FOR THE REST OF THE HOLIDAY WEEKEND LOOKS
TO BE MILD WITH HIGHS IN THE 50S WARMING TO NEAR 60 BY MONDAY.
MORNING LOWS WILL GENERALLY BE WITHIN A FEW DEGREES OF EITHER SIDE
OF FREEZING. HOWEVER...GIVEN THE AFOREMENTIONED UNCERTAINTY OF THE
STRENGTH AND ALIGNMENT OF THE COLDER AIRMASS...CONFIDENCE IS
SOMEWHAT LOW ATTM.

I am going to take a guess both offices will be making changes to the downside probably when the event is right on our doorstep.

[gofrogs]

I wonder what the 18z gfs said.

[msstateguy83]

the gfs just pulled one of its long rangers putting a LOT, i mean hellva alot of snow
across ok/tx by around the 5th of jan.. but as we have said before the gfs in longrange=garbage forecasting system lol so i take that serriously with a grain of salt until we get closer...

[gofrogs]

But i also liked the 31st threw the 2nd as realistic possiblities for the fort worth area.

[amawea]

I'm beginning to think the long range aspects of the gfs is based more on climo than where things are right now and where it thinks they will be on a given date. You know things like average temps, precipitation, time of year etc. It just seems to repeat itself 10 days or more out based on the time of year it is and the area concerned. I'm going to start calling it the guessing model!

[lrak]

Pros and Amateurs alike are watching too many of the Sunday morning talk shows....

The models are almost like the political poles "Flip Flop"

"Did we win?" "WAIT...I see a hanging chad, hold the forecast!" I know but heh got have a sense of humor!

I've been telling all my clients to prepare for really cold weather during the holidays...."Do you think it will snow" they asked, I said its possible! "WOW" was their response Now thats how you forecast!

[msstateguy83]

i think as everyone has pointed out even the noaa long range forecast had jan getting
better for the below norm temps, above normal precip... so i think as we head out of christmas towards the new year and just after the first even i would expect mulitple rounds of winter storm systems to head our way.. could be an interesting time coming up but iam not gonna go totally off the gfs becouse yeah basically its been repeating it self in the 240 hr + time frame for awhile now and you just cant buy into something like that.

[Ntxw]

I'm really confused, the chances for snow/ice keep coming and going for different time frames. And of course the closer we get to it nothing happens (or it's too far north, south (eats your heart out), east, and\or west ). I hope things do pick up.

[iorange55]

I'm really confused, the chances for snow/ice keep coming and going for different time frames. And of course the closer we get to it nothing happens (or it's too far north, south, east, and\or west ). I hope things do pick up.

It happens a lot I learned it last year don't get excited for a storm thats over 8 days out. 4-7 days you can get a little excited but still cautious, and if gets below the 4 day period then you can get excited.

[rainman31]

I thought the GFS nailed the latest snow storm in Houston several days out.

[Ntxw]

Well so far the 0z gfs puts the low still north. Even Oklahoma doesn't look to get too much wintry stuff (except maybe in the far northern sections).

[serenata09]

FWIW, Accuweather mentions snow a few times for Dallas in the long range New Years Eve and on. Still fun to look at...:-\

http://www.accuweather.com/us/tx/dallas ... 1&metric=0

[Ntxw]

That's way out in lalaland but yeah fun to look at

[rainman31]

That link for accuweather in dallas has the temp for Thursday at 57 that seems high to me. Has something changed to push the cold air back a few days?

[Portastorm]

Well so far the 0z gfs puts the low still north. Even Oklahoma doesn't look to get too much wintry stuff (except maybe in the far northern sections).

Right you are Ntxw! Both the 0z GFS and Euro show the low moving further north than before. The area of Oklahoma previously thought to get some snow would be essentially dry slotted.

[Portastorm]

As its looking right now and based on the GFS, Euro, and CMC ... the only part of Texas who might see snow for Christmas would be the upper half of the Panhandle. A few flakes might even fall as east as Vernon but that would be it.

For the rest of us, it'll be cold and breezy on Christmas Eve and Christmas with high temps about 10-15 degrees below normal. The 0z CMC still suggests a slight possibility of precip encroaching on southern Texas over the weekend but it remains the outlier.

The longer-range Euro from the 0z run is interesting in that it shows an active Southern jet cranking up. Really for the last two weeks or so the southern jet has not been much of a factor in our weather. That appears about to change. Now if we could only combine that with a cold-enough airmass (Portastorm lapses into dreaming).

[srainhoutx]

Yep Portastorm, guidance does suggest dry slotting will occur. Just a word of caution though. The HPC does not seem to have a lot of confidence right now as to how things will unfold. Remember I stated that we may not know until we are 24-36 hours out if then, concerning what may in fact happen regarding the forecast. I am certainly not try to give anyone false hopes, but the we must remember that guidance does not always "play out" with what will actually happen. I will say this. It will be chilly behind the storm. The air mass is not extremely deep, but CAA over an area that gets snow to our N in blizzard conditions will feel mighty cold. A quick look at longer range does suggest a very active STJ with multiple storms riding further S than we have seen lately. The Arctic Region is suggested by Long Range CPC Ensembles to reload as we move into the January time frame. Also remember that I have suggested that the pattern would "wash, rinse and repeat" about every 20 days or so. The -AO continues as well as a -NOA and more Tropical forcing is suggested as well as another Greenland Blocking event. We must keep in mind that January and February is actually the "best months" to see snow across TX. So all "hope" is not lost as this pattern we are seeing has very few analogs to "compare" with. Meanwhile, the morning Winter Storm Update from the HPC...

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
442 AM EST TUE DEC 22 2009

VALID 12Z TUE DEC 22 2009 - 12Z FRI DEC 25 2009

...WEST INTO NRN/CENTRAL PLAINS AND UPPER MS VLY...
ITS BECOMING MORE AND MORE APPARENT THAT A BLOCKBUSTER WINTER
STORM IS GOING TO IMPACT A LARGE MAJORITY OF THE UPPER MIDWEST ON
WED... THURS AND INTO FRI MORNING.

BEFORE THEN... HVY SNOW IS EXPECTED ACROSS A GOOD PORTION OF THE
WEST... AS A DYNAMIC CLOSED LOW/SHORT WAVE TROUGH DIGS FROM THE NW
TO THE FOUR CORNERS REGION AND AN ARCTIC SHORT WAVE DIGS FROM WRN
CANADA INTO THE NRN ROCKIES. THE TREMENDOUS SWRLY DIFLUENT FLOW
AHEAD OF EACH TROUGH AND IMPRESSIVE THERMAL ZONE SWEEPING THROUGH
THE WEST SHOULD BE IDEAL FOR ENHANCED VERTICAL LIFT AND IMPRESSIVE
OROGRAPHIC FLOW INTO THE WASATCH/SAN JUAN MTNS/CO ROCKIES AND
MOGOLLON RIM FOR HVY SNOWFALL.

THE SRN STREAM FEATURE WILL THEN EJECT OUT OF THE FOUR CORNERS
REGION INTO THE CENTRAL PLAINS... GRADUALLY BEGIN TO PHASE WITH
THE NRN STREAM... INDUCE AN AREA OF LOW PRESSURE OVER THE SRN
PLAINS AND TAP INTO A PLETHORA OF AVAILABLE LL MOISTURE FROM THE
GULF OF MEXICO. NOW EVEN THOUGH THIS SOUNDS REALLY CERTAIN... THE
MODEL GUIDANCE STILL INDICATES ENOUGH SPREAD AND UNCERTAINTY...
ESPECIALLY IN THE DETAILS... THAT KEEPS THIS FCST VERY FLUID. IN
FACT... TWO OF THE CRITICAL ITEMS WILL BE HOW MUCH WARM SECTOR
CONVECTION PROHIBITS THE DEEP LL MOISTURE TO FLOURISH IN THE COLD
SECTOR AND HOW DENSE THE COLD AIR MASS IS ACROSS THE UPPER
MIDWEST. RIGHT NOW... THE GUIDANCE MIGHT NOT BE REACTING VERY WELL
TO EITHER. HPC FOLLOWED A BLEND OF THE 00Z GFS AND 12Z/21 ECMWF
FOR CRITICAL QPF AND THERMAL PROFILES BOTH DAYS.

SO ON WED... AN ACTIVE LL JET WILL FUNNEL NORTH 1.25 INCH PWS
NORTH AND SOME OF THIS MOISTURE WILL BEGIN TO OVERRUN INTO THE
COLD SECTOR. A VORT LOBE LIFTING NORTH AND LEFT EXIT REGION OF A
100 KT 250 MB JET SHOULD PRODUCE A BAND OF HVY SNOWFALL FROM
CENTRAL NE NEWRD INTO SERN SD... WHILE AN INVERTED TROUGH AXIS AND
BROAD LARGE SCALE LIFT/UPSLOPE COMPONENT PRODUCES WIDESPREAD LIGHT
TO MDT SNOWFALL FROM THE DAKOTAS BACK INTO ERN MT/WY. MEANWHILE TO
THE EAST... A COMBINATION OF SNOW AND ICING IS LIKELY AS
TREMENDOUS MID-LEVEL WARMING OVERRUNS A VERY SHALLOW AIR MASS.
THIS AXIS APPEARS LIKELY TO SET UP FROM ERN NE/SRN MN EAST TO SRN
WI/MUCH OF IA INTO NRN IL.

THEN ON THURS... THE SURFACE CYCLOGENESIS WILL TAKE OVER WITH THE
SYSTEM... AS THE LOW LIFTS FROM NERN OK/NWRN AR INTO SWRN IA.
TREMENDOUS DYNAMIC COOLING AND A VERY HEALTHY DEFORMATION ZONE
SHOULD ALLOW BANDING HVY SNOW TO DEVELOP FROM ERN KS NORTH THROUGH
ERN NE INTO SERN SD/NWRN IA AND SOUTH CENTRAL MN... WHILE LARGE
SCALE LIFT AND INVERTED TROUGH AXIS SHOULD PRODUCE MDT TO HVY
SNOWFALL ACROSS THE REST OF THE DAKOTAS. TO THE EAST ONCE AGAIN...
ICING COULD BE AN ISSUE FROM ERN IA INTO SRN WI/NRN IL AND PARTS
OF LWR MI.

NEEDLESS TO SAY... IF THIS ALL PANS OUT AND LARGE SCALE BLIZZARD
WILL IMPACT THE REGION.


...NRN NEW ENGLAND...
A STRONG UPPER CLOSED LOW WILL SLOWLY SLIDE ACROSS NEW ENGLAND
OVER THE NEXT TWO DAYS AND TEAM WITH A DEVELOPING THERMAL ZONE TO
PRODUCE HVY SNOWFALL. THE MODEL GUIDANCE IS IN REALLY GOOD
AGREEMENT AND DEFINITELY TRENDING TOWARD A RATHER SIGNIFICANT
EVENT ACROSS MUCH OF ME. THE COMBINATION OF THE CLOSED LOW...
THERMAL ZONE AND INFLUX OF ATLANTIC MOISTURE ARRIVING FROM THE
NORTH AND EAST SHOULD YIELD ENHANCED VERTICAL LIFT... FRONTOGENTIC
FORCING AND A LARGE MOISTURE CONTENT FOR SUBSTANTIAL SNOWFALL WITH
UP TO 10 TO 12 INCHES ON TUES INTO WED MORNING AND ANOTHER SOLID
HALF FOOT ON WED INTO THURS MORNING ACROSS ME... AS A INVERTED
TROUGH AXIS DEVELOPS. HPC GENERALLY FOLLOWED A BLEND OF THE GFS
AND ECMWF ON THE HANDLING OF THIS FEATURE AND FOR THE HVY SNOWFALL
PROBS.


MUSHER

See what I mean RE Low Confidence.