Texas Winter 2012-2013

[HockeyTx82]

So have the trends gone colder and more chance of snow for Christmas now? Just yesterday it seemed like the hope was gone.

[wxman57]

So have the trends gone colder and more chance of snow for Christmas now? Just yesterday it seemed like the hope was gone.

For now, it's just one run of the European model showing significant snow in central Oklahoma south to the Red River area. Canadian shows a weaker impulse passing on Christmas Day. GFS has the system passing farther north with snow in northern OK and KS (more in Kansas).

[amawea]

Oh, no! Even Wxman is teasing people with maps now. I'll be spending Christmas and the day after with some family who live just outside of Decatur. Let's keep the trend going!

Model watch Christmas 2012 has officially started.

Maybe it's his Christmas gift to us snow lovers!!!

[wxman57]

Oh, no! Even Wxman is teasing people with maps now. I'll be spending Christmas and the day after with some family who live just outside of Decatur. Let's keep the trend going!

Model watch Christmas 2012 has officially started.

Maybe it's his Christmas gift to us snow lovers!!!

Christmas is an appropriate day for cold and snow. I can tolerate the cold (and possible snow) for a couple of days each winter. That's all, though.

[Ntxw]

The southern plains is going to go on a wild ride the rest of December. Don't get over juiced on one run of models (but do post them!) And don't feel overly depressed if it shows opposite. This is no 2011-2012, this is a great pattern even if it doesn't seem like it right now!

-EPO/-AO and Subtropical Jet (think SOI) WILL DELIVER

[TeamPlayersBlue]

Wow, what a run! Where's the STJ for us SE Texans in that run? Its often that the models dont pick up on that though. Lets hope a trend starts. Fingers crossed.

[Portastorm]

The 12z GFS run just finishing now is something to behold. I count not one but two winter weather threats for portions of west/north/central Texas in the run between Christmas Eve and New Years. Heh, late in the run it brings a 1057mb high into Montana.

http://raleighwx.americanwx.com/models/12zgfs.html

[iorange55]

Wow, Porta! That 12z GFS almost brings a tear to my eye. Apparently, Santa has finally received my long Christmas list that just read, "Snow!!!!!!!!!!!!!!!!!!!!!!!!!" over and over again.

It's still only just a few model runs, though. Must contain excitement.

[Ntxw]

A little lengthy, but sums it up well.

****
EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
1050 AM EST MON DEC 17 2012

VALID 12Z THU DEC 20 2012 - 12Z MON DEC 24 2012

HIGH LATITUDE BLOCKING OVER NORTHEASTERN CANADA WILL COMBINE WITH
REINFORCED RIDGING SOUTH OF THE ALEUTIANS TO KEEP AN ACTIVE
SOUTHERN STREAM THROUGH THE CONUS OVER THE NEXT WEEK. THESE
NORTHERN POSITIVE HEIGHT ANOMALIES CORRELATE WELL WITH EACH OTHER
THROUGH TELECONNECTIONS AND BOTH ACT TO SUPPORT ROBUST SYSTEMS.
THE SYNOPTIC DIFFERENCES AMONG THE GUIDANCE ARE RELATIVELY
SMALL... BUT THE DETAILS WILL BE IMPORTANT DOWN THE ROAD. IN
ADDITION... CONTINUITY REMAINS GOOD WITH FEW CHANGES FROM RECENT
HPC FORECASTS.

FOR THE FIRST PART OF THE FORECAST... THU-SAT/D3-5... THE
NORTHWEST AND NORTHEAST PORTION OF THE CONUS WILL BE THE MOST
ACTIVE. IN THE NORTHEAST PACIFIC... A DEVELOPING OMEGA BLOCK OVER
ALASKA WILL DROP AN UPPER LOW OUT OF THE GULF WHICH WILL PAUSE FOR
A FEW DAYS OFF THE PAC NW. THE CONTINUED ONSHORE FLOW WILL WRING
OUT SEVERAL INCHES OF PRECIPITATION ALONG THE COAST AND INTO THE
TERRAIN... INCLUDING UP TO SEVERAL FEET OF SNOW. DOWNSTREAM OVER
THE EAST... A DEEPENING CYCLONE WILL MOVE OUT OF THE MID-MS VALLEY
INTO THE GREAT LAKES AND THEN INTO NORTHERN NEW ENGLAND AS IT
SLOWS ITS EXIT AMID AMPLIFYING FLOW. THIS SHOULD SPREAD
INCREASINGLY HEAVY PRECIP... WITH SNOW ON THE NW SIDE... THROUGH
THE CENTRAL AND NORTHEASTERN STATES ESPECIALLY ON THURSDAY INTO
FRIDAY. THE GFS REMAINS A BIT QUICKER THAN THE GEFS MEAN WITH THE
PROGRESSION OF THIS SYSTEM... AND EACH ARE JUST AHEAD OF THE
ECMWF/ECENS MEAN. GIVEN THE GOOD CONTINUITY OF THE ECMWF AND A
SLOWER TREND IN THE GFS... BASED THE FIRST PART OF THE FORECAST ON
THE 00Z ECMWF.

BY SUN-MON/D6-7... THE 00Z ECMWF BECOMES QUITE SLOW TO EXIT THE
SYSTEM IN THE NORTHEAST COMPARED TO THE OTHER ECMWF/GEFS ENSEMBLE
MEMBERS AS A RESULT OF A VERY BLOCKY FORECAST BOTH OVER NORTHEAST
CANADA AND OVER THE CENTRAL CONUS. THE GFS REMAINS FLATTER WITH
THE FLOW FROM THE NORTHEAST PACIFIC INTO THE WEST COAST WHILE THE
ECMWF AND CANADIAN MAINTAIN A DEEPER UPPER LOW. THE GEFS AND ECMWF
ENSEMBLE MEANS FALL IN BETWEEN WITH THE FORMER A BIT FLATTER THAN
THE LATTER. GIVEN THE TENDENCY FOR THE GFS/GEFS TO UNDERAMPLIFY
THE FLOW... OPTED TO GRAVITATE TOWARD THE 00Z ECMWF ENSEMBLE MEAN
AS A HEDGED INTERMEDIATE POINT. THIS WILL SET UP A SYSTEM JUST
EAST OF THE SOUTHERN ROCKIES BY EARLY NEXT WEEK. THE PRECIPITATION
OVER THE WEST MAY NOT LET UP MUCH UNTIL THE VERY END OF THE MEDIUM
RANGE ONCE THE UPPER TROUGH MOVES INLAND.

[Ntxw]

Christmas Day on the latest Euro. Plenty of time to fine tune.

[iorange55]

Yup, the latest Euro is still looking good. Will it be one of these storm systems that arrive earlier than expected, perhaps setting up a Christmas Eve/Christmas miracle? Or could it be pushed back? Or might it not even happen at all?

Everything will be answered soon enough. It just feels nice to be model watching again; it feels like it's been so long.

[GRAYSONCO.WX]

Is there an accumulation map for the 12Z ECMWF?
Thanks

[gboudx]

We drive back from NOLA on 12/26, so looks like we could be driving either during bad weather, after the bad weather already passed, or trying to beat the bad weather before it starts. Is any of this looking like wintry precip from about I-20 north?

[Ntxw]

We drive back from NOLA on 12/26, so looks like we could be driving either during bad weather, after the bad weather already passed, or trying to beat the bad weather before it starts. Is any of this looking like wintry precip from about I-20 north?

It potentially could be. The euro is showing a deepening system crossing I-20 into Arkansas. Systems like this (verbatim) generally develops a backlash snow/ice event. Not that dissimilar from 09, it's also cold in the wake of it, so the travel back could be problematic. Again very far out, but I would prepare for it anyway!

[ThunderSleetDreams]

That's a hell of a ice storm even for Houston on the 27th... 1/4 to 1/2 inch of ice...

[gboudx]

It potentially could be. The euro is showing a deepening system crossing I-20 into Arkansas. Systems like this (verbatim) generally develops a backlash snow/ice event. Not that dissimilar from 09, it's also cold in the wake of it, so the travel back could be problematic. Again very far out, but I would prepare for it anyway!

Thanks for the info. I'm always here so I look forward to the updates. I can't keep up with reading the models anymore, like I used to, but you guys do a great job.

From DFW NWS regarding this:

A STRONG SYSTEM...CURRENTLY LOCATED EAST OF THE KAMCHATKA
PENINSULA...IS PROGGED TO MOVE FIRST INTO THE GULF OF ALASKA AND
THEN INTO THE PACIFIC NORTHWEST SUNDAY MORNING. THE GFS AND ECMWF
THEN MOVE THE UPPER SYSTEM INTO THE SOUTHERN PLAINS. EVEN THOUGH
IT IS A LONG WAYS OFF AND THERE WILL BE NUMEROUS MODEL
CHANGES...IT APPEARS THAT NORTH TEXAS WILL SEE A MAJOR COOL OFF
WITH AT LEAST DECENT CHANCES FOR RAIN BY THE MIDDLE OF NEXT WEEK.
SHOULD THE UPPER SYSTEM TRACK FAR ENOUGH SOUTH...THIS COULD ALSO
BRING WINTER WEATHER TO AT LEAST PARTS OF NORTH TEXAS.

THE 12Z ECMWF TRACKS THE LOW ACROSS NORTH TEXAS CHRISTMAS
EVENING...AND WITH HEIGHTS AT ITS CENTER OF 538 DM IT IS A STRONG
SYSTEM. HOWEVER...THE 12Z GFS MOVES THE LOW SLOWER...AND HAS THE
UPPER TROF CENTERED IN EASTERN NEW MEXICO AT THAT TIME. IT IS
ALSO NOT AS STRONG WITH LOWEST HEIGHTS IN NORTH TX ABOVE 541 DM.
WITH BOTH MODELS BRINGING A STRONG COLD FRONT THROUGH TUESDAY
AFTERNOON...THE TEMPERATURES WILL DROP QUICKLY BELOW FREEZING
TUESDAY EVENING AND IF THERE IS ANY MOISTURE LEFT IN THE
ATMOSPHERE AND ANY FORCING TO LIFT IT...WINTRY PRECIP WOULD BE
EXPECTED.

AGAIN...IT IS MUCH TOO EARLY TO GUARANTEE A WINTER EVENT...MODEL
SOLUTION ERRORS TEND TO GROW LARGE THAT FAR IN THE FUTURE. WE CAN
SAY WITH SOME CONFIDENCE THAT WE CAN EXPECT SOME TYPE OF
EVENT THAT MAY INCLUDE WINTER WEATHER. MUCH COOLER TEMPERATURES
ARE ALSO POSSIBLE AFTER CHRISTMAS DAY. WITH MUCH OF THE COUNTRY
TRAVELING FOR THE HOLIDAYS...THIS LARGE AND POWERFUL SYSTEM HAS
THE POTENTIAL TO IMPACT AIR AND ROAD TRAVEL ON A LARGE SCALE
AS IT MOVES ACROSS THE COUNTRY. BE AWARE THAT CHANGES ARE COMING
AND KEEP TRACK OF THE FORECAST AS THE EVENT EVOLVES. UPDATE YOUR
WINTER WEATHER PLAN.

[wxman57]

Is there an accumulation map for the 12Z ECMWF?
Thanks

I'm looking at it on my workstation. The 12Z Euro is considerably farther north with the heavy snow compared to the 00Z run. About 200-300 miles farther. 00Z had the bullseye over south-central Oklahoma (10-15"). 12Z today has that bullseye over NE Kansas into NW Missouri. However, the 12Z Euro has a couple of inches of snow along the Red River on Christmas.

12Z GFS is a little colder than the 12Z Euro as far as post-frontal temps along the upper TX coast, but the Euro is indicating stronger cold advection at 192 hrs. VERY different 500mb patterns and timing when I plot the 12Z GFS and Euro 500 mb heights for next week. Give it another 2-4 days before the models come into better agreement.

Neither indicates any frozen precip over SE TX, but there is the potential for a hard freeze along the upper TX coast on the 26th-27th.

[TeamPlayersBlue]

That's a hell of a ice storm even for Houston on the 27th... 1/4 to 1/2 inch of ice...

where are you see this?

[Portastorm]

Is there an accumulation map for the 12Z ECMWF?
Thanks

I'm looking at it on my workstation. The 12Z Euro is considerably farther north with the heavy snow compared to the 00Z run. About 200-300 miles farther. 00Z had the bullseye over south-central Oklahoma (10-15"). 12Z today has that bullseye over NE Kansas into NW Missouri. However, the 12Z Euro has a couple of inches of snow along the Red River on Christmas.

12Z GFS is a little colder than the 12Z Euro as far as post-frontal temps along the upper TX coast, but the Euro is indicating stronger cold advection at 192 hrs. VERY different 500mb patterns and timing when I plot the 12Z GFS and Euro 500 mb heights for next week. Give it another 2-4 days before the models come into better agreement.

Neither indicates any frozen precip over SE TX, but there is the potential for a hard freeze along the upper TX coast on the 26th-27th.

It is interesting to note that the 12z Euro ensembles support a low (500mb) track from just west of Amarillo to central Arkansas, while the 12z GFS ensembles show a track starting slightly north of the Euro and ending up in central/NW Missouri.

One thing seems more certain ... a very pronounced storm/cold front will impact much of Texas right after Christmas. Stormier period ahead!

[Ntxw]

I don't buy into the northern tracks. -NAO Hudson block says no, it has to go around it at the base of the trough not drill into the block. I've never seen a storm try and punch into it, always goes around or stalls below the signal. Also models may be too quick in trying to move the storm. Anyone good at reading severe weather charts have an input?