December-Wet/Stormy New Years Eve Ahead

[wxman57]

Rainfall amounts across the county varied from about 1/2 inch to 2.5 inches. I received 1.0" in Westbury, making a total of 59.77" so far this year. Last year I measured 21.6". I don't think I've ever measured over 60" in a year since I've been here in 1980.

12Z GFS still doesn't indicate any really cold air for Christmas week. Temps in the low 60s falling to the upper 50s during the day with 2+ inches of rain. 12Z Euro indicates mild temps through Christmas Day then a weak cold front moving through Christmas night followed by a stronger front on the day after Christmas. Doesn't look extremely strong. Euro doesn't go out far enough to get a low temp for the 27th, but it has lows in Amarillo of about 20. That equates to about 40F here, as bringing that air down to our elevation dry adiabatically results in a warming of about 20 degrees. Assuming the air might be a little colder than that, we could see lows in the mid 30s in the day or two following Christmas.

Anyone forecasting lows in the 20s and highs in the 30s (or 40s) is not going by any model guidance, at least from the past 2-3 days.

[Baseballdude2915]

00z GFS shows a rain event after Christmas just ahead of a decent cold front that will put us around 50/30 for a couple of days. Even though its in la-la land, it then shows a warm front bringing rains and steamy temperatures for the end of the year.

With that, I've all but given up on 2012 for extreme cold/excitement... January is historically better for that anyway.

[Belmer]

00z GFS shows a rain event after Christmas just ahead of a decent cold front that will put us around 50/30 for a couple of days. Even though its in la-la land, it then shows a warm front bringing rains and steamy temperatures for the end of the year.

With that, I've all but given up on 2012 for extreme cold/excitement... January is historically better for that anyway.

Don't write this winter off. It's not done by a long shot.
As for January, that month has been (at least the past couple of years) boring for SE TX. We may see a cold snap, but not too much of an exciting month. February is our last exciting month to see an arctic blast with precip.

[wxman57]

Here's the 00Z GFS in graphical form.

[srainhoutx]

The overnight guidance suggests a potent storm complex and associated trough/Canadian cold front will sweep S Wednesday. Modest moisture returns begin on Tuesday that may bring our next chance for showers/isolated storms Wednesday as the storm system ejects. ENE from Colorado into the Mid West. At that time a potent Winter Storm appears to wrap up bringing potentially heavy snows and possibly near blizzard conditions across the Panhandle to the Great Lakes Region. Snow may well extend as far S as the Colorado front range into the Southern Plains. In the warm sector, the SPC as outlined a Slight Risk for severe weather across Arkansas/Northern Louisiana/W Tennessee.

Freezing temps for inland locations are expected Thursday night into Friday across most of Texas. There still is some uncertainty, but another storm system perhaps tracking a bit further S across the US is expected on Christmas as the progressive pattern continues. The 00Z Operational Euro and its ensembles are down right chilly across New Mexico/Texas/Oklahoma/Louisiana following the Christmas storm, but that is day 9/10 in model world, so expect changes.

The attachment 12172012 00Z OP Euro 00zeuro500mbHeightAnomalyNA216.gif is no longer available

The attachment 12172012 00Z OP Euro 00zeuro500mbHeightAnomalyNA240.gif is no longer available

Looking further out in the Long Range, the 16 member CFSv2 ensemble guidance continues to trend cold to very cold during the first week of January across the eastern 2/3 of the CONUS. More on that later.

[wxman57]

People in Oklahoma and along the Red River might be interested in the 00Z Euro's forecast for snow on the 25th/26th. Note that the map below depicts 24hr snowfall but it's the liquid equivalent in millimeters. 25mm = about 1" liquid = about 7-10" of snow, typically. It shows up to 35mm of liquid over OK, maybe 10-15" snow. Nothing down here except temps near freezing after Christmas.

[MontgomeryCoWx]

Need that snowfall map to move about 2 counties south and I'll be set on Christmas/Day After

[MontgomeryCoWx]

12z GFS forecasts some fun for a healthy chunk of Texas the days after Christmas

[srainhoutx]

^^

The GFS certainly trended more in line with what the Euro has suggested. The HPC is beginning to ramp up their interest in the period ahead and as we get closer to the Holidays when folks are away and busy travel/festivities and such, it bears watching in the next few days.

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.


FRACASSO

[srainhoutx]

The GFS Ensembles have trended 'cooler' for the mid week Canadian air mass dropping S behind the cold front. That guidance continues to advertise a rather strong storm system ejecting ENE from the Great Basin into the Plains and Mid West.

[MontgomeryCoWx]

your image isnt showing up

[srainhoutx]

The 12Z operational euro also suggests a fairly strong storm system during the mid week time frame dropping a Canadian front SE in the wake of the low tracking ENE. Closer to the Christmas time frame, the euro still maintains a southern storm track solution moving onshore in Southern California and slowly trekking E across the Great Basin into S of Lubbock. That solution matches well with what we have seen for the day after Christmas and perhaps could mean some very chilly air settling well S across the Region. We will see.

[MontgomeryCoWx]

Wow, 1/4 inch of Freezing Rain is nothing to sneeze at.... That will bring down tons of dead trees in my area.

Not that I'm complaining, I love Winter Weather.

[biggerbyte]

I like winter weather too. Anything but freezing rain, unless it can be followed by some good snowfall.

[srainhoutx]

For what it's worth, the 12Z euro ensembles suggest a somewhat similar track of the Christmas Day Storm with a surface low reflection crossing Central/SE TX on into Louisiana along with the 500mb low and very chilly air with gusty N winds in its wake for next Wednesday into Thursday.

[srainhoutx]

Afternoon update from NWS Dallas/Ft Worth:

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.

NWS Lubbock:

INTERESTING SYSTEM TO WATCH AT THE VERY END OF
THE PERIOD...IE MONDAY AND BEYOND. CERTAINLY WAY TOO EARLY TO PUT
VERY MUCH FAITH IN SPECIFICS BUT ECMWF AND GFS HAVE COME A LITTLE
MORE IN LINE WITH 12Z RUNS WITH DEPICTION OF DEEPENING UPPER LOW
DIGGING SOUTH ACROSS THE ROCKIES MONDAY AND TUESDAY OF NEXT WEEK.
GIVEN DRY PROGRESSIVE PATTERN...WILL NOT INSERT MENTIONABLE POPS AT
THIS TIME...BUT GIVEN THE UPCOMING CHRISTMAS HOLIDAY THIS SYSTEM
CERTAINLY BEARS WATCHING.

NWS San Angelo:

NOW THAT WE ARE PAST THE MIDPOINT OF DECEMBER...THE WEATHER
FORECAST FOR CHRISTMAS IS BEGINNING TO COME INTO PLAY. BOTH THE
ECMWF AND GFS ARE SHOWING A STRONG TROUGH MOVING ACROSS THE
ROCKIES BY 00Z TUESDAY. THERE ARE SOME SUBTLE DIFFERENCES IN THE
SMALLER SCALE FEATURES BUT THIS IS TO BE EXPECTED AT F180. THE
ECMWF IS A BIT FASTER WITH THE COLD FRONT /AND DEEPER WITH THE
SURFACE LOW/ WITH MUCH COLDER TEMPERATURES ANTICIPATED FOR
TUESDAY. NEITHER OF THE MODELS DEVELOP MUCH QPF OVER THE
CWA...KEEPING THE BULK OF THE PRECIPITATION TO OUR NORTH AND EAST.
THE ECMWF AND GFS HAVE EFFECTIVELY SWAPPED ROLES TODAY...WITH THE
GFS BEING THE DEEPEST OF THE TWO...WITH REGARD TO THE
AFOREMENTIONED TROUGH.. THE POTENTIAL FOR WINTRY PRECIPITATION
DOES EXIST BUT IT IS A LOW PROBABILITY EVENT AT THIS JUNCTURE. IT
WILL REQUIRE A WATCHFUL EYE OVER THE COMING DAYS.


NWS Houston/Galveston:

LOOKING FURTHER AHEAD INTO NEXT WEEK. LONG RANGE MODELS CONTINUE
TO HINT AT AN ACTIVE PERIOD RIGHT AROUND CHRISTMAS DAY. NOT SURE
HOW MUCH THIS WEATHER WILL AFFECT SANTA`S FLIGHT PATH BUT TRENDS
NOT LOOKING PROMISING ATTM.

[srainhoutx]

Winter Storm Watches and a Blizzard Watches have been hoisted for our mid week Winter Storm from Colorado (front range and Plains) into Kansas where the Blizzard Watch has been issued on NE into SE NE, NW MO, IA & WI.

[srainhoutx]

18Z GFS for the Christmas Storm...

[SusieinLP]

Today was beautiful...

[weatherguy425]

Unfortunately, I'll be back in SETX for this storm system. However, I love the GFS' idea of holding back energy to the west as we continue to have reinforcing shots of cooler air intrude the central/southern plains through January 1st.