Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 3

[Ed Lizard]

I think the UK Met supports a White Christmas, but the PSU e-Wall display loses the 6 hour precip display. But cold air and 700 mb RH looks good...

[Srain]

Interestingly the 12Z Euro keeps clouds and some moisture around until Monday...

[Srain]

A bit intriguing to see a Coastal low develops on the Euro. That feature has not been present on any guidance I've seen, but does seem reasonable with a persistent coastal trough...

[Srain]

Updated QPF Disco...

CNTRL TO UPR COASTAL REGION OF TX...LOWER MS VALLEY..TN VALLEY..

WIDESPREAD HVY PCPN EXPECTED TO DEVELOP RAPIDLY TONIGHT ALONG

LARGE PORTIONS OF THE TX GULF COAST AHEAD OF THE NEXT WELL DEFINED

AREA OF HT FALLS TO EJECT OUT OF THE SWRN MEAN TROF PSN. HIGH PW

VALUES JUST OFF THE TX GULF COAST WL PUSH BACK INLAND TONIGHT IN

RESPONSE TO THE UPSTREAM HT FALLS STRENGTHENING THE ONSHORE LOW

LEVEL FLOW. THIS ALONG WITH FAVORABLE RT ENTRANCE REGION JET

DYNAMICS WL SUPPORT A RAPIDLY INCREASING AREA OF HVY RAINS

SPREADING FROM THE CNTRL TO UPR TX GULF COAST TONIGHT INTO THE

LOWER MS VALLEY/TN VALLEY REGION THU. THE 1200 UTC NAM AND 1200

UTC GFS WERE ON THE SLOW END OF THE GUIDANCE IN SPREADING THE HVY

RAINFALL DOWNSTREAM...WITH THE 0000 UTC ECMWF...1200 UTC

CMC...1200 UTC UKMET AND 1200 UTC HI RES ARW AND NMM FAVORING THE

FASTER DOWNSTREAM SOLN. AT THE MOMENT...THIS FASTER DOWNSTREAM

PUSH OF HVY PCPN WAS FAVORED AS THESE HT FALLS WL BE ACCELERATING

ENEWD IN RESPONSE TO ADDITIONAL HT FALLS DROPPING SWD INTO THE

MEAN SWRN TROF PSN. WIDESPREAD AREAL AVG .50-1"+ PCPN AMTS

DEPICTED ACRS THESE AREAS...WITH LOCALLY HEAVIER TOTALS LIKELY

WHERE CONVECTION BECOMES ORGANIZED.

[Srain]

HPC Final Afternoon Update regarding the Holiday Weekend into early next week:

EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD

228 PM EST WED DEC 21 2011

VALID 12Z SAT DEC 24 2011 - 12Z WED DEC 28 2011

THE NORTH ATLANTIC OSCILLATION (NAO) WILL BE QUITE POSITIVE OVER

THE NEXT WEEK. HEIGHTS WILL CONTINUE WELL BELOW NORMAL OVER MOST

OF THE HIGH LATITUDES AND WELL ABOVE NORMAL OVER MUCH OF THE

MIDDLE LATITUDES. THE ONLY AREAS THAT WILL AVERAGE BELOW NORMAL IN

A 5 DAY MEAN IN THE MID LATITUDES WILL BE THE SWRN STATES AT THE

BEGINNING OF THE MEDIUM RANGE...AND THE NERN STATES AROUND DAY 7.

UPDATED PRELIMS HAD USED THE ORIGINAL DAYS 3-4 GRAPHICS THEN

SWITCHED TO ENTIRELY ECENS/GEFS MEAN BY TUE/WED DAYS 6-7...WHEN

RUN TO RUN CONTINUITY CHANGES IN THE DETERMINISTIC MODELS BECOME

MORE UNRELIABLE. ENSEMBLE SPAGHETTI PLOTS SHOW MODELS STILL HAVING

TROUBLE RESOLVING A POSITIVE TILTED MEAN TROF ACROSS THE SWRN

STATES...WITH THE GEFS FAMILY OF SOLUTIONS INITIALLY NW OF THE

ECMWF FAMILY OF SOLUTIONS WITH THE AXIS OF THIS TILTED MEAN TROF.

HOWEVER THE GEFS MEAN BY DAY 5 BEGINS TO SHEAR ENERGY OUT OF THE

SRN PLAINS MORE QUICKLY THAN THE ECENS MEAN...SHOWING MORE

INTERACTION WITH ENERGY FARTHER N. THE NEW 12Z GEFS MEAN STILL

SHOWS THIS INTERACTION TO SOME EXTENT.

BY DAY 4...ALL THE 12Z DETERMINISTIC MODELS HAVE MADE A DECIDED

TREND TOWARDS A DEEPER TROF MOVING ACROSS THE GRT LAKES ON DAY 4.

THE SIGNIFICANCE OF ANY SHORTWAVE SHEARING OUT OF THE SWRN STATES

HAS BEEN DOWNPLAYED IN NEW MODEL RUNS UNTIL MON/TUE. IN THIS

CASE...THE CLIPPER SYSTEM DIGGING INTO GREAT LAKES AT THE END OF

THE SHORT RANGE IS MORE DOMINANT THAN IT THE 00Z/20 ECMWF

RUN....SQUASHING THE WAVE EMERGING FROM TEXAS THAT MIGHT HAVE

BROUGHT A WHITE CHRISTMAS TO PORTIONS OF THE OH VLY/SRN NEW ENG.

12Z FINAL PROGS SUPPRESSED THIS FEATURE EVEN MORE THAN THE

PRELIMS. BY DAY 5...THE ECMWF/UKMET/CANADIAN ARE SHOWING A

TENDENCY FOR AN UPPER LOW TO FORM OVER W TX/NM. MODELS ARE

SHOWING THIS FEATURE FORMING ATOP DRY HIGH PRES...HOWEVER THE

ECMWF DOES SHOW SOME CYCLONIC CURVATURE DEVELOPING IN THE WRN

GULF ON MON DAY 5. WE WILL BE MONITORING THIS FOR ANY FURTHER

DEVELOPMENT TOWARDS THE MIDDLE OF NEXT WEEK.

OTHERWISE...FINAL GRAPHICS STAYED WITH THE BLEND USED IN THE

UPDATED PRELIM...STARTING OFF WITH A BLEND OF THE 12Z/20 AND 00Z

/21 ECMWF RUNS AND SWITCHING TO AN EVEN BLEND OF THE 00Z/21 ECENS

AND GEFS MEANS.

[cvgram]

Quick question if I might....is this going to be another "north of I10" system where the bulk of the precip occurs in that area as opposed to Wharton/Fort Bend counties? I'm speaking of the system timed for late this evening and tomorrow. I know these imby questions are just generally annoying but at this time of year, when some of us are still running around like idiots prepping for this weekend, it's helpful to know so we can plan our activities accordingly. Jeff's morning email, if I recall correctly did seem to indicate as such and wondered if anything had come into play to change that scenario.

Suz

[Ed Lizard]

Quick question if I might....is this going to be another "north of I10" system where the bulk of the precip occurs in that area as opposed to Wharton/Fort Bend counties? I'm speaking of the system timed for late this evening and tomorrow. I know these imby questions are just generally annoying but at this time of year, when some of us are still running around like idiots prepping for this weekend, it's helpful to know so we can plan our activities accordingly. Jeff's morning email, if I recall correctly did seem to indicate as such and wondered if anything had come into play to change that scenario.

Suz

18Z NAM just started running, but 12Z NAM seems to have heaviest precip along US 59...

[Ed Lizard]

I hope it works out. I've worked in Midland and Monahans...

[DoctorMu]

The split jet is starting to blow a tongue of soaking rain toward CLL. A cool, wet bath is at hand. I like where the ULL starts, and am not counting anything out on Saturday as far east as Austin - potential for more drought suppressing PCP here.

[Srain]

Quick question if I might....is this going to be another "north of I10" system where the bulk of the precip occurs in that area as opposed to Wharton/Fort Bend counties? I'm speaking of the system timed for late this evening and tomorrow. I know these imby questions are just generally annoying but at this time of year, when some of us are still running around like idiots prepping for this weekend, it's helpful to know so we can plan our activities accordingly. Jeff's morning email, if I recall correctly did seem to indicate as such and wondered if anything had come into play to change that scenario.

Suz

I hope it work out for you folks, Suzie. I know the last several events have been rather dry for areas SW of the Houston Metro. The 18Z 4km NAM was encouraging. Fingers crossed...

[Srain]

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0654 PM CST WED DEC 21 2011

VALID 220100Z - 221200Z

...NO SVR TSTM AREAS FORECAST...

...WRN/CNTRL GULF COAST...

WRN PORTION OF QUASI-STATIONARY FRONT OVER THE WRN GULF HAD BEGUN TO

SLOWLY RETREAT OFF THE LOWER TX GULF COAST IN RECENT SATELLITE

IMAGERY. THIS BOUNDARY WILL CONTINUE TO LIFT NWD AS SHORT WAVE

TROUGH OVER N-CNTRL MEXICO/BIG BEND AREA SHIFTS E/NEWD INTO

CNTRL/SRN TX OVERNIGHT. STRENGTHENING LOW-LEVEL WAA/MID-LEVEL DCVA

WILL RESULT IN A BROAD REGION OF SHOWERS AND EMBEDDED TSTMS

DEVELOPING ACROSS SRN/ERN TX INTO WRN/NRN LA. OPERATIONAL AND

CONVECTION-ALLOWING MODEL GUIDANCE ARE CONSISTENT THAT APPRECIABLE

SURFACE-BASED INSTABILITY WILL REMAIN OFFSHORE OUTSIDE OF COASTAL

SERN LA...WITH STORMS ROOTED WITHIN A WEAKLY UNSTABLE ENVIRONMENT

ABOVE A SHALLOW NEAR-SURFACE LAYER. ALTHOUGH IT APPEARS UNLIKELY

THAT SURFACE-BASED TSTMS WILL FORM PRIOR TO 12Z...WILL MAINTAIN

LOW-END SEVERE PROBABILITIES FOR A MARGINAL CONDITIONAL RISK.

[Srain]

It appears all areas saw some beneficial rains overnight and even some thunder as well as gusty winds as a coastal low developed about 30 miles offshore of Galveston. Rains should tapper off W to E by mid/late morning and quieter conditions should settle in before the arrival of a cold front late tonight/early tomorrow morning.

An upper low is sagging S into New Mexico this morning setting the stage for a Winter Storm in New Mexico/W Texas. The overnight guidance is in better agreement regarding wintery mischief, but some questions still remain. Austin/San Antonio is now mentioning a wintry mix for Friday night into Saturday for some Hill Country locations. The fly in the ointment is just how fast and how far W the H5 features become established. The trends have been to cut off an upper low over Old Mexico and eject disturbances in pieces before the main low moves E early next week. The other area of interest is any developing coastal trough/low Friday night into Saturday. Those with travel plans N and W of Houston should continue monitoring for further updates in this changeable forecast.

[Srain]

Special Weather Statements being issued for this Friday into Saturday for W and Central TX...

SPECIAL WEATHER STATEMENT

NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX

708 AM CST THU DEC 22 2011

TXZ171>173-183>194-202>209-217>225-228-222100-

LLANO-BURNET-WILLIAMSON-VAL VERDE-EDWARDS-REAL-KERR-BANDERA-

GILLESPIE-KENDALL-BLANCO-HAYS-TRAVIS-BASTROP-LEE-KINNEY-UVALDE-

MEDINA-BEXAR-COMAL-GUADALUPE-CALDWELL-FAYETTE-MAVERICK-ZAVALA-

FRIO-ATASCOSA-WILSON-KARNES-GONZALES-DE WITT-LAVACA-DIMMIT-

INCLUDING THE CITIES OF...LLANO...BURNET...GEORGETOWN...DEL RIO...

ROCKSPRINGS...LEAKEY...KERRVILLE...BANDERA...FREDERICKSBURG...

BOERNE...BLANCO...SAN MARCOS...AUSTIN...BASTROP...GIDDINGS...

BRACKETTVILLE...UVALDE...HONDO...SAN ANTONIO...NEW BRAUNFELS...

SEGUIN...LOCKHART...LA GRANGE...EAGLE PASS...CRYSTAL CITY...

PEARSALL...PLEASANTON...FLORESVILLE...KARNES CITY...GONZALES...

CUERO...HALLETTSVILLE...CARRIZO SPRINGS

708 AM CST THU DEC 22 2011

...A LIGHT MIX OF WINTER PRECIPITATION IS POSSIBLE ACROSS PARTS OF

SOUTH CENTRAL TEXAS FRIDAY NIGHT INTO SATURDAY...

A COLD FRONT WILL MOVE INTO SOUTH CENTRAL TEXAS TONIGHT...AND AN

UPPER LEVEL DISTURBANCE WILL APPROACH TEXAS FROM THE ROCKY

MOUNTAINS. THE SLOW MOVING UPPER LEVEL DISTURBANCE IS EXPECTED TO

PRODUCE AN OVERRUNNING PATTERN OF LIGHT RAIN ACROSS MUCH OF SOUTH

CENTRAL TEXAS BY FRIDAY EVENING...WITH SOME OF THE RAIN POSSIBLY

MIXING WITH OR CHANGING OVER TO SLEET AND SNOW LATE FRIDAY NIGHT

INTO SATURDAY. THE CHANCE OF PRECIPITATION IS EXPECTED TO DECREASE

OVER THE AREA SATURDAY EVENING.

THE POTENTIAL TO SEE SLEET OR SNOW WILL BE BEST ACROSS THE HILL

COUNTRY AND SOUTHERN EDWARDS PLATEAU...OR GENERALLY NORTH OF A DEL

RIO TO COMFORT TO GEORGETOWN LINE. DUE TO THE VERY LIGHT AMOUNTS

EXPECTED TO FALL AND GROUND TEMPERATURES THAT ARE EXPECTED TO STAY

ABOVE FREEZING...NO ICE OR SNOW ACCUMULATION IS EXPECTED.

HOWEVER...THOSE WITH INTERESTS IN THE HILL COUNTRY AND THE

ADJACENT AREAS TO THE NORTH AND WEST SHOULD MONITOR THE LATEST

FORECASTS REGARDING THIS WINTER WEATHER SYSTEM.

SPECIAL WEATHER STATEMENT

NATIONAL WEATHER SERVICE SAN ANGELO TX

639 AM CST THU DEC 22 2011

TXZ049-054-064>066-071>073-076>078-098-099-113-114-127-128-139-

140-154-155-168>170-222200-

FISHER-NOLAN-STERLING-COKE-RUNNELS-IRION-TOM GREEN-CONCHO-

CROCKETT-SCHLEICHER-SUTTON-HASKELL-THROCKMORTON-JONES-SHACKELFORD-

TAYLOR-CALLAHAN-COLEMAN-BROWN-MCCULLOCH-SAN SABA-MENARD-KIMBLE-

MASON-

INCLUDING THE CITIES OF...ROTAN...ROBY...SWEETWATER...

STERLING CITY...ROBERT LEE...BRONTE...BALLINGER...WINTERS...

MERTZON...SAN ANGELO...EDEN...OZONA...ELDORADO...SONORA...

HASKELL...THROCKMORTON...WOODSON...STAMFORD...ANSON...HAMLIN...

ALBANY...ABILENE...CLYDE...BAIRD...CROSS PLAINS...COLEMAN...

BROWNWOOD...BRADY...SAN SABA...MENARD...JUNCTION...MASON

639 AM CST THU DEC 22 2011

...SNOW EXPECTED ACROSS MUCH OF WEST CENTRAL TEXAS FRIDAY NIGHT AND

SATURDAY...

A STRONG UPPER LEVEL STORM SYSTEM WILL MOVE ACROSS WEST TEXAS LATE

FRIDAY INTO SATURDAY. A MIXTURE OF LIGHT RAIN OR SNOW MAY DEVELOP

AS EARLY AS FRIDAY AFTERNOON BUT PRECIPITATION CHANCES WILL

INCREASE MARKEDLY FRIDAY NIGHT AND SATURDAY. THE BEST CHANCE FOR

ACCUMULATING SNOW WILL BE NORTH OF A LINE FROM OZONA...TO PAINT

ROCK...TO CROSS PLAINS. SNOW IS EXPECTED TO DEVELOP FRIDAY NIGHT

AND CONTINUE THROUGH THE DAY SATURDAY BEFORE GRADUALLY ENDING FROM

WEST TO EAST SATURDAY EVENING. TOTAL SNOWFALL AMOUNTS OF 1 TO 2

INCHES ARE POSSIBLE...ESPECIALLY TO THE WEST OF A LINE FROM

SWEETWATER...TO ROBERT LEE...TO MERTZON. LIGHT RAIN...POSSIBLY

MIXED WITH SNOW AT TIMES...IS EXPECTED ACROSS MUCH OF THE

HEARTLAND AND NORTHWEST HILL COUNTRY.

CONSIDERABLE UNCERTAINTY EXISTS REGARDING IN THE TRACK AND TIMING

OF THIS SYSTEM. MINOR CHANGES IN THE FORECAST TRACK OF THE UPPER

LOW COULD RESULT IN SUBSTANTIAL DIFFERENCES IN THE SNOWFALL

FORECAST. RESIDENTS ACROSS WEST CENTRAL TEXAS SHOULD CONTINUE TO

MONITOR THE LATEST FORECASTS REGARDING THIS DEVELOPING WINTER

WEATHER SYSTEM.

SPECIAL WEATHER STATEMENT

NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX

448 AM CST THU DEC 22 2011

NMZ027>029-033-034-TXZ045>048-050>053-057>063-067>070-074-075-

079>082-258-222300-

GUADALUPE MOUNTAINS OF EDDY COUNTY-EDDY COUNTY PLAINS-

NORTHERN LEA COUNTY-CENTRAL LEA COUNTY-SOUTHERN LEA COUNTY-GAINES-

DAWSON-BORDEN-SCURRY-ANDREWS-MARTIN-HOWARD-MITCHELL-

VAN HORN AND HIGHWAY 54 CORRIDOR-

REEVES COUNTY AND UPPER TRANS PECOS-LOVING-WINKLER-ECTOR-MIDLAND-

GLASSCOCK-WARD-CRANE-UPTON-REAGAN-DAVIS/APACHE MOUNTAINS AREA-

PECOS-PRESIDIO VALLEY-MARFA PLATEAU-BIG BEND AREA-TERRELL-

GUADALUPE MOUNTAINS-

INCLUDING THE CITIES OF...QUEEN...ARTESIA...CARLSBAD...

CARLSBAD CAVERNS NP...TATUM...HOBBS...LOVINGTON...EUNICE...JAL...

SEMINOLE...LAMESA...GAIL...SNYDER...ANDREWS...STANTON...

BIG SPRING...COLORADO CITY...VAN HORN...PECOS...MENTONE...

RED BLUFF LAKE...KERMIT...ODESSA...MIDLAND...GARDEN CITY...

MONAHANS...CRANE...MCCAMEY...RANKIN...BIG LAKE...ALPINE...

FORT DAVIS...FORT STOCKTON...PRESIDIO...MARFA...BIG BEND NP...

MARATHON...SANDERSON...GUADALUPE MOUNTAINS NP...PINE SPRINGS

448 AM CST THU DEC 22 2011 /348 AM MST THU DEC 22 2011/

...ACCUMULATING SNOWS ARE POSSIBLE ACROSS SOUTHEAST NEW MEXICO AND

PORTIONS OF WEST TEXAS THURSDAY NIGHT AND FRIDAY WITH FURTHER EXPANSION

INTO THE PERMIAN BASIN AND TRANS PECOS FRIDAY NIGHT AND SATURDAY...

ANOTHER UPPER LEVEL STORM SYSTEM WILL DEVELOP OVER NEW MEXICO LATER

TODAY AND INTO FRIDAY...JUST AFTER A STRONG COLD FRONT SURGES THROUGH

SOUTHEAST NEW MEXICO AND WEST TEXAS. LIFT AHEAD OF THE STORM SYSTEM

COULD BRING AN INCREASING CHANCE OF SIGNIFICANT SNOW ESPECIALLY FOR

THE GUADALUPE MOUNTAINS...AND MOST OF THE SOUTHEAST NEW MEXICO PLAINS.

A WINTER STORM WATCH CONTINUES FOR SNOW TOTALS OF 4 TO 6 INCHES WITH

HIGHER AMOUNTS IN THE HIGHEST ELEVATIONS FROM LATE TONIGHT THROUGH

FRIDAY.

THIS WINTER WEATHER SYSTEM WILL CONTINUE TO AFFECT THE OUTLOOK AREA

INTO FRIDAY NIGHT AND SATURDAY WHEN ACCUMULATING SNOWS OF 1 TO 3

INCHES WILL BE POSSIBLE FARTHER EAST INTO THE PERMIAN BASIN AND SOUTH

INTO THE TRANS PECOS INCLUDING THE DAVIS MOUNTAINS.

THERE IS STILL UNCERTAINTY IN THE TIMING AND TRACK OF THIS STORM

SYSTEM AS IT MOVES ACROSS THE AREA SO LOCATIONS AND SNOW AMOUNTS

COULD CHANGE. WINTER WEATHER WARNINGS OR ADVISORIES MAY EVENTUALLY

BE ISSUED. RESIDENTS ACROSS SOUTHEAST NEW MEXICO AND WEST TEXAS

SHOULD CONTINUE TO MONITOR THE LATEST FORECASTS REGARDING THIS

DEVELOPING WINTER WEATHER SYSTEM AND BE PREPARED TO TAKE ACTION

INCLUDING ALTERNATE TRAVEL PLANS.

[Ed Lizard]

Whatever that bayou is called that runs under I-10 at I-45 was well outside its concrete banks. Which suggests Buffalo Bayou is running high as well.

[Srain]

Whatever that bayou is called that runs under I-10 at I-45 was well outside its concrete banks. Which suggests Buffalo Bayou is running high as well.

That's White Oak Bayou. Some interesting trends this morning via the 12Z WRF/NMM. That guidance is suggesting a bit stronger coastal low developing Saturday (Christmas Eve) and abundant moisture with over running precip for Coastal TX and inland into Central TX/SE TX and a bit closer to the TX Coast. That model also suggests a bit strong upper air feature crossing W and N Central TX as well.

[DoctorMu]

The NAM is indeed slowing and leaning towards a colder solution up to Austin. This ULL can be a portable cold sink coming off the Rockies with that remarkably cold air. Colorado is in the deep freeze.

An interesting Christmas weekend ahead for the weather elves.

[Srain]

The 12Z GFS remains a bit too dry in W TX and also seems a bit too progressive. It also suggests a weak cut off H5 hanging back in Old Mexico. The Canadian is also drier for N TX, but suggests a stronger upper level feature near El Paso. The Canadian is on the slow side ejecting the upper low and suggests clouds and over running precip lingers into Christmas Day for SE TX as a coastal trough/low develops near or just S of Corpus. The Canadian, if correct, would keep us in the clouds until mid next week and additional rains Monday night into Tuesday when the upper level low finally ejects ENE. We will see.

[Srain]

Confidence grows concerning wintry weather in W TX via the 12Z Euro. That model has made some changes today suggesting a strong upper air feature across W TX and a bit quicker ejection of the upper level trough throughout the Holiday Weekend. It appears borderline for parts of the Edwards Plateau and Hill Country and N TX appears to escape the wintry threat altogether.

For S Central and SE TX, chilly conditions with over running precip looks likely beginning late on Friday continuing on into Christmas morning as a coastal low/trough develops offshore of Corpus Christi.

[Srain]

And with that, the HPC says not so fast re: Model Diagnostic Discussions...

...TROF PUSHING SWD THRU THE GRT BASIN/ROCKIES INTO THE SRN HI

PLNS...

MDLS ARE SIMILAR WITH DROPG ENERGY THRU THE ROCKIES INTO THE SWRN

U.S....THEN ALLOWING SOME ENERGY TO SHEAR NEWD AND PHASE WITH

ENERGY DIGG INTO THE GRT LKS ON DAY 3. MDLS ARE SHOWING VARIED

SOLUS AT 5H WITH THE NAM THE MORE PROGRESSIVE WITH A 5H CENTER

INTO THE SRN PLNS...ECMWF SHOWING THE SAME CENTER OVER THE TX

PANHANDLE...WHILE THE CAN/UKMET/GFS SHOWS THE MAIN CLOSED LOW

REMAINING OVER NRN MEXICO. WOULD LIKE TO REMOVE THE NAM FM THE MIX

DUE TO IT BEING A STG OUTLIER...ALSO THINK THE ECMWF MIGHT BE TOO

FAR NE WITH THE CLOSED LOW...MOSTLY DUE TO THE FACT THAT THESE SYS

CONT TO DEVELOP OVER SRN AZ/NRN MEX REGION THE PAST MONTH OR SO

AND THE LRG SCALE PTRN HAS NOT CHANGED. THEY THEN HAVE BEEN

TENDING TO ONLY SLOWLY LIFT NEWD INTO THE SRN PLNS. ALSO...THE

OPERATIONAL ECMWF/NAM 5H SOLUS DO NOT FIT THE LATEST ECMWF/GEFS

ENSEMBLE MEAN PTRN THRU THIS REGION.

[bubba hotep]

Was looking for the GFS to trend towards the NAM (Ha! Someone has to step up and be a full blown weenie) but no dice. The NAM remains the outlier with the stronger solution. The 12z EURO might get some snow to the western edge of DFW and I guess is close enough to leave the slightest hope that we will see some flurry action. Maybe the 18z runs will bring better news...

[Srain]

Rare afternoon e-mail from Jeff:

Widespread wetting rains overnight with another chance of widespread rainfall this weekend.

Highly active split flow pattern continues to bring welcomed rains to TX helping with the ongoing exceptional drought. Overnight rainfall averaged 1-2 inches across nearly all of SE TX per radar and actual ground truth gage reports. Combination of Tuesday morning rains and last night rains have lead to rises on area watersheds not control by urban run-off suggesting that water is once again flowing in some of the creeks and rivers that feed our lakes and water supply.

Clouds have been slow to break up/erode from the west over much of the area today as moisture is trapped near the surface. Visible images show a slow wet to east erosion in the deck with sunny skies currently west of a line from College Station to Victoria. Slow clearing is likely this evening reaching I-45 by sunset.

Cold front over NW TX is clearly noted on the visible images as leading edge of thick stratus cloud deck expanding southward. Front should move southward across the region tonight as the next storm system over the four corners currently digs south in S AZ/N MX. Increasing northerly winds into Friday as the surface cold high pressure moves southward down the plains and into TX while aloft SW flow will develop with increasing clouds atop surface cold dome. Upper level storm digging into MX will help position the sub-tropical jet back toward TX by late Friday while at the surface another coastal trough/low begins to develop off the lower/middle TX coast. Combination of above mentioned features will result in another period of overrunning clouds/rainfall similar to the early Thursday morning event (minus the thunder and heavy rainfall). Temperatures will be colder also, but not cold enough for any but liquid across all of SE TX. Some chances for snow over W TX and possibly into the hill Country late Friday into Saturday, but amounts look to be on the light side given meager moisture that far north and west.

Clouds will lower and thicken Friday afternoon as Gulf air mass is forced up and over the surface cold dome by the developing coastal trough and sub-tropical jet aloft. Expect periods of light to moderate rainfall to develop and spread NNE to NE across the region starting early Saturday morning and continuing into Saturday night. NE surface winds, rain, and clouds will hold temperatures nearly steady in the 40’s on Saturday.

May see rainfall linger into early Sunday especially near the coast as the upper trough lags back over MX into early next week. Cold conditions will continue into Christmas Day with lows in the 40’s and highs in the lower 50’s under cloudy and mostly cloudy skies by afternoon.

Rainfall amounts Fri PM-Sun AM will average a widespread .25-.75 of an inch with a few isolated amounts of 1.0-1.5 inches especially near the coast. Current forecast models suggest this coastal low event will be displaced slightly more offshore and the heaviest rains will be closer to the coast and offshore compared to the Thursday AM storm. Will take what we can get as the wet pattern of late looks to be ending next week with more zonal flow aloft and closing of the southern US storm track.

[Srain]

MAF issues Winter Storm Watches for the Guadalupe Mountians/Davis Mountains and the higher terrain along I-20 and I-10.

[Srain]

SPECIAL WEATHER STATEMENT

NATIONAL WEATHER SERVICE LUBBOCK TX

320 PM CST THU DEC 22 2011

TXZ021>044-230530-

PARMER-CASTRO-SWISHER-BRISCOE-HALL-CHILDRESS-BAILEY-LAMB-HALE-

FLOYD-MOTLEY-COTTLE-COCHRAN-HOCKLEY-LUBBOCK-CROSBY-DICKENS-KING-

YOAKUM-TERRY-LYNN-GARZA-KENT-STONEWALL-

INCLUDING THE CITIES OF...FRIONA...BOVINA...DIMMITT...HART...

TULIA...SILVERTON...QUITAQUE...MEMPHIS...TURKEY...CHILDRESS...

MULESHOE...LITTLEFIELD...OLTON...PLAINVIEW...FLOYDADA...LOCKNEY...

MATADOR...ROARING SPRINGS...PADUCAH...MORTON...LEVELLAND...

LUBBOCK...SLATON...WOLFFORTH...CROSBYTON...RALLS...DICKENS...

SPUR...GUTHRIE...PLAINS...DENVER CITY...BROWNFIELD...TAHOKA...

ODONNELL...POST...JAYTON...ASPERMONT

320 PM CST THU DEC 22 2011

...ACCUMULATING SNOWFALL POSSIBLE ACROSS THE AREA TONIGHT THROUGH

SATURDAY EVENING...

AN UPPER LEVEL STORM SYSTEM WILL CONTINUE TO MOVE SOUTH ACROSS THE

ROCKIES TODAY AND TONIGHT...AND APPROACH WEST TEXAS ON FRIDAY. A

COLD FRONT HAS MOVED THROUGH WEST TEXAS EARLIER THIS MORNING

WHICH LOWERED TEMPERATURES ACROSS THE REGION AHEAD OF THIS UPPER

LEVEL STORM SYSTEM. THE AREA THAT WILL SEE THE BEST CHANCE OF

ACCUMULATING SNOWFALL WILL BE ACROSS THE SOUTHWESTERN SOUTH

PLAINS...SOUTHERN SOUTH PLAINS AND LOW ROLLING PLAINS. DEPENDING

ON THE SPEED OF THE SYSTEM...THE ONSET OF SNOWFALL COULD POSSIBLY

BEGIN AS EARLY AS LATE TONIGHT AND PERSIST INTO SATURDAY EVENING.

SNOWFALL ACCUMULATIONS MAY RANGE FROM A DUSTING TO THREE INCHES.

HIGHEST ACCUMULATIONS ARE EXPECTED TO BE ACROSS THE WESTERN AND

SOUTHWESTERN SOUTH PLAINS.

AREA RESIDENTS SHOULD CONTINUE TO MONITOR THE LATEST FORECASTS AND

BE PREPARED TO TAKE ACTION WITH ANY POSSIBLE WATCHES...WARNINGS OR

ADVISORIES.

SPECIAL WEATHER STATEMENT

NATIONAL WEATHER SERVICE SAN ANGELO TX

322 PM CST THU DEC 22 2011

TXZ049-054-064>066-071>073-076>078-098-099-113-114-127-128-139-

140-154-155-168>170-230600-

FISHER-NOLAN-STERLING-COKE-RUNNELS-IRION-TOM GREEN-CONCHO-

CROCKETT-SCHLEICHER-SUTTON-HASKELL-THROCKMORTON-JONES-SHACKELFORD-

TAYLOR-CALLAHAN-COLEMAN-BROWN-MCCULLOCH-SAN SABA-MENARD-KIMBLE-

MASON-

INCLUDING THE CITIES OF...ROTAN...ROBY...SWEETWATER...

STERLING CITY...ROBERT LEE...BRONTE...BALLINGER...WINTERS...

MERTZON...SAN ANGELO...EDEN...OZONA...ELDORADO...SONORA...

HASKELL...THROCKMORTON...WOODSON...STAMFORD...ANSON...HAMLIN...

ALBANY...ABILENE...CLYDE...BAIRD...CROSS PLAINS...COLEMAN...

BROWNWOOD...BRADY...SAN SABA...MENARD...JUNCTION...MASON

322 PM CST THU DEC 22 2011

...SNOW EXPECTED ACROSS MUCH OF WEST CENTRAL TEXAS FRIDAY NIGHT AND

SATURDAY...

A STRONG UPPER LEVEL STORM SYSTEM WILL MOVE ACROSS WEST TEXAS LATE

FRIDAY INTO SATURDAY. A MIXTURE OF LIGHT RAIN OR SNOW MAY DEVELOP

AS EARLY AS TOMORROW ACROSS THE WESTERN BIG COUNTRY AND CONCHO

VALLEY. HOWEVER...PRECIPITATION CHANCES WILL INCREASE MARKEDLY

TOMORROW NIGHT AND SATURDAY. ACCUMULATING SNOW IS EXPECTED TO

BEGIN TOMORROW NIGHT AND CONTINUE THROUGH SATURDAY...BEFORE

GRADUALLY ENDING FROM WEST TO EAST SATURDAY EVENING. THE MOST

LIKELY AREA FOR ACCUMULATING SNOW WILL BE NORTH AND WEST OF A

LINE FROM SONORA...TO EDEN...TO BROWNWOOD. TOTAL SNOWFALL AMOUNTS

OF 1 TO 3 INCHES ARE POSSIBLE...ESPECIALLY TO THE NORTH AND WEST

OF A LINE FROM OZONA...TO SAN ANGELO...TO SWEETWATER. ACROSS MUCH

OF THE HEARTLAND AND NORTHWEST HILL COUNTRY...EXPECT LIGHT

RAIN...POSSIBLY MIXED AT TIMES WITH SNOW.

CONSIDERABLE UNCERTAINTY EXISTS REGARDING THE TRACK AND TIMING OF

THIS SYSTEM. MINOR CHANGES IN THE FORECAST TRACK OF THE UPPER LOW

COULD RESULT IN SUBSTANTIAL DIFFERENCES IN THE SNOWFALL FORECAST.

RESIDENTS ACROSS WEST CENTRAL TEXAS SHOULD CONTINUE TO MONITOR THE

LATEST FORECASTS REGARDING THIS DEVELOPING WINTER WEATHER SYSTEM.

[Srain]

Interesting discussion from San Angelo explaining all the uncertainties regard this complex and evolving situation...

.LONG TERM...

A COMPLICATED FORECAST IS EXPECTED FOR THE HOLIDAY WEEKEND...WITH

THE POTENTIAL FOR WINTER WEATHER ACROSS MUCH OF WEST CENTRAL TEXAS.

FRIDAY NIGHT/SATURDAY MORNING...A LARGE UPPER LEVEL LOW WILL BE

LOCATED OVER THE NORTHERN STATE OF CHIHUAHUA AND SOUTHERN NEW

MEXICO. THIS UPPER LEVEL LOW IS WILL SLOWLY TRACK ACROSS WEST TEXAS

THROUGHOUT THE DAY ON SATURDAY THEN TOWARDS NORTHWEST TEXAS SATURDAY

NIGHT. THE GFS SOLUTION CONTINUES TO INDICATE A MUCH FASTER TRACK OF

THIS AFOREMENTIONED LOW...WITH WARMER TEMPERATURES AND LESS

PRECIPITATION. THE GFS REMAINS THE OUTLIER AND HAS BEEN DISCOUNTED

IN THIS FORECAST...WITH MOST OF THE GRIDS FOLLOWING CLOSER TO THE

ECMWF/NAM.

A COLD AIRMASS WILL BE ENTRENCHED ACROSS THE AREA AHEAD OF THE

PREVIOUSLY MENTIONED UPPER LEVEL LOW ON FRIDAY NIGHT. AS THE LOW

APPROACHES...LIFT WILL BEGIN TO INCREASE OVER THE AREA...WITH LIGHT

PRECIPITATION DEVELOPING OVER THE WESTERN CONCHO VALLEY...BIG

COUNTRY AND NORTHERN EDWARDS PLATEAU. LOOKING AT NAM BUFR SOUNDINGS

AND FORECAST 850/700MB TEMPERATURES...BELIEVE PRECIPITATION WILL

BEGIN AS SNOW OVER THE EXTREME WESTERN PORTIONS OF THE CWA...WITH A

RAIN/SNOW MIX FARTHER TO THE EAST...FROM ABILENE...TO SAN

ANGELO...TO OZONA...AND RAIN ELSEWHERE. AFTER 06Z...EXPECT AN

INCREASE IN PRECIPITATION...WITH PREDOMINATELY SNOW OVER MUCH OF THE

CWA...EXCEPT OVER THE NORTHWEST HILL COUNTRY AND PARTS OF THE

HEARTLAND...WHERE A RAIN/SNOW MIX CAN BE EXPECTED. SNOWFALL

ACCUMULATIONS THROUGH 12Z SATURDAY BETWEEN HALF AN INCH AND INCH ARE

EXPECTED ALONG AND WEST OF AN OZONA...TO SAN ANGELO...TO SWEETWATER

LINE. AS THE UPPER LEVEL MOVES INTO WEST TEXAS...PRECIPITATION

CHANCES WILL REMAIN HIGH...WITH THE BEST POPS ACROSS THE SOUTHERN

TWO THIRDS OF THE FORECAST AREA. SATURDAY MORNING...MOST OF THE

PRECIPITATION WILL FALL IN THE FORM OF SNOW...WITH A RAIN/SNOW MIX

OVER THE NORTHWEST HILL COUNTRY AND WESTERN HEARTLAND. AS

TEMPERATURES CLIMB SLIGHTLY SATURDAY AFTERNOON...A TRANSITION TO A

RAIN/SNOW MIX IS EXPECTED OVER MOST OF THE CWA...WITH MOSTLY RAIN

OVER THE NORTHWEST HILL COUNTRY AND SOUTHERN HEARTLAND. AN

ADDITIONAL 1...TO POSSIBLY 2 INCHES OF SNOW MAY ACCUMULATE AFTER

12Z...MAINLY ALONG AND WEST OF AN OZONA...TO SAN ANGELO...TO

SWEETWATER LINE. AS THE LOW TREKS TO THE NORTH AND EAST OF THE

AREA...A FEW LIGHT SNOW SHOWERS WILL BE POSSIBLE AFTER 00Z

SUNDAY...AND HAVE ADDED LIGHT SNOW TO THE GRIDS...WITH ALL

PRECIPITATION ENDING BY 06 SUNDAY. THE EXPECTED CLOUD

COVER/PRECIPITATION WILL ALLOW VERY LITTLE DIURNAL RANGE IN

TEMPERATURES WITH HIGHS RANGING FROM THE MID 30S ACROSS THE WESTERN

AND CENTRAL PORTIONS OF THE REGION...TO NEAR 40 AT JUNCTION AND

HASKELL. HIGH TEMPERATURES ON CHRISTMAS DAY WILL BE DEPENDENT ON THE

AMOUNT OF SNOW COVER ACROSS THE AREA. UNDERCUT GUIDANCE BY SEVERAL

DEGREES...WITH THE COLDEST TEMPERATURES OVER THE WESTERN COUNTIES.

ANOTHER BELOW NORMAL DAY IS FORECAST ON MONDAY...AS THE NEXT UPPER

LEVEL LOW KICKS OUT ACROSS THE REGION. A SLOW WARM UP WILL ENSUE

THROUGH THE MIDDLE OF NEXT WEEK.

THE CURRENT FORECAST IS CALLING FOR SNOWFALL ACCUMULATIONS BETWEEN 1

AND 3 INCHES ACROSS PARTS OF THE WESTERN CONCHO VALLEY...BIG COUNTRY

AND NORTHERN EDWARDS PLATEAU...WITH LIGHTER AMOUNTS ELSEWHERE.

UNCERTAINTY STILL REMAINS ON THE EXACT EVOLUTION OF THE UPPER LEVEL

LOW AND THE AMOUNT OF PRECIPITATION ACROSS THE AREA. LOCALLY HIGHER

AMOUNTS MAY OCCUR...AND SNOWFALL AMOUNTS MAY NEED TO BE INCREASED ON

FUTURE SHIFTS. AT THIS TIME...WILL HOLD OFF ON ISSUING ANY TYPE OF

WATCH OR ADVISORY FOR WEST CENTRAL TEXAS...BUT THE ISSUANCE OF A

WINTER STORM WATCH OR WINTER WEATHER ADVISORY MAY BE NECESSARY FOR

PORTIONS OF THE AREA LATER TONIGHT OR FRIDAY MORNING. CONTINUE TO

MONITOR FUTURE FORECAST FROM THE NATIONAL WEATHER SERVICE IN SAN

ANGELO...AS WINTER WEATHER MAY AFFECT HOLIDAY PLANS AND TRAVEL THIS

WEEKEND.

[bubba hotep]

Interesting that they went EURO/ NAM when HPC basically tossed that combo earlier. I am not betting on snow up our way but at least there is enough going on with this system to keep things interesting

[Srain]

Interesting discussion from FWD. I think we can all see this situation is still rather uncertain and evolving...

LOW OVER THE FOUR CORNERS WILL SLOWLY GRIND SOUTHWARD...REACHING

EL PASO AROUND MIDNIGHT FRIDAY NIGHT. DESPITE SOME LINGERING

INCONSISTENCIES AMONG THE MODELS THEREAFTER...A CONSENSUS REMAINS.

BUT UNLIKE PREVIOUS SOLUTIONS...THE CONSENSUS IS FOR THE INITIAL

SPOKE OF ENERGY TO BEHAVE MORE LIKE A CUT-OFF. ALTHOUGH AN OUTLIER

YESTERDAY...THE NAM HAS APPROPRIATELY SLOWED THE PROGRESSION OF

THIS FIRST IMPULSE.

ISENTROPIC LIFT WILL ENSUE IN WESTERN ZONES DURING THE EARLY

MORNING HOURS SATURDAY. MOISTURE WILL INITIALLY BE LIMITED...BUT

SOME LIGHT SNOW COULD OCCUR BEFORE DAYBREAK SATURDAY. AS THE LIFT

EXPANDS TO ENCOMPASS THE ENTIRE CWA...LIGHT RAIN OR SNOW WOULD

SPREAD EASTWARD. HAVE MAINTAINED A RAIN/SNOW LINE GENERALLY WEST

OF THE METROPLEX. HOWEVER...WITH CURRENT TEMP/TD FORECAST SATURDAY

MORNING AND THE LARGELY UNSATURATED PROFILE ALOFT...THERE IS

CONSIDERABLE POTENTIAL FOR EVAPORATIVE COOLING ELSEWHERE. BUT WITH

LIGHT PRECIPITATION...THIS EFFECT WOULD BE MINIMAL. WITH LIMITED

MOISTURE AND RATHER MEAGER LIFT...IT APPEARS THAT ANY PRECIP WOULD

BE RATHER LIGHT. WHERE SNOW IS FORECAST...THE COLUMN IS SUB-

FREEZING...BUT THE BULK OF THE LIFT IS BENEATH THE DENDRITIC

GROWTH ZONE. AS SUCH...CURRENT THINKING WOULD PUT ONE-INCH SNOW

ACCUMULATIONS IN WESTERN ZONES ON THE UPPER END OF LIKELY

OUTCOMES. LIFT WILL LIKELY EXHAUST LATE CHRISTMAS EVE...BUT WILL

MAINTAIN A SLOWER EASTWARD EXIT OF PRECIP DUE TO UNCERTAINTY.

CURRENTLY...THE DETERMINISTIC TEMPERATURE FORECAST SATURDAY

MORNING MIGHT IMPLY THE POTENTIAL FOR FREEZING RAIN IF NOT

SNOW...BUT THE SURFACE TEMPERATURES WILL DEPEND GREATLY ON THE

EVOLUTION OF THE PRECIPITATION AND THE TEMPERATURE/MOISTURE

PROFILES THE PRECIP ENCOUNTERS. AS SUCH...A FLAKE OF SNOW CANNOT

BE RULED OUT IN AREAS WHERE SNOW IS NOT CURRENTLY IN THE FORECAST.

[Srain]

EPZ issues Winter Storm Warning for portions of New Mexico and Winter Weather Advisories for the Rio Grande Basin into TX including El Paso.

[Srain]

Just for grins, this is what the 18Z 4km NAM is spitting out...

[Roy]

That NAM's hilarious. All the area offices are going with a NAM/Euro combo though. We are leaving for Abilene, TX tomorrow night from here in Midland. I HOPE it snows in Abilene, but it's not looking too promising for more than maybe 1/2 to an inch. Midland will get more unfortunately. If the NAM is actually right here, I would be ticked, but that won't happen of course.

And I left my home in Kansas on Monday right before the snowstorm there....arghh.

[bubba hotep]

Well, the 00z NAM is out to 33 hrs and I don't see any signs that it is going to fold to the GFS this run.