Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 6

[ams30721us]

Sure excited to see the normally way to warm modeled Euro actually paint 2M temps in the mid to upper 20s across most of East Texas by afternoon and evening with juiced up QPF. Quite impressive to see. Good to see agreement now among the GFS and Euro of the 20s by the afternoon hours with increased QPF.

 

[aggiegeog]

Sure excited to see the normally way to warm modeled Euro actually paint 2M temps in the mid to upper 20s across most of East Texas by afternoon and evening with juiced up QPF. Quite impressive to see. Good to see agreement now among the GFS and Euro of the 20s by the afternoon hours with increased QPF.

Agreed, with the GFS starting to look sane and the Euro showing something very similar I am starting to become far more confident in a winter storm for East Texas than I have at any point this season. Looks like we could make it two winters in a row to end with a significant winter storm in NE TX. Beyond this storm I am not quite buying a big mid-week warm up and conditions look ripe for a follow-up storm late in the week though who knows in what form.

[Quixotic1]

The 12z ECMWF is not cold enough at the surface for a significant winter storm at DFW. Raw model output shows surface temps are barely below freezing with -0.8°C the coldest (which is warmer than prior runs). H85 temps also warmed on this run. Temperatures must fall to at least 27°F for this to overcome the warm grounds. Though, QPF did increase on this run. It still looks very marginal to me and wouldn't be surprised if the afternoon AFD is very conservative this afternoon for the Metroplex counties.

 

Having said that, surrounding areas north and east of the Metroplex may get a decent event.

Nope.  

[ams30721us]

Snippet from FWD afternoon AFD:

 

 

 

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Area Forecast Discussion 
Issued by NWS Dallas/Fort Worth, TX

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000
FXUS64 KFWD 192205
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
405 PM CST THU FEB 19 2015

.DISCUSSION...
SKIES ARE PARTLY CLOUDY ACROSS NORTH TEXAS THIS AFTERNOON WITH
TEMPERATURES RANGING FROM NEAR 50 DEGREES AT PARIS TO NEAR 70
DEGREES IN THE SOUTHWEST PART OF THE CWA. SOUTHERLY WINDS ARE
HELPING TO TRANSPORT SOME MOISTURE NORTHWARD INTO THE REGION AND
THIS IS INDICATED BY AN AREA OF CUMULUS CLOUDS SPREADING NORTH
ALONG THE INTERSTATE 35 CORRIDOR. THESE SOUTHERLY WINDS ARE IN
RESPONSE TO DEEPENING LOW PRESSURE ACROSS THE TEXAS PANHANDLE
AHEAD OF A SHORTWAVE MOVING THROUGH THE ROCKIES. 3-HOUR PRESSURE
FALLS ARE ON THE ORDER OF 6-7MB ACROSS WEST TEXAS AND THIS WILL
CONTINUE TO HELP TIGHTEN THE PRESSURE GRADIENT ACROSS NORTH TEXAS
THROUGH THIS EVENING.

TODAY WILL BE THE LAST OF THE SUN WE WILL SEE FOR A WHILE AS
STRONG MOISTURE ADVECTION OVERNIGHT WILL LEAD TO A RAPID
INTRUSION OF LOW CLOUD COVER BY MORNING. AREAS OF DRIZZLE AND
PERHAPS SOME LIGHT RAIN ARE EXPECTED LATE TONIGHT INTO FRIDAY
MORNING...PARTICULARLY ALONG AND EAST OF THE I-35 CORRIDOR.
DESPITE THE CLOUD COVER...STRONG LOW LEVEL WARM ADVECTION WILL
ALLOW TEMPERATURES TO WARM INTO THE 70S AREAWIDE FRIDAY WITH THE
EXCEPTION OF THE FAR NORTHEAST WHERE PARIS WILL LIKELY REMAIN IN
THE LOWER 60S.

A SURFACE LOW IS EXPECTED TO DEVELOP ACROSS THE TEXAS PANHANDLE BY
FRIDAY NIGHT AS PERSISTENT HEIGHT FALLS CONTINUE TO OVERSPREAD THE
SOUTHERN PLAINS. THIS IS IN RESPONSE TO A LARGER SCALE TROUGH
MOVING INTO THE WESTERN US. BY EARLY SATURDAY...AS A LEAD
SHORTWAVE EJECTS EASTWARD...THE SURFACE LOW WILL MOVE EAST ACROSS
NORTH TEXAS AND DRAG A COLD FRONT THROUGH THE AREA. THIS INITIAL
FRONT WILL BE COLD...BUT MUCH COLDER AIR ASSOCIATED WITH A
STRONGER UPPER LOW OVER SOUTHEAST CANADA WILL FILTER INTO NORTH
TEXAS ON SUNDAY. IN THE MEANTIME...WILL MAINTAIN SOME LOW CHANCE
POPS BOTH FRIDAY NIGHT INTO SATURDAY JUST TO ACCOUNT FOR THE
MOISTURE IN PLACE AND WEAK ASCENT FROM THE SOUTHERN PLAINS
SHORTWAVE.

BY SUNDAY...MUCH COLDER AIR WILL MOVE INTO NORTH TEXAS DURING THE
MORNING HOURS. LOW LEVEL MOISTURE WILL REMAIN IN PLACE AND
FORECAST SOUNDINGS INDICATE THAT SATURATION WILL EXTEND FROM ABOUT
900-500MB. THIS SHOULD SET THE STAGE FOR AN INTERESTING SUNDAY
NIGHT INTO MONDAY ACROSS PARTS OF NORTH TEXAS. LATEST MODEL DATA
INDICATES THAT SURFACE TEMPERATURES WILL FALL TO BELOW FREEZING
ACROSS MUCH OF THE AREA LATE SUNDAY NIGHT. CONFIDENCE IS FAIRLY
HIGH THAT WE WILL SEE COLD TEMPERATURES...PARTICULARLY ACROSS THE
WESTERN HALF OF THE CWA. THINGS ARE LIKELY TO BE A LITTLE WARMER
EAST OF I-35. THE UPPER PATTERN SHOULD FEATURE A LARGE UPPER LOW
OVER SOUTHEAST CANADA WITH ANOTHER STRONG LOW OVER CALIFORNIA.
THIS PLACES NORTH TEXAS IN WEST-SOUTHWEST FLOW ALOFT DURING THIS
TIME. A WEAK UPPER LOW SOUTHWEST OF THE MAIN CALIFORNIA LOW WILL
QUICKLY GET ABSORBED INTO THE SOUTHWEST FLOW ALOFT. THE 12Z GFS
SEEMS TO BE STRONGEST WITH THIS FEATURE AND MOVES IT ACROSS NORTH
TEXAS LATE SUNDAY NIGHT. FORCING ASSOCIATED WITH THIS SHORTWAVE
REALLY HELPS TO RAMP UP THE LOW LEVEL WARM ADVECTION ATOP THE VERY
COLD AIR. THE 850MB FRONT IS LOCATED RIGHT ACROSS NORTH TEXAS AND
AS A RESULT...THE GFS GENERATES QUITE A BIT OF QPF WITH SUB-
FREEZING SURFACE TEMPERATURES. THE ECMWF ALSO SHOWS THIS FEATURE
ALTHOUGH IT IS NOT QUITE AS STRONG.

ANALYSIS OF LOW/MID LEVEL ISENTROPIC FIELDS SUGGESTS MODERATE TO
STRONG LIFT FROM 700-500MB LATE SUNDAY NIGHT...LIKELY AIDED BY
THIS ASCENT FROM THE EMBEDDED SHORTWAVE. THERE ARE A COUPLE OF
CONCERNS DURING THIS TIME. IT DOES APPEAR THAT TEMPERATURES WILL
BE COLD ENOUGH FOR SOME WINTRY PRECIPITATION LATE SUNDAY NIGHT
INTO MONDAY. MOISTURE DOES NOT APPEAR TO BE A PROBLEM BASED ON ALL
OF THE AVAILABLE GUIDANCE AND THE FACT THAT 850-700MB WINDS NEVER
REALLY GO NORTH TO SCOUR OUT ANY MOISTURE. THE MAIN CONCERN
THROUGH THIS TIME WILL BE LARGER SCALE FORCING FOR ASCENT. IF THE
EMBEDDED SHORTWAVE IS CONSIDERABLY WEAKER OR DOESNT EXIST AT
ALL...THE LIFT WILL BE HARD TO COME BY EVEN WITH THE 850MB FRONT
OVER NORTH TEXAS. AT THIS TIME...WE THINK AT LEAST SOME FORCING
WILL BE PRESENT SO HAVE INCLUDED WINTRY PRECIPITATION LATE SUNDAY
NIGHT INTO MONDAY.

FORECAST SOUNDINGS INDICATE THAT THE MAIN PRECIP TYPE WILL LIKELY
BE SLEET ACROSS THE NORTHWEST COUNTIES...WITH A SLIGHT WARM NOSE
IN THE 800-700MB LAYER AND SURFACE TEMPERATURES IN THE MID/UPPER
20S. IF TEMPERATURES WARM BY A FEW DEGREES IN THIS LAYER THEN WE
MAY BE DEALING WITH MORE OF A FREEZING RAIN EVENT. FOR NOW WILL
INDICATE A MIX OF SLEET AND FREEZING RAIN ACROSS A GOOD PORTION OF
NORTH TEXAS. COLDEST TEMPERATURES AND WORST IMPACTS AT THIS TIME
APPEAR TO BE ACROSS OUR NORTHWEST COUNTIES INTO MONDAY. WE WILL
CONTINUE TO ASSESS THE UPPER PATTERN OVER THE NEXT 48 HOURS AND IF
IT APPEARS THAT THE STRONG FORCING INDICATED BY THE LATEST MODELS
WILL INDEED BE PRESENT...THEN WE WILL LIKELY HAVE TO ISSUE SOME
WINTER WEATHER WATCH/ADVISORY OVER THE WEEKEND.

THE PRECIPITATION WOULD LIKELY COME TO AN END DURING THE DAY
MONDAY WITH COLD TEMPERATURES PERSISTING THROUGH THE WEEK. AS THE
MAIN UPPER LOW SHEARS OUT AND MOVES EAST MID/LATE WEEK WE MAY SEE
ADDITIONAL RAIN CHANCES.

DUNN

 

Welp....haven't mentioned watches or warnings yet this season really.

[ams30721us]

And something little from SHV:

 

 

 

 

 

Area Forecast Discussion 
Issued by NWS Shreveport, LA

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000
FXUS64 KSHV 192218
AFDSHV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
418 PM CST THU FEB 19 2015

.DISCUSSION...
THE NEXT SEVEN DAYS WILL BE QUITE ACTIVE AND PRESENT QUITE THE
FORECASTING CHALLENGE. FIRST...A SFC LOW OVER THE SRN HIGH PLAINS
WILL BEGIN TO MOVE SEWD WHILE A WARM FRONT LIFTS NEWD ACROSS THE
AREA TONIGHT. PRECIP SHOULD DEVELOP AFTER MIDNIGHT ACROSS MUCH OF
THE NW HALF OF THE CWA AS ISENTROPIC ASCENT INCREASES. TEMPS
SHOULD FALL BELOW FREEZING TONIGHT NORTH OF A LINE FROM ERN
MCCURTAIN COUNTY...TO KTXK...TO KELD. IN THESE AREAS...FCST
SOUNDINGS ARE STRONGLY SUPPORTIVE OF FREEZING RAIN DURING THE
EARLY MORNING HRS OF FRIDAY. PRECIP SHOULD TRANSITION TO ALL
LIQUID RAIN BY MID MORNING FRIDAY AS THE WARM FRONT MOVES NWD AND
TEMPS WARM. PRECIP RATES SHOULD BE LIGHT BUT ICE ACCUMULATIONS UP
TO ONE TENTH OF AN INCH WILL BE POSSIBLE. THUS...A FREEZING RAIN
ADVISORY HAS BEEN ISSUED.

PERIODS OF RAIN ARE LIKELY AREAWIDE THROUGH MUCH OF THE WEEKEND.
THE ENTIRE AREA SHOULD BE IN THE WARM SECTOR DURING THE WEEKEND
AND STRONG SLY WINDS ON SATURDAY WILL ALLOW FOR A VERY WARM AND
MOIST AIRMASS TO STREAM INTO THE AREA. IN FACT...HIGH TEMPERATURES
SATURDAY COULD VERY WELL BE IN THE MID 70S FOR MUCH OF THE AREA
SOUTH OF I-30. THE WARM AND MOIST AIR SHOULD RESULT IN ENOUGH
INSTABILITY TO SUPPORT SOME CONVECTION AHEAD OF THE STRONG COLD
FRONT DUE TO ARRIVE LATE SATURDAY AND INTO SUNDAY.

AS ARCTIC AIR FILTERS INTO THE REGION...MORE WINTRY PRECIP WILL BE
POSSIBLE SUNDAY NIGHT/MONDAY MORNING AND AGAIN MONDAY EVENING. THE
CHANCES FOR WINTRY PRECIP WILL LIKELY EXTEND FARTHER SOUTH ACROSS
MUCH MORE OF THE CWA. /09/

 

[Srain]

Afternoon briefing from Jeff:

 

Hope everyone enjoyed today…an extended period of cloudy cold weather will onset by Sunday and last much of next week.

 

Surface high moving eastward and a surface trough developing over west TX has allowed southerly winds to return to the region. Afternoon temperatures range from the upper 60’s around Matagorda Bay to the mid 50’s near the TX/LA state line. Warm air advection will increase tonight with a thick low level deck moving inland off the western Gulf of Mexico. Just enough lift is noted in the high resolution guidance to suggest a few passing showers or drizzle late tonight into much of Friday. Temperatures will warm into the 70’s on Friday with warm air advection even with extensive cloud cover.

 

Decent looking short wave will move across the area on Saturday with enough lift to likely generate a few showers and thunderstorms. Highs on Saturday will reach well into the 70’s…and this will be the warmest day by far of the next several. This system will more importantly usher in another strong arctic cold front on Sunday. Front will progress across the area during the day with temperatures falling from the 60’s and 70’s in the morning into the 40’s during the afternoon hours. Guidance is likely not handling this very cold shallow air mass very well and it is possible that temperatures could fall into the 30’s by Sunday evening. Troughing hangs back over the SW US keeping warm air riding up and over the surface cold dome into early next week for a soggy and cold forecast. Do not expect temperatures to make it out of the 40’s on Monday and would not be surprised to see some areas remain in the 30’s all day.

 

Critical time period is narrowing in on Monday night into Tuesday morning as near/sub freezing temperature line may push southward into the region especially if the models are under-forecasting the intensity of this cold air mass. Moisture and lift will likely be maintained into Monday night/Tuesday morning suggesting a potential for P-type concerns. Main concern area at the moment will be along and north of a line from College Station to Livingston. Forecast model profiles show a strong warm nose (pocket of above freezing air) a few thousand feet above the surface suggesting main P-type would be rain or possibly freezing rain where surface temperatures fall to freezing. GFS is much colder than the ECMWF model which keeps most of the area above freezing. For now will keep all precipitation liquid across the entire area, but watch temperature trends very closely over the weekend. If the ECMWF begins to trend toward the colder GFS solution then a very challenging forecast would be possible for early next week across SE TX.

[DFWWeather]

Nope.  

 

For the immediate Metroplex, they were pretty conservative with a caveat it could go either way. Admittedly, it all depends where the 850mb front hangs up and if there is the lift expected as advertised covered in the discussion. If this is an all sleet event it will help tremendously getting temperatures down. If it ends up being freezing rain, then it depends on how heavy as that could end up warming the surface. The current 12z ECMWF is too warm though.

[vwgrrc]

For the immediate Metroplex, they were pretty conservative with a caveat it could go either way. Admittedly, it all depends where the 850mb front hangs up and if there is the lift expected as advertised covered in the discussion. If this is an all sleet event it will help tremendously getting temperatures down. If it ends up being freezing rain, then it depends on how heavy as that could end up warming the surface. The current 12z ECMWF is too warm though.

But I guess freezing rain causes much more troubles than sleet does

[vwgrrc]

Snippet from FWD afternoon AFD:

Welp....haven't mentioned watches or warnings yet this season really.

Wondering why there's no special statement at this time...giving this setup

[ams30721us]

Wondering why there's no special statement at this time...giving this setup

 No need to this early...

[vwgrrc]

18z GFS hints an almost 24-hour frz precip event for dfw metro. But again surface temps kinda of marginal!

[aggiegeog]

The key to all of this is how far south the West Coast low digs before shearing out. The further south the better for getting good moisture and forcing into our area. Also if it digs then it is more likely to come across as a strong low late in the week. if it shears out over north central CA then all we will get is a series of weak waves.

[vwgrrc]

No need to this early...

Interestingly enough, they issued special statement last Friday for the potential Tuesday event. And they were similarly pro active for most cold rain events we had this winter. I guess NWS probably don't think this can be a significant one.

[ams30721us]

Interestingly enough, they issued special statement last Friday for the potential Tuesday event. And they were similarly pro active for most cold rain events we had this winter. I guess NWS probably don't think this can be a significant one.

LOL...

They don't think this can be a significant event but even mention the potential of even a Winter Storm Watch likely being issued this weekend if trends continue??

 

FWD:

 

 

 WE WILL

CONTINUE TO ASSESS THE UPPER PATTERN OVER THE NEXT 48 HOURS AND IF

IT APPEARS THAT THE STRONG FORCING INDICATED BY THE LATEST MODELS

WILL INDEED BE PRESENT...THEN WE WILL LIKELY HAVE TO ISSUE SOME

WINTER WEATHER WATCH/ADVISORY OVER THE WEEKEND.

[bubba hotep]

At this point, I'm not worried about temps and am more concerned with the impulse that kicks out across Texas to make or break this event. Models may not truly pickup on that until Sunday. Now to peruse the afternoon AFDs on the train ride.

[vwgrrc]

0z comes in, very consistent. A bit wetter

[bubba hotep]

0z comes in, very consistent. A bit wetter

 

The main changes that I noticed, the subtle S/W kicking out was a bit more energetic and the warm nose doesn't look as deep.  Those are minor fluctuations that could be the start of a trend or just model noise. 

[vwgrrc]

The main changes that I noticed, the subtle S/W kicking out was a bit more energetic and the warm nose doesn't look as deep. Those are minor fluctuations that could be the start of a trend or just model noise.

It also hints the p type transition happens earlier late Sunday. If that holds true, we probably will have a significant event, the ones would bring power outages.

[aggiegeog]

It sure is looking like a widespread sleet event from late Sunday through Monday especially north of I-20 where not everyone looks to get over .5 inches of sleet and depending on how strong the system is some may get closer to 2 inches of sleet.

[vwgrrc]

It sure is looking like a widespread sleet event from late Sunday through Monday especially north of I-20 where not everyone looks to get over .5 inches of sleet and depending on how strong the system is some may get closer to 2 inches of sleet.

But GFS also shows surface temps at 40 late Sunday night. Does that mean no accumulation even sleet/fr fall?

[aggiegeog]

But GFS also shows surface temps at 40 late Sunday night. Does that mean no accumulation even sleet/fr fall?

We will just have to watch the temperature trends for when the freezing precip will start as models will struggle to nail it down as we have often seen. I do expect most of Texas to stay below freezing on Monday.

[DoctorMu]

ice very possible in SE Texas.  

The shallow cold will (overperform)  Timing is everything.

 

 

 

 

 

[vwgrrc]

ice very possible in SE Texas.

The shallow cold will (overperform) Timing is everything.

dfw 8 inches of snow...lol

[David Reimer]

Closer look at what precipitation the 0Z GFS expects Sunday Night into Monday. Keep in mind this graphic shows liquid equivalents of all p-types. The normal ratio of sleet/liquid is 3:1 with snow around 10:1. Many factors determine what the actual ratio is for an event. 

 

[ams30721us]

Chengong910 can get interested now....FWD has issued a "Special Weather Statement!" 

 

 

 

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
421 AM CST FRI FEB 20 2015

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-202230-
MONTAGUE-COOKE-GRAYSON-FANNIN-LAMAR-YOUNG-JACK-WISE-DENTON-COLLIN-
HUNT-DELTA-HOPKINS-STEPHENS-PALO PINTO-PARKER-TARRANT-DALLAS-
ROCKWALL-KAUFMAN-VAN ZANDT-RAINS-EASTLAND-ERATH-HOOD-SOMERVELL-
JOHNSON-ELLIS-HENDERSON-COMANCHE-MILLS-HAMILTON-BOSQUE-HILL-
NAVARRO-FREESTONE-ANDERSON-LAMPASAS-CORYELL-BELL-MCLENNAN-FALLS-
LIMESTONE-LEON-MILAM-ROBERTSON-
INCLUDING THE CITIES OF...BOWIE...NOCONA...GAINESVILLE...
SHERMAN...DENISON...BONHAM...PARIS...GRAHAM...OLNEY...JACKSBORO...
DECATUR...BRIDGEPORT...DENTON...LEWISVILLE...FLOWER MOUND...
THE COLONY...PLANO...GREENVILLE...COMMERCE...COOPER...
SULPHUR SPRINGS...BRECKENRIDGE...MINERAL WELLS...WEATHERFORD...
BRIAR...FORT WORTH...ARLINGTON...DALLAS...ROCKWALL...TERRELL...
KAUFMAN...FORNEY...WILLS POINT...CANTON...GRAND SALINE...VAN...
EDGEWOOD...EMORY...POINT...EAST TAWAKONI...CISCO...EASTLAND...
RANGER...GORMAN...STEPHENVILLE...DUBLIN...GRANBURY...
OAK TRAIL SHORES...GLEN ROSE...CLEBURNE...BURLESON...WAXAHACHIE...
ENNIS...MIDLOTHIAN...GLENN HEIGHTS...ATHENS...GUN BARREL CITY...
COMANCHE...DE LEON...GOLDTHWAITE...HAMILTON...HICO...CLIFTON...
MERIDIAN...VALLEY MILLS...HILLSBORO...CORSICANA...TEAGUE...
FAIRFIELD...PALESTINE...LAMPASAS...COPPERAS COVE...GATESVILLE...
KILLEEN...TEMPLE...FORT HOOD...WACO...MARLIN...MEXIA...
GROESBECK...BUFFALO...CENTERVILLE...JEWETT...OAKWOOD...CAMERON...
ROCKDALE...HEARNE...FRANKLIN...CALVERT
421 AM CST FRI FEB 20 2015

...WINTER STORM OUTLOOK FOR NORTH AND CENTRAL TEXAS...

AN UPPER LEVEL STORM SYSTEM IS EXPECTED TO MOVE OVER NORTH AND
CENTRAL TEXAS FROM SUNDAY NIGHT THROUGH MONDAY BRINGING A CHANCE
OF WINTRY PRECIPITATION ACROSS THE REGION.

PRECIPITATION IS EXPECTED TO DEVELOP ACROSS THE REGION FROM WEST
TO EAST SUNDAY EVENING. PRECIPITATION MAY START OUT IN LIQUID
FORM...HOWEVER AS TEMPERATURES DROP SUNDAY EVENING AND
OVERNIGHT...RAINFALL IS EXPECTED TO CHANGE OVER TO FREEZING RAIN
OR SLEET FOR PARTS OF THE REGION. WHEREVER TEMPERATURES ARE BELOW
FREEZING...FREEZING RAIN AND SLEET ACCUMULATIONS WILL BE POSSIBLE.
THE FREEZING LINE IS EXPECTED TO EXIST SOMEWHERE ACROSS NORTH
CENTRAL TEXAS DURING THIS EVENT...COMPLICATING THE FORECAST.

AT THIS TIME...LOCATIONS ALONG AND NORTHWEST OF A LINE FROM
COMANCHE TO DALLAS TO BONHAM ARE THE MOST LIKELY TO SEE
SUBFREEZING TEMPERATURES WHILE PRECIPITATION IS FALLING...HOWEVER
CONFIDENCE IN THE EXACT POSITION OF THE FREEZING LINE IS SOMEWHAT
LOW AT THIS TIME. PRECIPITATION AMOUNTS ARE SUPPORTIVE OF ICE AND
SLEET ACCUMULATIONS THAT COULD CAUSE TRAVEL AND POWER PROBLEMS
AS EARLY AS MONDAY MORNING IF TEMPERATURES ARE COLD ENOUGH. AS A
RESULT...THIS WINTER STORM OUTLOOK IS BEING ISSUED TO HIGHLIGHT
THE POTENTIAL FOR TRAVEL AND POWER DISRUPTIONS FROM LATE SUNDAY
NIGHT THROUGH MONDAY EVENING.

ANY SIGNIFICANT WINTRY ACCUMULATIONS ARE EXPECTED TO COME TO AN
END FROM NORTHWEST TO SOUTHEAST MONDAY EVENING.

CHECK THE FORECAST THROUGHOUT THE WEEKEND AS SLIGHTLY WARMER OR
COOLER TEMPERATURES WILL LIKELY RESULT IN SIGNIFICANT CHANGES TO
THE IMPACTS OF ANY WINTRY PRECIPITATION ACROSS THE REGION.

[ams30721us]

and...SHV follows:

 

 

 

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
403 AM CST FRI FEB 20 2015

ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077-
TXZ096-097-108>112-124>126-136>138-149>153-165>167-211400-
SEVIER-HOWARD-LITTLE RIVER-HEMPSTEAD-NEVADA-MILLER-LAFAYETTE-
COLUMBIA-UNION AR-CADDO-BOSSIER-WEBSTER-CLAIBORNE-LINCOLN-
UNION LA-DE SOTO-RED RIVER-BIENVILLE-JACKSON-OUACHITA-SABINE LA-
NATCHITOCHES-WINN-GRANT-CALDWELL-LA SALLE-MCCURTAIN-BOWIE-
FRANKLIN-TITUS-CAMP-MORRIS-CASS-WOOD-UPSHUR-MARION-SMITH-GREGG-
HARRISON-CHEROKEE-RUSK-PANOLA-NACOGDOCHES-SHELBY-ANGELINA-
SAN AUGUSTINE-SABINE TX-
INCLUDING THE CITIES OF...DE QUEEN...NASHVILLE...ASHDOWN...HOPE...
PRESCOTT...TEXARKANA...LEWISVILLE...MAGNOLIA...EL DORADO...
SHREVEPORT...BOSSIER CITY...MINDEN...HOMER...RUSTON...
FARMERVILLE...MANSFIELD...COUSHATTA...BIENVILLE...JONESBORO...
MONROE...MANY...NATCHITOCHES...WINNFIELD...COLFAX...COLUMBIA...
JENA...IDABEL...CLARKSVILLE...MT VERNON...MT PLEASANT...
PITTSBURG...DAINGERFIELD...ATLANTA...QUITMAN...GILMER...
JEFFERSON...TYLER...LONGVIEW...MARSHALL...RUSK...HENDERSON...
CARTHAGE...NACOGDOCHES...CENTER...LUFKIN...SAN AUGUSTINE...
HEMPHILL
403 AM CST FRI FEB 20 2015

...A BITTERLY COLD AIRMASS WILL AFFECT THE FOUR STATE REGION
SUNDAY NIGHT INTO MONDAY WITH WINTER PRECIPITATION EXPECTED ACROSS
A LARGE PORTION OF THE REGION...

THE LEADING EDGE OF A STRONG ARCTIC AIRMASS WILL BEGIN TO MOVE
INTO THE REGION LATE SATURDAY WITH REINFORCING PIECES OF COLD AIR
DROPPING SOUTH OUT OF THE SOUTHERN PLAINS SUNDAY INTO SUNDAY
NIGHT. DISTURBANCES FROM THE WEST WILL PROVIDE THE LIFT NECESSARY
FOR OVERRUNNING MOISTURE TO MOVE BACK IN THE REGION ON SUNDAY WITH
JUST A COLD RAIN EXPECTED.

HOWEVER...AS WE MOVE INTO SUNDAY NIGHT...COLD AIR ADVECTION IS
STRONG IN THE LOWER LEVELS OF THE ATMOSPHERE AND THIS WILL ALLOW
FOR THE COLD RAIN TO TRANSITION OVER TO MIXED WINTER PRECIPITATION
ACROSS THE REGION. WHILE PRECIPITATION TYPE IS VERY UNCERTAIN AT
THIS TIME...A MIXTURE OF FREEZING RAIN AND SLEET APPEARS PROBABLY
ACROSS NORTH LOUISIANA AND MUCH OF NORTHEAST TEXAS...WHILE FURTHER
NORTH ACROSS SOUTHERN ARKANSAS AND SOUTHEAST OKLAHOMA...A MIXTURE
OF SLEET AND SNOW WILL BE POSSIBLE. THIS PRECIPITATION IS LIKELY
TO CONTINUE INTO MONDAY WITH MANY AREAS STRUGGLING TO GET MUCH
ABOVE FREEZING DURING THE DAY...IF AT ALL.

AS THE EVENT NEARS...AMOUNTS WILL BECOME MORE CERTAIN...AS WILL
THE PRECIPITATION TYPE. PLEASE STAY TUNED AND CONTINUE TO MONITOR
THE WEATHER FORECAST AS THIS POTENTIAL WINTER STORM MOVES INTO THE
FOUR STATE REGION SUNDAY NIGHT INTO MONDAY.
 

[ams30721us]

SHV AM AFD:

 

 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
506 AM CST FRI FEB 20 2015

.DISCUSSION...
A LOT GOING ON THIS FCST PACKAGE. INCREASING LIFT ACROSS AREA THIS
MORNING BEGINNING TO PREDUCE VERY LGT WARM AIR ADVECTION PRECIP
ACROSS THE AREA THIS MORNING. CANCELLED FRZG RAIN ADVISORY FOR
MORNING HOURS OVER SW AR/SE OK...AS TEMPS HAVE SLOWLY RISEN
OVERNIGHT TO JUST ABOVE FRZG...AND ANY PRECIP THAT REACHES THE
GROUND LIKELY TO REMAIN TOO LGT TO TAKE ADVANTAGE OF LOW DEWPOINTS
FOR SIGNIFICANT EVAP COOLING. GRADUAL INCREASE OF ELEVATED
INSTABILITY ABOVE LOW LVL INVERSION WILL MAKE PRECIP MORE SHOWERY
BY AFTN. S-SE WINDS OVER NE TX TO INCREASE TO 15 TO 20 MPH BY MIDDAY...
WARRANTING A LAKE WIND ADVISORY WHICH WILL EXTEND UNTIL MID
MORNING SATURDAY...WHICH WILL BE APPROX TIME OF COLD FRONT
WINDSHIFT. THESE SOUTH WINDS WILL ALSO ALLOW TEMPS TO REMAIN
STEADY OR EVEN RISE OVERNIGHT FRIDAY NIGHT. REMAINING PORTIONS OF
AREA WILL LIKELY NEED TO BE INCLUDED IN A SEPARATE LAKE WIND
ADVISORY...WHICH DAY SHIFT WOULD ISSUE FOR THE EVE AND OVERNIGHT
HOURS FOR SE OK/SW AR/NRN LA. AS 50 TO 60 KT LOW LVL JET...ALONG
WITH EXIT REGION OF STG MID LVL JET...AND ERASURE OF LOW LVL
INVERSION...COMBINE TO PRODUCE TSTMS BY LATE FRIDAY NIGHT INTO
EARLY SAT. PORTIONS OF LA THAT RECEIVE AMPLE DAYTIME HEATING
BEFORE FROPA SAT AFTN MAY SEE RATHER VIGOROUS TSTM ACTIVITY...WITH
SVR WX NOT OUT OF THE QUESTION.
A COLD POST FRONTAL RAIN SATURDAY NIGHT WILL DIMINISH.
HOWEVER...OVERRUNNING MOISTURE RETURNING ON SUNDAY WITH TEMPS
REMAINING NEAR STEADY DURG THE DAYTIME...WILL LIKELY TRANSITION TO
A WINTRY MIX OVER NORTHERN SECTION OF THE AREA SUNDAY
NIGHT...INITIALLY AS FRZG RAIN UNTIL WARM NOSE ALOFT DISAPPEARS
WITH CONTINUED COLD AIR ADVECTION. DEEP SUBFREEZING MOISTURE
LAYERS ON MONDAY MAY HOLD TEMPS TO BELOW FRZG THROUGHOUT THE
DAY...WITH AN INCREASING CHANCE FOR SLEET AND SNOW TO AND POSSIBLE
LIGHT ACCUMULATION....BEFORE PRECIP ENDS FROM THE NORTH MONDAY
EVE. TEMPS TO REMAIN UNSEASONALLY COLD IN THIS DEEP ARCTIC AIRMASS
THROUGH MOST OF THE WEEK...WITH RAIN AND POSSIBLY A WINTRY MIX FOR
LATE IN THE WORKWEEK./VII/

[1900hurricane]

HGX has thrown in a mention of freezing rain here in College Station.

[Srain]

HGX is suggesting IAH may flirt with freezing temperatures Monday afternoon/evening and that the overnight models trended a bit colder. That said it is going to be a close call and with warm ground temperatures, not many issues are expected across Metro Houston but they are going to monitor the trends very closely today into the weekend. The 09Z SPC SREF Ensemble longer range does suggest there may be some p-type issues, but we will need to watch the trends into tomorrow to see if there is any real shot of a wintry mix across Metro Houston. Remember these events are always a forecast challenge and depending on sounding data and temperature profiles beyond 12 to 24 hours out is like rolling the dice at a craps table in Las Vegas.

 

 

[bubba hotep]

My disdain for the SREF may only be eclipsed by DFWwxs disdain for the 06z/18z GFS runs  But here we go anyway, 09 SREF mean has DFW down to 25 by 15z on Monday with mean QPF at 0.41 with about half of that coming after DFW goes below freezing.   

 

ETA:  Morning Graphic from FWD