More cold air on the way next week!?

[Kludge]

WxMan57... AUS and DFW are exact duplicates? Could be a typo.....?

[sleetstorm]

And a rain snow mix?

[wxman57]

WxMan57... AUS and DFW are exact duplicates? Could be a typo.....?

I think that's your imagination - look again.

Thanks for catching it, I had two Austin meteograms.

[wxman57]

I thought that upper to mid thirties were cold enough to support sleet guys?

Sleet isn't determined by the temperature at the surface, sleetstorm. Well, it sort of is, if it's 90 degrees at the surface then sleet would melt before hitting the ground. Sleet forms when rain falls into a sub-freezing layer above the surface. This layer of sub-freezing air could be 1000-2000 feet above the ground while temps at the ground are in the 30s or 40s. The rain falls into the freezing air, freezes into sleet, then falls to the ground without melting first if the temps near the surface aren't too warm. Additionally, snow could fall into a warm layer, melt, then re-freeze 2000-5000 feet above the ground and fall as sleet.

But just because the surface temperature is in the 30s doesn't mean there is a sub-freezing layer just above the surface. Sometimes, we're in the 30s at the ground with air temperature in the 40s or even 50s aloft. A vertical profile like that allows for only cold rain. And that's what it looks like for us next week. Too thick a warmer layer aloft to allow for anything frozen to survive to the ground.

[Andrew]

I think at this point it is way to early to say we will have no wintry precip etc. I mean if the temps are just a couple of degrees colder than what is expected, things could be a lot different. Let's hope for the best as I want some wintry precip because non Wintry precip cold weather is always bad. I hope summer comes fast.

[wxman57]

I think at this point it is way to early to say we will have no wintry precip etc. I mean if the temps are just a couple of degrees colder than what is expected, things could be a lot different. Let's hope for the best as I want some wintry precip because non Wintry precip cold weather is always bad. I hope summer comes fast.

Yes, it's too early to eliminate the possibility of winter precip (sleet in this case), but it's not too early to forecast the more likely scenario (cold rain with maybe a few sleet pellets mixed in as the precip ends). A forecast is always whatever a meteorologist thinks is most likely to happen. In most cases, a forecast doesn't preclude other possibilities.

[Andrew]

I think at this point it is way to early to say we will have no wintry precip etc. I mean if the temps are just a couple of degrees colder than what is expected, things could be a lot different. Let's hope for the best as I want some wintry precip because non Wintry precip cold weather is always bad. I hope summer comes fast.

Yes, it's too early to eliminate the possibility of winter precip (sleet in this case), but it's not too early to forecast the more likely scenario (cold rain with maybe a few sleet pellets mixed in as the precip ends). A forecast is always whatever a meteorologist thinks is most likely to happen. In most cases, a forecast doesn't preclude other possibilities.

Well yes and as most of the time cold rain happens. Just hoping for that 5% chance we will have another wintry event.

[srainhoutx]

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
211 PM EST SUN FEB 07 2010

VALID 12Z WED FEB 10 2010 - 12Z SUN FEB 14 2010


...ANOTHER WINTER STORM BREWING FOR PARTS OF THE MID ATLANTIC AND
NORTHEAST...


PRELIMINARY UPDATE...

USED THE 00Z/07 GEM GLOBAL...DILUTED WITH ONE-THIRD 00Z/07 ECENS
MEAN...FOR DAY 3 ACROSS THE NATION...WITH AN EVEN BLEND OF THIS
GUIDANCE THEREAFTER THROUGH DAY 7. THE GEM GLOBAL AND UKMET ARE
THE FARTHEST SOUTH OF THE DETERMINISTIC MODELS WITH THE EAST COAST
CYCLONE DAYS 3 AND 4...CLOSER TO THE CLIMATOLOGY OF THIS WINTER.
THE BLOCK OVER EASTERN CANADA DOES LOOK AS IF IT WILL RELAX ENOUGH
TO ALLOW THE STORM TO DEVELOP NORTH OF THE MOST RECENT
SYSTEM...WITH A GREATER THREAT TO NEW YORK CITY AND THE SOUTHERN
COAST OF NEW ENGLAND. STILL...THE COMMA HEAD PART OF THE CYCLONE
MAY PASS ACROSS SOME OF THE AREAS HARDEST HIT BY THIS PAST
WEEKENDS SNOWSTORM. ELSEWHERE...THE FLOW IS RATHER
SUPPRESSED...WITH CALIFORNIA THE MOST UNSETTLED REGION DUE TO THE
ONGOING PACIFIC JET DIVING INTO THE STATE. A WAVE IS EXPECTED TO
CROSS THE GULF OF MEXICO DURING THE SECOND HALF OF THE
PERIOD...AND THERE IS PLENTY OF ROOM FOR THE LOW TO TRACK FARTHER
NORTH BY THE TIME IT REACHES THE SOUTHEAST COASTAL WATERS.


FINAL...

THE GFS TRENDED STRONGLY TOWARD THE LAST COUPLE GEM SOLUTIONS THIS
RUN OFF THE MID ATLANTIC COAST...AND WITH THE SUPPORT OF THE
UKMET...COMMITTED MORE FIRMLY TO ANOTHER SIGNIFICANT WINTER STORM
OVER THE MID ATLANTIC REGION FOR THE FINAL PACKAGE...INCLUDING NEW
YORK CITY AND LONG ISLAND DAYS 3 AND 4. THE ECMWF TRENDED
SOUTHWARD SINCE ITS 00Z/07 RUN...BUT STILL IS NOT CLUSTERED WITH
THE OTHER MODELS WITH A SOLUTION THAT FITS THE CLIMATOLOGY OF THIS
WINTER SEASON. A MAJOR CHANGE FOR THE FINAL PROGS WAS MADE ALONG
THE GULF COAST...WHERE THE GFS AND GEM GLOBAL CAME MARKEDLY NORTH
WITH THE WAVE PASSING ACROSS THE REGION DAYS 5 AND 6. USED THE
TIMING OF THE GEM GLOBAL TO ADJUST THE FINAL MAPS...BUT TURNED THE
CYCLONE MORE SHARPLY TOWARD THE SOUTHEAST COAST DAY 6 TO AT LEAST
TREND TOWARDS CLIMATOLOGY. WOULD NOT BE SURPRISED TO SEE THE
MODELS TREND ALL THE WAY TO CAPE HATTERAS WHEN ALL IS SAID AND
ONE.

CISCO

[kayci]

Folks from Del Rio to Austin, College Station and points E and N may have some issues with wintery precip if the 12Z GFS is correct. A long way to go just yet and we know things will change several times between now and Friday, but bears watching IMHO.

To all my friends/family in Austin & Buda... get ready and bundle up!!!!!

[sleetstorm]

What computer model or models showed southeast Texas feasbily receiving frozen winter precipitation, srainhoutx, wxdata, Portastorm, Don, and Mr. T

[wxman57]

What computer model or models showed southeast Texas feasbily receiving frozen winter precipitation, srainhoutx, wxdata, Portastorm, Don, and Mr. T

No model predicts freezing or frozen precip here, sleetstorm.

[harpman]

What computer model or models showed southeast Texas feasbily receiving frozen winter precipitation, srainhoutx, wxdata, Portastorm, Don, and Mr. T

No model predicts freezing or frozen precip here, sleetstorm.

Boy, he's tryin', huh?

[srainhoutx]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
338 PM CST SUN FEB 7 2010

.DISCUSSION...
MOISTURE WILL CONTINUE TO ADVECT INTO THE LOWER LEVELS THIS EVENING
AND OVERNIGHT. ANOTHER ROUND OF FOG AND DRIZZLE WILL DEVELOP TONIGHT.
PATCHY DENSE FOG IS POSSIBLE ESPECIALLY IN THE NEAR-DAYBREAK HOURS.
WITH OVERCAST AND DAMP CONDITIONS OVERNIGHT...MONDAY MORNING LOW
TEMPERATURES WILL ONLY BE A FEW DEGREES COOLER THAN WHAT WE HAD
FOR TODAY`S HIGHS.

CHANCES FOR MEASURABLE RAIN WILL INCREASE OVERNIGHT AND INTO
MONDAY AHEAD OF AN APPROACHING COLD FRONT. A FEW THUNDERSTORMS ARE
POSSIBLE MAINLY ACROSS THE EASTERN HALF OF THE REGION MONDAY
AFTERNOON...WITH THE RAIN ENDING FROM WEST TO EAST MONDAY EVENING
AS THE COLD FRONT PUSHES THROUGH. STRONG NORTH WINDS WILL SETTLE
IN MONDAY NIGHT THROUGH TUESDAY AFTERNOON...AND WILL PROBABLY
REACH WIND ADVISORY CRITERIA (26 MPH OR GREATER). THE STRONG WINDS
COUPLED WITH THE COLD AIR ADVECTION WILL ENABLE WIND CHILL READINGS
TUESDAY MORNING TO DROP INTO THE 20S WITH UPPER TEENS POSSIBLE
ACROSS THE HILL COUNTRY. WINDS WILL GRADUALLY DECREASE ON TUESDAY
AND A FREEZE IS EXPECTED ACROSS MUCH OF THE REGION TUESDAY NIGHT.

BY WEDNESDAY THE FORECAST BECOMES A BIT TRICKIER WITH MODELS STILL
HAVING A DIFFICULT TIME AGREEING ON AN APPROACHING UPPER LEVEL
TROUGH. THE GFS SOLUTION CONTINUES TO BE SLOWER WITH THE PROGRESSION
OF THIS SYSTEM AND THUS IS A VERY WET OUTLIER. BOTH THE CANADIAN
AND ECMWF SOLUTIONS ARE MORE PROGRESSIVE. HAVE GONE WITH A BLEND
RESULTING IN DRIER CONDITIONS THAN HINTED AT BY THE GFS...BUT
STILL A WET PATTERN FOR THE MIDDLE OF THE WEEK. THE CONCERN THEN
SHIFTS TO WHETHER THE PRECIP WILL BE LIQUID OR A MIX OF WINTERY
PRECIP. FORECAST SOUNDINGS FOR SOUTH CENTRAL TEXAS SHOW THE
POSSIBILITY OF A SNOW/RAIN MIX FOR WEDNESDAY BECOMING A
SNOW/RAIN/SLEET MIX WEDNESDAY NIGHT BEFORE TURNING TO ALL RAIN BY
THURSDAY MORNING AS THE LOWER LEVELS BECOME MORE SATURATED.
DESPITE THE FRUSTRATINGLY LOW CONFIDENCE OVER A MIXED-BAG
FORECAST...CONFIDENCE IS MUCH HIGHER THAN SHOULD WINTERY
PRECIPITATION OCCUR...LITTLE TO NO ACCUMULATIONS ARE EXPECTED.

San Angelo...

.LONG TERM...
GFS ENSEMBLE CONTINUES TO BE IN FAVOR OF DIGGING A TROF OF LOW
PRESSURE OFF OF THE PACIFIC NW COAST SOUTH TOWARDS NORTHERN BAJA
BY WEDNESDAY AFTERNOON. AT THIS POINT...THE UPPER TROF BECOMES A
CLOSED LOW. THE ECMWF MODEL CONTINUES TO BECOME IN BETTER AGREEMENT
WITH THE GFS. HOWEVER...THE ECMWF DOESN`T DIG THE SYSTEM AS MUCH
AS THE GFS ENSEMBLE.

FOR NOW...PLAN TO GO WITH THE GFS ENSEMBLE SOLUTION BECAUSE OF ITS
CONSISTENT PERFORMANCE LATELY. AS THIS OCCURS...ISENTROPIC LIFT SHOULD
DEVELOP ACROSS A LARGE PART OF WC TX BY WED AFTERNOON AND EVENING.
TOP DOWN APPROACH WITH TEMPS AT OR BELOW THE MID 30S ON WED AND
THEN WET BULBING TO NEAR FREEZING WED NIGHT SHOULD SUPPORT LIGHT
SNOW ACROSS A LARGE PART OF THE REGION.

THE TRICKY PART OF THE FORECAST COMES INTO PLAY THURSDAY INTO
THURSDAY NIGHT AS THE UPPER LOW APPROACHES WC TX. GFS SOUNDINGS
AND SURFACE PROG SHOW THE COLD UPPER LOW TO CROSS SOUTH OF THE
AREA THURSDAY NIGHT INTO FRIDAY MORNING. AS THIS OCCURS...THE LATEST
GFS MODEL SHOWS A SURFACE LOW DEVELOPING OFF THE LOWER TX COAST.
GFS SOUNDINGS INDICATED A COOLING AIR COLUMN THAT COULD BE
SUPPORTIVE OF MORE SNOW THURSDAY INTO FRIDAY MORNING.
HOWEVER...SINCE THERE IS MUCH UNCERTAINTY FROM THURSDAY THROUGH
FRIDAY MORNING...WILL CONTINUE TO MENTION A RAIN/SNOW MIX.

THIS PATTERN HAS THE POTENTIAL OF PRODUCING SIGNIFICANT SNOWFALL
ACROSS PARTS OF OUR CWA IF THE COLD AIR REMAINS IN PLACE...AND
THE UPPER LOW TRACKS JUST TO THE SOUTH OF THE CWA. PLAN TO ISSUE
AN SPS HIGHLIGHTING THE POTENTIAL OF VERY LIGHT WINTER WEATHER
MONDAY EVENING ACROSS THE BIG COUNTRY...AND THE SNOW POTENTIAL ON
WED...WED NIGHT AND BEYOND.

DECIDED TO CONTINUE TO UNDERCUT MOS TEMPS BY TRENDING SLIGHTLY
LOWER ON MAX TEMPS FOR WED THROUGH THURSDAY.

[Portastorm]

Ed, keep in mind the normally trusty Euro has been the one to come around to the GFS solution and not vice versa. I'm not suggesting that it's going to sleet or snow in your backyard ... but the Euro has been playing catch-up on this pattern and I would be cautious basing a forecast solely on the Euro.

Srainhoutx, I saw that AFD as well. Not sure what to think. How they can be so confident in "little to no accumulation" escapes me unless they expect QPF to be light until Thursday when they expect the entire air column to warm and be fully saturated. I dunno.

[sleetstorm]

What computer model or models showed southeast Texas feasbily receiving frozen winter precipitation, srainhoutx, wxdata, Portastorm, Don, and Mr. T

No model predicts freezing or frozen precip here, sleetstorm.

Okay, thank you, wxman57.

[sleetstorm]

What computer model or models showed southeast Texas feasbily receiving frozen winter precipitation, srainhoutx, wxdata, Portastorm, Don, and Mr. T

No model predicts freezing or frozen precip here, sleetstorm.

Boy, he's tryin', huh?

Who is trying, harpman, me or wxman57, and trying to do what?

[DMWTex]

The great debate, To be or Not to be

[ticka1]

My question is when will the sun shine again?

[Paul]

IMO, we will have cold weather but not cold enough aloft to support snow or sleet. No model is showing such a scenario down here....there is no debate...

[Katdaddy]

Yep I agree with Wxman57 and Paul. To get frozen precip in the Hou-Gal area you must have the depth of freezing temps at all layers of the atmosphere. Remember we at sea level.....very difficult to get snow.