Texas winter wx thread (2009-2010)

[Portastorm]

Wxman57 or txagwxman ... when you see a particular progged surface temperature per a given computer model, does the model figure evaporative cooling into its equation?

In other words, if the 12z GFS says it will be 35 degrees at 12 noon tomorrow in Austin while snowing, has the model evaluated the potential evaporative cooling effect into its guess at what the temperature will be at that time?

[shibumi]

That doesn't sound right to me...I saw an earlier post on the snow maps...those maps should be "Accumulating" snow maps...meaning measured snow on the ground...not how much has fallen and melted...snow fallen but not sticking as a measurement in snow inches is not a statistic that the NWS collects

It has to be accumulated as there is no way to measure what melts directly....you would have to take the liquid equivalent and use some assumed ratio to estimate it....

Thus you can have snow in your forecast...have it fall for some time, and have no accumulations....which means you can be outside of those snow maps and still see snow...

They are snow accumulation maps, but they may not represent snow in the ground at any one time. Consider if you get an inch of snow in a burst. You can measure it - an inch. The snow melts over the next hour then you get another inch. That's 2" accumulated snow, but you don't have 2" on the ground at any one time. It's more complex when snow is falling then melting not long after then it snows again. At least, that's the way I understand it.

That sounds reasonable...but that requires manpower to actually properly measure it...and we all know the NWS has been parred down people wise for quite a while...will be hard to verify their forecast maps if that much work is required!

If the NWS suddenly switched from using the GFS for this event and none of the NAM data to suddenly only using the NAM, then looking at the 18Z NAM they will have to remove accumulating snows for most of east TX!

This is as good as it gets from the 18Z NAM for snow depth...

[southerngale]

I've got a Winter Storm Watch!

I'm on the very southern fringe of it, but still. I'm sure this will just make my disappointment that much worse when I get another cold rain. lol

Winter Storm Watch

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE LAKE CHARLES LA
208 PM CST MON FEB 22 2010

...LATE SEASON SNOW POSSIBLE OVER CENTRAL LOUISIANA AND LAKES REGION...

.FALLING PRESSURES JUST OFFSHORE BROWNSVILLE WILL INDUCE ANOTHER
GULF LOW BY EARLY MORNING TUESDAY. LARGE DIFFERENCES-IN-PRESSURE...
AND SUBSEQUENT STRONG BLUE NORTHERS...WILL CARRY CANADIAN AIR INTO
THE WESTERN UPPER GULF COAST STATES. AN OVERRUNNING RAIN SCENARIO
WILL BE IN THE WORKS BY MIDAFTERNOON TUESDAY...AS A PASSING
DISTURBANCE ALOFT INITIATES RAIN WHICH FALLS THROUGH THE CANADIAN
AIR. THE CHILLY RAIN WILL TRANSITION TO SNOW BY TUESDAY EVENING.
THE PRECIPITATION WILL BE COMING TO AN END ON WEDNESDAY...AS THE
GULF LOW EXITS INTO THE SOUTHWEST GULF OF MEXICO.

LAZ027>033-TXZ180>182-201-230600-
/O.NEW.KLCH.WS.A.0001.100224T0000Z-100224T1200Z/
VERNON-RAPIDES-AVOYELLES-BEAUREGARD-ALLEN-EVANGELINE-ST. LANDRY-
TYLER-JASPER-NEWTON-HARDIN-
INCLUDING THE CITIES OF...LEESVILLE...ALEXANDRIA...MARKSVILLE...
DERIDDER...OAKDALE...VILLE PLATTE...OPELOUSAS...WOODVILLE...
JASPER...NEWTON...LUMBERTON
208 PM CST MON FEB 22 2010

...WINTER STORM WATCH IN EFFECT FROM TUESDAY EVENING THROUGH LATE
TUESDAY NIGHT...

THE NATIONAL WEATHER SERVICE IN LAKE CHARLES HAS ISSUED A WINTER
STORM WATCH...WHICH IS IN EFFECT FROM TUESDAY EVENING THROUGH
LATE TUESDAY NIGHT.

OVERRUNNING RAIN WILL SPREAD FROM WEST TO EAST ACROSS THE WATCH
AREA BY TUESDAY AFTERNOON. THE CHILLY RAIN WILL TRANSITION TO SNOW
BY TUESDAY EVENING. SNOWFALL AMOUNTS BETWEEN 1 AND 2 INCHES IS
POSSIBLE ACROSS THE PINEY HILLS OF CENTRAL LOUISIANA AND THE
LAKES REGION OF SOUTHEAST TEXAS. LIGHT SNOW MAY REACH ALL THE WAY
TO THE COAST...ESPECIALLY ALONG THE I-10 CORRIDOR BETWEEN
BEAUMONT AND LAKE CHARLES. MOST FROZEN PRECIPITATION WILL BE
COMING TO AN END BY MIDMORNING WEDNESDAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.
CONTINUE TO MONITOR THE LATEST FORECASTS.

[JenBayles]

Dumb blonde question: I'm not worried about snow accumulations in west Houston, but what are the chances of this turning into more of an ice event here?

[setxweatherfreak]

I've got a Winter Storm Watch!

I'm on the very southern fringe of it, but still. I'm sure this will just make my disappointment that much worse when I get another cold rain. lol

Winter Storm Watch

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE LAKE CHARLES LA
208 PM CST MON FEB 22 2010

...LATE SEASON SNOW POSSIBLE OVER CENTRAL LOUISIANA AND LAKES REGION...

.FALLING PRESSURES JUST OFFSHORE BROWNSVILLE WILL INDUCE ANOTHER
GULF LOW BY EARLY MORNING TUESDAY. LARGE DIFFERENCES-IN-PRESSURE...
AND SUBSEQUENT STRONG BLUE NORTHERS...WILL CARRY CANADIAN AIR INTO
THE WESTERN UPPER GULF COAST STATES. AN OVERRUNNING RAIN SCENARIO
WILL BE IN THE WORKS BY MIDAFTERNOON TUESDAY...AS A PASSING
DISTURBANCE ALOFT INITIATES RAIN WHICH FALLS THROUGH THE CANADIAN
AIR. THE CHILLY RAIN WILL TRANSITION TO SNOW BY TUESDAY EVENING.
THE PRECIPITATION WILL BE COMING TO AN END ON WEDNESDAY...AS THE
GULF LOW EXITS INTO THE SOUTHWEST GULF OF MEXICO.

LAZ027>033-TXZ180>182-201-230600-
/O.NEW.KLCH.WS.A.0001.100224T0000Z-100224T1200Z/
VERNON-RAPIDES-AVOYELLES-BEAUREGARD-ALLEN-EVANGELINE-ST. LANDRY-
TYLER-JASPER-NEWTON-HARDIN-
INCLUDING THE CITIES OF...LEESVILLE...ALEXANDRIA...MARKSVILLE...
DERIDDER...OAKDALE...VILLE PLATTE...OPELOUSAS...WOODVILLE...
JASPER...NEWTON...LUMBERTON
208 PM CST MON FEB 22 2010

...WINTER STORM WATCH IN EFFECT FROM TUESDAY EVENING THROUGH LATE
TUESDAY NIGHT...

THE NATIONAL WEATHER SERVICE IN LAKE CHARLES HAS ISSUED A WINTER
STORM WATCH...WHICH IS IN EFFECT FROM TUESDAY EVENING THROUGH
LATE TUESDAY NIGHT.

OVERRUNNING RAIN WILL SPREAD FROM WEST TO EAST ACROSS THE WATCH
AREA BY TUESDAY AFTERNOON. THE CHILLY RAIN WILL TRANSITION TO SNOW
BY TUESDAY EVENING. SNOWFALL AMOUNTS BETWEEN 1 AND 2 INCHES IS
POSSIBLE ACROSS THE PINEY HILLS OF CENTRAL LOUISIANA AND THE
LAKES REGION OF SOUTHEAST TEXAS. LIGHT SNOW MAY REACH ALL THE WAY
TO THE COAST...ESPECIALLY ALONG THE I-10 CORRIDOR BETWEEN
BEAUMONT AND LAKE CHARLES. MOST FROZEN PRECIPITATION WILL BE
COMING TO AN END BY MIDMORNING WEDNESDAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.
CONTINUE TO MONITOR THE LATEST FORECASTS.

Orange isn't included? Well - thats just rude!!

[Weatherdude20]

Forecast High 43, now, 37.4.

[Big O]

That doesn't sound right to me...I saw an earlier post on the snow maps...those maps should be "Accumulating" snow maps...meaning measured snow on the ground...not how much has fallen and melted...snow fallen but not sticking as a measurement in snow inches is not a statistic that the NWS collects

It has to be accumulated as there is no way to measure what melts directly....you would have to take the liquid equivalent and use some assumed ratio to estimate it....

Thus you can have snow in your forecast...have it fall for some time, and have no accumulations....which means you can be outside of those snow maps and still see snow...

They are snow accumulation maps, but they may not represent snow in the ground at any one time. Consider if you get an inch of snow in a burst. You can measure it - an inch. The snow melts over the next hour then you get another inch. That's 2" accumulated snow, but you don't have 2" on the ground at any one time. It's more complex when snow is falling then melting not long after then it snows again. At least, that's the way I understand it.

That sounds reasonable...but that requires manpower to actually properly measure it...and we all know the NWS has been parred down people wise for quite a while...will be hard to verify their forecast maps if that much work is required!

If the NWS suddenly switched from using the GFS for this event and none of the NAM data to suddenly only using the NAM, then looking at the 18Z NAM they will have to remove accumulating snows for most of east TX!

This is as good as it gets from the 18Z NAM for snow depth...

Any one have thoughs on the dearth of accumulating snowfall on the 18z NAM?

[Big O]

I need to pull the trigger on whether to fly into Austin. If the 18z NAM is to be believed, I may just want to save some money and intercept a hurricane this summer. Any thoughts?

[Nederlander]

I need to pull the trigger on whether to fly into Austin. If the 18z NAM is to be believed, I may just want to save some money and intercept a hurricane this summer. Any thoughts?

Well if it were me and I had to choose, Id save for hurricane season.. theres always snow somewhere... but why not fly to waco or something?

[WacoWx]

I need to pull the trigger on whether to fly into Austin. If the 18z NAM is to be believed, I may just want to save some money and intercept a hurricane this summer. Any thoughts?

Well if it were me and I had to choose, Id save for hurricane season.. theres always snow somewhere... but why not fly to waco or something?

the first and last time i think I will ever hear that phrase!

[srainhoutx]

Dumb blonde question: I'm not worried about snow accumulations in west Houston, but what are the chances of this turning into more of an ice event here?

Doesn't look like an ice event for us Jen. Maybe a little wet snow.

[Big O]

I need to pull the trigger on whether to fly into Austin. If the 18z NAM is to be believed, I may just want to save some money and intercept a hurricane this summer. Any thoughts?

Well if it were me and I had to choose, Id save for hurricane season.. theres always snow somewhere... but why not fly to waco or something?

the first and last time i think I will ever hear that phrase!

Does Waco have an airport? I didn't think they did.

[Weatherdude20]

Waco Regional Airport

[Rockets420]

Winter storm warning for north Austin

[Nederlander]

Dumb blonde question: I'm not worried about snow accumulations in west Houston, but what are the chances of this turning into more of an ice event here?

Doesn't look like an ice event for us Jen. Maybe a little wet snow.

surface temps would have to be below freezing for an ice event...

(ice storms happen when there is a pocket of warm air aloft that melts the snow, and then the precip freezes again as it hits the surface.. which is why surface temps need to be below freezing)

[Portastorm]

Winter storm warning for north Austin

You sure about that? I see where Llano, Williamson, and Burnet counties are now under a Winter Storm Warning ... Travis County looks to still be under a "Watch."

[cycloneye]

Winter Storm Warning for much of Northern Texas

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE FORT WORTH TX
139 PM CST MON FEB 22 2010

...A WINTER STORM WATCH IS IN EFFECT FOR PORTIONS OF NORTH TEXAS
FROM EARLY TUESDAY MORNING THROUGH TUESDAY EVENING...

TXZ141>143-147-148-156>162-174-175-230345-
/O.UPG.KFWD.WS.A.0002.100223T0900Z-100224T0300Z/
/O.NEW.KFWD.WS.W.0002.100223T0900Z-100224T0300Z/
COMANCHE-MILLS-HAMILTON-FREESTONE-ANDERSON-LAMPASAS-CORYELL-BELL-
MCLENNAN-FALLS-LIMESTONE-LEON-MILAM-ROBERTSON-
INCLUDING THE CITIES OF...COMANCHE...DE LEON...GOLDTHWAITE...
HAMILTON...HICO...TEAGUE...FAIRFIELD...PALESTINE...LAMPASAS...
COPPERAS COVE...GATESVILLE...KILLEEN...TEMPLE...FORT HOOD...
WACO...MARLIN...MEXIA...GROESBECK...BUFFALO...CENTERVILLE...
JEWETT...OAKWOOD...CAMERON...ROCKDALE...HEARNE...FRANKLIN...
CALVERT
139 PM CST MON FEB 22 2010

...WINTER STORM WARNING IN EFFECT FROM 3 AM TO 9 PM CST TUESDAY...
...WINTER STORM WATCH NO LONGER IN EFFECT...

THE NATIONAL WEATHER SERVICE IN FORT WORTH HAS ISSUED A WINTER
STORM WARNING FOR HEAVY SNOW...WHICH IS IN EFFECT FROM 3 AM TO 9
PM CST TUESDAY. THE WINTER STORM WATCH FOR HEAVY SNOW IS NO
LONGER IN EFFECT.

SNOW IS EXPECTED TO BEGIN FALLING OVER NORTH TEXAS...MAINLY WEST
OF INTERSTATE 35 EARLY TUESDAY BEFORE SPREADING ACROSS MUCH OF THE
REGION DURING THE DAY. BY LATE TUESDAY MORNING BANDS OF HEAVY
SNOWFALL ARE EXPECTED TO DEVELOP FOR AREAS GENERALLY ALONG AND SOUTH
OF A COMANCHE TO WACO TO PALESTINE LINE. SNOWFALL TOTALS WITHIN
THE WINTER STORM WARNING ARE EXPECTED TO BE IN THE 4 TO 6 INCH
RANGE WITH ISOLATED HIGHER AMOUNTS POSSIBLE. SNOWFALL RATES WITHIN
THE MOST INTENSE SNOW BANDS MAY BE AS HIGH AS 1 TO 2 INCHES PER
HOUR. SNOWFALL IS EXPECTED TO DISSIPATE FROM NORTHWEST TO
SOUTHEAST TUESDAY AFTERNOON...WITH SNOWFALL ENDING ACROSS THE
ENTIRE WARNING AREA TUESDAY EVENING.

AS SURFACE TEMPERATURES ARE EXPECTED TO REMAIN NEAR OR JUST ABOVE
FREEZING THROUGH THE EVENT SO MOST ROADWAYS WILL PICK UP A SLUSHY
ACCUMULATION. DURING PERIODS OF HEAVY SNOWFALL ROADWAYS MAY
ACCUMULATE SNOWFALL QUICKLY CREATING VERY HAZARDOUS DRIVING
CONDITIONS.

[WacoWx]

should a low of 28-30 refreeze on roadways or is the ground too warm?

[Weatherdude20]

... WINTER STORM WARNING IN EFFECT FROM 6 AM TUESDAY TO MIDNIGHT CST TUESDAY NIGHT...
...

THE NATIONAL WEATHER SERVICE IN AUSTIN/SAN ANTONIO HAS ISSUED
A WINTER STORM WARNING FOR LLANO...BURNET AND WILLIAMSON
COUNTIES...WHICH IS IN EFFECT FROM 6 AM TUESDAY TO MIDNIGHT CST
TUESDAY NIGHT. THE WINTER STORM WATCH IS NO LONGER IN EFFECT.

A WINTER STORM DEVELOPING LATE TONIGHT WILL BRING A WINTRY MIX OF
PRECIPITATION TO THE HILL COUNTRY AND MUCH OF SOUTH CENTRAL TEXAS
THROUGH TUESDAY EVENING. RAIN LATER TONIGHT WILL CHANGE OVER TO A
RAIN AND SNOW MIX AFTER MIDNIGHT. THIS WILL BECOME ALL SNOW FOR
THE HILL COUNTRY AND NORTHERN SECTIONS OF SOUTH CENTRAL TEXAS BY
TUESDAY MORNING.

SNOW ACCUMULATIONS TUESDAY THROUGH TUESDAY EVENING WILL RANGE
FROM 1 TO 3 INCHES.

AIR TEMPERATURES ARE EXPECTED TO REMAIN ABOVE FREEZING DURING
THIS SNOW EVENT AND SOIL TEMPERATURES ARE ALSO WARM. THUS SNOW
ACCUMULATIONS WILL OCCUR MAINLY IN GRASSY AREAS. THE SNOW WILL
MELT TO A SLUSHY MIX ON BRIDGES AND ROADWAYS. THIS WILL RESULT IN
SLIPPERY BRIDGES AND ROADWAYS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING MEANS ACCUMULATIONS OF SNOW...SLEET...
FREEZING RAIN OR FREEZING DRIZZLE ARE EXPECTED OR OCCURRING. THIS
WILL CAUSE CONSIDERABLE TRAVEL PROBLEMS AND MAY POSE A THREAT TO
LIFE AND PROPERTY.

[Weatherdude20]

Winter storm warning for north Austin

Not Quite