TX winter wx thread: Spring-like pattern

[Texas Snowman]

Both FW and OKC have posted point and click forecasts for the Red River counties in both states. As usual, the differences are amazing despite a 150-yard wide river separating the two states and two counties.

In Durant, Ok., some 20 miles to my north, there is a 100 percent chance of snow tomorrow night with accumulations ranging from 3-5 inches.

In Sherman/Denison, Tx., there is a 90 percent chance of rain and snow changing to snow after midnight with the possibility of thunder. Total accumulation of less than one inch expected.

Sure hope the OKC forecasters will be off about 20 miles to the south with their forecast!

Tx Snowman

[serenata09]

So no snow for Austin, again?

[jasons2k]

Well, the NWS point forecast is "up" a bit with me bottoming-out at 34F Saturday AM. I can certainly live with that if it verifies.

[Extremeweatherguy]

So no snow for Austin, again?

We'll see. The air will definitely be getting cold enough in the upper-levels, but the main question is whether or not the precipitation will still be a around when that happens. JB still thinks (as of this morning's videos) that up to 3" of snow could fall beginning in Lake Travis and then expanding northeastward, so hope is still alive!

[Johnny]

Alright, the family and I are going to head to the ARKLATEX region...specifically Texarkana. Do y'all think that is a good place to set up?

Quick edit: I'm holding off till the early morning to hit the road. I'd like to get a better feel on this before taking off but Texarkana looks like a good bet.

[Ed Mahmoud]

Just looking at AccuWx PPV 0Z WRF total snowfall map, and just North of TXK, a 10 to 15 inch bulleye...



I'd link the 3 hour WRF frpm PSU e-Wall, so you could enjoy it in living color, but it hasn't updated yet.


AccuWx PPV map shows Eastern half of Metroplex getting in excess of 3 inches...

[cheezyWXguy]

Just looking at AccuWx PPV 0Z WRF total snowfall map, and just North of TXK, a 10 to 15 inch bulleye...



I'd link the 3 hour WRF frpm PSU e-Wall, so you could enjoy it in living color, but it hasn't updated yet.


AccuWx PPV map shows Eastern half of Metroplex getting in excess of 3 inches...

does that include I-35? because plano is just east of there, and i would like 3 inches of snow.

[Extremeweatherguy]

Interesting update from the Houston/Galveston NWS office...

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
902 PM CST WED MAR 5 2008

.DISCUSSION...
CLOUDS JUST BEGINNING TO DEVELOP ALONG THE COAST AS THE NEXT UPPER
LEVEL TROUGH PUSHES EAST TOWARD THE AZ/NEW MEX LINE. AT 8 PM...A
PRE-FRONTAL TROUGH WAS LOCATED ALONG A TEXARKANA TO WACO TO
JUNCTION LINE. A COLD FRONT EXTENDED FRON PARIS TO BROWNWOOD. BOTH
FEATURES WILL CONTINUE TO PUSH SLOWLY TOWARD SOUTHEAST TEXAS
OVERNIGHT. LOW PRESSURE DEVELOPING OVER DEEP SOUTH TEXAS WILL PUSH
NORTHEAST ON THURSDAY. THIS WILL IMPEDE THE FRONTS MARCH TOWARD
THE COAST UNTIL THURSDAY EVENING. IT ALSO SETS UP SOME DECENT LOW
LEVEL CONVERGENCE. WILL TRIM POPS TONIGHT TO JUST 20S AS IT LOOKS
LIKE MOISTURE WON`T BE DEEP ENOUGH UNTIL THURSDAY MORNING FOR
PRECIP TO START. WILL RAISE POPS ON THURSDAY AFERNOON INTO
THURSDAY NIGHT AS THE COASTAL LOW AND FRONT TRIGGER WIDESPREAD
SHOWERS AND THUNDERSTORMS. SOUTHERN PART OF THE AREA IS OUTLOOKED
BY SPC AND JUST NOT SURE HOW MUCH LOW LEVEL INSTABILITY WILL BE
PRESENT. PLENTY OF HELICITY WITH STRONG DIRECTIONAL SHEAR. STORM
MOTION SHOULD BE AROUND 15-25 KNOTS WHICH IS FAST ENOUGH TO LIMIT
HEAVY RAIN THREAT BUT SOME BRIEF HEAVY RAIN CAN NOT BE RULED OUT
DUE TO THE SLOW MOVING SURFACE BOUNDARY. THU NIGHT INTO FRIDAY
ALSO LOOK INTERESTING. EC/UK AND CAN ALL SHOW LINGERING MOISTURE
AND 925-850 LAYER COLD ENOUGH TO SUPPORT SOME WINTRY PRECIP NORTH
OF A BRENHAM TO LIVINGSTON LINE. 00Z NAM IS COLD ENOUGH BUT SHUNTS
THE MSTR TO THE NORTHEAST OF THE REGION. WILL AWAIT 00Z GFS BEFORE
CONTEMPLATING ANY OTHER CHANGES. 43/40

[Ed Mahmoud]

Just looking at AccuWx PPV 0Z WRF total snowfall map, and just North of TXK, a 10 to 15 inch bulleye...



I'd link the 3 hour WRF frpm PSU e-Wall, so you could enjoy it in living color, but it hasn't updated yet.


AccuWx PPV map shows Eastern half of Metroplex getting in excess of 3 inches...

does that include I-35? because plano is just east of there, and i would like 3 inches of snow.

If we use DAL as being close to Plano (do you know a 3 letter airport closer?) using the handy MOS generator from AccuWx a change to snow between 6 pm and midnight. During that six hours, 0.32 inches liquid equivalent falls, but how much falls as rain and how much falls as snow, unknown. 0.4 inches midnight to six am, or ballpark 4 inches, with surface temp of +0.5ºC, so some would melt, precip with sub-freezing 850 mb and low thickness continues, a total of 0.42 Friday morning to Saturday morning, but mid-day temps rise to 3.5ºC, so it is tricky as to whether it would be snow or rain, and whether it would stick.

The AccuWx snow accumulation map doesn't show counties, and I use that little county (Rockwall?) to located Dallas and Tarrant, but it looks like roughly Eastern half of metroplex exceeds 3 inches accumulation.


of course, all this assumes 0Z WRF is generally correct.

[cheezyWXguy]

Just looking at AccuWx PPV 0Z WRF total snowfall map, and just North of TXK, a 10 to 15 inch bulleye...



I'd link the 3 hour WRF frpm PSU e-Wall, so you could enjoy it in living color, but it hasn't updated yet.


AccuWx PPV map shows Eastern half of Metroplex getting in excess of 3 inches...

does that include I-35? because plano is just east of there, and i would like 3 inches of snow.

If we use DAL as being close to Plano (do you know a 3 letter airport closer?) using the handy MOS generator from AccuWx a change to snow between 6 pm and midnight. During that six hours, 0.32 inches liquid equivalent falls, but how much falls as rain and how much falls as snow, unknown. 0.4 inches midnight to six am, or ballpark 4 inches, with surface temp of +0.5ºC, so some would melt, precip with sub-freezing 850 mb and low thickness continues, a total of 0.42 Friday morning to Saturday morning, but mid-day temps rise to 3.5ºC, so it is tricky as to whether it would be snow or rain, and whether it would stick.

The AccuWx snow accumulation map doesn't show counties, and I use that little county (Rockwall?) to located Dallas and Tarrant, but it looks like roughly Eastern half of metroplex exceeds 3 inches accumulation.


of course, all this assumes 0Z WRF is generally correct.

Good analysis, but it seems like a changeover would be more likely to occur a little earlier in the day, since the NWS is predicting that the temp will drop to 34 by 5 pm in my area...but well just have to see.

[cheezyWXguy]

P.S. updated forecast discussion for DFW:

Updated Special Weather Statement will be issued shortly...but will make no changes to
content. Available 00z model data maintaining considerable probability of precipitation
and excellent snow chances. New operational NAM run swings an
even more dynamic low right through North Texas Thursday night.
If such a solution verifies...a significant snow event could be in
store. 25

[Ed Mahmoud]

P.S. updated forecast discussion for DFW:

Updated Special Weather Statement will be issued shortly...but will make no changes to
content. Available 00z model data maintaining considerable probability of precipitation
and excellent snow chances. New operational NAM run swings an
even more dynamic low right through North Texas Thursday night.
If such a solution verifies...a significant snow event could be in
store. 25

That is what I said.

Looking at 0Z GFS leaking into AccuWeather, the accumulated snowfall map paints all of North Texas in the 0.1 inch to 1 inch area. So, apparently, the GFS isn't as exciting. But, the GFS drops 0.68 inches liquid before the meager snowfall, and all Thursday night/Friday morning through sun up surface temps AOB freezing, so even though snow amounts are looking meager, a fair amount of available moisture to freeze on bridges and overpasses. Somehwere between 0.12 and 0.18 inches of liquid equivalent should fall with everything a go for snow, or 1 to 2 inches, but Accumulated snowfall map says less than one inch.

[jasons2k]

This could get quite interesting for the Metroplex. For Plano, usually the DFW sounding is good. The temp contours run SW to NE, or roughly parallel to HWY 121.

[Ed Mahmoud]

3 hour WRF loop from PSU e-Wall

[Extremeweatherguy]

The 00z GFS now shows some precipitation falling in "cold enough" upper-level air for mixing here in the Houston area on Friday morning. Only about 0.01-0.02" of liquid equivalent falls during that brief period at Hooks airport in Tomball, but that is still more than enough for a fun event. Even just a few light flurries of snow would be 100 times better than having to see nothing at all.

[Ed Mahmoud]

The 00z GFS now shows some precipitation falling in "cold enough" upper-level air for mixing here in the Houston area on Friday morning. Only about 0.01-0.02" of liquid equivalent falls during that brief period at Hooks airport in Tomball, but that is still more than enough for a fun event. Even just a few light flurries of snow would be 100 times better than having to see nothing at all.

I don't know, two one hundreds of an inch liquid equivalent from a sub-freezing 850 mb layer while surface temps climb from about 3º to about 7ºC. A thumping heavy snow might make it all the way with those surface numbers, a couple of hundreds over a multi-hour period doesn't qualify as a thump.


Unless, maybe the GFS is too warm at the surface, but that is like overcoming a 5 point deficit with 3.9 seconds with your best shooter already fouled out and the team has already reached its team foul limit and has only one time out left.

[southerngale]

A local met said on the 6pm and 10pm news that it was *possible* for us to see some snow in SE TX, particularly in the northern zones , late Thursday night into Friday morning. He said no accumulation, but some snowflakes anytime around here is quite interesting, particularly in March. It wouldn't be unheard of though. Last year it snowed in Jasper (an hour north of Beaumont) the day before Easter, in April! Other areas of Texas had snow as well.... we had sleet here in Beaumont. I remember hoping the snow would make it down here, but it never did.

I won't hold my breath, but it sure would be something!

[Extremeweatherguy]

The 00z GFS now shows some precipitation falling in "cold enough" upper-level air for mixing here in the Houston area on Friday morning. Only about 0.01-0.02" of liquid equivalent falls during that brief period at Hooks airport in Tomball, but that is still more than enough for a fun event. Even just a few light flurries of snow would be 100 times better than having to see nothing at all.

I don't know, two one hundreds of an inch liquid equivalent from a sub-freezing 850 mb layer while surface temps climb from about 3º to about 7ºC. A thumping heavy snow might make it all the way with those surface numbers, a couple of hundreds over a multi-hour period doesn't qualify as a thump.


Unless, maybe the GFS is too warm at the surface, but that is like overcoming a 5 point deficit with 3.9 seconds with your best shooter already fouled out and the team has already reached its team foul limit and has only one time out left.

The freezing layer will actually extend all the way down to the 900-950mb level, so it may not take a heavy snow to reach the surface. With that said though, I think that if precipitation is actually falling in the first place, then surface temperatures will probably be cooler than shown anyway. Evaporational cooling would likely hold temperatures down until after the light leftover precipitation cleared the area.

[srainhoutx]

Updated SWS from KFWD...

WWUS84 KFWD 060407
SPSFWD

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
1007 PM CST WED MAR 5 2008

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-061200-
ANDERSON-BELL-BOSQUE-COLLIN-COMANCHE-COOKE-CORYELL-DALLAS-DELTA-
DENTON-EASTLAND-ELLIS-ERATH-FALLS-FANNIN-FREESTONE-GRAYSON-HAMILTON-
HENDERSON-HILL-HOOD-HOPKINS-HUNT-JACK-JOHNSON-KAUFMAN-LAMAR-LAMPASAS-
LEON-LIMESTONE-MCLENNAN-MILAM-MILLS-MONTAGUE-NAVARRO-PALO PINTO-
PARKER-RAINS-ROBERTSON-ROCKWALL-SOMERVELL-STEPHENS-TARRANT-VAN ZANDT-
WISE-YOUNG-
1007 PM CST WED MAR 5 2008

...COLD WEATHER RETURNS THURSDAY AND FRIDAY WITH THE POTENTIAL FOR A
SECOND SNOW EVENT IN LESS THAN A WEEK...

COLD AIR WILL CONTINUE FILTERING INTO NORTH TEXAS. DAYBREAK
TEMPERATURES WILL BE IN THE 30S AND 40S...AND WILL WARM LITTLE DURING
THE DAY ON THURSDAY. A VIGOROUS STORM SYSTEM WILL APPROACH FROM THE
WEST...MOVING THROUGH NORTH TEXAS THURSDAY NIGHT INTO FRIDAY.

RAIN WILL DEVELOP THURSDAY MORNING...AND PERSIST THROUGHOUT THE DAY.
A FEW EMBEDDED THUNDERSTORMS WILL ALSO BE POSSIBLE. A MIX OF RAIN AND
SNOW IS EXPECTED THURSDAY AFTERNOON THROUGH FRIDAY MORNING GENERALLY
ALONG AND NORTH OF A LINE FROM HAMILTON...TO CORSICANA AND ATHENS.
A TRANSITION TO ALL SNOW IS LIKELY THURSDAY NIGHT. BY FRIDAY
AFTERNOON...THE BULK OF THE PRECIPITATION WILL HAVE SHIFTED EAST.

SOME ACCUMULATION OF SNOW WILL BE POSSIBLE AS EARLY AS THURSDAY
AFTERNOON...PRIMARILY ON GRASSY AND ELEVATED SURFACES. TEMPERATURES
WILL FALL TO NEAR OR BELOW FREEZING THURSDAY NIGHT...ALLOWING FOR
GREATER ACCUMULATIONS...INCLUDING ON MAIN ROAD SURFACES. NEW
FORECAST DATA SUGGEST THE POTENTIAL FOR A SIGNIFICANT SNOW EVENT...
WITH CONSIDERABLE DISRUPTIONS TO TRAVEL.

STAY TUNED TO NOAA WEATHER RADIO...OR VISIT WEATHER.GOV/FORTWORTH
FOR UPDATES ON THIS DEVELOPING WINTER WEATHER SITUATION.

http://www.srh.noaa.gov/fwd/productview ... &version=0

[Ed Mahmoud]

The 00z GFS now shows some precipitation falling in "cold enough" upper-level air for mixing here in the Houston area on Friday morning. Only about 0.01-0.02" of liquid equivalent falls during that brief period at Hooks airport in Tomball, but that is still more than enough for a fun event. Even just a few light flurries of snow would be 100 times better than having to see nothing at all.

I don't know, two one hundreds of an inch liquid equivalent from a sub-freezing 850 mb layer while surface temps climb from about 3º to about 7ºC. A thumping heavy snow might make it all the way with those surface numbers, a couple of hundreds over a multi-hour period doesn't qualify as a thump.


Unless, maybe the GFS is too warm at the surface, but that is like overcoming a 5 point deficit with 3.9 seconds with your best shooter already fouled out and the team has already reached its team foul limit and has only one time out left.

The freezing layer will actually extend all the way down to the 900-950mb level, so it may not take a heavy snow to reach the surface. With that said though, I think that if precipitation is actually falling in the first place, then surface temperatures will probably be cooler than shown anyway. Evaporational cooling would likely hold temperatures down until after the light leftover precipitation cleared the area.

I hope I'm wrong and we get a foot of snow tomorrow night, Really, I do. But winter weather hoping in SE Texas can be a bitter and painful experience. Like rooting for the Houston Texans. Or the Detroit Lions.

Even when the models look promising you usually get burned, so I'm not expecting anything.

Bed time.

I will want to compare actual 6 am temps around Texas to forecast hour zero temps on the 12Z runs tomorrow. When the big NYC snowstorm busted about a month ago the WRF and the GFS were both showing temps several degrees cooler (Celcius!) at hour zero than actual, and with that snow event on the model being at marginal temps, I knew all was lost. I knew the change to snow would never happen.