Texas Winter 2010-2011

[TeamPlayersBlue]

i posted a link earlier in the thread that went into great details about the 2004 storm. Type into google and you can find the study noaa did on the event. Its very informative.

[wxman22]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
346 PM CST TUE FEB 1 2011

.DISCUSSION...
COLD WX HAS ARRIVED AND WILL PERSIST INTO THE FIRST PARTS OF THE
WEEKEND. HAVE GENERALLY FOLLOWED (AND MANY TIMES UNDERCUT) LOWEST
ENSEMBLE MOS SUGGESTIONS REGARDING TEMPS. HARD FREEZE WARNING WILL
OBVIOUSLY CONTINUE AND WILL NEED TO BE EXTENDED EACH NIGHT UNTIL
FRI MORNING. WIND CHILL ADVSY WILL BE ISSUED TONIGHT FOR WNW & NRN
COUNTIES TONIGHT WITH WIND CHILL VALUES FCST TO DIP SLIGHTLY BELOW
ZERO. WILL PROBABLY SEE SOME PERIODS OF SUN ON WED BUT WITH THE
COLD START AND ONGOING CAA DOUBT WE`LL SEE READINGS GET OUT OF THE
30S AND POSSIBLY NOT ABOVE FREEZING AT ALL NORTH.

EXPECT MOISTURE TO BEGIN OVERRUNNING THE COLD AIR AT THE SFC ON
THURS. STILL ANTICIPATING A WINTER WX EVENT BEGINNING AS EARLY AS
LATE AFTN THURS NEAR THE COAST AS SOUNDINGS BECOME INCREASINGLY
SATURATED...BUT MOSTLY DURING THE OVERNIGHT HOURS THURSDAY NIGHT
AND FRIDAY MORNING. MODELS CONTINUING TO SHOW TROF DROPPING INTO
MEXICO THURS THEN EJECTING INTO TX DURING THE OVERNIGHT HOURS.
SOME DISCREPANCY AS TO WHAT THE TEMP PROFILE BETWEEN MODELS THURS
EVENING AND WOULDN`T BE SURPRISED TO SEE PRECIP START OUT AS A MIX
NEAR THE GALVESTON BAY REGION BEFORE CONVERTING OVER TO SNOW. HAVE
SHIFTED THE HIGHER CHANCES EVEN FURTHER INLAND AND ALSO TWEAKED
ACCUMS UP INTO THE 1-3" RANGE. AM GETTING CONCERNED ABOUT AMOUNTS
THOUGH AND AT THIS POINT WOULDN`T BE SURPRISED TO SEE EVEN HIGHER
AMOUNTS IN BANDING WHERE EVER IT SETS UP. CANADIAN MODEL WILL NOT
BACK DOWN ON ACCUMS AND THIS RUN ACTUALLY SHOWS COLDER H85 TEMPS.
LOOKED AT MOST OF THE OTHER MODELS FCST SOUNDINGS AND THEY APPEARED
FAIRLY IMPRESSIVE AT TIMES AND KINDA WONDER WHY SOME DEPICT SUCH
LOW QPFS. WILL REALLY NEED TO WATCH THIS.

AT THIS POINT...IT`S IMPORTANT TO UNDERSTAND THE FCST IS SUSCEPTIBLE
TO SUBSTANTIAL QPF CHANGES...TYPE AND WHERE THE HIGHER AMOUNT
WILL OCCUR. ALTHOUGH THE HIGHEST AVAIL MOISTURE IS NEAREST THE
COAST AND SE AREAS...THE UPPER LOW/VORT LOOKS LIKE IT`LL TAKE A
MORE NRLY TRACK THAN WE SAW XMAS EVE 2004 HENCE TOOK THE HIGHER
AMOUNTS A LITTLE FURTHER N THAN PREVIOUS FCST.

[gboudx]

FTW AFD still only discussion through tonight. Current forecast there still show 20% chance of snow Thurs evening and Friday.

Area forecast discussion
National Weather Service Fort Worth Texas
1219 PM CST Tuesday Feb 1 2011


Update...
cold advection is strong and deep enough that it has caused nearly
adiabatic lapse rates in the first 3000 feet. Moisture is still
sufficient for weak convective snow showers...which are being
forced by horizontal convective rolls as seen on radar. Have added
scattered light snow showers to most of the County Warning Area...but minimal new
accumulations are expected. These convective clouds should
dissipate with sunset and leave much of the area with mostly clear
skies. Have lowered overnight lows tonight based on temperatures
upstream...strong cold advection continuing...and the few degrees
that will be lost to radiational cooling. This should result in
min temperatures well into the single digits across the northwest half of the
area...and low teens elsewhere. Due to the extreme cold and danger
to exposed pipes...a hard freeze warning has been issued. Tr.92


&&

DFW now has their PM AFD out. I'm not going to post it here since I think everyone knows where to find it. Still only a 20% chance of snow on Thursday.

[Portastorm]

Here is the most relevant snippet from the NWSFO Austin/San Antonio AFD, just issued:

LIGHT SNOW ACCUMULATIONS APPEAR LIKELY FOR AREAS ALONG AND EAST OF
I-35...WITH 1 TO 2 INCHES STILL LOOKING REASONABLE BASED ON GOOD
MODEL AGREEMENT. THE CENTER OF THE UPPER LOW IS EXPECTED TO TRACK
RIGHT INTO SOUTH CENTRAL TEXAS THURSDAY NGHT AND OPEN UP INTO A MORE
OPEN TROUGH AS IT PASSES THROUGH FRIDAY. THIS COMBINED WITH THE
LOW AMOUNTS OF MOISTURE AVAILABLE SHOULD SUGGEST STORM TOTALS
BELOW 3 INCHES WITH THE HIGHER TOTALS GENERALLY SE OF OUR FORECAST
AREA. THE MODEL AGREEMENT ALLOWS ME TO TRIM DOWN SOME OF THE
TIMING WITH THE BEST ACCUMULATIONS EXPECTED TO OCCUR FROM 06Z TO
12Z FRIDAY. COLD AIR LEFT BEHIND THE FROZEN PRECIP HAS
TEMPERATURES MODIFIED BELOW THE GFS GUIDANCE FOR FRIDAY.

[BigB0882]

I don't want to overhype this or anything but signals are just getting too strong. North Texas/Oklahoma is frozen, Houston is going to get snow and the potential true 'motherload' of cold air is lurking for early next week while everyone is still freezing their bums off. Is this not reminiscent of 1899 or what? Of course not that cold, but something else is at play here.

I mentioned this in another thread! I have always read that the big events (1899 being one of them) was a result of multiple blasts of cold air and that is the key to big events in the south. We have cold air from this and a potentially colder surge coming (depending where you live, the next one FOR NOW appears to go more East) so what happens if a Low bombs in the Gulf? Could be huge. I don't think any models are seeing that but its definitely too far out to know. All I will say is it seems things are lining up better than they have for as long as I have been interested in weather. It may or may not all come together but this is getting closer and closer.

[Air Force Met]

18z GFS starting to update! I hope it continues the trend of more snow for Central/SE Texas!

So far...its wetter at 700...

[BigB0882]

Why has the GFS consistently shown a small area just north of the FL panhandle that has .1 - .25 inches of snow? It has been there for many runs. I keep assuming it is some kind of mistake but is it?

[Ivanhater]

Why has the GFS consistently shown a small area just north of the FL panhandle that has .1 - .25 inches of snow? It has been there for many runs. I keep assuming it is some kind of mistake but is it?

No mistake..looks right to me

[Kelarie]

From Shreveport....they are talking about Th/F and next week and winter weather

EXTENDED FORECAST...WITH COLD AIR REMAINING IN PLACE...THE MODELS
BRING ANOTHER STRONG UPPER LEVEL SYSTEM TO THE AREA THURSDAY
NIGHT. A SURFACE LOW WILL LIFT OUT OF THE GULF AHEAD OF THIS
SYSTEM...DRIVING MOISTURE BACK INTO THE AREA. ATTM WE HAVE ALL
SNOW IN THE FORECAST FOR THE ENTIRE AREA THURSDAY NIGHT AND FRIDAY
MORNING...BUT I WOULD NOT BE SURPRISED IF WE SAW SOME
SLEET OR FREEZING RAIN IN PARISHES TO THE SOUTH OF I20. A DRY AND
WARMER WEEKEND WILL SET UP...WITH TEMPERATURES FINALLY GOING
ABOVE 50 DEGREES. THEN AS WE START THE NEXT WORK WEEK...ANOTHER
ARCTIC AIRMASS DECIDES TO VISIT...AND WILL BRING WITH IT ANOTHER
CHANCE OF WINTRY PRECIP.

[Portastorm]

18z GFS starting to update! I hope it continues the trend of more snow for Central/SE Texas!

So far...its wetter at 700...

I definitely like this run!

[Ntxw]

I definitely like this run!

Follow the upper low Portastorm! Models are undermodeling it. Lift lift lift!

[South Texas Storms]

18z GFS starting to update! I hope it continues the trend of more snow for Central/SE Texas!

So far...its wetter at 700...

I definitely like this run!

Me too Portastorm!

[Ntxw]

18z GFS

[Portastorm]

I definitely like this run!

Follow the upper low Portastorm! Models are undermodeling it. Lift lift lift!

I hope you're right ... but what worries me is something where the ULL gets sheared out and its energy transfers to the coastal trough (which I have seen happen in winter). Would be a killer to me but a big win for our friends along the middle and upper Texas coast.

[gboudx]

18z GFS

That shows 1+ in the metroplex. I thought we were done with only a small chance on Thursday?

[Ntxw]

I hope you're right ... but what worries me is something where the ULL gets sheared out and its energy transfers to the coastal trough (which I have seen happen in winter). Would be a killer to me but a big win for our friends along the middle and upper Texas coast.

SE Texas is going to get their snow from the surface low in the gulf, that's basically a given source of moisture there. You'll be different. A stronger cutoff upper low will help and on the east/northern side of it will provide enough vertical lifting for snow. Nothing major, but enough imo! Of course right now it appears to be virga but if models are underdoing it, never know

[downsouthman1]

I definitely like this run!

Follow the upper low Portastorm! Models are undermodeling it. Lift lift lift!

I hope you're right ... but what worries me is something where the ULL gets sheared out and its energy transfers to the coastal trough (which I have seen happen in winter). Would be a killer to me but a big win for our friends along the middle and upper Texas coast.

I don't think this will get sheared. It's traveled south from Canada. You can see it right now basically following the wake left from the storm that came through today. If it was gonna get sheared apart, I would have expected it earlier today when it was closer to today's storm.

Current water vapor loops show this ULL organizing already.

http://www.atmo.arizona.edu/products/wx ... 0mbwv.html

[Air Force Met]

I definitely like this run!

Follow the upper low Portastorm! Models are undermodeling it. Lift lift lift!

I hope you're right ... but what worries me is something where the ULL gets sheared out and its energy transfers to the coastal trough (which I have seen happen in winter). Would be a killer to me but a big win for our friends along the middle and upper Texas coast.

Well...the 18z is still not wet enough in the lower levels (IMO) but the 700 is more moist...and the trof is deeper than the previous runs.

Has more snow depth over Hou than the 12z run...and more than the 00z run.

Keeping in mind, too, that they were showing nothing in 2004. I think we are not just looking at a coastal event here...but a widespread event from San Antonio-Aus-TYR with heaveir amounts SE. Some of this will also depend on if we get something going on Thur afternoon..which seems to be the trend.

[Hook'em Horns!]

Porta, are you starting to believe? Would love even an inch in Austin but have a gut feeling we may be in for a real surprise!

[South Texas Storms]

Thanks for your imput AFM. I hope you're right!