December Weather Discussion. Will We See Rain?

[Mr. T]

Nothing extreme in terms of cold coming up, but definitely a back and forth type pattern with global models showing some deep troughs making a swing through the state... Problem being, these troughs won't have extreme cold since Canada will be warming up quite a bit after this week. For us, warm periods will outweigh the cold in terms of averages, but at least this isn't a stagnant warm pattern. We'll still get our cold fronts with our chance of thunderstorms. It'd be nice if we could get some severe threats to go with that.

[C2G]

Some nice wintertime thunderstorms.......now you're talking Mr. T.

[Mr. T]

This is just for fun, folks

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _348.shtml

A big ol 1057 mb high swoops on in... This run shows us reaching 17 degrees, but it could've been a lot colder... The source region in Canada isn't really all that cold, but the near record strong high (lol) being depicted by the GFS helps to push whatever cold air there is straight down the Rockies into our area.

See, it would've been more fun had Canada actually been pretty cold which would have translated to single digits predicted here. Oh well... I'm sure another GFS fantasy run sometime this year will show that.

[srainhoutx]

HPC:

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
743 AM EST THU NOV 25 2010

VALID 12Z MON NOV 29 2010 - 12Z THU DEC 02 2010


AGAIN TODAY GOOD MODEL AND ENSEMBLE AGREEMENT WITHE THE CURRENT
DEEP STRONG CLOSED MID LEVEL LOW OVER THE DAKOTAS MOVING NEWD TO
THE CANADIAN MARITIMES AND THEN NWD INTO LABRADOR AS IT ENCOUNTERS
STRONG RIDGING OVER THE N ATLC BY DAY 3 SUN. UPSTREAM GOOD
AGREEMENT WITH THE NEXT DIGGING EPAC TROF COMING INTO THE WEST
COAST REACHING THE LOWER GREAT BASIN REGION. BUILDING EPAC HTS
BEHIND THIS TROF MOVE INTO THE WEST COAST MON/TUE AS THE MAIN FULL
LATITUDE TROF MOVES INTO THE SRN PLAINS AND MS VALLEY TUES-WED.
BUILDING EAST COAST/WEST ATLC HTS ALLOW SHARPENING OF THE TROF AS
IT MOVES THRU THE MAS VALLEY WED AND THE MAIN TROF LIFTS NEWD AS
IT MOVES OFF THE EAST COAST BY THURSDAY WITH A BRIEF PERIOD OF
ZONAL FLOW OVER CONUS BEFORE REPEATING THE PATTERN OVER AGAIN WITH
ANOTHER DEEP TROF DEVELOPING OVER THE WEST LATE NEXT WEEK AND
WEEKEND.

USED ECMWF THRU DAYS 3-6 SUN-WED. MAIN MODEL DIFFERENCE IS THE
LOWER HTS/DEEPER B.C. TROF SLIDING DOWN THE CANADIAN COAST DAY 6
AND 7 AS PER ECMWF. PREFER TO TEMPER THIS A BIT DUE TO UNCERTAINTY
WITH ENSEMBLES. LATEST 06Z GFS INDICATING A GREATER POTENTIAL FOR
SECONDARY WAVE DEVELOPMENT ALONG THE STRONG N-S ORIENTED COLD
FRONT AS IT MOVES INTO THE ERN COASTAL PLAIN WED-THURS.

HIGH PRESSURE BUILDING INTO THE GREAT BASIN MON-TUES SETTING UP AN
OFFSHORE EVENT/SANTA ANA OVER CA MON-TUES. SHARPENING MID LEVEL
TROF AND N-S ORIENTED COLD FRONT WITH GOOD LOW AND MID LEVEL
INFLOW WILL BRING MDT-HVY FRONTAL RAINS THRU THE CENTRAL AND LOWER
MS VALLEY MON AND TUES SPREADING NEWD THRU THE TN AND OH
VALLEYS/APPLACHNS INTO THE MID ATLC AND NORTHEAST WED. STRONGER
POTENTIAL FRONTAL WAVE DEVELOPMENT INDICATED BY 06Z GFS CONSIDERED
AS IT IS SUPPORTED BY A STRONGER LOW LEVEL COLD AIR INJECTION OFF
THE SRN TX COAST AND A COLDER POOL AT H850 COMING INTO THE LOWER
OH VALLEY.THIS WOULD SUPPORT THE STRONGER WAVE AND HEANY RAIN
POTENTIAL FOR NEW ENGLAND DAY 6 WED IF THIS OCCURS. FOLLOWING THE
COLD FRONT WILL BE THE THREAT OF THE FIRST STRONG INCURSION OF
COLD AIR INTO MUCH OF THE SOUTH AND EAST WITH POTENTIAL WIDESPREAD
FREEZING TEMPS AS FAR EAST AS THE COAST AND AS FAR SOUTH AS SRN
GA. NEXT ROUND OF PAC NORTHWEST RAINS AND INLAND HIGHER ELEV SNOWS
INTO THE ROCKIES TUES-THURS.

[srainhoutx]

Oh boy...

[ticka1]

What is this model run showing Srain? For us novices

[srainhoutx]

What is this model run showing Srain? For us novices

That is the 12Z GFS La La Land 312 hours. But that model has been rather insistent suggesting a chilly air mass and a strong high pressure dome that will linger for several days with reinforcing shots of colder air. We will see.

[Andrew]

Possible winter weather? (could we have snow early again?) The gfs has been coming in strong for these last two runs. While this is far out there it is encouraging for us snow enthusiasts.

[helloitsb]

For what its worth the GFS 12z and 18z shows us having insanely cold temperatures from 12/7-12/10

[TexasMetBlake]

00z says NOPE!

BTW...GIG'EM AGGIES! We've won 6 in a row and stopped Texas from going to a bowl game! Whoop!

[srainhoutx]

As we move toward Decemeber there are some signals that will need to be watched. We have seen via the GFS some crazy runs depicting a very chilly regime of strong cold troughing across the US and ridging the Aletuian Islands as well as a Greenland Block ridge. There are likely some modeling issues and the HPC points this out in the morning Prelim Discussions...

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
722 AM EST FRI NOV 26 2010

VALID 12Z TUE NOV 30 2010 - 12Z FRI DEC 03 2010


PACIFIC FLOW PATTERN BECOMES MORE ZONAL THIS PERIOD LEAVING BEHIND
SEVERAL CUTOFF LOWS AT LOWER LATITUDES WITH A TIGHT BAND OF
STRONGER MID LEVEL FLOW OVER THE CENTRAL PACIFIC. THERE ARE TWO
SIGNIFICANT ANOMALY AREAS OVER THE NRN HEMISPHERE THAT SHOULD
CONTROL THE FLOW PATTERN AND CONTINUE TO OFFER CONFLICTING
RESULTS. A STRONG AGREED UPON POSITIVE HT ANOMALY JUST S OR SE OF
CAPE FAREWELL WOULD GIVE A TELECONNECTION INDICATING WRN CONUS
RIDGING AND AN ERN CONUS TROF. THIS WAS SUPPOSED TO HAPPEN THIS
WEEKEND ACCORDING TO LAST WEEKS D+8 SOLUTIONS. ANY OCCURENCE OF
THIS WILL LAST ABOUT 12 HOURS THIS WEEKEND. THIS ANOMALY IS AGAIN
IN PLACE THIS FORECAST PERIOD AND WOULD GIVE THE SAME RESULT. MOST
OPERATIONAL MODEL GUIDANCE BY THE END OF THE FORECAST PERIOD DOES
NOT SUPPORT THIS. ONLY THE CMC WOULD LEAD INTO IT AROUND DAY 9-10.

THE OTHER STRONG POSITIVE ANOMALY IS NEAR THE FAR WRN ALEUTIANS.
THIS TELECONNECTS TO A DOWNSTREAM TROF FROM CANADA TO THE CENTRAL
WEST COAST WITH A BROAD WEAKER DOWNSTREAM TROF IN THE MS VALLEY.
LAST WEEKS LONGER TERM FORECAST BY GFS/ECMWF WHILE MATCHING A N
ATL TELECONNECTION PROVED TO BE TOO PROGRESSIVE WHILE THE WRN
TELECONNECTION DID NOT FIT WELL EITHER. WE CAN CONCLUDE THAT THERE
WILL BE A TRANSITION COMING IN THE LONGER TERM. HOWEVER DAILY
MODELS DO NOT FIT WELL TO EITHER TELECONNECTION BUT FORTUNETLY
THEY BASICALLY AGREE AT LEAST FOR THE NEXT WEEK. USED A BLEND OF
GFS/ECMWF ENS MEANS THROUGH THE PERIOD FOR UPDATED FORECAST PROGS.

A STRONG MID LEVEL TROF AND ASSOCIATED STRONG SFC FRONT WILL MOVE
THRU THE PLAINS DAY 3 MON/MS VALLEY TUES THEN SWEEP THRU THE
APPLCHNS REACHING THE COAST WED. N-S ORIENTED FRONT WITH GOOD LOW
AND MID LEVEL MOISTURE INFLOW/STRONG DYNAMICS WILL BRING HEAVY
FRONTAL RAINS FROM THE LOWER MS VALLEY MONDAY NEWD INTO THE OH
VALLEY TUES AND THRU THE MID ATLC REGION AND NORTHEAST WED.
WESTWARD ON THE BACKSIDE UNDER THE COLD MID LEVEL TROF MDT TO
LOCALLY HEAVY SNOW IS POSSIBLE ACROSS THE UPPER MS VALLEY AND WRN
GREAT LAKES REGION. COLD AIR WILL PENETRATE WELL SOUTH BEHIND THE
FRONT BRINGING THE FIRST WIDESPREAD COLD OUTBREAK WITH FREEZING
TEMPERATURES DEEP INTO THE SOUTH AND TO THE MID ATLC COAST AND
PORTIONS OF THE SOUTHEAST COAST. THIS WILL MODERATE SOMEWHAT AS
FLOW BECOMES MORE ZONAL AGAIN LATE WEEK TO WEEKEND. ANOTHER
OFFSHORE/SANTA ANA EVENT APPEARS TO BE SETTING UP MONDAY AS STRONG
HIGH PRESSURE MOVES INTO THE GREAT BASIN.

[Mr. T]

Our yearly early season snow is depicted on the 6z GFS around the 7th, lol

[srainhoutx]

00Z Euro 240 Hour says lol what?...

[wxman57]

Our yearly early season snow is depicted on the 6z GFS around the 7th, lol

I believe it's forecasting snow to our north. Not very believable, though.

Here's a good site for getting model projections of snow depth. Just click the "GFS" tab (or whatever model) and the "Winter" tab on the left frame and choose "Snow Depth":

[srainhoutx]

Well, the 12Z GFS continues to suggest a mighty chilly and even wintry pattern for parts of TX...

[srainhoutx]

Oh my...

11262010 12Z GFS Snow Cover GFS_3_2010112612_F312_SNOWIN_SURFACE.png

[Andrew]

Oh my...

11262010 12Z GFS Snow Cover GFS_3_2010112612_F312_SNOWIN_SURFACE.png

That would be a good 1-3 inches for us but then again this is 300 hours out. It is good to see some sort of consistency though. It would be really exciting if for a third year in a row we got some snow.

[srainhoutx]

Here are the 12Z GFS and Euro at hour 240 for comparison...

[Andrew]

18z not as promising:

[sambucol]

Khambrell Marshall on Ch 2 just said on the 6pm news that Dec 9/10 timeframe there will be enough moisture in the atmosphere and the temps will be below freezing that we may get snow. He said he was going on the record with that.