December: Warm Days & Cool-Foggy Nights To End 2011

[wxman57]

I'm not seeing any chance of sleet near southeast Texas next week. The frozen precip should remain in far west and northwest parts of the state. Latest GFS is quite a bit warmer than yesterday's runs. Euro is warmer, too. Canadian is colder, but still no precip indicated here in the cold air.

Here's a meteogram from the 6Z GFS. It had been forecasting 31 deg on Tuesday. Now only the low 40s.

[redneckweather]

Thanks for the feedback wxman and srain. As of now, what are y'all thinking for the Meridian area from Friday thru Sunday? Cold the entire time with over running precip?

[srainhoutx]

Thanks for the feedback wxman and srain. As of now, what are y'all thinking for the Meridian area from Friday thru Sunday? Cold the entire time with over running precip?

The GFS and Canadian suggest the front won't be that far S until early Sunday morning. Both of those models do suggest showers starting Friday night throughout the weekend. There could be some heavier rains with the frontal passage. On to the Euro...

[srainhoutx]

The 12Z Euro has trend stronger with the cold air behind the front. That model also suggests the front will progress S early on Sunday. The guidance is in fairly good agreement of showers throughout the weekend into Monday with some over running. It does appear that Winter Weather Watches will be hoisted for parts N MX, W TX and the TX Panhandle later today for a 1-2 punch of wintry mischief as a couple of upper air disturbances eject E from Arizona. We will see...

[srainhoutx]

And for the cold weather lovers...a much colder Euro...

[srainhoutx]

HPC Final afternoon Update:..flip flopping along...

12Z GFS REMAINS CONSISTENT WITH ITS 00Z RUN WHILE 12Z CMC REMAINS
MORE SIMILAR TO THE ECMWF OF LEAVING SIGNIFICANT ENERGY BEHIND AS
A CLOSED LOW IN THE SOUTHWEST BY DAYS 4-5 AND TAKES MORE NRN
STREAM ENERGY EASTWARD. THE 12Z UKMET HOWEVER HAS SWITCHED TOWARDS
THE GFS/CMC SOLUTION FROM ITS PRIOR TREND CLOSER TO THE 00Z ECMWF.
12Z ECMWF HAS ALSO SWITCHED TOWARDS THE GFS SOLUTION THIS RUN.
THIS WAS THE ORIGINAL ECMWF SOLUTION SEVERAL DAYS AGO WITH THE
EARLIER GFS RUNS LOOKING LIKE YESTERDAYS AND THE OVERNIGHT 00Z
ECMWF. THIS DOES NOT INSPIRE CONFIDENCE. HPC PROGS WILL REMAIN
UNCHANGED FOR NOW BUT WITH LOWER CONFIDENCE THAN PRIOR ISSUANCE
WITH OR WHEN ANY SUCCEEDING RUNS CONVERGE ON A BETTER AGREED UPON
SOLUTION THEN HPC GUIDANCE WILL CHANGE.

[skidog38]

snow sunday night

[srainhoutx]

For redneckweather and his deer hunting trip from Dallas/Ft Worth NWS:

ISENTROPIC ASCENT WILL BE A BIG PLAYER IN RAINFALL BEGINNING
THURSDAY NIGHT AND CONTINUING THROUGH THE WEEKEND. IN
ADDITION...SYNOPTIC SCALE LIFT WILL BE AIDED BY THE SHORTWAVE ON
SATURDAY AND FALLING HEIGHTS THE FIRST OF NEXT WEEK. COLD HIGH
PRESSURE OVER THE NORTHERN ROCKIES WILL SLIDE SOUTHWARD THIS
WEEKEND AND ENTER INTO NORTH TEXAS LATE SATURDAY NIGHT AS A
DEEPENING SURFACE CYCLONE MOVES THROUGH OUT OF THE PANHANDLE AND
ACROSS OKLAHOMA. A COLD RAIN WILL ENSURE FOR SUNDAY THROUGH MONDAY
BEFORE ENDING NORTHWEST TO SOUTHEAST.

PWATS CLIMB TO ONE INCH BY FRIDAY AND REMAIN HIGH INTO SATURDAY
NIGHT. THIS HIGH MOISTURE CONTENT COMBINED WITH STRONG ISENTROPIC
PRESSURE ASCENT SHOULD RESULT IN VERY BENEFICIAL RAINFALL OF 1 TO 2+
INCHES FOR MUCH OF NORTH TEXAS. INSTABILITY FOR THUNDER WILL BE
MARGINAL OVER THE SOUTHERN THIRD ON SATURDAY AND HAVE INCLUDED
ISOLATED THUNDER WITH THE RAIN.

AS MUCH COLDER AIR SPILLS SOUTHWARD INTO NORTH TEXAS ON
MONDAY...THE RESULTING COLD AIR ADVECTION WILL SHUT OFF THE
PRECIPITATION PROCESS JUST AS FORECAST SOUNDINGS BECOME COLD
ENOUGH FOR A WINTRY MIX MONDAY AFTERNOON/EVENING.

AS FOR TEMPS...WE USED A BIAS ADJUSTED BLEND FROM THE GFS AND MOS
THROUGH THE WEEKEND AND ON MONDAY...THEN HEDGED TOWARD THE COLDER
ECMWF FOR TUESDAY (25-33) AND WEDNESDAY (25-31). WEDNESDAY LOWS
COULD BE MUCH COLDER THAN CURRENTLY FORECAST IF THE ECMWF/S VERY
DEEP 500MB CORE (TEMPS DOWN TO -28C) MOVING ALONG THE RED RIVER
PANS OUT.

[srainhoutx]

For weatherguy425 attending college in Lubbock:

THE LONG TERM FORECAST HAS BECOME A LITTLE MORE CLEAR DEPENDING ON
HOW YOU LOOK AT IT. THE NAM CONTINUES TO BE THE OUTLIER WITH
RESPECT TO OTHER MODEL GUIDANCE BEING NOTABLY FASTER AND COOLER.
IN FACT...NO OTHER MODEL SOLUTION CAN BE FOUND THAT EVEN RESEMBLES
THE NAM SOLUTION. EVEN THE ENSEMBLES ARE MUCH CLOSER TO THE
SLOWER AND WARMER SOLUTIONS. THE NAM WILL THEREFORE BE DISCOUNTED
DUE TO ITS SIGNIFICANT DIFFERENCE WITH OTHER MODEL GUIDANCE. THE
COLD FRONT ON THURSDAY WILL BE COMPLETELY THROUGH THE AREA BY 00Z
FRIDAY WITH STRONG CAA OVER THE REGION THURSDAY NIGHT AND EARLY FRIDAY
MORNING. LOW LEVEL MOISTURE WILL MARKEDLY INCREASE ON THURSDAY
NIGHT WITH THIS MOISTURE REMAINING IN PLACE DURING THE DAY FRIDAY.
DEEPER SATURATION WILL OCCUR FRIDAY EVENING IN TIME FOR THE UPPER
LEVEL WAVE TO KICK OUT OVER THE AREA. THE MAIN UPPER LEVEL LIFT
WILL OCCUR FROM LATE FRIDAY NIGHT THROUGH EARLY SATURDAY MORNING.
AT THE SAME TIME...STRONG LOW LEVEL WAA WILL OCCUR WITH A 40KT LOW
LEVEL JET DEVELOPING. VERY STRONG ISENTROPIC ASCENT WILL OCCUR
AROUND THE 290-295K LAYER WITH 40KT OF FLOW. DURING THE DAY ON
FRIDAY THE PRIMARY LIFTING MECHANISM WILL BE FROM WEAKER
ISENTROPIC LIFT THOUGH WITH ONLY 15-25KT OF FLOW AROUND THE
285-290K LAYER. FRONTOGENESIS WILL SLOPE BACK FROM EAST TO WEST ON
FRIDAY MAINLY ON THE CAPROCK. MID LEVEL FRONTOGENESIS COMES INTO
THE AREA EARLY SATURDAY WITH THE UPPER LEVEL LIFT AND STRONGER
VALUES IN THE SOUTHWESTERN PANHANDLE. WITH THE MID LEVEL
FRONTOGENESIS WILL ALSO BE NEAR SATURATION OVER THE ENTIRE COLUMN. AT
THIS TIME...THERE WILL BE HIGHER PROBABILITIES FOR FREEZING RAIN
THAN FOR FREEZING DRIZZLE FOR THE NORTHWEST ZONES. THE STRONG WARM
PUSH FROM THE WAA WILL CHANGE THE FREEZING PRECIPITATION TO MOSTLY
RAIN ON FRIDAY NIGHT. GENERALLY...THERE WILL BE MOSTLY WIDESPREAD
FZDZ DURING THE DAY FRIDAY CHANGING TO RAIN FOR EASTERN AREAS
DURING THE AFTERNOON...THEN CENTRAL AREAS DURING THE EVENING. THE
NORTHWEST WILL REMAIN UNDER THE FREEZING PRECIP/RAIN MIX FOR THE
DURATION OF THE EVENT. DESPITE THE LIFT INTERACTING WITH A
SATURATED DENDRITIC LAYER THE SURFACE TEMPERATURES WILL BE TOO
WARM FOR SNOWFALL. THE ONLY EXCEPTION WILL BE IN THE SOUTHWESTERN
PANHANDLE WHERE SURFACE TEMPERATURES MAY BE COLD ENOUGH FOR
FREEZING PRECIPITATION THROUGH SATURDAY. THIS AREA WILL BE HARD
PRESSED TO SEE SIGNIFICANT ICE ACCUMULATIONS GIVEN THE LIGHT
PRECIPITATION NATURE EXPECTED. HOWEVER...THE FREEZING DRIZZLE
WILL CREATE ENOUGH OF AN IMPACT TO LIKELY WARRANT FUTURE
ADVISORIES.

ON SATURDAY AFTERNOON...THE MODELS ARE VERY AGGRESSIVE IN
ISENTROPIC DOWNGLIDE LEADING TO WARMER TEMPERATURES THAN
PREVIOUSLY ANTICIPATED. ON MONDAY...MODELS HAVE COME INTO AN
AGREEMENT BRINGING A POSITIVELY TILTED TROUGH OVER THE AREA WITH
LIGHT PRECIP AMOUNTS. SATURATED PROFILES AND A COLD PUSH ON MONDAY
WILL LEAD TO ANY PRECIPITATION AS SNOWFALL THOUGH IS EXPECTED TO
BE LIGHT.

[weatherguy425]

Excited for the Monday threat! My AMS meeting should be interesting on Monday... weather nerds unite!

[Portastorm]

Nothing for Austin?

I guess I'll be building a cold rainman once again.

[TexasMetBlake]

I live in Jacksonville. I'd kill for cold rain. Lord knows I'll never see anything else. Sigh.

[djjordan]

Here's a bit of good news regarding Lake Conroe's water releases for the city of Houston. Hopefully the trend can continue this winter.

http://www.slideshare.net/texasnetwork/ ... ake-conroe

[srainhoutx]

The overnight guidance has trended a bit colder and suggests a freeze is likely next Monday night/Tuesday morning. There still remain some wrinkles to iron out, but light rain chances beginning as early as Thursday night through Friday and into the weekend appear to be in the works. It still looks as if we could see some over running light precip behind the front as the second upper air disturbance begins to eject E from Arizona. There is a chance that parts of Central and N Texas may need to keep an eye out for some possible very light wintry mischief behind that strong front on Sunday night into Monday morning and possibly extending into Monday night. We will see. This is still an evolving situation and caution is advised and the forecast is subject to changes over the next several days. Stay tuned, as they say...

[biggerbyte]

I don't want to get anyone's hopes up, and this is beyond the three day reality forecasting realm...
Just something to watch as the days evolve to the Monday through Tuesday timeframe. We'll have to see how things play out as far as atmospheric conditions go, but the moisture and cold air look to be in place. This far out the outlook will only evolve, but everything from a cold rain, to sleet/snow/rain mix, or even freezing rain if we drop below 32 at some point. Again, we will need to see how things shape up.

The NWS is NOT currently calling for ANY winter precipitation through this period, but they are forecasting 32 degrees with a 50% chance of precipitation Tuesday night. You do the math. Also remember that we do not have to have freezing temps at the surface to get falling winter precipitation. This is several days out, so things can change to just cold and dry as we inch closer to Tuesday night. The rain could move out as the colder air moves in. Let's look at it again on Saturday or Sunday.

[Andrew]

Unfortuantly I still don't see much in the way of wintry precip for SE Texas. Looking at the longer range GFS the MOS output shows cold weather with lows getting down to 29 for areas around College Station but I do believe the precipitation will end before it gets cold enough for any type of wintry precipitation.

Here is the GFS 6z Sounding for Tuesday:

GFS Sounding.GIF

As you can see we should have saturation to support moisture and precipitation in the area but mostly all areas near and just above the ground are above freezing. It is still 130+ hours out but it is not looking good for us so far. Just a cold rain!

Keep an eye out though you never know what could happen.

[wxman57]

Yes, looks like cold rain Tuesday and possibly a light freeze on Wednesday of next week. Here's a 06Z GFS meteogram. I added in 850mb (5000ft up) temps. Air aloft is well above freezing on Tuesday during the precip.

[redneckweather]

Who here remembers the snow bust from this past February? That event left me completely numb. Because of that bust alone, I will never ever get my hopes up for snow again.....EVER. I will believe it when I see it falling from the sky.


Thanks for the updates everyone.

[srainhoutx]

The biggest change in the overnight progs is the QPF forecast. Rainfall chances have increased, particularly to our N and E. In this ongoing drought, we'll take all we can get...

[JackCruz]

Unfortuantly I still don't see much in the way of wintry precip for SE Texas. Looking at the longer range GFS the MOS output shows cold weather with lows getting down to 29 for areas around College Station but I do believe the precipitation will end before it gets cold enough for any type of wintry precipitation.

Here is the GFS 6z Sounding for Tuesday:

GFS Sounding.GIF

As you can see we should have saturation to support moisture and precipitation in the area but mostly all areas near and just above the ground are above freezing. It is still 130+ hours out but it is not looking good for us so far. Just a cold rain!

Keep an eye out though you never know what could happen.

Hope that changes soon!!!!! I fyou click on Tuesday there's a 5% chance of snow....but they had a 5% chance of snow also when it was like 43 degress so I don't know id it's relevant. http://www.intellicast.com/Local/Weathe ... n=USTX0617