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***ROLLTIDE*** · 12-01-2009, 06:12 PM

18Z GFS

Stormlover · 12-02-2009, 12:08 AM

how about it Mobile and Louisiana folks
[Image: us__00120snow.gif]

Joe-Nathan · 12-02-2009, 01:38 AM

This is going to mess up my duck huntin on Saturday.

If we get accumilating sneaux Friday night, it means I will have to take the kids out the levee to go dinner tray sliding.

Now Sunday will be a killer duck huntin morning.

But I hope we get a lot of sneaux!!!!!!!!!!!!!!!!!!!!!!

[COLOR="Blue"]Local mets are stating that this could be the first time in recorded weather history that SW LA has received sneaux two years in a row during early December.
[/COLOR]

***ROLLTIDE*** · 12-02-2009, 02:19 AM

***ROLLTIDE*** · 12-02-2009, 07:36 AM

Jackson , MS

Quote:LONG TERM…WHAT I HAD FEARED LAST NIGHT IS BECOMING MORE OF A
POSSIBILITY AS THE OUTLYING MODEL…WHICH WAS DEVELOPING SNOW ACROSS
THE AREA…IS NOT THE OUTLIER ANYMORE. THE GFS…IS NOW LEADING THE
WAY AND HAS STRONG SUPPORT FROM THE SREF AND MOST OF ITS ENSEMBLE
MEMBERS AND SOME SUPPORT FROM THE NAM AND EURO. 8 OF 12 ENSEMBLE
MEMBERS GENERATE MEASURABLE SNOW FRI NIGHT ACROSS THE CWA AND SNOW
PROBABILITIES FROM THE SREF ARE RANGING FROM 40-60%. SUCH SUPPORT
HAS TO BE TAKEN SERIOUSLY AND THE RESULT WILL BE SIGNIFICANT CHANGES
FOR THE FRI NIGHT FORECAST WRT POPS AND PRECIP TYPE BECOMING AT
LEAST LIGHT SNOW.
ONE MAY BE ASKING…WHAT HAS CHANGED TO NOW INCLUDE THIS INTO THE
FORECAST? MAINLY DEEPER MOISTURE AND STRONGER SUPPORT FROM MORE
MODELS. FORECAST LEADING INTO FRI/FRI NIGHT HAS GENERALLY ALWAYS
PORTRAYED SOME SORT OF S/W MOVING THROUGH THE BASE OF THE LONG WAY
TROUGH. HOWEVER…THE TREND LAST NIGHT WAS FOR THE S/W TO BE
STRONGER. WITH THAT…THE LARGE MAJORITY OF THE MODEL GUID WAS
GENERALLY DRY AND ONLY HAD CLOUDS WITH THAT TROUGH PASSAGE. THE GFS
WAS REALLY THE ONLY MODEL SHOWING SNOW ALONG WITH A COUPLE OF ITS
ENSEMBLE MEMBERS. SINCE LAST NIGHT…MUCH MORE SUPPORT HAS COME IN
FROM VARIOUS GUID AND BASICALLY THERE HAS BEEN A 180 SWITCH AND NOT
THE OUTLYING SOLUTION IS THE DRIER VERSION.
AS FOR SOME OF THE DETAILS…THE S/W IN QUESTION WILL BE RATHER
POTENT AND PROVIDE STRONG ASCENT ACROSS THE REGION ALONG WITH
HELPING TO DEVELOP A SFC LOW ACROSS THE N GULF. IT WILL BE THIS SFC
LOW DEVELOPMENT THAT WILL GIVE THE S/W THE MOISTURE TAP TO DEVELOP
PRECIP ABOVE THE COLD AIRMASS. I WILL SAY…THAT UNCERTAINTY IS
STILL FAIRLY HIGH IN THIS SOLUTION AS IT IS SOME 60-72 HRS OUT AND
ANYTIME WE ARE DEALING WITH WINTRY PRECIP IN OUR AREA…THINGS OFTEN
CHANGE. THE GENERAL SETUP FOR THIS WINTRY POTENTIAL FRI NIGHT IS
QUITE FAVORABLE AS WE WILL SEE CAA ONGOING FRI INTO FRI NIGHT WITH
SFC PRESSURES RISING AS HIGH PRESSURE BUILDS IN FROM THE N. THE
COMBINATION OF THE DEVELOPING GULF LOW IS ALSO SUPPORTIVE B/C IT
PROVIDES MOISTURE. THE FLY IN THE OINTMENT IS WILL THE COLDER AIR
MOVING SOUTHWARD BE TOO DRY AND EVAPORATE ALL OF THE FALLING PRECIP.
THAT TYPICALLY HAPPENS. ADDITIONALLY…THE AIRMASS THAT WILL BE IN
PLACE WILL NOT BE VERY COLD AND HIGH TEMPS FRI SHOULD BE IN THE
MID/UPPER 40S. IF CLOUD COVER THICKENS FASTER AND VIRGA DEVELOPS
EARLIER THE EVAP COOLING PROCESS WILL KEEP TEMPS COOLER AND MORE
NEAR 40 DEGREES. WITH FREEZING CONDITIONS NOT ALREADY IN PLACE…WE
WILL NEED OTHER MEANS TO GENERATE SNOW. THAT DOES NOT LOOK TO BE A
PROBLEM AS DYNAMIC COOLING FROM THE STRONG S/W WILL PROVIDE THAT AS
STRONG ASCENT WILL GENERATE PRECIP ALOFT WHICH WILL EVAPORATE AND
COOL ANY LAYER THAT IS ABOVE FREEZING. ALSO…THIS ALL LOOKS TO COME
TOGETHER FRI NIGHT AND WILL BE AIDED BY DIURNAL COOLING WHICH WILL
MAKE IT EASIER TO DROP TEMPS TO CRITICAL LEVELS FOR PRECIP TO BECOME
LIGHT SNOW. IT APPEARS AS MOISTURE VALUES…VERTICAL MOTION AND
DURATION WILL ONLY SUPPORT LIGHT ACCUMULATIONS FROM 1/4 INCH TO
POSSIBLY 1 INCH. THIS WILL ALSO OCCUR WITH TEMPS 31-34
DEGREES…SIMILAR TO PREV SNOW EVENTS OVER THE PAST TWO WINTER
SEASONS. HOWEVER…THOSE EVENTS HAD MUCH HIGHER MOISTURE TO WORK
WITH WHICH RESULTED IN MORE ACCUMULATIONS OF WET SNOW. THIS LOOKS TO
BE MUCH LIGHTER AT THIS POINT. ANY ACCUMS SHOULD BE ON GRASSY SFC`S
OR ELEVATED SFC`S AND BE 1 INCH OR LESS.
IN THE WAKE OF THIS S/W FEATURE…SAT-SUN LOOK TO BE QUIET.
HOWEVER…THAT MAY NOT LAST TOO LONG AS THE PATTERN WILL BE MORE OF
FAST SW ALOFT WHICH OFTEN MAKES FOR QUICK TRANSITIONS AND A OVERALL
WETTER PATTERN. WHILE DETAILS WILL BE VERY TOUGH TO GET
DOWN…FOLLOWING THE GENERALITIES OF THE GUID SEEMS THE BEST WAY TO
GO FOR SUN NIGHT THROUGH WED. DECENT PRECIP CHANCES AND A WARMING
TREND LOOK TO BE IN STORE AND GUID VALUES WERE ACCEPTED.
AS FOR TEMPS/POPS AND WEATHER FOR FRI-SAT…I DID LOWER HIGHS ON FRI
DUE TO THE CLOUD COVER AND EVAP COOLING POTENTIAL. ENSEMBLE MOS
SUPPORTS THIS AS WELL. I DID LOWER POPS ON FRI AS I FEEL THE ON SET
OF ANY LIGHT PRECIP WILL BE LATE AND MAINLY IN THE FRI NIGHT PERIOD.
FOR FRI NIGHT…I LOWERED LOWS TO GET INTO THAT 31-34 RANGE WHICH
COVERS THE WET BULB EFFECT AND FOLLOWS THE ENSEMBLE MEAN WHICH HAS
BEEN LOWER THAN THE OPS GUID FOR THE PAST FEW RUNS. POPS WERE TOUGH
AS MY INTUITION WOULD BE TO LOWER POPS DUE TO THE UNCERTAINTY.
HOWEVER…ALL THE DATA I HAVE LOOKED SAYS TO JUST STAY WITH THE
LATEST GUID POPS AS MEASURING JUST A COUPLE HUNDREDTHS OF LIQUID
EQUIVALENT IS VERY POSSIBLE. FOR NOW…LIGHT SNOW WORDING FITS THE
SITUATION AS ANY SNOW ACCUM SHOULD BE AROUND 1 INCH OR LESS. /CME/
&&

dkmac · 12-02-2009, 07:43 AM

N.O. NWS:

Quote:.LONG TERM...
BIGGEST CHANGE MADE IN THE EXTENDED FORECAST PERTAINS TO WINTRY
PRECIP. GFS HAS CONTINUED TO INDICATE THE DEVELOPMENT OF A SFC LOW
THAT TRACKS EASTWARD ACROSS THE NORTHERN GULF. THE ECMWF STILL HAS
NOT COME AROUND TO THIS SOLUTION BUT MODELS DO AGREE THAT A DEEP
TROUGH WILL SWING THROUGH...PROVIDING ENOUGH LIFT FOR PRECIP TO
DEVELOP. MODEL SOUNDINGS AT BTR AND MCB SHOW SATURATION IN THE -10
TO -20C DENDRITIC GROWTH ZONE AS WELL AS COLUMN TEMPS BELOW FREEZING
FROM AROUND 1500KFT AND UPWARDS AFTER 06Z SAT. THIS TYPE OF SOUNDING
WOULD PRODUCE STRICTLY SNOW. FOR THESE REASONS...HAVE DECIDED TO ADD
-SN TO THE FORECAST FROM BTR TO POPLARVILLE AND NORTHWARD. LATEST
MEX CAME IN AT 70PCT AND PREVIOUS RUN HAD MID 40S. B/C OF SUCH A BIG
CHANGE...DECIDED TO STAY ON THE LOW SIDED OF GUIDANCE AT 40PCT WITH
POSSIBLE ACCUMULATIONS UP TO 1 INCH. STILL PLENTY OF UNCERTAINTY
WITH THIS EVENT. LAST YEAR/S SNOW ON DEC 11TH WAS THE EARLIEST ON
RECORD...SO CLIMATOLOGY SUGGESTS THE A LOW PROBABILITY OF SNOW
DEVELOPING. WILL HAVE TO CONTINUE TO CLOSELY MONITOR.

***ROLLTIDE*** · 12-02-2009, 07:49 AM

Mobile , NWS

Quote:FRIDAY NIGHT...SOME INTERESTING DEVELOPMENTS AS LATEST MEDIUM RANGE
GUIDANCE IS FAVORING THE POSSIBILITY OF SOME WINTRY STUFF OVER OUR
FAR NORTHERN ZONES. IT APPEARS ANOTHER LOW PRESSURE SYSTEM WILL FORM
UP AND MOVE EASTWARD OVER THE CENTRAL GULF. THIS WILL ALLOW COLDER
AIR TO PUSH SOUTHWARD OVER THE DEEP SOUTH. AT THE SAME TIME...THERE
ARE INDICATIONS THAT A MID LEVEL SHORTWAVE TROF WILL PROGRESS
EASTWARD AND BRING A REGION OF DEEP LAYER MOISTURE ACROSS THE GULF
COAST...WELL NORTHWEST OF THE SURFACE LOW. LATEST FORECAST SOUNDINGS
INDICATE A SUBFREEZING DEEP MOIST COLUMN STARTING OUT NEAR H95
MB...WITH MORE OF SPREAD IN TEMPERATURE/DEWPOINT PROFILES/DRIER AIR
NOTED AT THE SURFACE OVER THE NORTHERN ZONES OVERNIGHT
FRIDAY/SATURDAY MORNING. AS PRECIPITATION FALLS...THE SURFACE
TEMPERATURES WILL COOL TO NEAR FREEZING...SUPPORTING A CHANCE OF A
CHANGE OVER TO LIGHT SNOW. WE HAVE THIS POTENTIAL IN THE LATEST
GRIDDED WEATHER FORECASTS LATE FRIDAY NIGHT OCCURRING ALONG AND NORTH
OF A LINE FROM RICHTON MISSISSIPPI TO CHATOM...MONROEVILLE...TO
BRANTLEY ALABAMA. LITTLE TO NO ACCUMULATION IS EXPECTED...BUT IT IS
STILL EARLY TO GET OVERLY SPECIFIC IN THIS DEPARTMENT. LATEST
OPERATIONAL GFS MOS POP FOR FRIDAY NIGHT HAS COME IN WITH CATEGORICAL
NUMBERS (~80%) FOR FRIDAY NIGHT OVER ENTIRE AREA. KIND OF ROBUST FOR
THREE DAYS OUT...SO HAVE FOLLOWED THE LOWER ENSEMBLE MEAN FOR POP
THEN. COLDEST DAYTIME HIGHS EXPECTED ON SATURDAY WITH HIGHS LOOKING
TO STRUGGLE TO GET OUT OF THE 40S OVER THE INTERIOR AND OUT OF THE
LOWER 50S OVER THE SOUTHERN ZONES.

satx_pilot · 12-02-2009, 10:22 AM

San Antonio, Texas

Quote:...SNOW POSSIBLE ACROSS THE HILL COUNTRY AND SOUTH CENTRAL TEXAS LATE THURSDAY NIGHT AND FRIDAY...

...HARD FREEZE EXPECTED ACROSS THE HILL COUNTRY AND SOUTH CENTRAL TEXAS LATE FRIDAY NIGHT INTO SATURDAY MORNING...

AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE HILL COUNTRY AND SOUTH CENTRAL TEXAS LATE THURSDAY INTO FRIDAY. PRECIPITATION WILL DEVELOP AFTER MIDNIGHT THURSDAY NIGHT AND BECOME MORE WIDESPREAD DURING THE DAY ON FRIDAY. COLD AIR WILL CONTINUE TO PLUNGE SOUTH INTO TEXAS TODAY THROUGH FRIDAY. ENOUGH COLD AIR WILL BE PRESENT THAT THE PRECIPITATION WILL START OUT AS A COLD RAIN OR A RAIN SNOW MIX. THE DEPTH OF COLD AIR WILL DEEPEN ON FRIDAY AND THE PRECIPITATION WILL TURN TO ONLY SNOW. THE SNOW WILL END FRIDAY EVENING AS THE DISTURBANCE MOVES EAST OF THE AREA.

CURRENTLY, SNOW ACCUMULATIONS UP TO 2 INCHES OF SNOW ARE POSSIBLE WITH THE HIGHEST EXPECTED ACROSS THE HILL COUNTRY TO ALONG THE ESCARPMENT. WINTER WEATHER ADVISORIES MAY HAVE TO BE ISSUED.

CLEARING SKIES...LIGHT WINDS AND LOW DEWPOINTS WILL ALLOW FOR AHARD FREEZE LATE FRIDAY NIGHT INTO SATURDAY MORNING ACROSS THE AREA. LOWS IN THE UPPER TEENS TO MID 20S ARE EXPECTED ACROSS THE HILL COUNTRY WITH MID 20S TO AROUND 30 ACROSS SOUTH CENTRAL TEXAS.

STAY TUNED TO NOAA WEATHER RADIO...THE NATIONAL WEATHER SERVICE WEBSITE...OR YOUR PREFERRED WEATHER INFORMATION SOURCE FOR THE LATEST FORECASTS...STATEMENTS AND POSSIBLE ADVISORIES.

Stormlover · 12-02-2009, 10:45 AM

Chances for some snow in the deep south Friday night/Saturday seems to be on the increase. Stay tuned.

***ROLLTIDE*** · 12-02-2009, 10:50 AM