Deep South Winterwx Discussion 2015-2016

[Ivanhater]

Had this thread last year, so here it is for this year. This thread is for us in the deep south, Louisiana, Mississippi, Alabama, Georgia, Carolinas, and Florida for threat of snow and arctic blasts.

18Z GFS showing arctic blast for 1st week of December further east

[JonathanBelles]

oOo!!! I likey!! even though I dont think it wont play out. I guess ill have to stat paying attention to the GFS again.

[ronjon]

Both the 00z and 06Z GFS show a deep highly amplified trough extending down into the SW and central GOM early next allowing a cold air mass to dive southward into the gulf coast states. If the GFS verifies, possible record breaking early wintry precipiation event will exist for for GA, Carolinas, and the FL panhandle on Dec 1 and 2. A cutoff low with the trough is forecast to dive to central MS and move SE into north FL. If the GFS verifies, even the west coast of FL (say Clearwater) could see some snow flurries next Tuesday morning - the 0 deg 850 mb temp runs right through Tampa Bay on Tuesday morning with some light precipitation indicated by the GFS (may be due to upper low proximity or gulf effect snow showers). Anyway, doubt this will verify but will be a cold shot none-the-less.

[Agua]

If the GFS verifies, even the west coast of FL (say Clearwater) could see some snow flurries next Tuesday morning - the 0 deg 850 mb temp runs right through Tampa Bay on Tuesday morning with some light precipitation indicated by the GFS (may be due to upper low proximity or gulf effect snow showers).

Yeah, the proverbial snowball's chance ...

[jinftl]

Here is the current extended forecast from NWS Tampa Bay for November 30 - December 2 for Tampa...

Sunday And Sunday Night...Partly cloudy with a 30 percent chance of showers. Highs in the lower 70s. Lows in the mid 50s.

Monday...Partly cloudy with a 20 percent chance of showers. Highs in the lower 70s.

Monday Night And Tuesday...Partly cloudy. Lows in the upper 40s. Highs around 70.

If the GFS verifies, even the west coast of FL (say Clearwater) could see some snow flurries next Tuesday morning - the 0 deg 850 mb temp runs right through Tampa Bay on Tuesday morning with some light precipitation indicated by the GFS (may be due to upper low proximity or gulf effect snow showers).

Yeah, the proverbial snowball's chance ...

[Ivanhater]

12z GFS..more wrap around wintry precip and faster with the arctic air in this run for the deep south

[ronjon]

Here is the current extended forecast from NWS Tampa Bay for November 30 - December 2 for Tampa...

Sunday And Sunday Night...Partly cloudy with a 30 percent chance of showers. Highs in the lower 70s. Lows in the mid 50s.

Monday...Partly cloudy with a 20 percent chance of showers. Highs in the lower 70s.

Monday Night And Tuesday...Partly cloudy. Lows in the upper 40s. Highs around 70.

If the GFS verifies, even the west coast of FL (say Clearwater) could see some snow flurries next Tuesday morning - the 0 deg 850 mb temp runs right through Tampa Bay on Tuesday morning with some light precipitation indicated by the GFS (may be due to upper low proximity or gulf effect snow showers).

Yeah, the proverbial snowball's chance ...

What a surprise..the NWS not biting on a GFS long range forecast! LOL. Looks like they trust the Euro - can't blame them. Still, its rare for even the GFS to forecast such a cold blast for so early in the winter.

[jinftl]

Not even so long range at this point....talking 4 and 5 days out...at some point soon, the models and the forecasts have to start to correlate...or one (or both) are just plain wrong. My money is on the NWS.


NWS Jacksonville not picking up on much either for early next week (forecast for Gainesville):

Sunday: A 40 percent chance of showers. Mostly cloudy, with a high near 69.

Sunday Night: A 30 percent chance of showers. Mostly cloudy, with a low around 47.

Monday: A 20 percent chance of showers. Mostly cloudy, with a high near 68.

Monday Night: Partly cloudy, with a low around 43.

Tuesday: Sunny, with a high near 67.

Here is the current extended forecast from NWS Tampa Bay for November 30 - December 2 for Tampa...

Sunday And Sunday Night...Partly cloudy with a 30 percent chance of showers. Highs in the lower 70s. Lows in the mid 50s.

Monday...Partly cloudy with a 20 percent chance of showers. Highs in the lower 70s.

Monday Night And Tuesday...Partly cloudy. Lows in the upper 40s. Highs around 70.


What a surprise..the NWS not biting on a GFS long range forecast! LOL. Looks like they trust the Euro - can't blame them. Still, its rare for even the GFS to forecast such a cold blast for so early in the winter.

[Brent]

This is going to be a fun winter.

[Agua]

Step back from the models and think how ludicrous it is. It's not going to snow in peninsular Florida (or SE TX or LA/Miss/AL Gulf Coast) in early December.

[JonathanBelles]

And why is nobody looking at the surface temps?

[jinftl]

Taking a step back is the best advice I've heard.....the GFS is a model....not the sole basis for weather forecasts. Every winter we see 'fantasy runs'...just as we see all types of doomsday runs during hurricane season bringing a Cat 5 into Miami 2 weeks out....models are just that.



NWS New Orleans....no snow in the forecast either

Sunday: Partly sunny, with a high near 59.

Sunday Night: Mostly cloudy, with a low around 45.

Monday: Partly sunny, with a high near 59.

Monday Night: Partly cloudy, with a low around 44.

Tuesday: Mostly sunny, with a high near 64.

Step back from the models and think how ludicrous it is. It's not going to snow in peninsular Florida (or SE TX or LA/Miss/AL Gulf Coast) in early December.

[Brent]

Just chatting online with Jason Simpson, one of the greatest meteorologists of modern times, and the great American weather legend, JB Elliott, and we were looking over the latest GFS model run - the 12Z run. And it represents a BIG change from the earlier run.

Both runs are depicting a cold Monday, but the 12Z run seems to be faster and somewhat more vigorous with the approaching storm. In fact, IF the 12Z run should be correct, we could be looking at some winter weather possibilities for the Southeast including Alabama.

The age old dilemma for meteorologists in southern climes is the arrival of cold air before the departure of the moisture. We see it many times where the cold air arrives right on the heels of the moisture, so we end up at best with flurries.

This latest run also paints a big change for Saturday with considerably wetter conditions for Iron Bowl action. But as we all should know, models flip on solutions three and four days out, so as James Spann frequently mentions, it’s probably not a good idea to change the forecast just yet until we see if this model trend is picking up on the right solution.

In the meantime, it makes for some great speculation.

http://www.alabamawx.com/?p=12891

[ronjon]

Latest GFS still showing dramatic cool down over the deep south. The 0 deg line right through Tampa Bay with light prec predicted - could be flurries. NWS offices now trending colder on Monday-Tuesday forecasts.

[ronjon]

NWS Tallahassee AFD:

LONG TERM...SAT THRU WED...FOLLOWING THE 00Z GFS THIS PACKAGE
WHICH IS NOT AS INTENSE WITH MAJOR SYSTEM AS PRIOR RUN...BUT
STRONGER THAN ECMWF. AS SIG UPR RIDGE BUILDS OVR WEST COAST...
WILL SEE NRN STREAM TROUGH DIVE ACRS PLAINS LATE SAT INTO
SUN...POTENTIALLY PHASING WITH SRN STREAM SYS. INIT S/W WILL
LIKELY BE PUSHED EAST AHEAD OF MAIN SYS ON SAT...LIKELY PRODUCING
PCPN ALNG/N OF DVLPG WARMFRONT OVER SRN GA. WILL RANGE POPS SAT
FROM 50 NRN ZNS TO 30 SRN ZNS. PCPN AND CLOUD COVER WILL KEEP HIGH
TEMPS DOWN.

INITIAL S/W WILL SERVE TO INITIATE LLVL GULF MOISTURE RETURN
WHICH WILL INCREASE SAT NGT/EARLY SUN WITH DVLPG LLVL JET.
GFS SUGGESTS AREA OF STRONG UPR DIVERGENCE DVLPS OVER GA/FL/
ERN GULF LIKELY SUPPORTING A LINE OF HEAVIER SHOWERS AND
PERHAPS SOME TSRA. IF SQUALL LINE DEVELOPS AND MOVES ACRS FCST
AREA SUN AS EXPECTED...DAMAGING WIND THREAT WILL EXIST WITH LINE.

MUCH COLDER AIR MOVES IN BEHIND FRONT SUN NGT/MON...WITH MODELS
SHOWING RATHER LOW 850MB TEMPS AND LLVL THICKNESS VALUES. WILL
LOWER FCST TEMPS SUN NGT THRU TUE IN UPCOMING PACKAGE TO REFLECT
THIS...NOT GOING AS LOW AS NEW MEX GUIDANCE...BUT WOULDN`T BE
SURPRISED TO SEE TEMPS DROP A LITTLE MORE IN SUBSEQUENT FCST
PACKAGES.

[jinftl]

Still no snow in north florida forecast....big difference between a decemeber 'normal' cold front and snow flurries in tampa.

NWS Jacksonville forecast for Gainesville:
Sunday: Showers likely and possibly a thunderstorm. Cloudy, with a high near 72. Chance of precipitation is 70%.

Sunday Night: A slight chance of showers. Partly cloudy, with a low around 46. Chance of precipitation is 20%.

Monday: A 20 percent chance of showers. Mostly cloudy, with a high near 60.

Monday Night: Partly cloudy, with a low around 34.

Tuesday: Mostly sunny, with a high near 58.

Tuesday Night: Mostly clear, with a low around 38.

Wednesday: Sunny, with a high near 69.

[ronjon]

Still no snow in north florida forecast....big difference between a decemeber 'normal' cold front and snow flurries in tampa.

NWS Jacksonville forecast for Gainesville:
Sunday: Showers likely and possibly a thunderstorm. Cloudy, with a high near 72. Chance of precipitation is 70%.

Sunday Night: A slight chance of showers. Partly cloudy, with a low around 46. Chance of precipitation is 20%.

Monday: A 20 percent chance of showers. Mostly cloudy, with a high near 60.

Monday Night: Partly cloudy, with a low around 34.

Tuesday: Mostly sunny, with a high near 58.

Tuesday Night: Mostly clear, with a low around 38.

Wednesday: Sunny, with a high near 69.

Ah yeh of such little faith. You should know by now that NWS is very conservative on forecasts past 3 days. Now, I'm not saying the GFS is going to verify but the forecast is trending colder. It would take a number of factors to come together to bring flurries to the west coast of FL (i.e. cold air, lower thicknesses, and moisture). Not unheard of though to get a few flurries -particularly near the coast. I believe it happened last winter. You certianly don't need surface temps to be below freezing to get flurries if the upper air conditions are adequate.

[jinftl]

I really and truly believe that if the kind of weather that would bring about snow...i.e., temps near freezing...even in the 35-40 range...were forecast in the next 120 hours, the NWS would mention it....to give agriculture and local officials time to prepare. Not talking 2 weeks out...talking 72 to 96 hours. How many times has the 'conservative' NWS led to unexpected snow in tampa? exactly.

No question cold temps may take place....but again...given the frequency of flurries in tampa...not ready to tell folks there to buy shovels. Colder weather? Sure. Temps in the 30s? Possibly. Snow? Wouldn't bet any money on that...yet.


NWS Tampa forecast for inland Tampa metro area:
Sunday: A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 74. Southwest wind between 8 and 10 mph.

Sunday Night: A chance of showers. Mostly cloudy, with a low around 54. West wind around 10 mph. Chance of precipitation is 40%.

Monday: A 30 percent chance of showers. Partly cloudy, with a high near 67. West northwest wind between 10 and 16 mph, with gusts as high as 23 mph.

Monday Night: A 20 percent chance of showers. Partly cloudy, with a low around 44.

Tuesday: Mostly sunny, with a high near 63.

Tuesday Night: Partly cloudy, with a low around 43.

Wednesday: Mostly sunny, with a high near 70.

Still no snow in north florida forecast....big difference between a decemeber 'normal' cold front and snow flurries in tampa.

NWS Jacksonville forecast for Gainesville:
Sunday: Showers likely and possibly a thunderstorm. Cloudy, with a high near 72. Chance of precipitation is 70%.

Sunday Night: A slight chance of showers. Partly cloudy, with a low around 46. Chance of precipitation is 20%.

Monday: A 20 percent chance of showers. Mostly cloudy, with a high near 60.

Monday Night: Partly cloudy, with a low around 34.

Tuesday: Mostly sunny, with a high near 58.

Tuesday Night: Mostly clear, with a low around 38.

Wednesday: Sunny, with a high near 69.

Ah yeh of such little faith. You should know by now that NWS is very conservative on forecasts past 3 days. Now, I'm not saying the GFS is going to verify but the forecast is trending colder. It would take a number of factors to come together to bring flurries to the west coast of FL (i.e. cold air, lower thicknesses, and moisture). Not unheard of though to get a few flurries -particularly near the coast. I believe it happened last winter. You certianly don't need surface temps to be below freezing to get flurries if the upper air conditions are adequate.

[x-y-no]

HPC still isn't buying into it ...

RIGHT OFF THE BAT... THE OPERATIONAL AND ENSEMBLE MED RANGE
GUIDANCE SHOWED CONSIDERABLE SPREAD STARTING ON DAY 3 SUN. THE
CULPRIT IS A SPLIT FLOW UPPER TROUGH EXTENDING THROUGH THE ENTIRE
MS VLY AND ITS POSSIBLE EVOLUTION DOWNSTREAM TOWARD THE ERN
SEABOARD ON MON AND TUES. DURING THE SHORT RANGE FCST PERIOD...
THE GFS WAS A STRONG OUTLIER WITH A SRN STREAM VORT MAX MOVING
TOWARDS THE BASE OF THIS TROUGH. THIS CONTINUED TO BE THE CASE
WITH IT STARTING OFF NEAR THE LOWER MS VLY/WRN GULF COAST STATES
ON SUN MORNING. THIS SHORT WAVE SHOULD REMAIN WEAK BEFORE IT GETS
LIFTED TOWARD THE SERN/MID-ATL COASTLINE...OR AHEAD OF THE DIGGING
NRN STREAM JET OVER THE UPR MS VLY/GRT LAKES. THE MODEL GUIDANCE
THAT BEST REPRESENTED THIS IN THE EARLY PRELIM RELEASE WERE THE
00Z ECMWF AND UKMET.. UPDATED PRELIM PROGS SUBSTITUTED THE 00Z/27
GEFS ENSEMBLE MEAN FOR THE 00Z UKMET IN ORDER TO BE ABLE TO CREATE
A BLEND INTO DAY 7. THIS EJECTING SRN STREAM FEATURE SHOULD INDUCE
A COASTAL LOW THAT WILL RIDE UP INTO THE COAST THROUGH NEW
ENGLAND. WHILE THIS IS HAPPENING... THE MASSIVE UPPER RIDGE OVER
THE WEST WILL CONTROL THE WEATHER SUN AND MOST OF MON BUT HEIGHTS
WILL BEGIN TO CRASH ACROSS THE PAC NW/NRN ROCKIES ON TUES.

[jinftl]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL

EXTENDED FORECAST...WILL KEEP LOW/MID RANGE CHANCE POPS SUN-MON...
SLIGHT CHANCE MON NIGHT AND THEN DROP POPS ON TUE. FOR NOW WILL KEEP
PRECIPITATION GENERALLY LIMITED TO SHOWERS ALTHOUGH THERE MAY BE
ENOUGH ENERGY OUT AHEAD OF THE FRONT SUN TO SUPPORT SLIGHT CHANCE
T-STORMS IN THE AFTERNOON.

TEMPERATURES NEAR OR JUST ABOVE AVERAGE AS THE WEEKEND
ENDS GRADUALLY DROP THROUGH WED...WHEN THE NORTH COULD
APPROACH FREEZING...AND THEN WARM SOME THU...