Snow Flurries For FL: Reports of Flurries/sleet in South FL

[otowntiger]

The 12z GFS just came in on NCEP, looks way better than the 00z and 6z for snow in South Florida. More moisture, more cold air advection. Central Florida still looking good too.

Cool! Or should I say:

[ronjon]

From NWS Melbourne AFD this afternoon:

TONIGHTS FORECAST CHALLENGES REMAIN ON AMOUNT OF COOL DOWN AS WELL
AS THE PRECIPITATION POTENTIAL. FORECAST SOUNDINGS FROM NAM/GFS @
12Z SAT BOTH INDICATE TEMPERATURE CURVES REMAINING AT OR BELOW 3C
BELOW A NEAR SATURATED LAYER ALOFT DOWN TO THE GROUND SURFACE. THE
"UNDERRUNNING" PROCESS THROUGH FORCED PARCEL LIFTING IN STRONG COLD
AIR ADVECTION ARGUES FOR THE DEVELOPMENT OF A POST FRONTAL MIXED
PHASE PRECIPITATION DEVELOPMENT WITH A LIGHT RAIN...SLEET
COMBINATION...POSSIBLY CHANGING TO A RAIN/SNOW/SLEET COMBINATION
SATURDAY MORNING ACROSS ORANGE COUNTY AND NORTH BREVARD NORTHWARD.
EVAPORATIVE COOLING IN THE DRY NEAR SURFACE LAYER MAY ASSIST IN
CHANGEOVER TO SLEET/OR FLURRIES EARLY SATURDAY MORNING. WITH
CONSIDERABLE CLOUD COVER HAVE SIDED ON TEMPERATURES REMAINING ABOVE
FREEZING ACROSS THE AREA...WHICH IS ABOVE GUIDANCE. WILL KEEP THE
CURRENT FREEZE WATCH IN PLACE FOR FURTHER EVALUATION WITH EVENING
GUID PKG HOWEVER. VERY COLD WIND CHILLS WILL DEVELOP OVERNIGHT
PROMOTING THE EARLIER WIND CHILL ADVISORY WITH 20S COMMON BY
DAYBREAK SATURDAY.

SATURDAY...A RARE DAY FOR THE SUNSHINE STATE WITH A POSSIBLE EARLY
MIXTURE OF ISOLATED LIGHT RAIN/SLEET SNOW EARLY OVER THE
ORANGE/NORTH BREVARD COUNTY AREA AND LIGHT RAIN SPRINKLES IN THE
MORNING TO EARLY AFTERNOON ACROSS THE REMAINDER OF THE AREA.

[JonathanBelles]

Looking like a rain/sleet mixture here. Better than nothing I suppose.

[vbhoutex]

1st time in 17 years as a NWS employee that the man that put the snow in the forecast has done it too. 15 of those years have been in S FL, maybe all at Melbourne. I know that for a fact since he posted it on his facebook. We are having virga showers here in the Houston metro area. Hope you guys get the real thing making it all the way to the ground.

[jpigott]

not every day, heck, not ever, do you see a forecast like this from Miami NWS:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
411 PM EST FRI JAN 8 2010

...WIDESPREAD CLOUDS AND COLD RAIN TOMORROW FOLLOWED BY POTENTIAL
FOR A HISTORICAL FREEZE AND EXTRAORDINARILY LOW WIND CHILL
VALUES ON SUNDAY MORNING...

.DISCUSSION...
OVERALL...THERE HAS BEEN VERY LITTLE CHANGE IN BOTH MODEL GUIDANCE
AND METEOROLOGICAL REASONING FOR THE SHORT TERM PORTION OF THE
FORECAST. AN UNUSUALLY POWERFUL COLD FRONT...MARKING THE LEADING
EDGE OF A SIBERIAN AIR MASS...CONTINUES TO SURGE RAPIDLY
SOUTHEASTWARD TOWARD SOUTH FLORIDA THIS AFTERNOON. PARTLY CLOUDY
SKIES AND LIGHT/MODERATE SOUTHWEST WINDS IN ADVANCE OF THE FRONT
WILL CONTINUE TO ALLOW TEMPERATURES TO WARM INTO THE UPPER
60S/LOWER 70S...WITH THIS THE WARMEST AIR THAT SOUTH FLORIDA WILL
EXPERIENCE FOR QUITE SOME TIME.

THE COLD FRONT IS STILL ON SCHEDULE TO ARRIVE IN THE NORTHWEST
PORTION OF THE FORECAST AREA BETWEEN 22-24Z...SHOULD BE LOCATED
NEAR OR JUST SOUTH OF A LINE FROM NAPLES TO THE SOUTHERN SHORE OF
LAKE OKEECHOBEE BY 09/00Z...AND WILL SURGE RAPIDLY SOUTHEASTWARD
ACROSS THE REMAINDER OF SOUTH FLORIDA AND OFFSHORE BY 09/04Z. THE
COVERAGE OF LOW CLOUDS AND RAIN CHANCES WILL INCREASE
SIGNIFICANTLY FOLLOWING PASSAGE OF THE FRONT...AS MID-LEVEL
FORCING FOR UPWARD VERTICAL MOTION FROM SHORTWAVE FEATURES
EMBEDDED IN STRONG SUBTROPICAL JET STREAM INCREASES...IN
CONJUNCTION WITH STRONG/ELEVATED WARM ADVECTION REGIME JUST ABOVE
THE SHALLOW COLD AIR MASS. POCKETS OF ENHANCED LIFT OVER THE GULF
OF MEXICO ARE ALREADY EVIDENT IN IR SATELLITE DATA...AND EXPECT
THIS TO LEAD TO A WIDESPREAD COVERAGE OF LIGHT/MODERATE RAIN...
BEGINNING ACROSS THE NORTHERN HALF OF THE FORECAST AREA LATE
TONIGHT AND ENDING ALONG THE EAST COAST EARLY SATURDAY NIGHT. THE
PARTIAL THICKNESS METHOD OF FORECASTING P-TYPE STILL SUGGESTS THAT
A FEW ICE PELLETS MAY MIX WITH THE RAIN BEFORE PRECIP COMES TO AN
END ON SATURDAY. IF THIS WERE TO OCCUR AT ALL...IT WOULD BE MOST
LIKELY BE TO THE NORTH OF A LINE EXTENDING ROUGHLY FROM EVERGLADES
CITY TO WEST PALM BEACH. REGARDING TEMPERATURES...IT IS IMPORTANT
TO NOTE THAT HIGH TEMPERATURES FOR THE DAY ON SATURDAY MAY BE
READINGS AT MIDNIGHT...WITH CLOUDS/RAIN...AND PERSISTENT COLD
ADVECTION RESULTING IN VERY LITTLE DIURNAL RISE TOMORROW. THUS...
FORECASTED HIGH TEMPERATURES FOR THE PERIOD FROM 09/12Z-10/00Z
WILL BE CLOSE TO OR ONLY SLIGHTLY ABOVE MINIMUM TEMPERATURES ON
SATURDAY MORNING FOR MOST LOCATIONS.

MODELS AGREE THAT AXIS OF THE SUBTROPICAL JET WILL SHIFT SOUTHEAST
OF THE AREA BY SATURDAY NIGHT...ALLOWING PRECIPITATION CHANCES
TO DIMINISH QUICKLY. AT THE SAME TIME...A POWERFUL/SECONDARY MID-
LEVEL TROUGH -- CURRENTLY DROPPING SOUTHWARD ACROSS THE NORTHERN
PLAINS -- IS FORECAST TO BE SPREADING EASTWARD OVER THE
SOUTHEASTERN U.S. AND SHOULD INDUCE A BROAD REGION OF SURFACE
CYCLOGENESIS BETWEEN THE NORTHEASTERN BAHAMAS AND BERMUDA. THIS
WILL FURTHER INCREASE THE PRESSURE GRADIENT ACROSS SOUTH FLORIDA
AS 1040 MB HIGH SINKS SOUTHWARD TOWARD THE OZARKS...AND NORTHWEST
WINDS WILL INCREASE THROUGH THE NIGHT...MAINTAINING THE SOUTHWARD
ADVECTION OF VERY COLD AIR AND LEADING TO DANGEROUSLY LOW WIND
CHILLS FOR THE ENTIRE AREA. A WIND CHILL WATCH AND FREEZE WATCH
WILL BE ISSUED FOR ALL OF MAINLAND SOUTH FLORIDA...INCLUDING EVERY
COASTAL ZONE ON BOTH COASTS...WITH WIND CHILL/FREEZE WARNINGS
LIKELY REQUIRED BY TOMORROW. THIS WILL IN ALL LIKELIHOOD BE A
SIGNIFICANT ADVECTIVE FREEZE EVENT FOR SOUTH FLORIDA...WITH
PROJECTED THICKNESS VALUES AND EXTREMELY LOW DEW POINTS POINTING
TO THE POTENTIAL FOR A HISTORICAL FREEZE. COLD TEMPERATURES AND
LOW WIND CHILL CONCERNS WILL CONTINUE THROUGH THE DAY ON SUNDAY...
AND WILL MAKE MAJOR DOWNWARD ADJUSTMENTS TO MOS -- AS HIGH
TEMPERATURES IN THE 50S TO AROUND 60 SEEM UNREALISTIC.

[HurricaneBelle]

Get ready, Tampa Bay area....frozen stuff being officially added to the forecast:

FXUS62 KTBW 090153
AFDTBW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
853 PM EST FRI JAN 8 2010

.UPDATE...WE MUST NOW CONSIDER THE POSSIBILITY FOR SOME FROZEN
PRECIPITATION IN THE FORECAST. THE MAV GUIDANCE IS DOING A
TERRIBLE JOB WITH TEMPERATURES RIGHT NOW. BROOKSVILLE IS 42
DEGREES AT 8 PM. THE MAV ONLY BREAKS THROUGH 42 DEGREES AT
09Z...OR 4 AM...WHEN IT SHOWS 41. AT LEAST THE MET HAS 39 AT
03Z...OR 10 PM...WHICH IS EASILY OBTAINABLE. IT MAKES SENSE THAT
THE MET GUIDANCE IS COLDER SINCE IT DOES NOT SHOW NEAR THE OVER-
RUNNING THAT THE GFS DOES. THE TRUTH MAY END UP SOMEWHERE BETWEEN
THE TWO MODELS.

THE BUFKIT TOOL SHOWS MIXED PRECIPITATION POSSIBLE FROM ABOUT
HILLSBOROUGH/PINELLAS COUNTIES NORTH. IT LOOKS LIKE LEVY COUNTY
WILL DRY OUT SO DO NOT HAVE FROZEN PRECIPITATION THERE. THE GFS
PRECIPITATION TYPE ALGORITHM IS SHOWING SNOW AND ICE PELLETS MIXED
IN WITH THE RAIN AS WELL. WE WILL ONLY HAVE ABOUT A 2000 TO 3000
FOOT LAYER OF AIR ABOVE THE SURFACE THAT WILL HAVE TEMPERATURES
ABOVE FREEZING. EVEN THIS LAYER IS CLOSE TO FREEZING...PERHAPS
NEAR 34 DEGREES. IF THAT LAYER IS COOLED...WE WILL SEE RAIN AND
SNOW MIXED. IF THE LAYER REMAINS ABOVE FREEZING...WE WILL PROBABLY
SEE MORE OF A RAIN AND ICE PELLET MIX. OF COURSE...IF THE LAYER IS
WARMER AND DEEPER THAN MODELS NOW SUGGEST...WE WILL STILL JUST SEE
RAIN. WITH ALL THIS IN MIND...

SEVERAL CHANGES ARE BEING MADE WITH THIS UPDATE. FIRST...WE ARE
ADDING SOME MIXED LIGHT SNOW AND ICE PELLETS TO THE RAIN SHOWERS
TONIGHT FOR THE NATURE COAST AND SATURDAY MORNING FOR
PINELLAS...HILLSBOROUGH AND POLK. IT IS VERY IMPORTANT TO NOTE
THAT NOTHING WILL STICK ON THE GROUND. TEMPERATURES JUST 4 INCHES
BELOW THE SURFACE ARE STILL RUNNING IN THE 50S ACCORDING TO LOCAL
OBSERVATIONS. ALSO...RAIN MIXED IN WITH THE FROZEN PRECIPITATION
WILL HASTEN THE MELTING AS WELL. ALSO...WE ARE NOT LOOKING FOR
LONG PERIODS OF FROZEN PRECIPITATION...JUST SOME MIXED IN WITH THE
RAIN HERE AND THERE.

THE OTHER CHANGES HAVE TO DO WITH OUR FREEZE WATCHES. WIND
DIRECTIONS AND LOW-LEVEL TEMPERATURES SUPPORT 3 OR MORE HOURS OF
FREEZING TEMPERATURES IN MUCH OF NORTHERN PINELLAS COUNTY AND AT
LEAST THE EASTERN HALF OF LEE COUNTY. WE ARE ADDING THOSE COUNTIES
TO THE WATCHES FOR BOTH SATURDAY NIGHT AND SUNDAY NIGHT.

THE GRIDDED FORECAST HAS ALREADY BEEN UPDATED. THE ZONES SHOULD BE
READY TO GO BY 930 PM.

[JonathanBelles]

I have NEVER NEVER NEVER seen this icon in St. Pete!! WOW!!! Sleepless night ahead!!

[Tireman4]

Wow. What a winter. What a winter. What next....?

[gatorcane]

I have NEVER NEVER NEVER seen this icon in St. Pete!! WOW!!! Sleepless night ahead!!

Yes truly amazing for sure. St. Petersburg is usually the warm spot in Central FL during cold snaps --

The chance of snow flurries across Central FL is certainly real. In the Tampa Bay area, the last time it happened was 1989 I believe on Christmas eve. That night I was outside the house where I grew up in the Clearwater area witnessing that event. The snow even accumulated some that night.

[HurricaneBelle]

Yes truly amazing for sure. St. Petersburg is usually the warm spot in Central FL during cold snaps --

The chance of snow flurries across Central FL is certainly real. In the Tampa Bay area, the last time it happened was 1989 I believe on Christmas eve. That night I was outside the house where I grew up in the Clearwater area witnessing that event. The snow even accumulated some that night.

You're close. It was actually on the 23rd of December 1989, happened late on a Saturday afternoon into early evening. The snow/sleet mix stuck to the cars but not the ground in Palm Harbor, just N of Clearwater. Much more substantial show fell in N FL, Jacksonville & Gainesville had a White Christmas.

And the last time before that in the TB area was the infamous January 1977 outbreak, which saw flurries as far south as Homestead. My family had just moved to Florida two months earlier to get away from the snow and cold, so it wasn't the big deal to me that it should have been.

I'm excited for my boys, who have never seen frozen precipitation. Hopefully some will come through tomorrow morning.

Tuning in to the local 11:00 news broadcasts now, should be interesting.

[Extremeweatherguy]

This threat for wintry precipitation looks pretty legitimate IMO. I was skeptical at first, but considering that Orlando International is already sitting at 38F with a dewpoint of 34F this evening (both of which continue to fall each hour), some mixing with or a changeover to snow flakes or sleet pellets seems very possible by tomorrow morning and would not surprise me one bit. Should be an interesting day across the sunshine state.

[CrazyC83]

Snow or sleet seems quite realistic now as far south as a line from Pasco County, maybe Lakeland through Kissimmee and east to near Cocoa Beach.

As for in the immediate Tampa Bay area itself, it is still in the low 40s now and only supposed to get to the high 30s, so snow doesn't seem quite so likely there - it would need to cool off more and fast before it dries out.

[Cookiely]

Ice showing up in this radar.
http://www.accuweather.com/radar-region ... al&large=0

[JonathanBelles]

Basically its a race. The moisture is here. The cold air is coming in and nothing is stopping it. The cold air has to reach the moisture before it dries up. NWS Tampa Bay thinks it will reach the mouth of Tampa Bay, but im not too confident.

[Cookiely]

Its kind of wierd but many times when I lived in Forest Hills I would see flurries in the Northgate Mall back in the sixties. Anyone else live in that area notice the flurries? I've always wondered why that particular area would be more prone.

[NDG]

00z gfs & nam still look good for some snow across central FL, gfs once again gives as much as 1/2" of snow to Orlando. Best time looks to be between 6 AM & 12 noon before moisture leaves the area with plenty of space for evaporational cooling at H85.

[ronjon]

Looks like the changeover is already happening from Crystal River north now with frozen precip on the radar. Crystal River at 37 deg and Brooksville at 38 deg now. Seems like the precip is not hitting the ground in Citus-Levy Counties yet but heavier returns are now filling up the eastern GOM. Based on current temp and RADAR trends, it is looking very likely for snowfall somewhere over central FL starting in the next few hours. If precip is heavy enough, evaporative cooling will drop temps further since current dewpoints are in the 20s. FYI - Orlando Int'l is now down to 35 deg.

http://www.accuweather.com/radar-state.asp?partner=accuweather&traveler=0&zipcode=&level=state&type=SIR&anim=1&site=FL_

[NDG]

2 AM, there's a lot of virga going on in N FL, but the darker green and yellow across poarts of central FL and more to come from the GOM looks to definitely be hitting the ground and as the atmosphere starts cooling, in just a few hours we may start seeing the reports of some sleet across interior areas of central FL.

[JonathanBelles]

I've got heavy rain here!

[NDG]

I have to question KMCO's current temp of 35, all surrounding areas around the airport just a few miles away are a good 4 to 5 degrees warmer.