Snow In Florida

[Thomas F. Giella NZ4O]

It looks like some other Meteorologists are now jumping on "my" snow in Florida scenario. Paul Dellegatto mentioned it yesterday evening on Fox 13 and he's a pretty conservative (unlike me) and very accurate weather forecaster. 

I honed my brash aviation/marine weather forecasting skills in the U.S. military and for Uncle Sam in other capacities. But I'm also now rusty skill wise as I retired from for profit weather forecasting in 2004 and not for profit weather forecasting in 2007.

Anyway Meteorologist Alan Huffman (see link below) has also now picked up on the possible snow in Florida scenario. However just because more of us are mentioning it doesn't increase the likelihood of it happening.

http://www.examiner.com/x-4053-Raleigh-Weather-Examiner~y2010m1d6-Very-cold-weather-to-grip-the-US-deep-into-Texas-and-Florida?cid=examiner-email .


Also here is part of the latest forecast discussion from NWS Miami-

.....TO PUT IT BLUNTLY...THE WEATHER ACROSS SOUTH FLORIDA FROM FRIDAY  
NIGHT THROUGH EARLY SUNDAY MORNING SHOULD BE MISERABLE...AS  
MODELS CONTINUE TO INDICATE AN ACTIVE SUBTROPICAL JET RESULTING IN  
WIDESPREAD CLOUD COVER AND SHOWER ACTIVITY...WITH COLD AND  
BLUSTERY CONDITIONS AT THE SURFACE...AS A SIBERIAN SURFACE HIGH  
DROPS SOUTHWARD ACROSS THE CENTRAL PLAINS. THERE IS THE POTENTIAL  
FOR HIGH TEMPERATURES ON SATURDAY TO BE SIGNIFICANTLY COOLER THAN  
EVEN MEX GUIDANCE SUGGESTS...AND MAY NOT MAKE IT OUT OF THE 40S IN  
SOME AREAS. ALTHOUGH UNCERTAINTY PRECLUDES ADDING MIXED  
PRECIPITATION TO THE FORECAST AT THIS TIME...THERE IS ALSO A  
REMOTE CHANCE THAT SOME SLEET OR ICE PELLETS MAY MIX WITH RAIN IN  
THE LAKE OKEECHOBEE AREA ON SATURDAY/SATURDAY NIGHT. REGARDLESS...  
A VERY COLD AIR MASS WILL CONTINUE TO SPREAD ACROSS THE AREA ON  
SATURDAY NIGHT...WITH RAIN CHANCES AND CLOUD COVER GRADUALLY  
DIMINISHING FROM NORTH TO SOUTH. THERE IS AN ELEVATED POTENTIAL  
FOR FREEZING TEMPERATURES ON SATURDAY NIGHT...BUT THIS WILL BE  
DEPENDENT ON HOW QUICKLY CLOUDS DEPART. THE GFS/ECMWF AGREE THAT A  
SECONDARY MID-LEVEL VORT MAX MOVING AROUND BASE OF DEEP UPPER  
TROUGH OVER EASTERN NORTH AMERICA WILL MOVE ACROSS THE PENINSULA  
ON SUNDAY...AND INDUCE SURFACE CYCLOGENESIS OVER THE ATLANTIC  
WATERS EAST OF THE PENINSULA. THIS WILL ALLOW BRISK NORTHWEST  
WINDS TO INCREASE EVEN FURTHER...WITH COLD TEMPERATURES EXPECTED  
THROUGH THE DAY ON SUNDAY...AND AN EVEN HIGHER FREEZE POTENTIAL ON  
SUNDAY NIGHT/MONDAY MORNING. A GRADUAL WARMING TREND IS STILL  
EXPECTED FROM MONDAY-WEDNESDAY......  


NWS Melbourne-

WOULD BE REMISS IF I DIDN'T MENTION THE POSSIBILITY OF SOME LIGHT   
MIXED PRECIP BEHIND THE INTIAL FRONTAL SURGE. DATA FROM BOTH GLOBAL   
AND MESOSCALE MODELS INCLUDING TIME SECTIONS/RAOBS INDICATE STRONG   
LOW LEVEL ADVECTION OF COLD DRY AIR BENEATH A SATURATED AIR MASS   
ABOVE H8-H7 AS THE POS TILT H50 TROUGH LAGS WELL BEHIND THE FRONT.   
NEAR THE END OF THE EVENT...BEFORE THE DRY AIR DEEPENS...GUIDANCE   
CONTINUE TO SPIT OUT SOME PRECIP OUT OF THE MID LEVELS AS THE 0C H85   
LINE SHIFTS SWD INTO THE NRN/CTRL CWA (BREVARD/OSCEOLA COUNTIES NWD)   
SOUNDINGS INDICATE THAT ANY FROZEN P-TYPE COULD FALL AS SOME LIGHT   
SNOWFLAKES/GRAUPEL OR SLEET. OF COURSE...TEMP/RH FIELDS WOULD HAVE   
TO ALIGN JUST RIGHT FOR THIS TO TAKE PLACE - FOR EXAMPLE COLD AIR   
ADVECTION COULD LAG...OR DRY ADVECTION COULD OCCUR STRONGER/FASTER  
THAN MODELS ADVERTISE - SO A LOT CAN HAPPEN TO CAUSE MIXED PRECIP   
*NOT* TO FALL IN THIS CASE. HOWEVER...FROZEN PRECIP IS NOT AS RARE   
IN ECFL (E.G. 2003, 2006 AND 2008) AS ONE MIGHT THINK.  



And last but not least NWS Tampa Bay-

.....INTERESTING SCENARIO TO SET UP   
FRIDAY NIGHT INTO SATURDAY BEFORE FINISHING THE COLD SNAP. LATEST   
MODELS DEEPEN MID-UPPER TROUGH INTO THE W GULF WITH SERIES OF   
VORTICITY MAXES ROTATING OFF THE CENTRAL TO E GULF OVER THE AREA IN   
FAST JET SW FLOW. SURFACE COLD FRONT STALLING OVER THE SOUTHERN TIP   
OF THE FL PENINSULA WITH COLD ARCTIC HIGH PRESSURE BUILDING INTO THE   
REGION FROM THE PLAINS STATES. MODELS SOUNDINGS AND TIME HEIGHT   
SECTIONS FROM AROUND THE AREA SHOWING OVERRUNNING TYPE RAIN SHIELD   
AND WITH GOOD UPPER DYNAMICS AFTER 06Z. MOS POPS HAVE INCREASED WITH   
THIS SET UP AS WELL AND HAVE RAISED POPS AREAWIDE BY 10 PERCENT TO   
SLIGHT CHANCE N AND CHANCE CENTRAL AND SOUTH LATE FRIDAY NIGHT AND   
SATURDAY MORNING. NOW THE COMPLICATED PART... SURFACE TEMPS TO BE   
COLD WITH OVERNIGHT LOWS IN THE 20S OVER THE NATURE COAST...LOWER TO   
MID 30S AROUND THE BAY AREA AND MID TO UPPER 30S SOUTHERN AND   
COASTAL AREAS. THESE LOW SURFACE TEMPS COMBINED WITH POPS WOULD   
INDICATED THE SLIGHT CHANCE FOR SOME FROZEN PRECIP...SO WILL   
CAUTIOUSLY DISCUSS. AROUND 12Z SATURDAY EXPECT SATURATED ENVIRONMENT   
ABOVE 10K FT FOR LIGHT TO MODERATE PRECIP THEN WARM LAYER BETWEEN   
700-900MB FOR COLD RAIN..THEN COLDER BELOW FREEZING LAYER FROM   
900-1000MB THEN SOME WARMER SLIGHT ABOVE 32 DEGREE AIR AT/NEAR THE   
SURFACE. SO CURRENT THINKING IS PRIMARILY A COLD RAIN AND RAW   
CONDITIONS LATE FRIDAY NIGHT AND SATURDAY WITH THE SLIMMEST OF   
CHANCES OF A FROZEN MIX/BLEND AROUND 12Z SATURDAY.  
  
COLD DRY NW FLOW ALOFT AND ARCTIC HIGH PRESSURE AT THE SURFACE OVER   
THE REGION TO PRODUCE ANOTHER ROUND OF HARD FREEZE AND FREEZING   
CONDITIONS AREAWIDE TO END THE WEEKEND AND INTO EARLY NEXT WEEK.....  
 

If frozen precipitation does occur it could just be some sleet/ice pellets and or a mix to include snowflakes and most likely across the central peninsula and even south central peninsula. Or it could be a measureable 1-3" like fell across the central peninsula in January 1977. As I mentioned in a previous email the synoptic weather pattern is identical to the January 1977 snow episode.

Also tonight looks to be another significant freeze event. With a new influx of cold dry air today (dewpoints in the single digits and teens), tonight could be the coldest night yet as winds should die down considerably to near calm to at times totally calm for extended periods of time, as it now appears that the Arctic high pressure system will settle across the central peninsula later tonight. However a bit of subtropical jet stream cirrus/CS is headed for the central peninsula and this could hold temperatures up some.

So we could see a hard freeze event (<27 deg. for at least four hours) deep into inland rural south peninsula. Coastal and even urban areas are likely to see temperatures near, at or just below freezing. 

In reality minimum temperatures could dip as low as the mid and upper teens in inland rural areas of the north and north central peninsula. Upper teens to mid 20's in the inland rural central and south central peninsula and low to mid 20's in the inland rural south peninsula. Once again these temperatures are for inland rural agricultural areas, not major suburban and urban areas.

Happy New year 2010,
Thomas F. Giella, NZ4O
Lakeland, FL, US
nz4o at arrl.net
John 3:16 <><

CWOP #AR692/NZ4O
CoCoRaHs #FL-PK-18
NWS Skywarn #POL-10A

Lakeland FL Weather Observations: http://www.wcflunatall.com/index1.html 
Florida & U.S. Raw Weather Forecasting Resource Links: http://www.wcflunatall.com/nz4o13.htm 
Lakeland, FL Daily Climatological Weather Data Archive: http://www.wcflunatall.com/nz4o22.htm 
Harmful Man Induced Climate Change (Global Warming) Refuted: http://www.globalwarminglie.org
NZ4O Daily Solar Space Weather & Geomagnetic Data Archive: http://www.wcflunatall.com/nz4o1.htm  

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