FXUS62 KTAE 261849
AFDTAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
150 PM EST SAT DEC 26 2009
.SHORT TERM...(TONIGHT THROUGH MONDAY)...SURFACE HIGH PRESSURE
CURRENTLY CENTERED NEAR PENSACOLA WILL SLIDE EAST THROUGH SUNDAY AND
WEAKEN. A WEAK SURFACE LOW IS FORMING IN THE FAR WESTERN GULF JUST
OFF THE SOUTH TEXAS COAST THIS SATURDAY AFTERNOON. THE LOW IS
FORECAST TO MOVE EASTWARD AND ACROSS SOUTHERN FLORIDA OR THE KEYS ON
MONDAY. SINCE THIS LOW WILL PASS SO FAR TO OUR SOUTH...THERE IS VERY
LITTLE CHANCE OF SEEING RAIN ACROSS OUR CWA. JUST IN CASE THE LOW
MOVES FURTHER NORTH THAN EXPECTED I WILL KEEP ONLY A SLIGHT POP
ACROSS A FEW OF OUR COASTAL COUNTIES AND COASTAL WATERS SUNDAY.
OTHERWISE...THE SHORT TERM PERIOD WILL BE DRY WITH A RE-ENFORCING
SHOT OF DRY AIR FILTERING IN FROM THE NORTH ON MONDAY. TEMPERATURES
WILL CONTINUE BELOW SEASONAL LEVELS. FOR TONIGHT...LOWS WILL BE IN
THE LOWER TO MID 30S AWAY THE IMMEDIATE COAST WITH A BRIEF FREEZE
POSSIBLE ACROSS OUR NORTHERN TIER GEORGIA ZONES. MIN TEMPS SUNDAY
NIGHT SHOULD BE ABOVE FREEZING IN THE MIDDLE 30S. MAX TEMPS BOTH
DAYS WILL GENERALLY BE IN MID TO UPPER 50S.
&&
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)...THE PERIOD WILL BEGIN
WITH THE POTENTIAL FOR A LIGHT FREEZE OVER PARTS OF THE REGION LATE
MONDAY NIGHT AND TUESDAY MORNING...BUT THERE IS STILL PLENTY TO
QUESTION IN THE NAM...GFS...AND ECMWF...IF THE COLD SFC RIDGE WILL
BE IN A FAVORABLE ENOUGH POSITION TO ALLOW FOR ENOUGH RADIATIONAL
COOLING TO SUPPORT IT. DESPITE THE AVAILABLE NUMERICAL GUIDANCE
INDICATING A FAIRLY WIDESPREAD LIGHT FREEZE (NAMELY THE MEX AND MOS
GUIDANCE)...THE RAW GFS40 SFC DATA MAY HAVE A BETTER HANDLE ON THE
SITUATION SHOWING LOWS GENERALLY IN THE LOWER TO MID 30S...WHICH
DEFINITELY FITS THE SYNOPTIC PATTERN WITH THE CENTER OF THE SFC HIGH
WELL TO OUR NW. THIS SITUATION WOULD LIKELY KEEP SFC WINDS AT LEAST
3-5 MPH THROUGHOUT MUCH OF THE NIGHT...WHICH IS USUALLY PLENTY
STRONG ENOUGH TO PREVENT A RADIATIONAL COOLING LIGHT FREEZE.
THEREFORE...AM PLANNING ON BUMPING UP OUR CURRENT LOWS A BIT...WHICH
WILL STILL SHOW SOME BELOW FREEZING TEMPERATURES...BUT NOT COLD
ENOUGH OR WITH LONG ENOUGH DURATIONS FOR A TRUE LIGHT FREEZE.
THEN...OUR ACTIVE EL NINO PATTERN WILL GET BACK INTO ACTION WITH YET
ANOTHER GULF LOW POTENTIALLY ON OUR DOORSTEP AS EARLY AS WEDNESDAY
MORNING...JUST IN TIME TO CLOSE OUT THE 2009 CALENDAR YEAR WITH A
HEALTHY BATCH OF RAIN LASTING INTO AT LEAST THURSDAY MORNING. THE 12
UTC RUN OF THE ECMWF IS A BIT SLOWER...AND WOULD ALSO DEVELOP
ANOTHER SFC WAVE AND LINGER THE RAINFALL INTO THE FIRST HALF OF
FRIDAY...SO IT WILL BE INTERESTING TO SEE HOW THE NEW 00 UTC EURO
RUN TRENDS. ALSO...UNLESS THERE ARE MAJOR CHANGES DOWN THE LINE
EXPECT THE CWA TO GENERALLY REMAIN IN THE COOL SECTOR WITH THIS
EVENT...SO THE SVR WX POTENTIAL DOES NOT APPEAR TO BE AN ISSUE AT
THIS TIME. DESPITE ALL OF THE ABOVE INTERESTING WEATHER...PERHAPS
THE MOST INTERESTING PORTION OF THE FCST WILL COME AT THE VERY END
OF THE PERIOD AND WILL BE FURTHER DISCUSSED IN THE EXTENDED
DISCUSSION TOMORROW NIGHT...AS INDICATIONS ARE POINTING TO THE
POTENTIAL FOR AN EXTREMELY COLD AIR MASS TO HEAD OUR WAY BEHIND THIS
LOW FOR NEXT SATURDAY AND SUNDAY. THIS COULD VERY WELL LEAD TO OUR
FIRST HARD FREEZE OF THE SEASON.
&&
.AVIATION...HIGH PRESSURE CENTERED TO OUR WEST WILL FEED DRY AIR
INTO THE AREA THROUGH SUNDAY. A A WEAK LOW PRESSURE AREA WILL MOVE
EASTWARD ACROSS THE NORTHERN GULF DURING SUNDAY BRINGING SOME MID
LEVEL AND POSSIBLY LOW LEVEL CLOUDS BUT CEILINGS SHOULD REMAIN ABOVE
VFR LEVELS. NO SIGNIFICANT VSBY RESTRICTIONS AREA EXPECTED.
&&
.MARINE...WINDS AND SEAS WILL BE LOW UNTIL SUNDAY NIGHT OR MONDAY
MORNING. CONDITIONS MAY REACH ADVISORY LEVELS FOR THE OFFSHORE
SEGMENTS MONDAY WITH A DIMINISHING TREND MONDAY NIGHT THROUGH
TUESDAY. HOWEVER...ANOTHER GULF LOW WILL RAPIDLY RAMP UP WINDS AND
SEAS TO ADVISORY LEVELS ON WEDNESDAY AND GALE CRITERIA COULD BE MET
WEDNESDAY NIGHT AND THURSDAY.
&&
.FIRE WEATHER...A SMALL PORTION OF NORTH FLORIDA WILL SEE MINIMUM
RELATIVE HUMIDITIES APPROACHING CRITICAL DURATIONS THIS AFTERNOON.
ON SUNDAY...MINIMUM AFTERNOON RELATIVE HUMIDITIES MAY DROP BELOW 35
PERCENT FOR ONE TO THREE HOURS ACROSS THE EASTERN PORTIONS OF THE
FLORIDA BIG BEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TALLAHASSEE 32 59 36 55 29/ 10 10 0 0 0
PANAMA CITY 38 59 40 56 34/ 10 10 0 0 0
DOTHAN 33 56 35 51 29/ 10 0 0 0 0
ALBANY 31 58 33 54 28/ 0 0 0 0 0
VALDOSTA 33 58 33 56 29/ 0 10 0 0 0
CROSS CITY 33 60 38 59 28/ 10 20 10 0 0
APALACHICOLA 36 58 39 57 31/ 10 20 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
GA...NONE.
FL...NONE.
GM...NONE.
&&
$$
AVIATION/FIRE WEATHER...GOREE
LONG TERM...GOULD
REST OF DISCUSSION...BARRY
