FXUS62 KTAE 031907
AFDTAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
207 PM EST THU DEC 3 2009
.SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...UPPER FLOW ACROSS
THE CONUS CURRENTLY DOMINATED BY A DEEP TROUGH STRETCHING FROM THE
GREAT LAKES TO THE PACIFIC NORTHWEST. A SHORTWAVE IS CURRENTLY
DIVING DOWN THE BACKSIDE OF THE TROUGH INTO THE FOUR CORNER
REGION. AS THIS SHORTWAVE ROUNDS THE BASE OF THE TROUGH TONIGHT
AND FRIDAY...IT WILL INDUCED CYCLOGENESIS OVER THE WESTERN GULF
OF MEXICO BY SATURDAY MORNING. THE FLOW IS FORECAST TO TRACK EAST
NORTHEAST ACROSS THE CENTRAL GULF THROUGH EARLY SATURDAY AS THE
UPPER ENERGY MOVES ACROSS THE SOUTHEASTERN STATES.
AHEAD OF THIS SYSTEM...SKIES ARE EXPECTED TO PARTIALLY CLEAR
OVERNIGHT TONIGHT AND ALLOW TEMPERATURES TO FALL INTO THE UPPER
30S ACROSS MOST OF THE AREA. AS ISENTROPIC UPGLIDE COMMENCES
ACROSS THE GULF BAROCLINIC ZONE FRIDAY...CLOUDS WILL QUICKLY
INCREASE OVER THE FORECAST AREA AND HELP KEEP MAX TEMPS IN THE 50S
ON FRIDAY. STRATIFORM RAIN IS FORECAST TO GRADUALLY DEVELOP NORTH
INTO THE AREA FRIDAY AFTERNOON AS SOUTHWESTERLY FLOW ALOFT
OVERRUNS THE BAROCLINIC BOUNDARY. BEST RAIN AMOUNTS EXPECTED OVER
THE SOUTHEASTERN BIG BEND WHERE UPPER DIVERGENCE IS EXPECTED TO BE
MAXIMIZED AHEAD OF A LEAD SHORTWAVE.
THE COLD RAIN WILL CONTINUE TO SPREAD NORTH FRIDAY NIGHT AS THE
MAIN SHORTWAVE APPROACHES AND INCREASES UPPER DIVERGENCE. OVERALL
RAINFALL AMOUNTS SHOULD BE RELATIVELY LIGHT WITH UP TO INCH OVER
THE FAR SOUTHEAST ZONES TAPERING TO A QUARTER TO HALF INCH FOR
SOUTHEAST ALABAMA. WHILE THE RAIN WILL BE CHILLY EARLY
SATURDAY...TEMPS TO DROP INTO THE 30S ACROSS SOUTHEAST
ALABAMA...THERMAL PROFILES DO NOT SUPPORT ANY FROZEN PRECIP.
COOL HIGH PRESSURE WILL BUILD IN BEHIND THE SYSTEM FOR SATURDAY
AND SATURDAY NIGHT WITH HIGH TEMPS STRUGGLING INTO THE LOWER 50S.
A LIGHT FREEZE WILL BE POSSIBLE BY SUNDAY MORNING.
.LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY)...PERIOD BEGINS
WITH UPPER TROUGH MOVING OUT INTO ATLANTIC REPLACED BY BROAD
RIDGING. AT LOWER LEVELS...A GULF LOW IS FORECAST TO LIFT RAPIDLY
TO THE NE CROSSING CENTRAL FLORIDA AND TO OFF THE MID ATLANTIC
STATES. SOME MOISTURE MAY CROSS SE BIG BEND AND MAIN IMPACT WITH
BE TIGHTER GRADIENTS...ESPECIALLY OVER COASTAL WATERS AND COAST.
OTHERWISE LITTLE LOCAL IMPACT. IN ITS WAKE...SURFACE HIGH PRESSURE
BUILDS IN FROM THE NORTH ON SUNDAY AND REMAINS WITH US THROUGH
EARLY TUESDAY WITH ALMOST ZONAL FLOW ALOFT. THEN...NEXT SHORT WAVE
COMES OUT OF THE GULF. THIS WILL STIMULATE A STRONGER SURFACE
REFLECTION SO NEXT LOW PRESSURE SYSTEM IS FORECAST TO BEGIN TO
SPREAD RAIN INTO OUR CWA TUESDAY AFTN THROUGH WEDNESDAY BEFORE LOW
EXITS EWD AND DRY AIR FILTERS IN FROM W-E BY WED NIGHT. MAINLY
IMPACT WILL BE ON MARINE AREA WITH HIGH WINDS AND SEAS.
POPS WILL BE AOB ISOLD THRU MON NIGHT...INCHING TO WDLY SCT
OVERNIGHT INTO TUES MORN AND THEN INCREASE TO LOW AND THEN MID SCT
POPS TUES NIGHT THRU WED EVE. UNDER RELATIVELY CLOUDLESS SKIES MIN
TEMPS TEMPS WILL BE 5-10 DEGREES BELOW CLIMO (CLIMO 40-44) SAT NIGHT
INCHING TO NEAR CLIMO SUN NIGHT AND THEN WITH INCREASING CLOUDS
SPREADING NEWD ACROSS GULF...MIN TEMPS RISE UP TO AROUND 5 DEGREES
ABOVE NORMAL MON NIGHT AND 10 TO 15 DEGREES ABOVE NORMAL TUES NIGHT.
IN WAKE OF EXITING LOW...MINS WED NIGHT DROP TO 2-5 DEGREES ABOVE
CLIMO. MAX TEMPS WILL BE A FEW DEGREES BELOW CLIMO (CLIMO IS MID
60S) SUN AND MON THEN SLIGHTLY ABOVE CLIMO TUES AND WED AS WINDS
VEER AHEAD OF GULF LOW.
&&
.AVIATION...STUBBORN CLOUD DECK OVER WESTERN PART OF CWA...AFFECTING
ABY AND DHN TERMINALS. CLOUD DECK NOT LOOKING TO SCATTER OUT OVER
THE NEXT FEW HOURS IN THOSE TWO TERMINALS...HOWEVER THE LEADING EDGE
OF THE CLOUD DECK IS SLOWLY THINNING. LOW LEVEL MOISTURE LOOKS TO BE
TRAPPED UNDER MID LEVEL DRY AIR THROUGH THE NIGHTTIME
HOURS...THEREFORE WILL KEEP SKIES BKN UNTIL MORNING HOURS AT ALL
TERMINALS. MVFR CIG CONDITIONS EXPECTED THROUGH THE EVENING WITH
LIGHT WINDS OUT OF THE NW TURNING TO MORE NORTHERLY BY FRIDAY
MORNING. MORE CLOUDS WILL RETURN TOMORROW IN ASSOCIATION WITH YET
ANOTHER GULF LOW.
&&
.MARINE...WINDS WILL GRADUALLY INCREASE ONCE AGAIN OVER THE NEXT
12 TO 18 HOURS AS LOW PRESSURE DEVELOPS OVER THE WESTERN GULF AND
MOVES EAST. SMALL CRAFT ADVISORY CONDITIONS EXPECTED ONCE AGAIN BY
FRIDAY NIGHT AS THE LOW MOVES SOUTH AND THEN EAST OF THE WATERS.
LIGHT TO MODERATE NORTH TO NORTHEAST FLOW IS THEN EXPECTED FROM
SATURDAY THROUGH EARLY NEXT WEEK.
&&
.FIRE WEATHER...ANOTHER GULF LOW IS ANTICIPATED TO IMPACT THE REGION
ON FRIDAY. THIS LOW WILL INCREASE THE LOW LEVEL MOISTURE AGAIN AND
INCREASE THE CHANCES FOR RAIN ON FRIDAY AND SATURDAY. WITH THIS
INCREASE IN MOISTURE THERE SHOULD BE NO FIRE WX CONCERNS THROUGH
MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TALLAHASSEE 39 54 42 53 32 / 0 60 70 40 0
PANAMA CITY 44 56 43 54 38 / 0 50 70 30 0
DOTHAN 37 52 39 50 30 / 0 20 70 40 0
ALBANY 37 52 40 53 32 / 0 20 70 50 0
VALDOSTA 39 54 43 55 33 / 0 50 70 60 0
CROSS CITY 42 56 44 58 33 / 0 60 70 60 0
APALACHICOLA 45 58 44 58 39 / 0 60 70 40 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
GA...NONE.
FL...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR THE
FOLLOWING ZONES: WATERS FROM APALACHICOLA TO DESTIN FL FROM
20 TO 60 NM.
&&
$$
CAMP/T BARRY/M BARRY
