FXUS62 KTAE 151918
AFDTAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
218 PM EST TUE DEC 15 2009
...RAIN CHANCES WILL COME TO AN END TONIGHT FROM NORTH TO SOUTH...
.SHORT TERM...TONIGHT-THURSDAY NIGHT.
LIGHT TO MODERATE RAIN CONTINUES TO FALL ACROSS SOUTHEAST
ALABAMA...THE FLORIDA PANHANDLE...AND PORTIONS OF SOUTHWEST
GEORGIA AS A COLD FRONT NEARS THE AREA FROM THE NORTHWEST.
ADDITIONAL ACCUMULATIONS HAVE FORTUNATELY BEEN VERY LIGHT THROUGH
THE DAY SO FAR. HOWEVER...OVER THE PAST THREE DAYS PORTIONS OF
OUR SOUTHEAST ALABAMA AND SOUTHWEST GEORGIA COUNTIES HAVE REACHED
THE 10 INCH MARK OR BETTER. THIS HAS LEAD TO A CONSIDERABLE AMOUNT
OF FLOODING WITH MANY ROADS CURRENTLY IMPASSIBLE. SEVERAL RIVERS
HAVE REACHED MODERATE LEVELS WITH A FEW AT OR AROUND MAJOR FLOOD
STAGE AND STILL RISING.
THE MODELS ARE ALL IN DECENT AGREEMENT OVER THE NEXT FEW DAYS AND
INDICATED NORTHERLY WINDS AND A MUCH DRIER AIRMASS FILLING IN
ACROSS THE AREA FROM NORTH TO SOUTH AS THE FRONT MOVES ACROSS THE
AREA TONIGHT AND HIGH PRESSURE BUILDS OVER THE REGION. THIS WILL
BRING AN END TO THE RAIN TEMPORARILY. TEMPERATURES ARE FORECAST TO
DROP BACK DOWN TO AROUND NORMAL BEGINNING TOMORROW AND CONTINUING
INTO THURSDAY (HI 60-65/LO 40-50).
ANOTHER GULF LOW WILL BEGIN TO TAKE SHAPE OFF THE TEXAS COAST
THROUGH THE DAY THURSDAY IN RESPONSE TO A SHORTWAVE TROUGH OVER
TEXAS. THE ECMWF...GFS...NAM ALL CONTINUE TO INDICATE THE CENTER
OF THIS FEATURE TAKING AN EAST-NORTHEAST TRACK TOWARD THE NORTH-
CENTRAL GULF BY THE END OF THE THURSDAY NIGHT PERIOD. ISENTROPIC
LIFT WILL BEGIN OVER OUR AREA COME THURSDAY EVENING AND THROUGH
THE OVERNIGHT HOURS AS THIS LOW APPROACHES FROM THE SOUTHWEST. AS
A RESULT...EXPECT INCREASING RAIN CHANCES BEGINNING ACROSS THE
PANHANDLE WATERS AS EARLY AS THURSDAY AFTERNOON...THEN SPREADING
NORTH OVER THE REST OF THE FORECAST AREA THURSDAY NIGHT.
ADDITIONAL RAINFALL ACCUMULATIONS AROUND A HALF OF AN INCH WILL
BE POSSIBLE ACROSS THE PANHANDLE AREA BY THE END OF THE PERIOD.
.LONG TERM...FRIDAY THROUGH TUESDAY.
EXTENDED BEGINS WITH THE GFS FINALLY FALLING IN LINE WITH THE
EURO. MODELS SHOW THE LOW PRESSURE CENTER TRACKING EASTWARD
ACROSS THE MIDDLE OF THE FLORIDA PENINSULA ON FRIDAY AFTERNOON AND
EVENING...AND BREAKING OUT INTO THE ATLANTIC ON SATURDAY MORNING.
AN ADDITIONAL COLD SURGE WILL PROBABLY MOVE THROUGH THE FORECAST
AREA ON SATURDAY AFTERNOON AND EVENING. THE ONLY WAY TO TELL THE
TIMING ON THIS SURGE IS BY THE INCREASED PRESSURE GRADIENT
ASSOCIATED WITH IT. MOS GUIDANCE HAS TAKEN A REAL PLUNGE SINCE
YESTERDAY DROPPING 8F DEGREES IN 24 HOURS ON MONDAY MORNING AT
KTLH.
ALOFT...OVERALL PATTERN SHOWS RIDGING IN THE WEST AND A COLD DEEP
ELONGATED TROUGH ACROSS THE NATIONS MID SECTION EXTENDING EASTWARD
INTO THE WESTERN ATLANTIC. A QUASI-STATIONARY UPPER LOW IS PARKED IN
THE CANADIAN MARITIMES. A COMBINATION OF ENERGETICS APPEAR TO COME
TOGETHER WITH THE NEW GULF LOW. FIRST A SHORT WAVE TRAVERSING
NORTHERN MEXICO GETS THINGS GOING ON WEDNESDAY. ANOTHER SHORT WAVE
BARRELING DOWN THE FRONT SIDE OF THE UPPER RIDGE SEEMS TO ARRIVE AT
THE RIGHT TIME ON SUNDAY TO DEEPEN THE LOW OF THE SOUTHEAST U.S.
COAST.
ALL IN ALL...OUR WEATHER APPEARS TO IMPROVE SIGNIFICANTLY SUNDAY
WITH CLEARING SKIES AND MUCH COLDER TEMPERATURES. I GUESS I'M NOT
READY TO TAKE THE MEX SUGGESTION AS YET AND DROP THE TEMPS ON MONDAY
AND TUESDAY MORNINGS INTO THE MID 20S. WILL PROBABLY KEEP THEM
AROUND 30-32. TEMPS MODERATE SIGNIFICANTLY ON FRIDAY FROM THE
PREVIOUS FORECAST...ONLY DROPPING INTO THE MID 40S...AS THE GULF LOW
PASSES TO OUR SOUTH. LOOKS LIKE RAIN BEGINNING THURSDAY NIGHT AND
CONTINUING INTO SATURDAY AFTERNOON WITH AMOUNTS ON THE ORDER OF 1 TO
2 INCHES.
&&
.MARINE...AN APPROACHING COLD FRONT WILL MOVE ACROSS THE MARINE
AREA TONIGHT WITH GUSTY NORTHERLY WINDS FOLLOWING ITS PASSAGE.
ADVISORY CONDITIONS WILL BE EXPECTED LATER TONIGHT ACROSS THE
PANHANDLE WATERS...THEN ACROSS THE BIG BEND WATERS WEDNESDAY.
HIGHEST SEAS WILL REMAIN AWAY FROM THE IMMEDIATE COAST WITH THE
OFFSHORE FLOW IN PLACE OVER THE NEXT FEW DAYS. ANOTHER GULF LOW
WILL BEGIN TO DEVELOP THROUGH THE DAY THURSDAY...THEN TRACK
NORTHEAST TOWARD THE MARINE AREA THURSDAY NIGHT AND FRIDAY. WINDS
AND SEAS WILL REMAIN ELEVATED THROUGH THIS TIME AND WILL REMAIN UP
INTO THE WEEKEND WITH PERIODS AT OR NEAR ADVISORY LEVEL.
&&
.AVIATION...SCATTERED SHRA WILL BE THE PRIMARY CONCERN FOR
AVIATION INTERESTS THROUGH THE AFTERNOON. A LARGE CLUSTER OF SHRA
WAS LOCATED OVER THE FL PANHANDLE INTO SOUTHEAST AL AND SOUTHWEST
GA. THIS CLUSTER OF RAIN IS ASSOCIATED WITH LOW CIGS/VSBYS. THE
PRIMARY CONCERN WILL BE FOR CIGS TO DROP TO IFR/LIFR LEVELS AS THE
CLUSTER MOVES EASTWARD. MOST MODELS SHOW A GRADUAL DECREASE IN
SHOWER ACTIVITY AS THE SYSTEM MOVES EAST. THERE IS A CHANCE
HOWEVER THAT THE ACTIVITY WILL PERSIST THROUGH THE EVENING. FOR
THIS REASON...TEMPO GROUPS WILL BE LEFT IN FOR SHRA AND LOWERED
CIGS/VSBYS. SHRA WILL DECREASE THROUGH LATE WEDNESDAY MORNING AS A
COLD FRONT CLEARS THE AREA AND DRY AIR MOVES IN. EXPECT VFR/MVFR
CONDITIONS OUTSIDE OF ANY SHOWER ACTIVITY THIS AFTERNOON AND
EVENING DETERIORATING TO MVFR/IFR OVERNIGHT AND IMPROVING TO VFR
BY TOMORROW AFTERNOON.
&&
.FIRE WEATHER...WET WEATHER WILL CONTINUE AS A COLD FRONT MAKES
ITS WAY ACROSS OUR AREA. ONCE THE FRONT EXITS THE REGION SOME
SLIGHTLY DRIER AIR WILL FILTER INTO THE SOUTHEAST. A NEW STORM
SYSTEM IS FORECAST TO DEVELOP IN THE EASTERN GULF WEDNESDAY NIGHT
INTO THURSDAY. THIS WILL KEEP RELATIVE HUMIDITY WELL ABOVE
CRITICAL LEVELS. AFTER THIS SYSTEM EXITS OUR AREA...COOLER DRIER
AIR WILL MOVE IN FOR THE WEEKEND WITH A POSSIBILITY OF LOW
RELATIVE HUMIDITIES FOR THE BEGINNING OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TALLAHASSEE 55 65 43 60 50 / 40 0 0 20 60
PANAMA CITY 51 63 46 57 48 / 40 0 0 30 70
DOTHAN 45 62 38 56 46 / 30 0 0 20 50
ALBANY 48 62 36 58 44 / 40 0 0 10 40
VALDOSTA 53 64 40 60 50 / 40 10 0 20 50
CROSS CITY 57 67 47 66 55 / 30 10 0 20 60
APALACHICOLA 56 64 48 57 52 / 40 10 10 40 70
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...FLASH FLOOD WATCH UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: COFFEE...DALE...GENEVA...HENRY...HOUSTON.
GA...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR THE FOLLOWING
ZONES: BAKER...BEN HILL...CALHOUN...CLAY...DOUGHERTY...
EARLY...IRWIN...LEE...MILLER...MITCHELL...QUITMAN...
RANDOLPH...TERRELL...TIFT...TURNER...WORTH.
FL...NONE.
GM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 4 AM EST
THURSDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM
APALACHICOLA TO DESTIN FL OUT 20 NM...WATERS FROM
APALACHICOLA TO DESTIN FL FROM 20 TO 60 NM.
&&
$$
SHORT TERM/MARINE...GIBBS
LONG TERM...WATSON
REST OF DISCUSSION...AUSTIN
