548
FXUS62 KTAE 241857
AFDTAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
257 PM EDT MON SEP 24 2018
NEAR TERM [THROUGH TONIGHT]
CWA REMAINS UNDER THE INFLUENCE OF HIGH PRESSURE SITUATED OVER THE
ATLANTIC, WITH SOUTH TO SOUTHEAST WINDS, AND THIS WILL CONTINUE
THROUGH TONIGHT. FOCUS FOR CONVECTION THIS AFTERNOON WILL CONTINUE
TO BE THE WESTERN HALF OF THE CWA, GENERALLY ACROSS THE FLORIDA
PANHANDLE AND SOUTHEAST ALABAMA. WITH DRIER AIR ALOFT, EXPECT THE
EASTERN HALF, THE BIG BEND AND SOUTHEAST GEORGIA, TO BE LIMITED IN
CONVECTION FOR THE REMAINDER OF THE AFTERNOON. EVEN WITH THE WEAK
SEABREEZE THAT IS PUSHING WEST FROM THE EAST COAST, THIS SHOULD
ENCOUNTER THE DRIER AIR AS IT MOVES INTO THE SUWANEE VALLEY.
CONVECTION SHOULD QUICKLY DIMINISH THIS EVENING WITH ANY SHOWERS AND
THUNDERSTORMS OVERNIGHT LIMITED TO THE MARINE AREA AND COASTAL
WESTERN BIG BEND AND FLORIDA PANHANDLE. LOWS WILL REMAIN ABOVE
AVERAGE IN THE LOW TO MID 70S.
SHORT TERM [TUESDAY THROUGH WEDNESDAY NIGHT]
THE MEAN LOW TO MID-LEVEL FLOW VEERS FROM SOUTHEAST ON TUESDAY TO
SOUTHWEST ON WEDNESDAY AS A SQUEEZE PLAY TAKES PLACE BETWEEN THE
SUBTROPICAL RIDGE TO THE EAST AND A FRONTAL BOUNDARY APPROACHING
FROM THE NORTHWEST. ON TUESDAY, THE SOUTHEAST FLOW WILL FAVOR THE
REDEVELOPMENT OF SEABREEZE DRIVEN CONVECTION ACROSS THE AREA W/ THE
EXCEPTION OF THE CENTRAL BIG BEND NORTH INTO GA, WHERE SUBSIDENCE
WILL FAVOR POPS AROUND 20 PCT. OTHERWISE, POPS GENERALLY 40-60 PCT.
THERE ARE INDICATIONS HEAVIER PRECIP MAY REDEVELOP ONCE AGAIN ACROSS
THE GULF OF MEXICO AND PROPAGATE NORTHWEST INTO THE WESTERN BIG BEND
ALONG AN AXIS OF HIGHER INSTABILITY AND PRECIPITABLE WATER VALUES.
WITH A MORE SOUTHERLY LOW-LEVEL FLOW TUESDAY NIGHT AND RECENT
PRECIPITATION, LOW CLOUDS AND FOG MAY DEVELOP AFTER MIDNIGHT,
ESPECIALLY NORTH OF I-10.
ON WEDNESDAY, THE FRONTAL BOUNDARY MOVES INTO THE TENNESSEE VALLEY
WHILE THE MID-LEVEL RIDGE AXIS APPROACHES FROM THE SOUTH, SETTING UP
A MEAN SOUTHWESTERLY FLOW. THIS SHOULD LEAD TO GREATER COVERAGE OF
PRECIP ACROSS THE AREA, WITH POPS RANGING FROM 40-60 PCT. THERE IS
SOME UNCERTAINTY REGARDING SHOWER AND THUNDERSTORM COVERAGE DUE TO
THE PROXIMITY OF THE MID-LEVEL RIDGE AND THE POTENTIAL FOR GREATER
SUBSIDENCE, THEREFORE POPS MAY BE TOO GENEROUS. MID-LEVEL LAPSE
RATES AROUND 6.5 C/KM, MIXED LAYER CAPE IN EXCESS OF 1.5K J/KG, AND
500 HPA WINDS APPROACHING 25 KTS WILL FAVOR LOCALIZED STRONG AND
ISOLATED SEVERE THUNDERSTORM WIND GUSTS, MAINLY NORTHWEST OF THE
BIG BEND.
HIGH TEMPERATURES ON TUESDAY AND WEDNESDAY WILL BE IN THE UPPER 80S
TO LOWER 90S. LOW TEMPERATURES TUESDAY NIGHT AND WEDNESDAY NIGHT IN
THE LOW TO MID-70S.
LONG TERM [THURSDAY THROUGH MONDAY]
WITH THE CONTINUED APPROACH OF A LONG WAVE TROUGH AND ATTENDANT
FRONTAL BOUNDARY IN THE TENNESSEE VALLEY, THE SOUTHWEST MEAN FLOW
WILL CONTINUE ON THURSDAY, WITH A TENDENCY FOR CONFLUENCE AS THE
DEEP LAYER RIDGE REMAINS JUST TO THE SOUTH. THIS MAY LIMIT PRECIP
CHANCES FURTHER AWAY FROM THE GREATER SYNOPTIC SCALE FORCING TIED TO
THE FRONTAL BOUNDARY. AS A RESULT, POPS RANGE FROM 40 TO 70 PCT,
LOWER IN THE SUWANEE VALLEY AND HIGHER IN SOUTHWEST AL. WHILE THE
MID-LEVEL WIND FIELD WILL BE SIMILAR TO WEDNESDAY, INCREASED CLOUD
COVER MAY LIMIT INSTABILITY. WHILE THERE IS THE POTENTIAL FOR STRONG
THUNDERSTORM WIND GUSTS MAINLY NORTHWEST OF THE BIG BEND, IT MAY BE
LESS COMPARED TO WEDNESDAY.
GIVEN THE MID-LEVEL FLOW BECOMING INCREASINGLY PARALLEL TO THE
FRONT, IT WILL LIKELY STALL AND UNDERGO FRONTOLYSIS IN THE VICINITY
OF THE REGION DURING THE FRIDAY THROUGH MONDAY TIME FRAME, AS THE
SUBTROPICAL RIDGE BECOMES SITUATED NEAR THE AREA. THIS WILL PRESENT
LITTLE IF ANY OPPORTUNITY FOR AN AIR MASS CHANGE, WITH CONTINUED
ABOVE AVERAGE TEMPERATURES AND HUMIDITY EXPECTED THROUGH THE PERIOD.
POPS 20-40 PCT ON FRIDAY DECREASE 20-30 PCT SATURDAY THROUGH MONDAY,
GIVEN THE RIDGING ALOFT AND LACK OF FORCING. IN FACT, FORCING WILL
BECOME INCREASINGLY DOMINATED BY THE SEABREEZE CIRCULATION AS THE
LOW TO MID-LEVEL FLOW TRANSITIONS FROM SOUTHWEST TO EASTERLY IN THE
FRIDAY AND SATURDAY TIME FRAME. HIGH TEMPERATURES IN THE UPPER 80S
TO LOWER 90S AND LOW TEMPERATURES IN THE UPPER 60S TO LOWER 70S
THROUGH THE PERIOD, WHICH WILL FAVOR DAILY MEANS OF SEVERAL DEGREES
ABOVE NORMAL.
AS WE NEAR THE END OF SEPTEMBER 2018, WE CAN NOW PROJECT THAT
TALLAHASSEE IS ON TRACK TO HAVE A SECOND WARMEST SEPTEMBER, WITH
THE PERIOD OF RECORD (POR) DATING BACK TO 1896. AT THIS TIME, THE
WARMEST SEPTEMBER WAS 1925 WITH A MEAN OF TEMPERATURE OF 84.0
DEGREES AND THE THIRD WARMEST WAS 2016 WITH A MEAN OF 81.9
DEGREES.
AVIATION [THROUGH 18Z TUESDAY]
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS AFTERNOON
GENERALLY WEST OF A LINE FROM TLH TO DHN. THE BEST CHANCES OF THE
TSRA MOVING INTO THE TAF SITES IS AT ECP AND DHN AND WHILE CURRENTLY
HAVE INCLUDED VCTS AT THESE LOCATIONS, A BRIEF TEMPO CANNOT BE RULED
OUT THIS AFTERNOON. AGAIN, GUIDANCE IS HINTING AT LOW CLOUDS
TOMORROW MORNING BUT CHANCES ARE ON THE LOWER SIDE FOR THIS SO HAVE
BEEN CONSERVATIVE IN THE TAFS FOR NOW WITH ONLY MVFR MENTIONED AT
DHN AND VLD.
MARINE
SOUTHEAST WINDS TONIGHT THROUGH TUESDAY NIGHT WILL SHIFT TO THE
SOUTH FOR WEDNESDAY AND THURSDAY, THEN TO THE EAST THURSDAY NIGHT
THROUGH SATURDAY, GENERALLY 15 KNOTS OR LESS. SEAS 1 TO 2 FEET
TONIGHT THROUGH TUESDAY NIGHT, INCREASING 2 TO 4 FEET WEDNESDAY
THROUGH SATURDAY. WINDS AND SEAS HIGHER IN THE VICINITY OF
THUNDERSTORMS.
FIRE WEATHER
HAZARDOUS FIRE WEATHER CONDITIONS ARE NOT EXPECTED THROUGH THE
NEXT SEVERAL DAYS. CHANCES FOR WETTING RAINS WILL EXIST ACROSS THE
REGION EACH DAY.
HYDROLOGY
AVERAGE TOTAL RAINFALL AMOUNTS OVER THE NEXT WEEK ARE EXPECTED
REMAIN AT OR BELOW ONE INCH ACROSS THE REGION, WHICH IS GENERALLY
BELOW THE LONG TERM AVERAGE. HOWEVER, LOCALIZED HIGHER AMOUNTS ARE
LIKELY IN HEAVIER SHOWERS AND THUNDERSTORMS. BUT, THIS SHOULD NOT
PRESENT AN ISSUE FOR RIVERS AND STREAMS, WHICH ARE EXPECTED TO
REMAIN BELOW ACTION STAGE THROUGH THE PERIOD.
SPOTTER INFORMATION STATEMENT
SPOTTER ACTIVATION IS NOT REQUESTED. HOWEVER, SPOTTERS ARE ALWAYS
ENCOURAGED TO SAFELY REPORT SIGNIFICANT WEATHER CONDITIONS WHEN THEY
OCCUR BY CALLING THE OFFICE OR TWEETING US @NWSTALLAHASSEE.
PRELIMINARY POINT TEMPS/POPS
TALLAHASSEE 72 90 73 91 73 / 20 40 30 50 20
PANAMA CITY 73 88 74 88 74 / 30 60 40 50 40
DOTHAN 71 89 71 89 71 / 20 60 40 60 30
ALBANY 73 92 74 92 73 / 20 20 20 50 30
VALDOSTA 71 91 73 91 72 / 10 30 30 40 20
CROSS CITY 73 92 73 91 74 / 30 30 30 40 20
APALACHICOLA 76 86 76 87 76 / 40 60 40 40 20
TAE WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
NEAR TERM...FIEUX
SHORT TERM...LF
LONG TERM...LF
AVIATION...FIEUX
MARINE...LF
FIRE WEATHER...PULLIN
HYDROLOGY...LF
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