571  
FXUS62 KTAE 181535  
AFDTAE  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TALLAHASSEE FL  
1035 AM EST WED DEC 18 2024  
   
..NEW UPDATE  
 
   
UPDATE  
 
ISSUED AT 1031 AM EST WED DEC 18 2024  
 
VISIBILITIES IN FOG HAVE BEEN SLOW TO IMPROVE THIS MORNING WITH  
REINFORCING MOISTURE ADVECTION FROM THE EAST. EXTENDED DENSE FOG  
ADVISORY TO 11 AM ET. ISOLATED SHOWERS AND A FEW RUMBLES OF  
THUNDER REMAIN POSSIBLE THIS AFTERNOON. KEPT HIGHS TODAY IN TACT  
WITH SOME SLIGHT MODIFICATIONS IN HOURLY TEMPERATURES AND  
DEWPOINTS.  
 
 
   
NEAR TERM  
 
(TODAY AND TONIGHT)  
ISSUED AT 331 AM EST WED DEC 18 2024  
 
THE BIGGEST FORECAST CHALLENGE WILL BE CONTENDING WITH FOG THIS  
MORNING IN THE MOIST ENVIRONMENT IN ADVANCE OF A COLD FRONT THAT  
WILL ENTER SOUTHEAST ALABAMA LATE THIS EVENING.  
 
MOIST ADVECTION HAS BEEN UNDERWAY EARLY THIS MORNING, WITH SURFACE  
DEWPOINTS IN THE 60S OVERRUNNING SURFACE TEMPERATURES IN THE 50S  
WEST OF THE FLINT RIVER AND APALACHICOLA RIVERS. VISIBILITIES HAVE  
ALREADY DROPPED BELOW 1 MILE ACROSS MANY INLAND AREAS, ESPECIALLY  
ALONG AND EAST OF U.S. HIGHWAY 19. FOG WILL CONTINUE TO EXPAND  
WESTWARD AND NORTHWESTWARD UNTIL 1-2 HOURS AFTER SUNRISE, SO HAVE  
THEREFORE EXPANDED THE DENSE FOG ADVISORY TO INCLUDE ALL AREAS  
EXCEPT THE PANHANDLE COAST. EVEN AFTER SUNRISE, FOG WILL BE  
UNCOMMONLY SLOW TO LIFT AND DISSIPATE, CONSIDERING THE MOIST STABLE  
BOUNDARY LAYER AND PUNY MID-DECEMBER SOLAR INSOLATION. SO THE DENSE  
FOG ADVISORY GOES ALL THE WAY OUT UNTIL 10 AM ET, AND A COUPLE SPOTS  
COULD HANG ON TO FOG A LITTLE LONGER THAN THAT.  
 
WATER VAPOR IMAGERY SHOWS A NICE SHORTWAVE CROSSING KANSAS AND  
OKLAHOMA EARLY THIS MORNING. THIS FEATURE WILL CONTINUE TO MOVE  
SOUTHEAST TODAY. A 500 MB HEIGHT FALLS BULLSEYE WILL PASS  
DIRECTLY ACROSS THE SERVICE AREA LATE TONIGHT AND EARLY THURSDAY,  
SUPPORTING SOME DYNAMICAL LIFT THIS AFTERNOON AND EVENING AS UPPER  
HEIGHTS FALL THE FASTEST. BY SUNRISE ON THURSDAY, IT WILL HAVE  
PUSHED A COLD FRONT INTO AREAS WEST OF THE FLINT AND APALACHICOLA  
RIVERS.  
 
MEANWHILE, WEAK OR POSSIBLY MODERATE CONVECTIVE INSTABILITY WILL  
DEVELOP THIS AFTERNOON, DEPENDING ON HOW MANY SUN BREAKS CAN  
DEVELOP. EVEN IF THE BOUNDARY LAYER REMAINS STABLE, SOME ELEVATED  
INSTABILITY WOULD DEVELOP THANKS TO COOLING MID-LEVEL TEMPERATURES.  
SO SQUATTY SHOWERS WILL DEVELOP THIS AFTERNOON AND EARLY EVENING  
WITH SCATTERED COVERAGE. BULK SHEAR OF ABOUT 25-40+ KNOTS WILL HELP  
SUSTAIN UPDRAFTS, AND STRONGER CELLS COULD PRODUCE A LITTLE  
LIGHTNING. LIMITED INSTABILITY AND PERHAPS THE ELEVATED NATURE OF  
INSTABILITY WOULD KEEP THIS AS A GENERAL THUNDER THREAT, WITH NO  
SEVERE WEATHER OUTLOOKED.  
 
 
   
SHORT TERM  
 
(THURSDAY THROUGH FRIDAY NIGHT)  
ISSUED AT 331 AM EST WED DEC 18 2024  
 
THE COLD FRONT EXITS THE SOUTHEAST BIG BEND EARLY THURSDAY  
MORNING, CLEARING OUT THE FOG AND AND LIGHT SHOWERS. HOWEVER, THE  
COOLER AIR LAGS BEHIND THE FRONT A BIT AS THIS ROUND DOESN'T HAVE  
AS STRONG OF A PUSH. THUS, TEMPERATURES REMAIN ABOVE NORMAL  
THURSDAY WITH HIGHS IN THE UPPER 60S TO MID 70S. LOWS THURSDAY  
NIGHT WILL LARGELY BE IN THE 40S.  
 
A STRONGER, RE-ENFORCING COLD FRONT SWEEPS THROUGH THE AREA FRIDAY  
AFTERNOON AND FRIDAY EVENING, BRINGING COLDER TEMPERATURES IN ITS  
WAKE. ADDITIONALLY, THE PRESSURE GRADIENT WILL TIGHTEN BEHIND THE  
FRONT AS HIGH PRESSURE BUILDS IN. FRIDAY'S HIGHS WILL BE IN THE  
60S. WITH LOWS IN THE 30S. GIVEN THE ELEVATED WINDS CONTINUING  
INTO FRIDAY NIGHT, WIND CHILLS FRIDAY NIGHT WILL BE IN THE UPPER  
20S TO LOWER 30S AREA-WIDE.  
 
 
   
LONG TERM  
 
(SATURDAY THROUGH TUESDAY)  
ISSUED AT 331 AM EST WED DEC 18 2024  
 
HIGH PRESSURE DOMINATES MUCH OF THE EASTERN HALF OF THE US THIS  
WEEKEND WITH COLD CANADIAN AIR SETTLING IN. TEMPERATURES SATURDAY  
AFTERNOON WILL ONLY MAKE IT TO THE 50S. THE HIGH'S POSITIONING TO  
OUR NORTH IS NOT THE MOST IDEAL PLACE FOR A RADIATIONAL COOLING  
SETUP. HOWEVER, THE 850 MB HIGH DOES MOVE OVER OUR AREA OVER THE  
WEEKEND, WHICH MAY HELP US DECOUPLE A LITTLE BIT MORE. SATURDAY  
NIGHT WILL LIKELY BE THE COLDEST NIGHT OF THIS EVENT WITH A  
WIDESPREAD LIGHT FREEZE AWAY FROM THE COAST, ESPECIALLY IF THE  
WINDS CAN GO CALM.  
 
THE HIGH SLIDES OVER THE APPALACHIANS SUNDAY INTO MONDAY, WHICH  
BRINGS A MORE NORTHEASTERLY FLOW BACK TO OUR AREA WITH A SLIGHTLY  
TIGHTER PRESSURE GRADIENT. THIS WILL HELP FUNNEL SOME COOL AIR  
DOWN FROM THE CAROLINAS INTO OUR AREA, KEEPING US RATHER COOL. THUS,  
HIGHS SUNDAY AND MONDAY WILL STILL MAINLY BE IN THE 50S. AND,  
THIS PRECLUDES A RADIATIONAL COOLING SETUP BOTH NIGHTS AS  
NORTHEASTERLY WINDS WILL KEEP US MIXED. HOWEVER, WITH THE COLD AIR  
MASS STILL ENTRENCHED, ANOTHER LIGHT FREEZE IS POSSIBLE (20-40%  
CHANCE), MAINLY IN THE ALABAMA AND GEORGIA COUNTIES, THOUGH LOWS  
EVERYWHERE WILL LIKELY FALL INTO THE 30S. WITH THE WIND YET AGAIN,  
WIND CHILLS WILL DROP BACK INTO THE 20S SUNDAY NIGHT.  
 
TEMPERATURES MODERATE HEADING INTO MONDAY NIGHT INTO TUESDAY AS  
THE HIGH STARTS SLIDING FARTHER TO THE EAST AND WE ENTER MORE OF  
AN EAST TO SOUTHEAST FLOW REGIME. LOWS WILL MODERATE BACK INTO THE  
40S MONDAY NIGHT WITH HIGHS ON TUESDAY IN THE UPPER HALF OF THE  
50S TO THE MID 60S.  
 
 
   
AVIATION  
 
(12Z TAFS)  
ISSUED AT 644 AM EST WED DEC 18 2024  
 
FOG, MIST, AND LOW STRATUS ARE AFFECTING ALL AREA TERMINALS THIS  
MORNING. THESE CONDITIONS ARE FAIRLY WIDESPREAD ACROSS THE  
SOUTHEAST U.S., SO ALTERNATE LANDING SITES MAY BE HARD TO FIND  
UNTIL AFTER ABOUT 15Z. EXPECT SLOW LIFTING AFTER ABOUT 15Z, BUT  
THE IMPROVING PROCESS WILL BE SLOW TODAY DUE TO THE MOIST, THE STABLE  
NEAR-SURFACE AIR MASS, AND WEAK DECEMBER SUNSHINE.  
 
A FEW SHOWERS WILL DOT THE LANDSCAPE THIS AFTERNOON AND EARLY THIS  
EVENING, IN ADVANCE OF A COLD FRONT. A QUICK BOUT OF LIGHTNING  
CANNOT BE RULED OUT, BUT WILL ONLY MENTION VCSH AT SOME TERMINALS  
FOR NOW. A SHIFT TO LIGHT NORTHWEST WINDS IS EXPECTED TONIGHT, AS  
THE FRONT ENTERS THE REGION. POST-FRONTAL STRATUS WILL BE  
PREVALENT THROUGH SUNRISE THURSDAY, AND LEFTOVER MOISTURE NEAR THE  
SURFACE WILL SUPPORT SOME MIST. HOWEVER, WEAK DRY AIR ADVECTION  
SHOULD PREVENT THICK FOG.  
 
 
   
MARINE  
 
ISSUED AT 331 AM EST WED DEC 18 2024  
 
ISOLATED LIGHT SHOWERS AND SOME SEA FOG WILL BE POSSIBLE THROUGH  
THE DAY BEFORE A COLD FRONT PASSES THROUGH TONIGHT. LIGHT WINDS  
WILL CLOCK AROUND FROM OUT OF THE EAST THIS AFTERNOON TO OUT OF  
THE NORTH BY TONIGHT. WINDS WILL INCREASE BEHIND ANOTHER RE-  
ENFORCING COLD FRONT FRIDAY WITH CAUTIONARY-LEVEL WINDS EXPECTED.  
MODERATE TO FRESH NORTHERLY BREEZES CONTINUE INTO THE WEEKEND AS  
HIGH PRESSURE DOMINATES MUCH OF THE EASTERN US.  
 
 
   
FIRE WEATHER  
 
ISSUED AT 331 AM EST WED DEC 18 2024  
 
LOW DISPERSIONS ARE FORECAST THIS AFTERNOON, DUE TO LOW MIXING  
HEIGHTS, WEAK TRANSPORT WINDS, AND THE STABILIZING EFFECT OF CLOUD  
COVER AND HIGH HUMIDITY. A COLD FRONT WILL PASS THE DISTRICTS FROM  
LATE TONIGHT THROUGH THURSDAY, WITH A COOLER AND DRIER AIR MASS  
FOLLOWING FROM LATER THURSDAY INTO FRIDAY AND THE WEEKEND.  
 
 
   
HYDROLOGY  
 
ISSUED AT 331 AM EST WED DEC 18 2024  
 
RAINFALL TODAY WILL GENERALLY BE LIGHT, AND LITTLE TO NO  
ADDITIONAL RAINFALL IS ANTICIPATED BEYOND TODAY. THUS, THERE ARE  
NO HYDROLOGIC CONCERNS.  
 
 
   
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 77 60 74 48 / 20 30 10 0  
PANAMA CITY 74 58 72 46 / 20 40 0 0  
DOTHAN 76 55 68 42 / 40 20 0 0  
ALBANY 77 56 70 44 / 30 40 10 0  
VALDOSTA 77 59 75 49 / 20 20 10 0  
CROSS CITY 80 61 77 52 / 20 20 20 0  
APALACHICOLA 71 60 71 50 / 20 40 10 0  
 
 
   
TAE WATCHES/WARNINGS/ADVISORIES  
 
FL...DENSE FOG ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR  
FLZ007>018-026-027-115-118-127.  
 
GA...DENSE FOG ADVISORY UNTIL 11 AM EST THIS MORNING FOR GAZ120>129-  
142>147-155>159.  
 
AL...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR ALZ066-067-  
069.  
 
GM...NONE.  
 
 
 
 
NEAR TERM...HANER  
SHORT TERM...YOUNG  
LONG TERM....YOUNG  
AVIATION...HANER  
MARINE...YOUNG  
FIRE WEATHER...HANER  
HYDROLOGY...YOUNG  
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