681
FXUS62 KTAE 201749
AFDTAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1249 PM EST FRI DEC 20 2024
..NEW AVIATION
UPDATE
ISSUED AT 1123 AM EST FRI DEC 20 2024
THE FORECAST IS IN GOOD SHAPE AND NO MORNING UPDATES ARE PLANNED.
SYNOPSIS
ISSUED AT 411 AM EST FRI DEC 20 2024
A STRONG BUT DRY REINFORCING COLD FRONTAL PASSAGE IS EXPECTED
TODAY, FOLLOWED BY A COLD AND DRY AIR MASS FOR THE WEEKEND. HIGH
PRESSURE WILL PASS BY TO THE NORTH ON SUNDAY AND MOVE INTO THE
ATLANTIC ON MONDAY AND TUESDAY, BRINGING A TURN TO MILDER AND
MOISTER EAST TO SOUTHEAST FLOW. THE MOISTURE WILL INTERACT WITH A
WEAKENING TROUGH ON CHRISTMAS DAY FOR THE NEXT CHANCE OF RAIN.
NEAR TERM
(TODAY AND TONIGHT)
ISSUED AT 411 AM EST FRI DEC 20 2024
NIGHTTIME MICROPHYSICS IMAGERY THIS MORNING SHOWS A PATCH OF LOW
STRATUS MOSEYING THROUGH THE FLORIDA BIG BEND. ADDITIONALLY, SOME
FOG HAS DEVELOPED IN THE LOW-LYING RIVER VALLEYS. THIS SHOULD ALL
END NEAR OR JUST AFTER SUNRISE WITH ABUNDANT SUNSHINE EXPECTED FOR
THE AFTERNOON. A STRONG COLD FRONT WILL MAKE ITS WAY THROUGH THE
AREA LATE THIS MORNING INTO THE AFTERNOON, BRINGING BREEZY WINDS TO
THE AREA. COLDER, DRIER AIR FILTERS IN BEHIND THE FRONT. PRIOR TO
THIS, WE SHOULD REACH THE LOWER TO MIDDLE 60S IN MOST AREAS FOR
HIGHS TODAY. STRONG COLD AIR ADVECTION CONTINUES INTO THE NIGHT WITH
WINDS STAYING ELEVATED. GIVEN THE RATHER SHALLOW NATURE OF THE AIR
MASS, HAVE OPTED TO TREND TOWARD THE COOLER HI-RES GUIDANCE, WHICH
OFTENTIMES PERFORMS BETTER ON TEMPERATURES IN THESE SETUPS. THUS, A
WIDESPREAD LIGHT FREEZE IS EXPECTED TONIGHT AWAY FROM THE COAST WITH
LOWS IN THE LOWER 30S, BUT MID-30S NEAR THE COAST.
ADDITIONALLY, WINDS REMAIN ELEVATED AROUND 5-10 MPH THROUGH THE
NIGHT, WHICH WILL MAKE IT FEEL COLDER. WIND CHILLS WILL BE IN THE
MID-20S TO LOWER 30S. IN FACT, THE 00Z HREF GUIDANCE SHOWS MEDIUM
CHANCES (40-60%) OF WIND CHILLS REACHING OUR COLD WEATHER ADVISORY
CRITERIA FOR THE FL COUNTIES (25F OR LOWER) AND LOW CHANCES (20-30%)
OVER AL AND GA (20F OR LOWER). GIVEN SOME OF THE UNCERTAINTY IN JUST
HOW COLD ACTUAL AIR TEMPERATURES WOULD GET, HAVE OPTED TO HOLD OFF
ON A COLD WEATHER ADVISORY IN THIS FORECAST PACKAGE AND LET THE NEXT
SHIFT REASSESS.
SHORT TERM
(SATURDAY THROUGH SUNDAY NIGHT)
ISSUED AT 411 AM EST FRI DEC 20 2024
THE MAIN STORY THIS WEEKEND WILL BE A COLD AND DRY AIR MASS.
SATURDAY WILL START OFF WITH AN ELONGATED MERIDIONAL SURFACE RIDGE
AXIS FROM NORTH OF LAKE SUPERIOR ALL THE WAY INTO EASTERN TEXAS.
THE LONG FETCH OF NORTHERLY WINDS TO ITS EAST WILL BRING A SUPPLY
OF COLD AIR WHICH WILL HOLD HIGHS ON SATURDAY IN THE 50S, OR ABOUT
10 DEGREES BELOW NORMAL. SATURDAY NIGHT SHOULD BE THE COLDEST
NIGHT OF THE UPCOMING STRETCH. A WIDESPREAD LIGHT FREEZE IS
EXPECTED FOR NEARLY ALL AREAS EXCEPT THE BEACHES, ALONG WITH
WIDESPREAD FROST. THERE IS ROOM FOR TEMPERATURES TO GO A FEW
DEGREES COLDER THAN FORECAST ON SUNDAY MORNING IF WE CAN GET THE
WINDS TO ACTUALLY GO CALM FOR A COUPLE HOURS.
SURFACE HIGH PRESSURE WILL MOVE EAST ACROSS THE GREAT LAKES ON
SUNDAY, SO WINDS WILL CLOCK AROUND FROM NORTH TO NORTHEAST. THE
COOLING TREND WILL COME TO AN END, BUT THE COLD AIR MASS WILL
STILL HOLD ON UNTIL WE CAN CLOCK WINDS AROUND TO ENOUGH OF AN
EASTERLY COMPONENT TO GET ATLANTIC-INFLUENCED AIR INTO THE
REGION.
LONG TERM
(MONDAY THROUGH THURSDAY)
ISSUED AT 411 AM EST FRI DEC 20 2024
A SURFACE RIDGE WILL BECOME ESTABLISHED ON MONDAY FROM EASTERN NC
OUT TO BETWEEN BERMUDA AND THE BAHAMAS. OUR LOW-LEVEL FLOW WILL
BECOME EASTERLY ON MONDAY, THEN SOUTHEASTERLY FROM TUESDAY THROUGH
THURSDAY. THIS WILL BRING AN INCREASINGLY MARITIME-INFLUENCED AIR
MASS INTO OUR REGION, MEANING A WARMING TREND WILL BE WELL
UNDERWAY ON MONDAY, AND THE ATMOSPHERIC MOISTURE WILL INCREASE AS
WELL. AS WARMER AND MOISTER AIR GLIDES OVER SOME OF THE REMAINING
COOL AIR NEAR THE SURFACE, SOME GUIDANCE HAS STARTED SHOWING SOME
LIGHT RAIN ON TUESDAY NEAR THE I-75 CORRIDOR. IF THIS TREND
CONTINUES, WE MAY NEED TO INTRODUCE CHANCES FOR LIGHT RAIN THERE.
THE WEATHER WILL START OFF RAIN-FREE ON MONDAY, AS A WEAK SOUTHERN
STREAM SHORTWAVE RIDGE PASSES EASTWARD ACROSS THE REGION. THEN
MID-LEVEL FLOW WILL BECOME MORE SOUTHWESTERLY ON TUESDAY AND
WEDNESDAY, IN ADVANCE OF A SOUTHERN STREAM SHORTWAVE TROUGH WILL
MOVE EAST OUT OF TEXAS ON TUESDAY. THAT WAVE WILL THEN MOVE ALONG
THE NORTHERN GULF COAST ON CHRISTMAS DAY. A SURFACE TROUGH IN
ADVANCE OF THIS FEATURE COULD BE A FOCUS FOR A BAND OF SHOWERS AND
THUNDERSTORMS TO DEVELOP IN CONFLUENT LOW-LEVEL SOUTHERLY FLOW.
AS THIS BAND OF CONVECTION MOVES EAST ACROSS THE FL PANHANDLE, THE
UPPER DYNAMICS WILL BE WEAKENING, AND THE SURFACE FEATURE WILL BE
WASHING OUT. SO THE HIGHER RAIN CHANCES ON CHRISTMAS DAY WILL BE
OFF TO THE WEST OVER THE FLORIDA PANHANDLE AND SOUTHERN ALABAMA,
WITH RAIN CHANCES TRAILING OFF EAST OF THERE.
NONETHELESS, SURFACE DEWPOINTS ARE FORECAST TO MOISTEN INTO THE
LOWER 60S ON CHRISTMAS DAY OVER OUR FLORIDA AND FAR SOUTH GEORGIA
COUNTIES, AND PRECIPITABLE WATER (PW) VALUES COULD REACH THE
1.2-1.4 INCH RANGE. THE MORE RICHLY MOIST ENVIRONMENT WOULD
CONTRIBUTE TO WEAK CONVECTIVE INSTABILITY. CONSIDERING
SOUTHEASTERLY LOW- LEVEL FLOW BENEATH 500 MB SOUTHWEST FLOW OF
ABOUT 30-45 KNOTS, THIS COULD BE ENOUGH TO SUSTAIN CONVECTIVE
UPDRAFTS AND SUPPORT ISOLATED ROTATING CELLS ON WED AND PERHAPS
THU. SUCH AN OUTCOME WILL BE DEPENDENT ON HOW MUCH INSTABILITY WE
CAN GENERATE. THERE WILL NOT BE MUCH LARGE-SCALE DYNAMIC LIFT, SO
THIS WILL ALSO LIMIT COVERAGE OF ANY STRONGER STORMS.
AVIATION
(18Z TAFS)
ISSUED AT 1241 PM EST FRI DEC 20 2024
ALTHOUGH VFR CONDS PREVAIL UNDER MOSTLY SKC, WIND IS THE MAIN
STORY FOR THIS TAF. NORTHWESTERLIES THIS AFTN INCREASE FURTHER
WITH THE PASSAGE OF A STRONG COLD FRONT DURING THE EVENING HRS.
GUSTS IN THE 20-25-KT RANGE ARE LIKELY DURING FROPA FOR
DHN/ABY/ECP BEGINNING AROUND OR JUST AFTER 0Z. FOR TLH/VLD, NW SFC
WINDS AROUND 10 KTS IS EXPECTED BENEATH A 35-40-KT LOW-LEVEL JET.
THIS SETUP SUGGESTS NOCTURNAL LLWS IS POSSIBLE, WHICH IS
ACCOUNTED FOR. WINDS GRADUALLY TURN OUT OF THE N TMRW NEAR 10 KTS.
MARINE
ISSUED AT 411 AM EST FRI DEC 20 2024
A REINFORCING COLD FRONTAL PASSAGE TODAY WILL BE FOLLOWED BY AN
INCREASE IN NORTHERLY BREEZES. THOSE BREEZES WILL BECOME STRONG
AFTER SUNSET THIS EVENING, CONTINUING UNTIL AFTER SUNRISE ON
SATURDAY. HIGH PRESSURE WILL MOVE BY TO THE NORTH ON SUNDAY AND
MONDAY, CAUSING MODERATE TO OCCASIONALLY FRESH BREEZES TO CLOCK
AROUND NORTHEAST ON SUNDAY AND MONDAY, THEN MORE EASTERLY ON
TUESDAY.
FIRE WEATHER
ISSUED AT 411 AM EST FRI DEC 20 2024
A STRONG REINFORCING COLD FRONT WILL MOVE THROUGH THE AREA LATE THIS
MORNING INTO THE AFTERNOON. IN THE WAKE OF THE FRONT, WINDS WILL
INCREASE OUT OF THE NORTHWEST AND BECOME GUSTY. DRIER AIR WILL ALSO
MOVE IN WITH MIN RH VALUES DROPPING INTO THE LOW TO MID 30S. GOOD
DISPERSIONS ARE EXPECTED AREA WIDE TODAY. WINDS WILL SUBSIDE HEADING
INTO THE WEEKEND AND TURN MORE NORTHERLY TO NORTHEASTERLY. DRY AIR
LINGERS IN PLACE THROUGH THE WEEKEND WITH MIN RH VALUES EACH
AFTERNOON BOTTOMING OUT IN THE LOWER 30S. DISPERSIONS WILL REMAIN
GOOD THROUGH THE WEEKEND.
HYDROLOGY
ISSUED AT 411 AM EST FRI DEC 20 2024
NO FLOODING IS EXPECTED FOR THE NEXT 7 DAYS.
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 37 54 35 57 / 0 0 0 0
PANAMA CITY 35 55 35 59 / 0 0 0 0
DOTHAN 32 52 31 55 / 0 0 0 0
ALBANY 32 53 31 55 / 0 0 0 0
VALDOSTA 34 55 33 57 / 0 0 0 0
CROSS CITY 36 58 32 62 / 0 0 0 0
APALACHICOLA 37 54 38 58 / 0 0 0 0
TAE WATCHES/WARNINGS/ADVISORIES
FL...HIGH RIP CURRENT RISK THROUGH SATURDAY MORNING FOR FLZ114.
GA...NONE.
AL...NONE.
GM...SMALL CRAFT ADVISORY FROM 6 PM EST /5 PM CST/ THIS EVENING TO 10
AM EST /9 AM CST/ SATURDAY FOR GMZ730-750-752-755-765-770-
772-775.
UPDATE...WOOL
SYNOPSIS...HANER
NEAR TERM...YOUNG
SHORT TERM...HANER
LONG TERM....HANER
AVIATION...IG3
MARINE...HANER
FIRE WEATHER...YOUNG
HYDROLOGY...HANER
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