991
WTNT43 KNHC 242054
TCDAT3
TROPICAL STORM MELISSA DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL AL132025
500 PM EDT FRI OCT 24 2025
AFTER THE PREVIOUS ADVISORY, THE LAST COUPLE OF AIRCRAFT FIXES FROM
THE C-130 INDICATED THAT MELISSA LIKELY COMPLETED A CENTER
RELOCATION AS A VERY LARGE BURST OF DEEP CONVECTION WITH CLOUD TOPS
BELOW -90C ROTATED UP-SHEAR OF THE CENTER. THIS EVOLUTION WAS ALSO
NICELY CAPTURED ON THE GOES-19 MESOSCALE SECTOR, WHERE GLM LIGHTNING
FLASHES, WHICH HAD BEEN PARKED DOWN-SHEAR EARLIER IN THE MORNING,
STARTED TO ROTATE CYCLONICALLY ALONG MELISSA'S EASTERN FLANK,
INDICATING CONVECTION WAS FINALLY STARTING TO WRAP AROUND THE
LOW-LEVEL VORTEX. A GMI MICROWAVE PASS AT 1527 UTC ALSO HINTED AT A
NASCENT INNER CORE FEATURE ON THE 37 GHZ CHANNEL AS THE CONVECTIVE
BURST WRAPPED AROUND THE CENTER. BEFORE THE AIR FORCE HURRICANE
HUNTERS LEFT MELISSA, THEY MEASURED A PEAK FLIGHT LEVEL WIND OF 59
KT, AND A PRESSURE DOWN TO 997 MB, SUPPORTING THE 50 KT INTENSITY
FOR THE INTERMEDIATE ADVISORY. HOWEVER, GIVEN THE IMPROVEMENT OF
MELISSA'S STRUCTURE SINCE THAT TIME, THE INITIAL INTENSITY IS BEING
RAISED TO 55 KT FOR THIS ADVISORY, IN BEST AGREEMENT WITH THE
T3.5/55-KT DVORAK INTENSITY ESTIMATE PROVIDED BY TAFB. ANOTHER AIR
FORCE RESERVE AND A NOAA-P3 RECONNAISSANCE MISSION WILL BE IN THE
STORM TONIGHT TO PROVIDE MORE DATA ON MELISSA'S INTENSITY AND
STRUCTURE.
NOW THAT THE CENTER IS BECOMING BETTER ALIGNED WITH ITS MID-LEVEL
VORTEX, IT ALSO APPEARS THE TROPICAL STORM HAS FINALLY TURNED MORE
NORTHWARD, WITH AN ESTIMATED MOTION OF 360/2 KT. THE SYNOPTIC TRACK
REASONING REMAINS SIMILAR TO THIS MORNING, WITH A SLOW MOTION
EXPECTED TO CONTINUE IN THE SHORT-TERM DUE LIGHT STEERING CURRENTS,
DUE TO COMPETING MID-LEVEL RIDGES TO THE SOUTHEAST AND NORTHWEST OF
MELISSA. AFTER 24 HOURS, THE MID-LEVEL RIDGE LOCATED TO THE
NORTHWEST IS EXPECTED TO STRENGTHEN TO THE NORTH OF MELISSA, AND THE
GUIDANCE IS COMING INTO BETTER AGREEMENT ON A VERY SLOW WESTWARD
MOTION THROUGH 72 HOURS. BEYOND THAT TIME FRAME, A STRENGTHENING
MID-LATITUDE TROUGH EXPECTED TO MOVE INTO THE SOUTHEASTERN U.S.,
PROVIDING A PATH FOR MELISSA TO TURN NORTHEASTWARD OUT OF THE
CARIBBEAN SEA INTO THE SOUTHWESTERN ATLANTIC BY THE END OF THE
FORECAST PERIOD. THE TRACK GUIDANCE THIS CYCLE HAS SHIFTED A BIT
EASTWARD BEYOND DAY 3, AND IS ALSO NOTABLY FASTER THAN BEFORE.
HOWEVER, IT SHOULD BE STRESSED THAT THERE REMAINS A SUBSTANTIAL
AMOUNT OF ALONG TRACK SPREAD. ON THE FORECAST TRACK, MELISSA COULD
POTENTIALLY BE NEAR JAMAICA BY DAY 4 AND MOVE ACROSS CUBA BEFORE THE
END OF THE FORECAST PERIOD, THOUGH THE TIMING OF THIS TRACK REMAINS
MORE UNCERTAIN THAN USUAL.
COMPARED TO YESTERDAY, THE UW-CIMSS SHEAR ESTIMATES HAVE DROPPED
FROM 25 KT A DAY AGO TO 15 KT CURRENTLY WITH MID-LEVEL SHEAR ALSO
DECREASING. THIS REDUCTION IN SHEAR, IN COMBINATION WITH THE
DRAMATICALLY IMPROVED STRUCTURE OF MELISSA THIS AFTERNOON, SUGGESTS
THAT THE SYSTEM IS READY TO TAKE ADVANTAGE OF OTHER FAVORABLE
ENVIRONMENTAL CONDITIONS (30-31 C SEA-SURFACE TEMPERATURES, A
MOISTENING DEEP-LAYER ENVIRONMENT). THE INTENSITY GUIDANCE IS
SHARPLY HIGHER THIS AFTERNOON IN THE SHORT-TERM, AND IT APPEARS THAT
MELISSA COULD BEGIN A PERIOD OF RAPID INTENSIFICATION (RI) AT ANY
TIME. THE NHC INTENSITY FORECAST RESPONDS TO THIS GUIDANCE CHANGE BY
EXPLICITLY SHOW RI EARLIER AND CONTINUING OVER THE WEEKEND. THE
FORECAST NOW SHOWS A 135 KT PEAK IN 60 H, AND THERE IS A DISTINCT
POSSIBILITY THAT MELISSA COULD BECOME A CATEGORY 5 HURRICANE DURING
THIS TIME PERIOD. IN FACT, THE LATEST 12Z GOOGLE DEEPMIND ENSEMBLE
DISTRIBUTION SHOWS THE MAJORITY OF ITS MEMBERS REACHING THIS LOFTY
INTENSITY. AFTER THAT TIME PERIOD, INNER-CORE STRUCTURAL CHANGES ARE
LIKELY TO CAUSE FLUCTUATIONS IN INTENSITY, AND LAND INTERACTION IN
BOTH JAMAICA AND CUBA WILL LIKELY LEAD TO SOME WEAKENING BY THE END
OF THE FORECAST. THE NHC INTENSITY FORECAST IS ON THE HIGH SIDE OF
THE GUIDANCE ENVELOPE, AND CLOSEST TOO THE GOOGLE DEEPMIND ENSEMBLE
MEAN (GDMI).
KEY MESSAGES:
1. JAMAICA: DUE TO MELISSA’S SLOW MOTION, A PROLONGED MULTI-DAY
PERIOD OF DAMAGING WINDS AND HEAVY RAINFALL RESULTING IN POTENTIALLY
CATASTROPHIC FLASH FLOODING AND NUMEROUS LANDSLIDES IS LIKELY TO
BEGIN LATE SATURDAY OR SUNDAY. THERE IS AN INCREASING RISK OF
LIFE-THREATENING STORM SURGE WHEN THE CENTER OF MELISSA NEARS
JAMAICA EARLY NEXT WEEK. PREPARATIONS TO PROTECT LIFE AND PROPERTY
SHOULD BE RUSHED TO COMPLETION.
2. HAITI: HEAVY RAINFALL WILL RESULT IN CATASTROPHIC FLASH FLOODING
AND LANDSLIDES ACROSS SOUTHWESTERN HAITI INTO EARLY NEXT WEEK.
EXTENSIVE DAMAGE TO ROADS AND BUILDINGS IS EXPECTED, POTENTIALLY
ISOLATING COMMUNITIES FOR AN EXTENDED PERIOD OF TIME. IMMEDIATE
PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE TAKEN. STRONG
WINDS COULD ALSO POTENTIALLY LAST FOR A DAY OR MORE OVER THE TIBURON
PENINSULA OF HAITI.
3. DOMINICAN REPUBLIC: HEAVY RAINFALL COULD PRODUCE POTENTIALLY
CATASTROPHIC FLASH FLOODING AND NUMEROUS LANDSLIDES IN SOUTHERN
PORTIONS OF THE DOMINICAN REPUBLIC.
4. EASTERN CUBA AND BAHAMAS: INTERESTS IN CUBA AND THE BAHAMAS
SHOULD MONITOR THE PROGRESS OF MELISSA SINCE THERE IS AN INCREASING
RISK OF A SIGNIFICANT STORM STORM SURGE, DAMAGING WINDS, AND HEAVY
RAINFALL BY THE MIDDLE OF NEXT WEEK. THE RISK OF LIFE-THREATENING
FLASH FLOODING AND LANDSLIDES IN EASTERN CUBA ARE INCREASING.
FORECAST POSITIONS AND MAX WINDS
INIT 24/2100Z 16.0N 74.3W 55 KT 65 MPH
12H 25/0600Z 16.2N 74.4W 65 KT 75 MPH
24H 25/1800Z 16.4N 74.8W 85 KT 100 MPH
36H 26/0600Z 16.5N 75.5W 105 KT 120 MPH
48H 26/1800Z 16.5N 76.0W 120 KT 140 MPH
60H 27/0600Z 16.5N 76.6W 135 KT 155 MPH
72H 27/1800Z 16.8N 77.4W 135 KT 155 MPH
96H 28/1800Z 17.9N 77.4W 120 KT 140 MPH...INLAND IN JAMAICA
120H 29/1800Z 21.5N 74.8W 95 KT 110 MPH...OVER WATER
FORECASTER PAPIN
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