685
AXNT20 KNHC 091717
TWDAT
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1815 UTC FRI OCT 9 2026
TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA, CENTRAL AMERICA
GULF OF AMERICA, CARIBBEAN SEA, NORTHERN SECTIONS OF SOUTH
AMERICA, AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 31N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY, WEATHER OBSERVATIONS, RADAR AND METEOROLOGICAL ANALYSIS.
BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1600 UTC.
..SPECIAL FEATURES
HURRICANE ISAIAS IS CENTERED NEAR 27.7N 87.3W AT 1500 UTC OR 170
NM S OF PENSACOLA, FL, MOVING NNE AT 14 KT. ESTIMATED MINIMUM
CENTRAL PRESSURE IS 959 MB. MAXIMUM SUSTAINED WIND SPEED IS 105 KT
WITH GUSTS TO 130 KT, MAKING ISAIAS A MAJOR HURRICANE. NUMEROUS
MODERATE TO SCATTERED STRONG CONVECTION IS ACROSS THE EASTERN GULF
N OF 26.5N BETWEEN 85W AND 88.5W, WITH THE STRONGEST STORMS
WITHIN 90 NM OF THE CENTER OF ISAIAS. SEAS NEAR THE CENTER ARE UP
TO 33 FT. A GENERAL NORTHWARD MOTION IS EXPECTED THROUGHOUT THE
REMAINDER OF TODAY, WITH LANDFALL EXPECTED WITHIN THE WARNING AREA
TONIGHT OR EARLY SATURDAY. LITTLE CHANGE IN STRENGTH IS
ANTICIPATEDBEFORE LANDFALL, AND ISAIAS WILL LIKELY REMAIN A
DANGEROUS HURRICANE UNTIL LANDFALL. SWELLS FROM ISAIAS ARE
AFFECTING THE COASTLINES OF MOST OF THE EASTERN GULF TO SE
LOUISIANA, AND WILL INCREASE ALONG THE GULF COASTS FROM SW FLORIDA
TO LOUISIANA THROUGHOUT THE AFTERNOON AND EVENING. THESE SWELLS
ARE LIKELY TO CAUSE LARGE AND POWERFUL SURF AND LIFE-THREATENING
RIP CURRENT CONDITIONS. PLEASE CONSULT PRODUCTS FROM YOUR LOCAL
WEATHER OFFICE.
PLEASE READ THE LATEST HIGH SEAS FORECAST ISSUED BY THE NATIONAL
HURRICANE CENTER AT WEBSITE -
HTTPS://WWW.NHC.NOAA.GOV/TEXT/MIAHSFAT2.SHTML AND THE LATEST
ISAIAS NHC FORECAST/ADVISORY AND PUBLIC ADVISORY AT
WWW.HURRICANES.GOV FOR MORE DETAILS.
..TROPICAL WAVES
AN EASTERN ATLANTIC TROPICAL WAVE IS ALONG 27W, SOUTH OF 19N,
MOVING WESTWARD AT 5 TO 10 KT. SCATTERED TO LOCALLY NUMEROUS
MODERATE ISOLATED STRONG CONVECTION IS OBSERVED FROM 05.5N TO 16N
AND EAST OF 29W TO THE COAST OF AFRICA.
A WESTERN CARIBBEAN TROPICAL WAVE IS ALONG 79W-80W, SOUTH OF 20N,
MOVING WESTWARD AT 10 KT. THIS WAVE CONTINUES TO INTERACT WITH AN
UPPER-LEVEL LOW OVER THE NW CARIBBEAN, AND IS PRODUCING SCATTERED
MODERATE ISOLATED STRONG CONVECTION FROM 13.5N TO 22N AND BETWEEN
76.5W AND 81.5W.
..MONSOON TROUGH/ITCZ
THE MONSOON TROUGH ENTERS THE ATLANTIC THROUGH THE COAST OF
MAURITANIA NEAR 14.5N17W AND CONTINUES SOUTHWESTWARD TO 09N24W TO
11.5N35W TO 09N40W. ITCZ EXTENDS FROM 09N48W TO 10N62W. SCATTERED
MODERATE CONVECTION IS NOTED FROM 07.5N TO 14N BETWEEN 30W AND
40W, AND FROM 090N TO 11N BETWEEN 50W AND 62W. SCATTERED MODERATE
TO STRONG CONVECTION IS NOTED FROM 11N TO 14.5N BETWEEN 44.5W AND
48W.
..GULF OF AMERICA
PLEASE READ THE SPECIAL FEATURES SECTION ABOVE FOR MORE INFORMATION
ON MAJOR HURRICANE ISAIAS CENTERED OVER THE NORTHEAST GULF OF
AMERICA. TROPICAL STORM FORCE WINDS HAVE MOVED TO NEAR OR ALONG
THE GULF COAST FROM APALACHICOLA, FL TO SE LOUISIANA LATE THIS
MORNING, WITH SEAS NOW 8 TO 15 FT AND RISING ACROSS THOSE WATERS.
A 30 TO 60 NM WIDE RAINBAND EXTENDS FROM THE EASTERN PERIPHERY OF
ISAIAS NEAR 29N84W SOUTH-SOUTHWESTWARD THROUGH THE YUCATAN
CHANNEL. FRESH TO STRONG CYCLONIC WINDS SPIRAL INTO ISAIAS FROM
THE YUCATAN CHANNEL NORTHWARD BETWEEN THE WESTERN FLORIDA COASTAL
WATERS AND THE CENTRAL LOUISIANA COASTAL WATERS NEAR 93W.
ELSEWHERE, A DISSIPATING STATIONARY FRONT EXTENDS ACROSS N
FLORIDA AND INTO THE NE GULF ALONG 29N. MODERATE TO FRESH CYCLONIC
N TO W WINDS PREVAIL ACROSS THE W AND SW GULF, WHERE SEAS ARE 4
TO 8 FT IN NE TO E SWELL FROM ISAIAS. SCATTERED SHOWERS ARE ACROSS
THE CENTRAL BAY OF CAMPECHE.
FOR THE FORECAST, ISAIAS WILL MOVE TO NEAR 29.7N 86.8W THIS
EVENING, THEN MOVE INLAND AND WEAKEN TO A TROPICAL STORM NEAR
32.1N 87.1W SAT MORNING WITH MAXIMUM SUSTAINED WINDS 55 KT, THEN
WEAKEN TO A TROPICAL DEPRESSION WELL INLAND BY SUN MORNING. SWELL
GENERATED BY ISAIAS WILL SPREAD NORTHWARD ACROSS THE BASIN
CENTRAL GULF THROUGH SAT NIGHT. IN THE WAKE OF ISAIAS, WEAK HIGH
PRESSURE WILL DEVELOP OVER THE NORTH- CENTRAL GULF BY SUN EVENING
RESULTING IN MODERATE OR WEAKER RETURN FLOW OVER THE WESTERN GULF
THROUGH MIDWEEK.
..CARIBBEAN SEA
PLEASE READ THE TROPICAL WAVES SECTION FOR DETAILS ON AN ACTIVE
TROPICAL WAVE IN THE WESTERN CARIBBEAN.
WEAK 1019 MB HIGH PRESSURE HAS SHIFTED SOUTHWARD INTO THE WESTERN
ATLANTIC NEAR 26N62W, TO THE SOUTH OF A COLD FRONT NOW ALONG
ABOUT 30N. THE ASSOCIATED PRESSURE GRADIENT IS SUSTAINING MODERATE
TO FRESH EASTERLY WINDS AND MODERATE SEAS TO 6 FT ACROSS THE
BASIN BETWEEN THE TROPICAL WAVE ALONG 79W-80W AND 63W. MODERATE
TO FRESH SOUTHERLY WINDS AND MODERATE SEAS ARE NOTED WEST OF 84W
THROUGH THE YUCATAN CHANNEL, BLOWING INTO THE GENERAL CIRCULATION
OF HURRICANE ISAIAS. LIGHT TO GENTLE WINDS AND SEAS OF 2-4 FT ARE
PREVALENT ELSEWHERE.
FOR THE FORECAST, A WEAK PRESSURE GRADIENT IS EXPECTED TO
CONTINUE ACROSS THE BASIN THROUGH THE NEXT FEW DAYS. WINDS WILL
PULSE TO STRONG SPEEDS AND SEAS WILL REACH 8 FT TONIGHT THROUGH
SUN NIGHT IN THE SOUTH- CENTRAL CARIBBEAN AND GULF OF VENEZUELA.
HURRICANE ISAIAS OVER THE CENTRAL GULF OF AMERICA IS PRODUCING
FRESH SOUTHERLY WINDS IN THE YUCATAN CHANNEL AND THESE WINDS WILL
LIFT NORTHWARD LATER TODAY. MEANWHILE, A TROPICAL WAVE NEAR 80W,
IN COMBINATION WITH AN UPPER- LEVEL LOW, IS PRODUCING SCATTERED
SHOWERS AND THUNDERSTORMS N OF 16N BETWEEN 76W AND 82W. UNSETTLED
WEATHER CONDITIONS WILL REMAIN ASSOCIATED WITH THIS WAVE AS IT
MOVES ACROSS THE WESTERN CARIBBEAN THROUGH THE WEEKEND.
..ATLANTIC OCEAN
A COLD FRONT HAS DRIFTED SOUTHWARD INTO THE NORTHERN WATERS,
EXTENDING FROM THE CENTRAL ATLANTIC THROUGH 31N60W TO 29N64W, THEN
MEANDERS WESTWARD ALONG ABOUT 30N INTO NE FLORIDA. A WEAK 1019 MB
HIGH HAS DEVELOPED SOUTH OF THIS FRONT NEAR 26N62W. FRESH TO
STRONG NE WINDS AND SEAS OF 5-7 FT ARE FOUND NORTH OF THE FRONT OFF
NE FLORIDA AND GA. SOUTH OF THE FRONT, A WEAK PRESSURE GRADIENT
PREVAILS WEST OF 50W, SUPPORTING MODERATE OR WEAKER WINDS AND
SEAS OF 3-6 FT.
AN UPPER-LEVEL TROUGH CONTINUES ACROSS THE CENTRAL ATLANTIC,
EXTENDING S-SW ACROSS THE AREA WATERS BETWEEN 45W AND 55W, AND
CONTINUES TO PRODUCE SCATTERED SHOWERS TO THE E BETWEEN 40W AND
52W. A SURFACE TROUGH ALONG ABOUT 52W IS DRIFTING WESTWARD. A
STRONG 1034 MB HIGH PRESSURE SYSTEM IS JUST NORTH OF THE AZORES
AND THE SURFACE TROUGH ALONG 52W COMBINE TO SUPPORT MODERATE TO
FRESH EASTERLY WINDS AND SEAS OF 4-8 FT NORTH OF THE MONSOON
TROUGH AND EAST OF 46W.
FOR THE FORECAST WEST OF 55W, THE STATIONARY FRONT ALONG ABOUT 30N
AND W OF 64W WILL LIFT N AS A WARM FRONT TONIGHT INTO SAT. FRESH
TO STRONG E WINDS AND ROUGH SEAS ARE EXPECTED TODAY OFF NE FLORIDA
AS HURRICANE ISAIAS TRACKS NORTHWARD ACROSS THE GULF OF AMERICA.
THESE WINDS WILL VEER TO THE SE AT MODERATE TO FRESH SPEEDS EARLY
ON SAT BEFORE WEAKENING TO GENTLE TO MODERATE SPEEDS BY SUN.
OTHERWISE, AS HIGH PRESSURE MOVES ACROSS THE WESTERN ATLANTIC, A
TIGHTENING PRESSURE GRADIENT WILL SUPPORT NE TO E WINDS OF FRESH
TO LOCALLY STRONG SPEEDS AND ROUGH SEAS BEHIND A COLD FRONT OVER
THE EASTERN WATERS, MAINLY N OF 26N, SUN INTO MON. LOOKING AHEAD,
A NEW COLD FRONT IS FORECAST TO PUSH OFF THE U.S. SOUTHEASTERN
COAST EARLY ON MON AND MOVE ACROSS THE WATERS N OF 29N THROUGH TUE
NIGHT WHILE IT WEAKENS. LIGHT TO GENTLE WINDS AND MODERATE SEAS
WILL DOMINATE MUCH OF THE BASIN EARLY NEXT WEEK.
STRIPLING
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page