926
AXNT20 KNHC 231804
TWDAT
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1815 UTC WED SEP 23 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
CENTRAL SUBTROPICAL ATLANTIC (FORMER TROPICAL STORM FAY):
THE REMNANT LOW PRESSURE OF 1013 MB IS CENTERED NEAR 30.5N37.5W.
WINDS OF 20-25 KT CONTINUE WITHIN 180 NM ACROSS THE N SEMICIRCLE,
WHERE BUOY OBSERVATIONS SUGGEST SEAS ARE 7 TO 10 FT. SCATTERED
MODERATE CONVECTION HAS INCREASED IN RECENT HOURS, AND WITHIN 90
NM ACROSS THE NE SEMICIRCLE OF THE LOW. WHILE ENVIRONMENTAL
CONDITIONS ARE ONLY MARGINALLY CONDUCIVE FOR DEVELOPMENT, THIS
SYSTEM COULD BECOME A TROPICAL DEPRESSION AGAIN TODAY OR TONIGHT
IF THE CURRENT THUNDERSTORM ACTIVITY PERSISTS. THE SYSTEM IS
FORECAST TO MOVE WESTWARD DURING THE NEXT COUPLE OF DAYS, AND BY
THE WEEKEND UPPER-LEVEL WINDS SHOULD INHIBIT FORMATION CHANCES.
THIS SYSTEM HAS A HIGH CHANCE OF FORMATION IN THE NEXT 48 HOURS.
FAR EASTERN TROPICAL ATLANTIC (AL90):
A NEW TROPICAL WAVE HAS EMERGED OFF THE COAST OF WEST AFRICA AND
HAS BEEN ANALYZED ALONG 18W, S OF 15W. SATELLITE DERIVED WINDS
ALSO DEPICTED A LOW ALONG THE WAVE AXIS NEAR 09N15W. NUMEROUS
MODERATE CONVECTION IS NOTED FROM 07.5N TO 13N AND EAST OF 22W.
THIS AREA OF LOW PRESSURE IS GRADUALLY BECOMING BETTER DEFINED,
AND THE ASSOCIATED SHOWER AND THUNDERSTORM ACTIVITY HAS INCREASED
SINCE YESTERDAY. THIS SYSTEM COULD BECOME A SHORT-LIVED TROPICAL
DEPRESSION ON THURSDAY OR FRIDAY WHILE IT MOVES NORTHWESTWARD TO
NORTHWARD. HOWEVER, STRONG UPPER-LEVEL WINDS SHOULD END THE
OPPORTUNITY FOR DEVELOPMENT BY THE WEEKEND. INTERESTS IN THE CABO
VERDE ISLANDS SHOULD MONITOR THE PROGRESS OF THIS SYSTEM AS GUSTY
WINDS, AREAS OF HEAVY RAIN AND FLASH FLOODING IS POSSIBLE THERE BY
FRIDAY. THIS SYSTEM HAS A MEDIUM CHANCE OF FORMATION IN THE NEXT
48 HOURS.
HEAVY RAINFALL IN CENTRAL AMERICA, JAMAICA, AND CUBA: A MID TO
UPPER-LEVEL TROUGH CURRENTLY EXTENDS FROM THE EASTERN GULF OF
AMERICA ACROSS THE YUCATAN PENINSULA AND NW CARIBBEAN, WHILE
RELATIVELY WARM SEA SURFACE TEMPERATURES AND ABUNDANT LOW LEVEL
MOISTURE ARE PRESENT. AN ELONGATED LOW LEVEL TROUGH WILL PREVAIL
ACROSS THIS AREA DURING THE NEXT SEVERAL DAYS, AND AID IN
FUNNELING ENHANCED TROPICAL MOISTURE ACROSS CENTRAL AMERICA AND
THE WESTERN CARIBBEAN, SUPPORTING PERIODS OF HEAVY RAINFALL
THROUGH SAT THE 26TH. THERE IS STILL SOME UNCERTAINTY REGARDING
THE EXACT LOCATION OF HEAVIEST RAINFALL, BUT FOR NOW HEAVY
RAINFALL LOOKS LIKELY ACROSS EXTREME SOUTHEASTERN MEXICO NEAR
CHIAPAS, SOUTHERN AND CENTRAL GUATEMALA, WESTERN HONDURAS, EL
SALVADOR, SOUTHERN AND EASTERN BELIZE, AS WELL AS ACROSS PORTIONS
OF COSTA RICA AND PANAMA. CURRENTLY, HEAVY RAINFALL IS ONGOING
FROM THE NW COASTAL WATERS OF JAMAICA, WESTWARD ACROSS THE CAYMAN
ISLANDS TO 87W AND THEN NORTHWARD ACROSS EAST-CENTRAL CUBA TO
ANDROS ISLAND IN THE BAHAMAS. SCATTERED MODERATE CONVECTION ARE
ELSEWHERE ACROSS THE GULF OF HONDURAS, AND THE REMAINDER OF THE
BAHAMAS. HEAVY RAINFALL IN THESE REGIONS WILL CREATE THE
POSSIBILITY OF LIFE-THREATENING FLASH FLOODING AND LANDSLIDES.
PLEASE REFER TO LOCAL WEATHER SERVICES AS WELL AS THE
INTERNATIONAL DESK AT THE WEATHER PREDICTION CENTER FOR MORE
INFORMATION.
..TROPICAL WAVES
A NEW TROPICAL WAVE HAS EMERGED OFF THE COAST OF WEST AFRICA AND
HAS BEEN ANALYZED ALONG 18W, S OF 15W. PLEASE REFER TO THE SPECIAL
FEATURES SECTION ABOVE FOR MORE INFORMATION ON THIS TROPICAL WAVE.
AN ATLANTIC TROPICAL
WAVE IS ANALYZED ALONG 45W, S OF 16N, MOVING WESTWARD AT 15 KT.
ISOLATED MODERATE CONVECTION IS FROM 09.5N TO 12N BETWEEN 42.5W
AND 46W.
AN ATLANTIC TROPICAL WAVE HAS ITS AXIS ALONG 60W SOUTH OF 15N,
MOVING WESTWARD AT 10 TO 15 KT. ISOLATED MODERATE CONVECTION IS
DEPICTED SOUTH OF 09N AND WEST OF 58W.
..MONSOON TROUGH/ITCZ
THE MONSOON TROUGH EXITS AFRICA NEAR 12N16.5W AND EXTENDS
SOUTHWESTWARD TO 07N48W, WHERE IT TRANSITIONS TO THE ITCZ AND
CONTINUES TO 09N58W. SCATTERED TO NUMEROUS MODERATE TO STRONG
CONVECTION IS NOTED FROM 04N TO 10N BETWEEN 22W AND 27W.
..GULF OF AMERICA
A WEAK PRESSURE GRADIENT REMAINS ACROSS THE GULF BASIN AS
WEAKENING HIGH PRESSURE ACROSS THE SE U.S. EXTENDS A RIDGE ACROSS
THE NORTHERN GULF. A BROAD AND PERSISTENT MIDDLE TO UPPER-LEVEL
TROUGH OVER THE EASTERN GULF IS SUPPORTING VERY ACTIVE
THUNDERSTORMS OVER PORTIONS OF THE NW CARIBBEAN AND ACROSS EASTERN
CUBA INTO THE BAHAMAS, WHILE CONVECTION ACROSS THE GULF HAS
DIMINISHED IN RECENT HOURS, WITH WIDELY SCATTERED MODERATE
CONVECTION ACROSS THE STRAITS OF FLORIDA AND INTO THE SW FLORIDA
WATERS ACROSS THE FORT MEYERS AREA. A WEAK SURFACE TROUGH LINGERS
FROM CENTRAL FLORIDA INTO THE THE SW GULF TO THE YUCATAN CHANNEL.
THE CURRENT SURFACE PATTERN IS GENERALLY PRODUCING LIGHT TO
GENTLE EASTERLY WINDS AND SLIGHT SEAS ACROSS THE GULF.
FOR THE FORECAST, A WEAK PRESSURE GRADIENT WILL GENERATE GENTLE
TO MODERATE WINDS ACROSS THE GULF THROUGH THU. AN UPPER-LEVEL
TROUGH WILL SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS OVER THE
SE GULF AND THE STRAITS OF FLORIDA FOR AT LEAST THE NEXT COUPLE OF
DAYS. A COLD FRONT IS FORECAST TO MOVE INTO THE NE GULF THU NIGHT
AND FRI. THE FRONT WILL SHIFT SOUTHWARD BEFORE STALLING OVER THE
SE GULF THIS WEEKEND.
..CARIBBEAN SEA
PLEASE REFER TO THE SPECIAL FEATURES SECTION ABOVE FOR INFORMATION
ON IMPACTFUL WEATHER ACROSS THE NORTHWESTERN CARIBBEAN.
OUTSIDE OF THE ACTIVE CONVECTION ACROSS THE NW CARIBBEAN, FAIR
WEATHER DOMINATES MOST OF THE BASIN. SCATTERED SHOWERS ACCOMPANY A
LOW-LEVEL TROUGH MOVING ACROSS THE VIRGIN ISLANDS. AT THE
SURFACE, A WEAK PRESSURE PATTERN PREVAILS ACROSS THE BASIN.
MODERATE TRADES PREVAIL ACROSS MOST OF THE BASIN, WHERE SEAS ARE 2
TO 4 FT, WHILE FRESH WINDS ARE S OF 14N TO THE COASTS OF NW
VENEZUELA AND EXTREME NE COLOMBIA, WHERE SEAS ARE 4 TO 6 FT.
OUTSIDE OF CONVECTION, LIGHT TO GENTLE WINDS AND SLIGHT SEAS
PREVAIL ACROSS THE SW CARIBBEAN.
FOR THE FORECAST, A WEAK PRESSURE GRADIENT WILL GENERATE MODERATE
TO FRESH TRADES OVER THE S CENTRAL CARIBBEAN, AND GENTLE TO
MODERATE WINDS ELSEWHERE. AN UPPER-LEVEL TROUGH WILL SUPPORT
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS OVER THE W
CARIBBEAN FOR AT LEAST THE NEXT COUPLE OF DAYS.
..ATLANTIC OCEAN
PLEASE SEE THE SPECIAL FEATURES SECTION ABOVE FOR MORE
INFORMATION ON THE CENTRAL SUBTROPICAL ATLANTIC SYSTEM (FORMER
TROPICAL STORM FAY).
SCATTERED SHOWERS AND THUNDERSTORMS REMAIN ACTIVE ACROSS
THE NW CARIBBEAN, ACROSS EASTERN CUBA AND OVER MUCH OF THE BAHAMAS
AND ADJACENT ATLANTIC WATERS W OF 67W. THIS ACTIVITY IS OCCURRING
DUE TO THE COMBINATION OF AMPLE MOISTURE ACROSS THE AREA AND
UNSTABLE CONDITIONS CREATED BY THE PERSISTENT AND DEEP LAYERED
UPPER TROUGH ACROSS THE EASTERN GULF OF AMERICA AND NW CARIBBEAN.
ANOTHER UPPER-LEVEL LOW IS DRIFTING WESTWARD NEAR 25N50W. THIS
FEATURE IS INTERACTING WITH SEVERAL SURFACE TROUGHS IN THE CENTRAL
ATLANTIC RESULTING IN AN AREA OF SCATTERED MODERATE CONVECTION
FROM 22N TO 28N BETWEEN 46W AND 53.5W. OUTSIDE OF THIS CONVECTION,
A WEAK PRESSURE GRADIENT CONTINUES ACROSS MUCH OF THE ATLANTIC.
THIS PATTERN IS SUSTAINING MOSTLY GENTLE TO MODERATE TRADES S OF
20N AND VARIABLE LIGHT TO GENTLE WINDS ELSEWHERE W OF 35W, EXCEPT
FOR MODERATE SE TO S WINDS OVER THE AREA N OF 26.5N BETWEEN 57W
AND 73W. SEAS ARE 3 TO 5 FT ACROSS THIS. ELSEWHERE, SEAS ARE 4 TO
6 FT.
FOR THE FORECAST WEST OF 55W, A WEAK PRESSURE GRADIENT WILL
SUPPORT GENTLE TO MODERATE TRADES ACROSS FORECAST WATERS THROUGH
TONIGHT. AN UPPER- LEVEL TROUGH WILL PRODUCE SCATTERED SHOWERS AND
THUNDERSTORMS WEST OF 65W FOR THE NEXT COUPLE OF DAYS. A COLD
FRONT WILL MOVE OFF THE SE UNITED STATES COAST LATE TONIGHT. THE
FRONT WILL SHIFT EASTWARD, REACHING FROM NEAR BERMUDA TO THE
STRAITS OF FLORIDA SAT NIGHT BEFORE STARTING TO WEAKEN. FRESH TO
STRONG WINDS AND INCREASING SEAS WILL FOLLOW THE FRONT ON THU AND
FRI, BEFORE DECREASING ON SAT.
KRV
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