843
AXNT20 KNHC 301712
TWDAT
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1815 UTC WED SEP 30 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
1700 UTC.
..TROPICAL WAVES
A WESTERN ATLANTIC TROPICAL WAVE HAS ITS AXIS ALONG 84W, SOUTH OF
21N, MOVING WESTWARD AT 10 KT. SCATTERED MODERATE TO ISOLATED
STRONG CONVECTION IS OBSERVED BETWEEN 16N AND 22N AND W OF 78W.
..MONSOON TROUGH/ITCZ
THE MONSOON TROUGH ENTERS THE ATLANTIC NEAR 12N16W, EXTENDS TO
16N30W, AND THEN TO 09N41W. THE ITCZ EXTENDS FROM 09N41W TO THE
COASTAL BORDER OF GUYANA AND VENEZUELA. SCATTERED MODERATE
CONVECTION IS SEEN FROM 09N TO 19N BETWEEN 29W AND 40W, AS WELL AS
FROM 07N TO 13N BETWEEN 21W AND 30W.
..GULF OF AMERICA
DEEP-LAYER TROUGHING CONTINUES TO SUPPORT SHOWERS AND
THUNDERSTORMS ACROSS THE FLORIDA STRAITS AND THE FAR SE GULF.
HIGH PRESSURE OVER THE EASTERN UNITED STATES SUPPORTS MODERATE TO
LOCALLY FRESH EASTERLY WINDS AND MODERATE SEAS OVER THE WESTERN
GULF WATERS, WHILE MODERATE OR WEAKER WINDS AND SLIGHT TO MODERATE
SEAS PREVAIL ELSEWHERE.
FOR THE FORECAST, SHOWERS AND THUNDERSTORMS WILL LINGER IN THE SE
GULF THROUGH AT LEAST THIS EVENING. THE PRESSURE GRADIENT BETWEEN
HIGH PRESSURE OVER THE EASTERN UNITED STATES AND LOWER PRESSURES
IN TEXAS AND MEXICO SUPPORT MODERATE TO FRESH EASTERLY WINDS OVER
THE WESTERN GULF WATERS. THESE WINDS WILL EXPAND EASTWARD ACROSS
THE BASIN BY TONIGHT AS THE PRESSURE GRADIENT TIGHTENS. THE
GRADIENT WILL WEAKEN FROM WEST TO EAST BY THE END OF THE WEEK INTO
THE WEEKEND AS A FRONTAL BOUNDARY APPROACHES THE WESTERN GULF
WATERS, POSSIBLY MOVING INTO THE BASIN BY THE END OF THE WEEKEND
WITH WEAKENING WINDS AND SUBSIDING SEAS AHEAD OF IT. INCREASING
WINDS AND BUILDING SEAS ARE POSSIBLE BEHIND THE VERY SLOW MOVING
FRONT.
..CARIBBEAN SEA
PLEASE REFER TO THE TROPICAL WAVES SECTION ABOVE FOR DETAILS ON
CONVECTION IN THE NW CARIBBEAN.
THE EAST PACIFIC MONSOON TROUGH EXTENDS ACROSS THE FAR SW
CARIBBEAN, AND IS SUPPORTING NUMEROUS STRONG CONVECTION S OF 16N
AND W OF 78W. HIGH PRESSURE NORTH OF THE AREA SUSTAINS MODERATE
TO FRESH EASTERLY TRADE WINDS ACROSS MUCH OF THE BASIN, INCREASING
TO STRONG SPEEDS OFF NORTHERN COLOMBIA AND ALONG THE NORTHERN END
OF THE TROPICAL WAVE ANALYZED ALONG 84W. SEAS OF 4-8 FT ARE
EVIDENT ACROSS THE CARIBBEAN, EXCEPT FOR SLIGHT SEAS IN THE LEE OF
CUBA AND WINDWARD PASSAGE.
FOR THE FORECAST, A PASSING TROPICAL WAVE AND DIVERGENT FLOW
ALOFT WILL SUPPORT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS W
OF 75W OVER THE NEXT FEW DAYS. HIGH PRESSURE NORTH OF THE AREA
WILL SUPPORT PULSING FRESH TO STRONG EASTERLY TRADE WINDS IN THE
CENTRAL CARIBBEAN AND IN THE GULF OF HONDURAS THROUGH THE
REMAINDER OF THE WEEK AND INTO THE WEEKEND. MODERATE OR WEAKER
WINDS WILL PREVAIL IN THE REST OF THE BASIN. LATER, A FRONTAL
BOUNDARY WILL SLIDE INTO THE GULF OF AMERICA AND WESTERN ATLANTIC
THIS WEEKEND, RESULTING IN A WEAKENING PRESSURE GRADIENT ACROSS
THE CARIBBEAN AS THE RIDGE RETREATS. MODERATE TO LOCALLY FRESH
WINDS WILL THEN DOMINATE THE BASIN INTO EARLY NEXT WEEK.
..ATLANTIC OCEAN
DEEP-LAYER TROUGHING CONTINUES TO SUPPORT SCATTERED MODERATE
CONVECTION ACROSS THE BAHAMAS AND AREAS SOUTHWARD TOWARD CUBA. TO
THE EAST, CONVERGENT SURFACE WINDS BETWEEN A 1019 MB HIGH SE OF
BERMUDA AND THE REMNANTS OF FAY ARE SUPPORTING SCATTERED MODERATE
CONVECTION FROM 21N TO 28N BETWEEN 55W AND 63W, AS WELL AS NEAR
THE CENTER OF FAY'S REMNANTS. OUTSIDE OF CONVECTION, GENTLE TO
MODERATE E TO NE WINDS AND MODERATE SEAS PREVAIL ACROSS MUCH OF
THE ATLANTIC. LOCALLY FRESH WINDS ARE SEEN IN SHOWERS N OF A
SURFACE TROUGH ANALYZED JUST E OF THE LESSER ANTILLES.
FOR THE FORECAST WEST OF 55W, HIGH PRESSURE WILL PERSIST ACROSS
THE REGION OVER THE REMAINDER OF THE WEEK AND INTO THE WEEKEND
SUPPORTING MODERATE TO LOCALLY FRESH EASTERLY WINDS SOUTH OF 25N.
MODERATE OR WEAKER WINDS WILL PREVAIL ELSEWHERE. MEANWHILE, THE
REMNANTS OF POST-TROPICAL CYCLONE FAY CURRENTLY EAST OF THE
OFFSHORE WATERS MAY MOVE WEST OF 55W BY TONIGHT. THIS SYSTEM WILL
CONTINUE TO WEAKEN AND MAY DISSIPATE LATE THIS WEEK. LOOKING
AHEAD, A FRONTAL BOUNDARY MAY REACH THE WATERS OFF NE FLORIDA
EARLY NEXT WEEK, RESULTING IN AN INCREASE IN WINDS AND SEAS BEHIND
THE BOUNDARY.
ADAMS
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