367
AXNT20 KNHC 121705
TWDAT
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1815 UTC SAT SEP 12 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
THE AXIS OF A TROPICAL WAVE IS NEAR 41W FROM 06N TO 20N, MOVING
WESTWARD AT AROUND 20 KT. SCATTERED SHOWERS ARE SEEN NEAR THE WAVE
AXIS.
..MONSOON TROUGH/ITCZ
THE MONSOON TROUGH ENTERS THE ATLANTIC THROUGH THE COAST OF
SENEGAL NEAR 13N17W, AND CONTINUES TO 10N24W TO 13N35W TO 10N44W.
THE ITCZ EXTENDS FROM 10N44W TO THE COAST OF VENEZUELA NEAR
10N61W. NUMEROUS MODERATE CONVECTION IS NOTED FROM 08N TO 14N
BETWEEN 44W AND 63W.
THE EASTERN EXTENSION OF THE EAST PACIFIC MONSOON TROUGH EXTENDS
ACROSS THE FAR SW CARIBBEAN. SCATTERED MODERATE AND ISOLATED
STRONG CONVECTION ARE SEEN ALONG AND NEAR THE COASTS OF NICARAGUA,
COSTA RICA, AND PANAMA.
..GULF OF AMERICA
AN UPPER LEVEL SHORTWAVE TROUGH OVER THE SE US AND CONVERGENT
SURFACE WINDS OVER THE EASTERN GULF ARE SUPPORTING WIDELY
SCATTERED MODERATE CONVECTION ACROSS A LARGE REGION N OF 24N AND E
OF 95W. ELSEWHERE, THE PRESSURE GRADIENT BETWEEN HIGHER PRESSURE
INLAND OVER MEXICO AND A SURFACE TROUGH IN THE BAY OF CAMPECHE
SUPPORTS MODERATE TO LOCALLY FRESH SE TO S WINDS AND SEAS OF 3-5
FT ACROSS THE BAY OF CAMPECHE AND THE FAR WEST GULF. GENTLE TO
MODERATE OR WEAKER WINDS AND SEAS OF 1-3 FT PREVAIL ELSEWHERE.
FOR THE FORECAST, HIGH PRESSURE CENTERED OVER THE NE GULF WILL
DOMINATE INTO THE START OF NEXT WEEK. WINDS WILL PULSE TO FRESH
SPEEDS EACH NIGHT OFF THE W YUCATAN PENINSULA DUE TO A DIURNAL
TROUGH MOVING TOWARD THE SW GULF. BY TUE NIGHT, A BUILDING RIDGE
OVER THE EASTERN UNITED STATES AND A FRONTAL TROUGH WILL COMBINE
TO INCREASE WINDS TO FRESH TO LOCALLY STRONG SPEEDS AND BUILD SEAS
OVER THE GULF WATERS N OF 23N INTO LATE NEXT WEEK.
..CARIBBEAN SEA
THE PRESSURE GRADIENT BETWEEN SURFACE RIDGING OVER THE WESTERN
N ATLANTIC AND THE COLOMBIAN LOW SUPPORTS FRESH TO NEAR GALE-FORCE
EASTERLY TRADE WINDS AND ROUGH SEAS OVER MUCH OF THE CENTRAL
CARIBBEAN S OF 18N. MODERATE TO FRESH EASTERLY WINDS AND MODERATE
SEAS ARE FOUND IN THE EASTERN CARIBBEAN, WHILE MODERATE OR WEAKER
WINDS AND SLIGHT SEAS ARE PREVALENT ELSEWHERE. AN UPPER-LEVEL
TROUGH OVER THE NW CARIBBEAN IS PRODUCING SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS. ALL OTHER CONVECTION IS DESCRIBED IN THE
MONSOON TROUGH/ITCZ SECTION ABOVE. FAIR WEATHER PREVAILS ACROSS
MOST OF THE CARIBBEAN E OF 77W.
FOR THE FORECAST, A TIGHT PRESSURE GRADIENT BETWEEN A SUBTROPICAL
RIDGE NORTH OF THE ISLANDS AND LOWER PRESSURES ASSOCIATED WITH
THE COLOMBIAN LOW WILL CONTINUE TO SUPPORT STRONG TO LOCALLY NEAR-
GALE EASTERLY TRADE WINDS AND ROUGH TO LOCALLY VERY ROUGH SEAS
OVER THE CENTRAL CARIBBEAN FOR THE NEXT SEVERAL DAYS. GUSTS TO
GALE FORCE ARE LIKELY TONIGHT OFF COLOMBIA. WINDS WILL PULSE TO
STRONG SPEEDS IN THE GULF OF HONDURAS THIS EVENING THROUGH MON
MORNING. MEANWHILE, MODERATE TO FRESH EASTERLY BREEZES ARE
EXPECTED OVER THE NEXT FEW DAYS IN THE EASTERN CARIBBEAN.
..ATLANTIC OCEAN
AN UPPER-LEVEL TROUGH IN THE SW N ATLANTIC AND SURFACE TROUGH
PARALLELING THE SE US COAST ARE PRODUCING SCATTERED MODERATE
CONVECTION N OF 23N AND W OF 72W. TO THE EAST, A FRONTAL REMNANT
TROUGH EXTENDS FROM 31N44W TO 26N55W TO JUST SOUTH OF BERMUDA. A
1017 MB LOW IS ANALYZED SE OF BERMUDA. INTERACTIONS BETWEEN THESE
FEATURES AND THE UPPER-LEVEL TROUGH ARE SUPPORTING MORE SCATTERED
MODERATE CONVECTION FROM 24N TO 30N BETWEEN 56W AND 67W, WHILE
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE OCCURRING ALONG
THE TROUGH AXIS FROM 52W NORTHEASTWARD. FINALLY, A SURFACE TROUGH
N OF THE TROPICAL WAVE NEAR 41W IS ALSO SUPPORTING ISOLATED
MODERATE CONVECTION ALONG THE TROUGH AXIS.
OUTSIDE OF CONVECTION, SURFACE RIDGING DOMINATES MUCH OF THE
TROPICAL ATLANTIC. MODERATE TO FRESH NE TO E WINDS AND MODERATE
SEAS DOMINATE MUCH OF THE BASIN E OF 34W, AS WELL AS S OF 20N AND
W OF 40W. GENTLE TO MODERATE OR WEAKER TRADES AND 3-5 FT SEAS
PREVAIL ELSEWHERE.
FOR THE FORECAST WEST OF 55W, SCATTERED THUNDERSTORMS BETWEEN
BERMUDA AND THE BAHAMAS IN ASSOCIATION WITH AN UPPER-LEVEL TROUGH
SHOULD DIMINISH TONIGHT. AT THE SURFACE, THE SUBTROPICAL RIDGE
WILL CONTINUE TO DOMINATE FOR THE NEXT SEVERAL DAYS. TRADES NORTH
OF HISPANIOLA INTO THE WINDWARD PASSAGE WILL BE FRESH TO LOCALLY
STRONG INTO EARLY NEXT WEEK. LOOKING AHEAD, A BUILDING RIDGE OVER
THE EASTERN UNITED STATES AND A FRONTAL TROUGH WILL COMBINE TO
INCREASE WINDS TO FRESH TO LOCALLY STRONG SPEEDS AND BUILD SEAS TO
ROUGH NORTH OF THE BAHAMAS AND W OF 70W STARTING TUE AND
CONTINUING INTO THU. ELSEWHERE, MODERATE OR WEAKER WINDS AND
SLIGHT TO MODERATE SEAS WILL PREVAIL.
ADAMS
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