858
AXNT20 KNHC 171743
TWDAT
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1815 UTC TUE MAR 17 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
1630 UTC.
..SPECIAL FEATURES
GULF OF AMERICA RESIDUAL SWELL:
RESIDUAL NW TO N WIND SWELL OCCURRING BEHIND THE STRONG GULF OF
AMERICA COLD FRONT, WILL MAINTAIN SEAS OF 12 TO 15 FT SEAS IN THE
SOUTHWESTERN GULF, SOUTH OF 23N AND WEST OF 85W, INCLUDING THE BAY
OF CAMPECHE THROUGH MID AFTERNOON, AND IN YUCATAN CHANNEL THROUGH
THIS EVENING. AFTERWARD, SEAS WILL CONTINUE TO SUBSIDE, FALLING
BELOW BELOW 12 FT TONIGHT.
PLEASE REFER TO THE LATEST HIGH SEAS AND OFFSHORE WATERS FORECASTS
ISSUED BY THE NATIONAL HURRICANE CENTER AT WEBSITES
HTTPS://WWW.NHC.NOAA.GOV/TEXT/MIAHSFAT2.SHTML AND
HTTPS://WWW.NHC.NOAA.GOV/MARINE/OFFSHORES.PHP FOR MORE DETAILS.
EAST ATLANTIC LONG-PERIOD N SWELL:
LARGE, LONG-PERIOD N SWELL GENERATED BY A LARGE FETCH OF GALE TO
STORM-FORCE WINDS IN THE NORTHEAST ATLANTIC, WILL CONTINUE TO
PROPAGATE SOUTHWARD OF 31N THIS MORNING THROUGH WED MORNING,
EXPECT SEAS TO QUICKLY BUILD TO BETWEEN 12 AND 16 FT FROM 27N TO
31N BETWEEN 35W AND 46W THIS AFTERNOON. THESE VERY ROUGH SEAS WILL
SHIFT FARTHER SOUTHWARD TONIGHT TO NEAR 23N WED MORNING, AND THEN
BECOME REINFORCED WITH ADDITIONAL LARGE N SWELL WED THROUGH THU.
SEAS ACROSS THESE NORTHEASTERN WATERS WILL REMAIN 12 FT AND
GREATER THROUGH AT LEAST FRI.
PLEASE REFER TO THE LATEST HIGH SEAS FORECAST ISSUED BY THE
NATIONAL HURRICANE CENTER AT WEBSITE
HTTPS://WWW.NHC.NOAA.GOV/TEXT/MIAHSFAT2.SHTML FOR MORE DETAILS.
..MONSOON TROUGH/ITCZ
A MONSOON TROUGH ENTERS THE ATLANTIC NEAR THE COAST OF GUINEA
NEAR 10N14W, THEN CURVES SOUTHWESTWARD TO 03N20W. AN ITCZ
CONTINUES FROM 01.5N24W TO THE COAST OF BRAZIL NEAR 02.5S43W.
SCATTERED MODERATE TO STRONG CONVECTION IS NOTED FROM 03.5N TO 06N
BETWEEN 10W AND 17W. SCATTERED MODERATE ISOLATED STRONG CONVECTION
IS NOTED SOUTH OF 04N BETWEEN 17W AND 49W.
..GULF OF AMERICA
PLEASE READ THE SPECIAL FEATURES SECTION ABOUT VERY ROUGH SEAS.
A STRONG COLD FRONT EXTENDS SOUTHWESTWARD FROM THE FLORIDA KEYS,
ACROSS THE STRAITS AND ALONG THE NW COAST OF CUBA TO INLAND ACROSS THE
YUCATAN PENINSULA NEAR 20N88W. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ARE OCCURRING UP TO 90 NM AHEAD OF THIS FRONT,
INCLUDING THE YUCATAN CHANNEL, AS WELL AS ACROSS COASTAL PORTIONS
OF MEXICO ACROSS THE BAY OF CAMPECHE. 1029 MB HIGH PRESSURE IS
CENTERED ALONG THE CENTRAL TEXAS COAST AND ACTING TO DRIVE FRESH
TO STRONG NORTHERLY WINDS ACROSS THE ENTIRE BASIN, STRONGEST
ACROSS THE BAY OF CAMPECHE. NORTHERLY WIND SWELL GENERATED BY
THESE WINDS IS PRODUCING SEAS OF 2-4 FT ACROSS THE NORTH GULF
COASTAL WATERS TO 12 TO 15 FT ACROSS THE BAY OF CAMPECHE, WHERE
SEAS LIKELY PEAKED AT 18 FT LAST NIGHT. STRONG TO NEAR GALE- FORCE
NW TO N WINDS AND SEAS AT 12 TO 15 FT PERSIST OFF VERACRUZ.
FOR THE FORECAST, THE COLD FRONT WILL DRIFT FURTHER SOUTHEASTWARD
INTO THE NW CARIBBEAN THROUGH THU BEFORE STALLING. WINDS AND SEAS
WILL GRADUALLY DECREASE THIS AFTERNOON AND EVENING, EXCEPT FOR
THE SOUTHEASTERN GULF, WHERE MODERATE TO STRONG N TO NE WINDS WILL
LINGER UNTIL LATE THIS EVENING. ROUGH TO VERY ROUGH SEAS BEHIND
THE FRONT WILL GRADUALLY SUBSIDE FROM NORTH TO SOUTH TODAY THROUGH
THIS EVENING. IN THE WAKE OF THE FRONT ON WED, HIGH PRESSURE WILL
BUILD ACROSS THE REGION AND PREVAIL INTO THE WEEKEND.
..CARIBBEAN SEA
CONVERGENT SOUTHEASTERLY TRADE WINDS CONTINUE TO TRIGGER SCATTERED
SHOWERS AND ISOLATED STRONG THUNDERSTORMS BETWEEN SOUTHEASTERN
CUBA, THE CAYMAN ISLANDS AND JAMAICA. RECENT SATELLITE SCATTEROMETER
AND ALTIMETER DATA CONFIRMED FRESH TO STRONG E WINDS WITH 8 TO 11
FT SEAS ACROSS THE EASTERN AND CENTRAL BASIN. THESE WINDS ARE
SUPPORTED BY STRONG HIGH PRESSURE OVER THE WEST-CENTRAL ATLANTIC.
MODERATE WITH LOCALLY FRESH E TO SE WINDS AND SEAS OF 3 TO 6 FT
ARE NOTED ELSEWHERE ACROSS THE BASIN.
FOR THE FORECAST, A BROAD SURFACE RIDGE EXTENDING SOUTHWESTWARD
FROM THE NORTH ATLANTIC TO THE CENTRAL BAHAMAS AND THE NE CARIBBEAN
WILL SUPPORT FRESH TO STRONG TRADE WINDS AND ROUGH SEAS ACROSS
THE TROPICAL ATLANTIC WATERS NEAR THE LESSER ANTILLES, AND THE
EASTERN AND CENTRAL CARIBBEAN, INCLUDING THE ATLANTIC EXPOSURES
AND PASSAGES THROUGH WED. A COLD FRONT IS EXPECTED TO ENTER THE
NORTHWESTERN CARIBBEAN FROM THE GULF OF AMERICA THIS AFTERNOON,
AND WILL SLOW DOWN AND POSSIBLY STALL FROM WESTERN CUBA TO THE
GULF OF HONDURAS BY EARLY WED MORNING BEFORE DISSIPATING. THIS
SHOULD DECREASE THE INFLUENCE FROM THE RIDGE AND ALLOW WINDS AND
SEAS ACROSS THE CENTRAL AND EASTERN CARIBBEAN TO GRADUALLY SUBSIDE
THROUGH SAT.
..ATLANTIC OCEAN
A STRONG COLD FRONT EXTENDS SOUTHWESTWARD FROM OFFSHORE OF THE SE
U.S., THROUGH THE CAROLINA COAST ACROSS 31N74W, ACROSS THE FAR NW
BAHAMAS AND THE FLORIDA KEYS, THEN THROUGH THE STRAITS OF FLORIDA
AND YUCATAN CHANNEL. SCATTERED MODERATE TO ISOLATED STRONG
CONVECTION CONTINUES TO FLARE UP WITHIN 200 NM SOUTHEAST OF THIS
FRONT, FROM THE CENTRAL BAHAMAS NORTHWARD. SCATTERED MODERATE
ISOLATED STRONG CONVECTION IS ALSO OCCRURING FROM THE CENTRAL
BAHAMAS ACROSS THE EASTERN HALF OF CUBA, TO A BROAD INVERTED
SURFACE TROUGH EXTENDING FROM JUST E OF THE COLD FRONT ACROSS
CENTRAL CUBA AND INTO THE CARIBBEAN. EAST OF THE FRONT, AN
EXPANSIVE AND STRONG SURFACE RIDGE DOMINATES THE BASIN, EXTENDING
FROM 1041 MB HIHG PRESSURE NEAR 41N47W, SOUTHWARD INTO THE TROPICS
N OF 10N. A WEAKENING COLD FRONT CURVES SOUTHWESTWARD FROM JUST
SOUTH OF THE AZORES ACROSS 31N25W TO NEAR 28N46W. STRONG NE WINDS
AND SEAS OF 10-13 FT IN N SWELL PREVAIL NORTH OF THE FRONT. SCATTERED
SHOWERS ARE SEEN UP TO 90 NM ALONG SOUTH OF THIS BOUNDARY. WELL
TO THE SOUTH, MODEST CONVERGENT TRADES ARE GENERATING SCATTERED
MODERATE CONVECTION NEAR THE COAST OF BRAZIL FROM SAO LUIS
WESTWARD TO NEAR THE AMAZON RIVER DELTA AREA.
FRESH TO STRONG S TO SW WINDS WITH SEAS OF 7 TO 10 FT PREVAIL
WITHIN A NARROW 90 NM WIDE BAND, NORTHEAST OF THE BAHAMAS AND EAST
OF THE WESTERN ATLANTIC COLD FRONT, WHILE FRESH NW WINDS WITH 8
TO 10 FT SEAS ARE SEEN BEHIND THE FRONT. TO THE EAST AND SOUTH,
FRESH TO LOCALLY STRONG ANTICYCLONIC NE TO SE WINDS, AND SEAS OF
8 TO 11 FT IN MIXED SWELL DOMINATE THE WATERS NORTH OF 10N
BETWEEN 35W AND 60W, AND FROM 20N TO 25N WEST OF 60W. ACROSS THE
REMAINDER OF THE ATLANTIC BASIN WEST OF 30W, MODERATE TO LOCALLY
FRESH NE WINDS AND SEAS AT 6 TO 8 FT IN NE SWELL PREVAILS.
FOR THE FORECAST WEST OF 55W, FRESH WINDS AND ROUGH SEAS WILL
SHIFT EASTWARD WITH THE COLD FRONT THROUGH WED MORNING. BY WED
AFTERNOON, THE FRONT WILL STALL FROM NEAR BERMUDA TO THE CENTRAL
BAHAMAS WHILE WEAKENING. THIS SHOULD ALLOW WINDS AND SEAS NORTH OF
26N TO GRADUALLY DECREASE DURING THE SECOND HALF OF THE WEEK. IN
RESPONSE TO THIS FRONT, FRESH TO STRONG E WINDS AND ROUGH SEAS
CURRENTLY FROM 10N TO 27N, INCLUDING THE CENTRAL AND SOUTHEAST
BAHAMAS SHOULD SLOWLY SUBSIDE TONIGHT THROUGH THU MORNING.
STRIPLING
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