511
AXNT20 KNHC 170628
TWDAT
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0615 UTC TUE DEC 17 2024
TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA, CENTRAL AMERICA
GULF OF MEXICO, 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0500 UTC.
..SPECIAL FEATURES
WESTERN ATLANTIC SIGNIFICANT SWELL EVENT: RESIDUAL NE SWELL
PERSISTS ACROSS THE CENTRAL ATLANTIC. IT IS SUSTAINING SEAS OF 12
TO 14 FT NORTH OF 27N BETWEEN 44W AND 60W. FRESH TO STRONG NE TO
ENE WINDS ARE OCCURRING OVER THIS AREA. THE SWELL WILL SLOWLY
DECAY TONIGHT AND TUESDAY, ALLOWING FOR SEAS TO SUBSIDE BELOW 12
FT BY TUE EVENING. PLEASE REFER TO THE LATEST HIGH SEAS AND
OFFSHORE WATERS FORECASTS ISSUED BY THE NATIONAL HURRICANE CENTER
AT WEBSITE:
HTTPS://WWW.NHC.NOAA.GOV/TEXT/MIAHSFAT2.HTML AND
HTTPS://WWW.NHC.NOAA.GOV/MARINE/OFFSHORES.PHP FOR MORE DETAIL.
..MONSOON TROUGH/ITCZ
A MONSOON TROUGH STAYS MOSTLY OVER THE AFRICA CONTINENT. AN ITCZ
EXTENDS WESTWARD FROM 06N16W THROUGH 03N35W TO 05N48W. WIDELY
SCATTERED MODERATE CONVECTION IS FOUND UP TO 50 NM ALONG EITHER
SIDE THE ITCZ.
..GULF OF MEXICO
A SURFACE TROUGH OVER NORTHERN AND CENTRAL FLORIDA IS TRIGGERING
SCATTERED SHOWERS AND ISOLATED STRONG THUNDERSTORMS OVER SOUTHERN
FLORIDA AND THE FLORIDA STRAITS. OTHERWISE, A SURFACE RIDGE RUNS
SOUTHWESTWARD FROM A 1028 MB HIGH OVER NORTHERN GEORGIA TO JUST
SOUTH OF TAMPICO, MEXICO. GENTLE ENE TO SE WINDS AND SEAS OF 3 TO
5 FT ARE PRESENT AT THE WESTERN GULF, WEST OF 94W. MODERATE TO
FRESH NE TO ESE WINDS AND 4 TO 7 FT SEAS PREVAIL FOR THE REST OF
THE GULF.
FOR THE FORECAST, MODERATE TO FRESH E TO NE WINDS WILL PREVAIL
THROUGH EARLY WED IN THE CENTRAL AND EASTERN GULF, WITH MODERATE
TO LOCALLY FRESH SE WINDS OCCURRING IN THE WESTERN GULF.
THEREAFTER, GENTLE TO MODERATE WINDS AND SLIGHT TO MODERATE SEAS
ARE EXPECTED THROUGH WED AFTERNOON. LOOKING AHEAD, A WEAK COLD
FRONT WILL ENTER THE NORTHWESTERN GULF WED EVENING, AND FRESH TO
STRONG N TO NW WINDS WILL OCCUR ALONG AND BEHIND THE FRONT. THE
FRONT WILL WEAKEN AND DISSIPATE OVER THE CENTRAL GULF BY EARLY
THU. BUILDING HIGH PRESSURE OVER THE SOUTH-CENTRAL UNITED STATES
WILL LEAD TO MODERATE N TO NE WINDS AND SLIGHT TO MODERATE SEAS
ACROSS THE GULF THU THROUGH SAT.
..CARIBBEAN SEA
A SURFACE TROUGH CURVES SOUTHWESTWARD FROM THE SOUTHEAST BAHAMA
ACROSS EASTERN CUBA TO OFFSHORE FROM THE COASTAL BORDER OF
HONDURAS AND NICARAGUA. WIDELY SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ARE OCCURRING OVER THE WINDWARD PASSAGE AND
NORTHWESTERN BASIN, INCLUDING THE GULF OF HONDURAS. MODERATE TO
FRESH NE TO E WINDS AND SEAS AT 4 TO 7 FT ARE FOUND AT THE
NORTHWESTERN AND CENTRAL BASIN, INCLUDING THE WINDWARD PASSAGE
AND WATERS NEAR THE ABC ISLANDS. GENTLE NE TO E WINDS AND 3 TO 5
FT SEAS PREVAIL ELSEWHERE IN THE CARIBBEAN SEA.
FOR THE FORECAST, A STRONG PRESSURE GRADIENT BETWEEN HIGH
PRESSURE OVER THE NORTHWESTERN ATLANTIC AND THE AFOREMENTIONED
SURFACE TROUGH WILL CONTINUE TO SUPPORT MODERATE TO LOCALLY FRESH
NE WINDS ACROSS THE NORTHWESTERN BASIN THROUGH TUE MORNING BEFORE
WINDS DIMINISH. AS THIS SAME TROUGH SLOWLY PROGRESSES
NORTHWESTWARD THROUGH MIDWEEK, A LOW PRESSURE WILL STRENGTHEN
OVER NORTHWESTERN COLOMBIA. IN RESPONSE, MODERATE TO FRESH TRADE
WINDS WILL DEVELOP OVER THE CENTRAL AND EASTERN CARIBBEAN BY
EARLY TUE AND CONTINUE THROUGH FRI. STRONG NE WINDS WILL OCCUR AT
TIMES OFF THE COAST OF COLOMBIA AND VENEZUELA, THROUGH THE MONA,
WINDWARD AND ATLANTIC PASSAGES AND IN THE LEE OF HISPANIOLA AND
PUERTO RICO, WITH THE STRONGEST WINDS OCCURRING AT NIGHT. LOCALLY
ROUGH SEAS WILL DEVELOP IN AREAS OF STRONG WIND.
..ATLANTIC OCEAN
PLEASE READ THE SPECIAL FEATURES SECTION ABOVE FOR INFORMATION
ON THE SIGNIFICANT SWELL EVENT.
A COLD FRONT CURVES WESTWARD FROM NEAR THE AZORES ACROSS 31N38W TO
28N56W, THEN CONTINUES NORTHWESTWARD AS A STATIONARY FRONT TO
31N62W. SCATTERED SHOWERS ARE OCCURRING UP TO 60 NM NORTH, AND 100
NM SOUTH OF THIS BOUNDARY. CONVERGENT TRADES ARE TRIGGERING
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS JUST EAST OF THE
LESSER ANTILLES. THE NORTHEASTERN END OF A SURFACE TROUGH IS
CAUSING SIMILAR CONDITIONS FROM THE SOUTHEAST BAHAMAS NORTHWARD TO
NEAR 25N. REFER TO THE MONSOON TROUGH/ITCZ SECTION FOR ADDITIONAL
CONVECTION IN THE ATLANTIC BASIN.
FOR THE WESTERN ATLANTIC INCLUDING THE BAHAMAS, FRESH TO STRONG
ENE TO E WINDS AND SEAS OF 8 TO 10 FT ARE PRESENT NORTH OF 20N
BETWEEN 60W AND THE GEORGIA/FLORIDA COAST. FOR THE CENTRAL
ATLANTIC SOUTH OF THE LARGE NE SWELL, GENTLE TO MODERATE ENE TO E
WINDS AND SEAS AT 8 TO 9 FT ARE EVIDENT FROM 20N TO 27N BETWEEN
35W AND 60W. IN THE TROPICAL ATLANTIC FROM 04N TO 20N BETWEEN 35W
AND THE LESSER ANTILLES, MODERATE WITH LOCALLY FRESH NE TO E WINDS
AND 8 TO 9 FT SEAS EXIST. GENTLE TO MODERATE SE WINDS AND SEAS OF 6
TO 8 FT IN MIXED MODERATE SWELLS PREVAIL FOR THE REMAINDER OF THE
ATLANTIC BASIN WEST OF 35W.
FOR THE FORECAST W OF 55W, THE TIGHT PRESSURE GRADIENT BETWEEN
STRENGTHENING HIGH PRESSURE IN THE NORTHWESTERN ATLANTIC AND
TROUGHING EXTENDING FROM THE SOUTHEASTERN BAHAMAS INTO CENTRAL
CUBA WILL CONTINUE TO SUPPORT WIDESPREAD FRESH E TO NE WINDS AND
ROUGH SEAS NORTH OF THE GREATER ANTILLES THROUGH TUE. ELSEWHERE,
A COLD FRONT IN THE CENTRAL ATLANTIC WILL PROGRESS SOUTHWARD
THROUGH WED, PRODUCING FRESH TO STRONG WINDS FOR AREAS NORTH OF
20N THROUGH THU. SOUTH OF 20N, MODERATE TO FRESH TRADES WILL
PREVAIL THROUGH LATE THIS WEEK. LOOKING AHEAD, THE NEXT COLD
FRONT IS FORECAST TO MOVE OFF THE NORTHEASTERN FLORIDA COAST WED
NIGHT, REACH FROM NEAR 32N71W TO THE CENTRAL BAHAMAS BY LATE THU
NIGHT AND STALL. A STRONG COLD FRONT MAY QUICKLY MERGE WITH THE
STALLED FRONT LATE ON FRI, FOLLOWED BY FRESH TO STRONG NW WINDS.
CHAN
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