806
AXNT20 KNHC 211729
TWDAT
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1815 UTC TUE JUL 21 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.
..SPECIAL FEATURE
TROPICAL STORM BERTHA IS CENTERED NEAR 29.3N 86.3W AT 21/1500
UTC OR 60 NM SSW OF PANAMA CITY FLORIDA, MOVING NNW AT 3 KT.
ESTIMATED MINIMUM CENTRAL PRESSURE IS 995 MB. MAXIMUM SUSTAINED
WINDS HAVE INCREASED TO 50 KT WITH GUSTS TO 60 KT. PEAK SEAS ARE
TO 13 FT IN THE SE QUADRANT. BERTHA REMAINS A SHEARED SYSTEM AS
OBSERVED ON SATELLITE IMAGERY, WITH THE LOW-LEVEL CENTER MOSTLY
EVIDENT NORTH OF DEEP CONVECTIVE ACTIVITY. THE CONVECTION CONSISTS
OF NUMEROUS STRONG THUNDERSTORMS FROM 26N TO 29N BETWEEN 84W AND
92W. BERTHA IS FORECAST TO TURN WNW THEN W OVER THE NEXT DAY OR
SO, THEN CONTINUE MOVING WESTWARD AT A SLOW RATE OF FORWARD SPEED
THROUGH MIDWEEK. BERTHA IS EXPECTED TO PRODUCE RAINFALL AMOUNTS
OF 2 TO 4 INCHES WITH ISOLATED HIGHER TOTALS AROUND 6 INCHES
THROUGH THU ALONG THE GULF COAST AND ADJACENT INLAND LOCATIONS
FROM WESTERN FLORIDA INTO SOUTHERN LOUISIANA, INCLUDING SOUTHERN
PORTIONS OF ALABAMA AND MISSISSIPPI. THIS RAINFALL MAY PRODUCE
ISOLATED FLASH FLOODING, ESPECIALLY IN URBAN AREAS. SWELLS
GENERATED BY BERTHA ARE AFFECTING PORTIONS OF THE GULF COAST OF
FLORIDA AND ARE LIKELY TO SPREAD WESTWARD DURING THE WEEK. THESE
SWELLS ARE LIKELY TO CAUSE LIFE-THREATENING SURF AND RIP CURRENT
CONDITIONS. PLEASE CONSULT PRODUCTS FROM YOUR LOCAL WEATHER
OFFICE.
PLEASE READ THE LATEST HIGH SEAS FORECAST ISSUED BY THE NATIONAL
HURRICANE CENTER AT WEBSITE -
HTTPS://WWW.NHC.NOAA.GOV/TEXT/MIAHSFAT2.SHTML AND THE LATEST TWO
NHC FORECAST/ADVISORY AND PUBLIC ADVISORY AT WWW.HURRICANES.GOV
FOR MORE DETAILS.
..TROPICAL WAVES
AN EASTERN ATLANTIC TROPICAL WAVE IS JUST W OF THE CABO VERDE
ISLANDS ALONG 29W FROM 09N TO 19W, MOVING W AT 10 TO 15 KT. DRY
AIR SURROUNDING THE WAVE IS PRECLUDING ANY CONVECTION NEAR IT AT
THIS TIME.
A CENTRAL ATLANTIC TROPICAL WAVE IS ITS AXIS ALONG 47W FROM 09N TO
23N, MOVING W AT AROUND 15 KT. SCATTERED MODERATE CONVECTION IS
NOTED FROM 20N TO 23N BETWEEN 42W AND 51W.
A TROPICAL WAVE OVER THE FAR SW CARIBBEAN IS MOVING INTO CENTRAL
AMERICA ALONG 83W, S OF 18N. IT IS MOVING W AT AROUND 10 KT.
SCATTERED MODERATE CONVECTION IS MAINLY INLAND OVER HONDURAS AND
WITHIN 90 NM OF THE COASTS OF NICARAGUA AND COSTA RICA.
..MONSOON TROUGH/ITCZ
THE MONSOON TROUGH ENTERS THE ATLANTIC THROUGH THE COAST OF
SENEGAL NEAR 14N17W, AND CONTINUES SOUTHWESTWARD TO 10N25W AND TO
09N35W, WHERE IT TRANSITIONS TO THE ITCZ TO 07N50W AND TO INLAND
SOUTH AMERICA AT 07N60W. SCATTERED MODERATE CONVECTION IS FROM 14N
TO 18N BETWEEN THE COAST OF AFRICA AND 20W, ALSO WITHIN 120 NM
SOUTH OF THE TROUGH BETWEEN 30W-35W, AND WITHIN 60 NM NORTH OF
THE TROUGH BETWEEN 21W-24W.
..GULF OF AMERICA
PLEASE REFER TO THE SPECIAL FEATURES SECTION FOR INFORMATION ON
TROPICAL STORM BERTHA LOCATED IN THE NE GULF.
ASIDE FROM TROPICAL STORM BERTHA, WEAK HIGH PRESSURE OF 1013 MB
IS CENTERED OVER THE WESTERN GULF AT NEAR 24N91W. THIS IS
SUPPORTING MODERATE OR WEAKER WINDS W OF 90W AND OVER THE
SOUTHEASTERN GULF WATERS.
FOR THE FORECAST, TROPICAL STORM BERTHA IS NEAR 29.2N 86.2W AT 11
AM EDT, AND IS MOVING SLOWLY NORTH-NORTHWEST AT 3 KT. MAXIMUM
SUSTAINED WINDS ARE 50 KT WITH GUSTS TO 60 KT, AND THE MINIMUM
CENTRAL PRESSURE IS 996 MB. BERTHA WILL MOVE TO 29.4N 87.0W THIS
EVENING, THEN WEAKEN SLIGHTLY AS IT MOVES TO 29.5N 88.0W WED
MORNING. BERTHA WILL CONTINUE TO 29.4N 89.5W WED EVENING, THEN
REACH 29.3N 91.3W BY THU MORNING. BERTHA WILL WEAKEN TO A TROPICAL
DEPRESSION NEAR 29.4N 93.1W THU EVENING OFF LOUISIANA, AND THEN
MOVE INLAND NEAR THE SABINE PASS TO 29.9N 94.9W FRI MORNING.
ELSEWHERE, WEAK HIGH PRESSURE OVER THE WESTERN GULF WILL
DISSIPATE BY MIDWEEK. AFTER MIDWEEK, ATLANTIC HIGH PRESSURE WILL
EXTEND WESTWARD TO THE CENTRAL GULF FOLLOWING BERTHA.
..CARIBBEAN SEA
THE PRESSURE GRADIENT BETWEEN THE AZORES-BERMUDA HIGH AND LOWER
PRESSURE OVER NW COLOMBIA IS RESULTING IN MODERATE TO FRESH
EASTERLY WINDS OVER MOST OF THE CENTRAL AND SW CARIBBEAN,
INCLUDING THE WINDWARD PASSAGE. MODERATE TO FRESH EASTERLIES ARE
ALSO ONGOING IN THE GULF OF HONDURAS. OFFSHORE COLOMBIA WINDS ARE
LOCALLY STRONG AND SEAS ROUGH TO 9 FT, OTHERWISE MODERATE SEAS
PREVAIL. FOR THE REMAINDER OF THE BASIN, WINDS ARE MODERATE OR
WEAKER, WITH SLIGHT TO MODERATE SEAS.
FOR THE FORECAST, THE ATLANTIC RIDGE COMBINED WITH THE COLOMBIAN
LOW WILL SUPPORT FRESH TO STRONG WINDS WITH MODERATE TO ROUGH SEAS
ACROSS THE SOUTH-CENTRAL CARIBBEAN THROUGH THE FORECAST PERIOD.
DURING THE SAME PERIOD, FRESH TO LOCALLY STRONG NE TO E WINDS ARE
EXPECTED IN THE WINDWARD PASSAGE, MAINLY AT NIGHT. FRESH WINDS
WILL PULSE ACROSS THE GULF OF HONDURAS THROUGH WED NIGHT. MODERATE
OR WEAKER WINDS WITH SLIGHT TO MODERATE SEAS WILL PREVAIL
ELSEWHERE.
..ATLANTIC OCEAN
A DEEP LAYER TROUGH AXIS EXTENDS SW FROM 31N51W TO 16N61W.
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OCCURRING W OF
THIS AXIS FROM 22N TO 30N, WESTWARD TO 65W. MODERATE TO FRESH NE
WINDS ARE IN THIS ZONE OF CONVECTION. E OF 45W, FROM 15N TO 25N,
MODERATE TO FRESH TRADES DOMINATE. ELSEWHERE IN THE BASIN, WINDS
ARE MODERATE OR WEAKER. MODERATE SEAS PREVAIL BASIN-WIDE.
FOR THE FORECAST WEST OF 55W, THE AFOREMENTIONED SURFACE TROUGH
WILL MOVE WESTWARD REACHING NEAR 70W BY WED AFTERNOON AND TO NEAR
75W BY THU MORNING. MODERATE TO FRESH WINDS AND MODERATE SEAS ARE
EXPECTED ON EITHER SIDE OF THE TROUGH AXIS. FRESH TO LOCALLY
STRONG TRADE WINDS ARE EXPECTED OFFSHORE HISPANIOLA, INCLUDING
APPROACHES TO THE WINDWARD PASSAGE THROUGH THE FORECAST PERIOD.
MODERATE OR WEAKER WINDS ALONG WITH MODERATE SEAS ARE FORECAST
ELSEWHERE E OF THE BAHAMAS THROUGH FRI, EXCEPT S OF 23N E OF ABOUT
77W WHERE MOSTLY FRESH TRADES ARE EXPECTED THROUGH SAT NIGHT.
KONARIK
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