607
AXNT20 KNHC 131017
TWDAT
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1215 UTC SUN JUL 13 2025
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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0930 UTC.
..TROPICAL WAVES
AN EASTERN ATLANTIC TROPICAL WAVE IS ALONG 34W-35W, SOUTH OF 18N,
MOVING WESTWARD AT 15 KT. SCATTERED MODERATE CONVECTION IS NOTED
AHEAD OF THIS WAVE, FROM 03.5N TO 10.5N BETWEEN 34W AND 39W.
A CENTRAL ATLANTIC TROPICAL WAVE IS ALONG 49W, SOUTH OF 18N,
MOVING WESTWARD AT 15-20 KT. SCATTERED MODERATE CONVECTION IS
OBSERVED FROM 03N TO 12N AND BETWEEN 42W AND 50W.
A WESTERN CARIBBEAN TROPICAL WAVE IS ALONG 86W, SOUTH OF 20N,
MOVING WESTWARD AT 15 KT. SCATTERED MODERATE ISOLATED STRONG
CONVECTION IS FOUND SOUTH OF 17N BETWEEN 82W AND 89W.
..MONSOON TROUGH/ITCZ
A MONSOON TROUGH ENTERS THE ATLANTIC THROUGH THE COAST OF
MAURITANIA NEAR 18N16W, CONTINUING SOUTHWESTWARD TO 11N22W TO
10N31W TO 1014 MB LOW PRES NEAR 11N43W TO 12N47W. ASSOCIATED
CONVECTION IS DESCRIBED ABOVE WITH THE TROPICAL WAVES.
..GULF OF AMERICA
A NEARLY STATIONARY UPPER LEVEL LOW OVER THE NW GULF CONTINUES TO
PROVIDE UNSTABLE CONDITIONS ACROSS MOST OF THE NORTHERN HALF OF
THE GULF THIS MORNING, WHERE WIDELY SCATTERED SHOWERS DOT THE GULF
WATERS NORTH OF 25N. A BROAD SUBTROPICAL RIDGE REACHES ACROSS
CENTRAL FLORIDA AND EXTENDS NORTHWESTWARD ACROSS THE NE GULF OF
AMERICA, RESULTING IN MODERATE TO LOCALLY FRESH E TO SE WINDS AND
SEAS OF 3-4 FT ACROSS THE SW HALF OF THE BASIN. ELSEWHERE,
MODERATE OR WEAKER WINDS AND SLIGHT SEAS PREVAIL IN THE REST OF
THE BASIN.
FOR THE FORECAST, WEAK HIGH PRESSURE ACROSS THE NE GULF THIS
MORNING WILL DRIFT SLOWLY WESTWARD AND INTO THE NW GULF BY WED.
THIS WILL ALLOW A BROAD AREA OF LOW PRESSURE EXPECTED TO FORM
ACROSS THE ATLANTIC EAST OF FLORIDA, TO SHIFT WESTWARD ACROSS
FLORIDA AND INTO THE EASTERN GULF ON TUE, THEN CONTINUE TO DRIFT
WESTWARD INTO THE CENTRAL GULF THROUGH THU, ACCOMPANIED BY ACTIVE
WEATHER. ENVIRONMENTAL CONDITIONS COULD BECOME MARGINALLY
CONDUCIVE FOR THE GRADUAL DEVELOPMENT OF THIS SYSTEM BY MID TO
LATE NEXT WEEK.
..CARIBBEAN SEA
SCATTERED SHOWERS AND THUNDERSTORMS ARE SEEN ACROSS THE SW
CARIBBEAN SOUTH OF 12N, ABOUT THE MONSOON TROUGH, AND BEHIND A
TROPICAL WAVE MOVING INTO CENTRAL AMERICA. NO OTHER SIGNIFICANT
CONVECTION IS NOTED ACROSS THE BASIN, AS SAHARAN AIR GENERALLY
PREVAILS EAST OF 77W. A BROAD SUBTROPICAL RIDGE OVER THE CENTRAL
ATLANTIC EXTENDS WESTWARD ALONG 30N TO NEAR 70W AND THEN WEST-
SOUTHWESTWARD INTO CENTRAL FLORIDA, SUPPORTING STRONG EASTERLY
TRADE WINDS IN THE SOUTH-CENTRAL CARIBBEAN. SEAS IN THESE WATERS
ARE 8-10 FT. MODERATE TO LOCALLY FRESH EASTERLY BREEZES AND
MODERATE SEAS ARE FOUND ELSEWHERE SOUTH OF 20N. IN THE REST OF THE
NW CARIBBEAN, MODERATE OR WEAKER WINDS AND SLIGHT TO MODERATE
SEAS PREVAIL.
FOR THE FORECAST, WEAK ATLANTIC HIGH PRESSURE ALONG 69W WILL
SHIFT NE AND COLLAPSE TODAY, LEAVING A WEAK ATLANTIC RIDGE EAST OF
75W THROUGH MON. HIGH PRESSURE WILL THEN BUILD WESTWARD ACROSS
THE REGION AND INTO FLORIDA TUE THROUGH THU. THIS PATTERN WILL
CONTINUE TO SUPPORT PULSING FRESH TO STRONG TRADES AND ROUGH SEAS
ACROSS THE SOUTH-CENTRAL CARIBBEAN THROUGH EARLY TUE THEN EXPAND
ACROSS MUCH OF THE CENTRAL BASIN LATE TUE THROUGH THU. FRESH E
WINDS ARE EXPECTED ACROSS THE GULF OF HONDURAS THROUGH TUE,
PULSING TO LOCALLY STRONG TONIGHT. MODERATE TO FRESH WINDS AND
MODERATE SEAS ARE EXPECTED IN THE EASTERN CARIBBEAN THROUGH TUE
WHILE GENTLE TO MODERATE WINDS AND SLIGHT TO MODERATE SEAS WILL
PREVAIL NW PORTIONS.
..ATLANTIC OCEAN
AN EXPANSIVE SUBTROPICAL RIDGE OVER THE CENTRAL ATLANTIC IS
CENTERED ON A 1025 MB HIGH NEAR 30N38W, AND DOMINATES THE
TROPICAL ATLANTIC WATERS BETWEEN 20W AND THE BAHAMAS. A BROAD
UPPER LEVEL LOW IS NOTED BETWEEN BERMUDA AND HISPANIOLA,
SUSTAINING A FEW CLUSTERS OF SCATTERED SHOWERS AND THUNDERSTORMS
NORTH OF 21N BETWEEN 62W AND THE BAHAMAS. OVERNIGHT SATELLITE
SCATTEROMETER DATA SHOWED MODERATE TO FRESH EASTERLY WINDS SOUTH
OF 25N AND BETWEEN 25W AND 65W, AND SOUTH OF 23N WEST OF 65W.
SEAS ACROSS THE TRADE WIND ZONE EAST OF 65W ARE 4-7 FT, AND 2-4 FT
WEST OF 65W. A TIGHTER PRESSURE GRADIENT IN THE EASTERN ATLANTIC
IS FORCING FRESH TO LOCALLY STRONG N-NE WINDS NORTH OF 19N AND
EAST OF 25W, WHERE SEAS ARE 6-9 FT. ELSEWHERE, MODERATE OR WEAKER
WINDS AND SLIGHT TO MODERATE SEAS ARE PREVALENT.
FOR THE FORECAST WEST OF 55W, 1020 MB ATLANTIC HIGH PRESSURE NEAR
29N69W WILL SHIFT NE AND COLLAPSE TODAY, LEAVING A WEAK ATLANTIC
RIDGE ALONG 30N AND EAST OF 75W THROUGH MON. HIGH PRESSURE WILL
THEN BUILD WESTWARD ACROSS THE REGION AND INTO FLORIDA TUE THROUGH
THU. A BROAD AREA OF LOW PRESSURE IS EXPECTED TO FORM OVER THE
NEXT FEW DAYS OFFSHORE OF THE SOUTHEASTERN U.S. COAST, AND BUILD
INTO THE WATERS NORTH OF THE BAHAMAS. THIS SYSTEM IS EXPECTED TO
MOVE GENERALLY WESTWARD ACROSS THE FLORIDA PENINSULA MON AND OVER
THE EASTERN AND NORTH-CENTRAL PORTION OF THE GULF OF AMERICA TUE
THROUGH WED. ACTIVE WEATHER IS EXPECTED OVER THE WATERS WEST OF
75W TODAY THROUGH TUE ASSOCIATED WITH THIS SYSTEM. THE PRESSURE
GRADIENT BETWEEN THE ATLANTIC RIDGE BUILDING WESTWARD AND THE AREA
OF LOW PRESSURE WILL SUPPORT MODERATE TO FRESH SE TO S WINDS
ACROSS THE BAHAMAS AND THROUGH THE NW ZONES TUE THROUGH EARLY THU.
STRIPLING
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