415
AXPZ20 KNHC 170310
TWDEP
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU APR 17 2025
TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM
03.4S TO 30N, EAST OF 120W INCLUDING THE GULF OF CALIFORNIA, AND
FROM THE EQUATOR TO 30N, BETWEEN 120W AND 140W. THE FOLLOWING
INFORMATION IS BASED ON SATELLITE IMAGERY, WEATHER OBSERVATIONS,
RADAR, AND METEOROLOGICAL ANALYSIS.
BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0220 UTC.
..SPECIAL FEATURE
GULF OF CALIFORNIA GALE WARNING: LOW PRESSURE OVER SOUTHERN
CALIFORNIA AND WESTERN ARIZONA EXTENDS SOUTHWARD INTO THE
NORTHERN GULF OF CALIFORNIA AND IS EXPECTED TO PERSIST THROUGH
FRI. HIGH PRESSURE IS WELL NW OF THE BAJA PENINSULA, AND EXTENDS
A WEAK RIDGE EASTWARD INTO THE BAJA SUR WATERS. THIS PATTERN IS
EXPECTED TO PRODUCE PULSING W TO SW GAP WINDS ACROSS BAJA NORTE
TURNING SW ACROSS THE FAR NORTHERN GULF OF CALIFORNIA EACH OF THE
NEXT FEW NIGHTS. THE HIGH PRESSURE WILL BUILD ACROSS BAJA AND
NORTHWESTERN MEXICO TONIGHT AHEAD OF A STRONG FRONTAL SYSTEM
DEVELOPING ACROSS THE SOUTHWESTERN U.S. TO INDUCE GALE-FORCE SW
WINDS ACROSS THE NORTHERN GULF WATERS LATE THIS EVENING THROUGH
MIDNIGHT BEFORE GRADUALLY DIMINISHING THU MORNING. A SIMILAR
SCENARIO IS EXPECTED THU NIGHT, BUT WITH WINDS LIKELY TO ONLY
REACH NEAR 30 KT. SEAS SHOULD PEAK AROUND 9 FT TONIGHT, AND TO
AROUND 8 FT ON THU NIGHT.
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH
A SURFACE TROUGH EXTENDS FROM 10N74W TO 07.5N79W TO 08.5N84W TO
05.5N96W. THE ITCZ THEN EXTENDS FROM 05.5N96W TO 05N117W TO
04N140W. A SOUTHERN HEMISPHERIC ITCZ IS ANALYZED FROM 02.5S109W
TO BEYOND 05.5S120W. SCATTERED TO LOCALLY NUMEROUS MODERATE TO
STRONG CONVECTION IS NOTED FROM 00N TO 07N E OF 86W. SCATTERED
MODERATE ISOLATED STRONG CONVECTION IS ELSEWHERE FROM 03N TO 07N
BETWEEN 86W AND 102W AND FROM 02.5N TO 07.5N BETWEEN 107W AND
117W.
..OFFSHORE WATERS WITHIN 250 NM OF MEXICO
SEE THE SPECIAL FEATURES SECTION INFORMATION ON AN NORTHERN
GULF OF CALIFORNIA GALE-FORCE GAP WIND EVENT.
A SURFACE RIDGE ACROSS THE WESTERN HALF OF THE GULF OF AMERICA
AND SOUTHEASTERN MEXICO CONTINUES TO SUPPORT STRONG N WINDS IN
THE GULF OF TEHUANTEPEC EXTENDING TO ABOUT 14.5N THIS EVENING,
WITH FRESH NE WINDS EXTENDING FARTHER SOUTH TO ABOUT 10N. PEAK
SEAS ARE NEAR 10 FT. DEEP LAYERED LOW PRESSURE OFFSHORE OF
SOUTHERN CALIFORNIA IS PRODUCING A WEAK SURFACE LOW THERE, WITH
AN ELONGATED TROUGH EXTENDING SOUTHWESTWARD TO NEAR 26N130W. THIS
AREA OF LOW PRESSURE IS BLOCKING HIGH PRESSURE FARTHER NW FROM
BUILDING UNOBSTRUCTED INTO THE BAJA WATERS. HOWEVER, THIS HIGH
PRESSURE DOES EXTEND A WEAK RIDGE EASTWARD AND BELOW THE SURFACE
TROUGH TO BAJA SUR. THE ASSOCIATED PRESSURE GRADIENT BETWEEN THE
RIDGE AND A SURFACE TROUGH ACROSS THE GULF OF CALIFORNIA IS
SUPPORTING GENTLE WINDS ACROSS THE WATERS OF CENTRAL AND NORTHERN
BAJA, AND MODERATE TO FRESH NNW WINDS OFF BAJA CALIFORNIA SUR
EXTENDING SOUTHWARD ACROSS THE REVILLAGIGEDO ISLANDS, WHERE SEAS
ARE 5-7 FT. GENTLE TO MODERATE NW WINDS PREVAIL ACROSS PORTIONS
OF THE SOUTHERN GULF OF CALIFORNIA WITH 3 TO 4 FT SEAS. ELSEWHERE
OVER THE PACIFIC OFFSHORE WATERS, WINDS ARE MODERATE OR WEAKER
WITH SEAS OF 4-5 FT IN MIXED NW AND S SWELL.
FOR THE FORECAST, STRONG NORTHERLY WINDS OVER THE GULF OF
TEHUANTEPEC WILL CONTINUE OVERNIGHT THEN GRADUALLY DIMINISH THU,
BEFORE THE GAP WIND FLOW ENDS THU NIGHT. OVER THE NORTHERN GULF
OF CALIFORNIA, FRESH SW TO W GAP WINDS, TO THE SOUTH OF A LOW
PRESSURE EXTENDING INTO BAJA NORTE, WILL PULSE TO GALE-FORCE
TONIGHT, AND THEN AGAIN TO STRONG TO NEAR GALE ON THU NIGHT.
ELSEWHERE, WINDS ACROSS THE MEXICAN OFFSHORE ZONES WILL BE
MODERATE OR WEAKER, EXCEPT FOR NW WINDS PULSING TO FRESH SPEEDS
OFF BAJA CALIFORNIA SUR.
...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,
AND WITHIN 750 NM OF ECUADOR...
HIGH PRESSURE ACROSS THE CENTRAL ATLANTIC AND EASTERN GULF OF
AMERICA EXTENDING INTO THE NW CARIBBEAN IS INDUCING GAP WINDS
ACROSS THE PACIFIC WATERS OF CENTRAL AMERICA, AND FRESH TO
LOCALLY STRONG NE TO E GAP WINDS ACROSS THE PAPAGAYO REGION THIS
EVENING. SEAS ARE CURRENTLY 5 TO 7 FT THERE. NE WINDS ACROSS THE
SW CARIBBEAN ARE INDUCING MODERATE TO LOCALLY FRESH N WINDS OVER
THE GULF OF PANAMA EXTENDING TO 06N, WHERE SEAS ARE 3 TO 5 FT.
ELSEWHERE, BETWEEN ECUADOR AND THE GALAPAGOS ISLANDS, WINDS ARE
MODERATE WITH 5-6 FT SEAS IN S SWELL. CLUSTERS OF HEAVY SHOWERS
AND STRONG THUNDERSTORMS CONTINUE TO SHIFT WESTWARD ACROSS THE
WATERS S OF 08N, MOVING OFFSHORE NORTHERN ECUADOR AND COLOMBIA
AND PASSING ALONG THE PACIFIC COASTS AND WATERS OF PANAMA AND
COSTA RICA E OF 86W. STRONG CONVECTION THERE HAS THE POTENTIAL TO
PRODUCE WIND GUSTS TO GALE FORCE AND LOCALLY ROUGH SEAS.
FOR THE FORECAST, SURFACE RIDGING FROM THE GULF OF AMERICA
EXTENDING INTO THE NW CARIBBEAN WILL SHIFT EASTWARD TO THE
WATERS BETWEEN SOUTH CAROLINA AND BERMUDA DURING THE NEXT SEVERAL
DAYS TO SUPPORT FRESH TO STRONG NE TO E GAP WINDS PULSING TO
NEAR 30 KT AT NIGHT ACROSS THE PAPAGAYO REGION THROUGH MON NIGHT.
THE SAME HIGH PRESSURE WILL FORCE MODERATE TO FRESH N WINDS
ACROSS THE GULF OF PANAMA TO 4.5N THROUGH SAT NIGHT WITH PEAK SEAS
TO 6 FT. LOCALLY STRONG NE WINDS ARE POSSIBLE IN THE GULF OF
PANAMA THU NIGHT AND FRI NIGHT.
..REMAINDER OF THE AREA.
A MODEST SURFACE RIDGE DOMINATES THE WATERS W OF 130W TONIGHT,
AND EXTENDS A WEAK RIDGE SOUTH THEN EASTWARD OVER THE
SUBTROPICAL WATERS W OF THE BAJA CALIFORNIA SUR WATERS, TO THE
SOUTH OF A SURFACE TROUGH EXTENDING FROM OFFSHORE OF SOUTHERN
CALIFORNIA TO NEAR 26N130W. ANOTHER SURFACE TROUGH IS JUST N OF
THE ITCZ FROM 10N134W TO 18N127W. THIS PATTERN CONTINUES TO
PRODUCE MODERATE TO LOCALLY FRESH NE WINDS BETWEEN THE ITCZ AND
21N, W OF 130W PER AFTERNOON SCATTEROMETER DATA. SEAS IN THIS
REGION ARE 7-8 FT IN N SWELL. N OF 21N, GENTLE TO MODERATE N TO
NE WINDS PREVAIL, WITH SEAS OF 6 TO 7 FT IN NW TO NE SWELL. S OF
20N BETWEEN 100W AND 130W, MODERATE TO LOCALLY FRESH TRADE WINDS
PREVAIL, WITH SEAS OF 5 TO 8 FT IN MIXED N AND E SWELL. SCATTERED
MODERATE IS OCCURRING NEAR THE ITCZ.
FOR THE FORECAST, LITTLE CHANGE IN THE WINDS ACROSS THE OPEN
WATERS IS EXPECTED FOR THE NEXT SEVERAL DAYS, EXCEPT FOR SLIGHTLY
STRONGER TRADES OCCURRING W OF 120W OVER THE WEEKEND. THE
PERSISTENCE OF THESE WINDS WILL LEAD TO BUILDING SEAS OF 8 TO 9
FT, SUBSIDING MON. OTHERWISE, NEW MODERATE NORTHERLY SWELL IS
FORECAST TO REACH OUR NORTHERN BORDER W OF THE BAJA CALIFORNIA
PENINSULA LATE MON WITH 8 FT SEAS.
STRIPLING
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