601
AXPZ20 KNHC 170745
TWDEP
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON AUG 17 2026
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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0720 UTC.
..SPECIAL FEATURES
HEAVY RAINFALL IN PANAMA AND COLOMBIA: A TROPICAL WAVE, CURRENTLY
ANALYZED NEAR 77W, IS CROSSING PANAMA WILL INTERACTING WITH THE
MONSOON TROUGH AND COMBINING WITH ENHANCED DIVERGENCE ALOFT TO
INDUCE THUNDERSTORMS, PARTICULARLY OVER THE DARIEN REGION OF
PANAMA AND THE CHOCO-COLOMBIA. HEAVY RAINFALL FROM THESE
THUNDERSTORMS MAY LEAD TO FLOODING.
..TROPICAL WAVES
THE AXIS OF A TROPICAL WAVE IS ALONG 77W FROM 02N NEAR THE BORDER
OF ECUADOR AND COLOMBIA NORTHWARD TO ACROSS EASTERN PANAMA NEAR
THE BORDER WITH COLOMBIA, AND CONTINUING INTO THE CARIBBEAN SEA,
MOVING WESTWARD AROUND 20 KT. REFER TO THE SPECIAL FEATURES
SECTION BELOW FOR ADDITIONAL DETAILS INCLUDING HEAVY RAINFALL.
THE AXIS OF A TROPICAL WAVE IS ALONG 97.5W FROM JUST OFFSHORE
OAXACA SOUTHWARD TO THE EQUATOR, MOVING QUICKLY WESTWARD AROUND
25 KT. NEARBY CONVECTION IS DISCUSSED IN THE ITCZ/MONSOON TROUGH
SECTION BELOW. AN AREA OF LOW PRESSURE COULD FORM SEVERAL
HUNDRED NAUTICAL MILES SOUTH OF THE COAST OF SOUTHERN MEXICO
AROUND THE MIDDLE PART OF THE WEEK.
THE AXIS OF A TROPICAL WAVE IS NEAR 123W FROM 17N SOUTHWARD,
MOVING WESTWARD AROUND 20 KT. NEARBY CONVECTION IS DISCUSSED IN
THE ITCZ/MONSOON TROUGH SECTION BELOW. A BROAD AREA OF LOW PRESSURE
COULD FORM WELL TO THE SOUTHEAST OF THE HAWAIIAN ISLANDS DURING
THE LATTER PART OF THE WEEK.
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH
THE MONSOON TROUGH EXTENDS FROM 1007 MB LOW PRESSURE NEAR THE
COAST OF NORTHERN COLOMBIA AT 10.5N73.5W TO ACROSS THE BORDER OF
COSTA RICA AND NICARAGUA TO THE GULF OF PAPAGAYO AT 11N84.5W TO
07N102W. THE ITCZ EXTENDS FROM 07N102W TO 08N122W, THEN RESUMES
WEST OF A TROPICAL WAVE FROM 07N124W TO BEYOND 05N140W. SCATTERED
TO NUMEROUS MODERATE AND ISOLATED STRONG CONVECTION IS NOTED
FROM 02N TO 14N BETWEEN 77W AND 106W, AND FROM 05N TO 13N BETWEEN
115W AND 131W.
..OFFSHORE WATERS WITHIN 250 NM OF MEXICO
SEE TROPICAL WAVES SECTION ABOVE FOR INFORMATION ON A TROPICAL
WAVE THAT HAS A POTENTIAL FOR TROPICAL DEVELOPMENT OFFSHORE
SOUTHERN MEXICO LATER THIS WEEK.
STRONG TO NEAR GALE NORTH GAP WINDS ARE OVER THE GULF OF
TEHUANTEPEC AS CONFIRMED BY A RECENT ASCAT SCATTEROMETER PASS.
FRESH NORTHWEST WINDS ARE NEAR THE PACIFIC COAST OF BAJA
CALIFORNIA, LOCALLY STRONG NEAR AND NORTH OF PUNTA EUGENIA, ALSO
CONFIRMED BY ASCAT. ELSEWHERE, WINDS ARE MODERATE OR WEAKER.
SEAS ARE 7 TO 10 FT OVER THE GULF OF TEHUANTEPEC, 4 TO 6 FT OVER
THE REMAINING OPEN PACIFIC OFFSHORE WATERS, EXCEPT TO 7 FT NEAR
PUNTA EUGENIA, AND 1 TO 3 FT OVER THE GULF OF CALIFORNIA. A
CLUSTER OF SCATTERED TO NUMEROUS THUNDERSTORMS IS PROPAGATING
FROM PORTIONS OF NW MEXICO INTO THE SOUTHERN GULF OF CALIFORNIA
BRINGING GUSTY WINDS AND SQUALLY WEATHER INCLUDING LOCALLY HIGHER
SEAS.
FOR THE FORECAST, THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE
OVER THE GULF OF AMERICA AND RELATIVELY LOWER PRESSURE SOUTH OF
MEXICO WILL CONTINUE TO INDUCE PULSES OF STRONG NORTH WINDS OVER
THE GULF OF TEHUANTEPEC THROUGH WED NIGHT, WITH MODERATE TO
FRESH PULSES THEREAFTER. WINDS WILL REACH REACH NEAR GALE FORCE
AT TIMES EARLY THIS MORNING, TONIGHT AND TUE NIGHT, WHILE
RESULTANT ROUGH SEAS ARE ALSO EXPECTED. FRESH NORTHWEST WINDS ARE
FORECAST OFF OF THE BAJA CALIFORNIA PENINSULA THROUGH TUE NIGHT,
WITH WINDS REACHING STRONG SPEEDS NEAR PUNTA EUGENIA THROUGH THIS
EVENING. MEANWHILE, A SURGE OF STRONG SE WINDS MAY MOVE FROM
NEAR CABO CORRIENTES UP ACROSS THE GULF OF CALIFORNIA TONIGHT
INTO EARLY TUE, LIKELY ASSOCIATED WITH ANOTHER DEVELOPING
COMPLEX OF CONVECTION.
...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,
AND WITHIN 750 NM OF ECUADOR...
SEE SPECIAL FEATURES SECTION ABOVE FOR INFORMATION ON HEAVY
RAINFALL THAT MAY CAUSE FLOODING OVER THE NEXT FEW DAYS IN
PORTIONS OF COLOMBIA AND PANAMA.
FRESH TO STRONG NORTHEAST TO EAST GAP WINDS ARE OVER THE
GULF OF PAPAGAYO REGION, WITH MODERATE TO FRESH WINDS EXTENDING
WELL AWAY FROM THE GULF TO NEAR 09N95W WHERE LOCALLY ROUGH SEAS
EXIST. ELSEWHERE, WINDS ARE MODERATE OR WEAKER NORTH OF THE
MONSOON TROUGH, AND MODERATE TO FRESH SOUTH OF THE MONSOON
TROUGH. SEAS ARE 4 TO 7 FT IN LONG-PERIOD SOUTHWEST SWELL OVER
THE REMAINDER OF FORECAST WATERS, EXCEPT TO 8 FT SOUTHWEST OF
THE GALAPAGOS ISLANDS. THUNDERSTORMS ARE PRESENT NEAR THE MONSOON
TROUGH AS DESCRIBED ABOVE ACROSS MUCH OF THE OFFSHORE WATERS,
WITH LOCALLY HIGHER WINDS AND SEAS POSSIBLE NEAR ANY CONVECTION.
FOR THE FORECAST, THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE
OVER THE WESTERN CARIBBEAN AND RELATIVELY LOWER PRESSURE OVER
CENTRAL AMERICA WILL LEAD TO FRESH NORTHEAST TO EAST GAP WINDS
OVER PAPAGAYO REGION, LOCALLY STRONG TO NEAR GALE-FORCE AT TIMES
WITH OCCASSIONALLY AND LOCALLY ROUGH SEAS AS A RESULT. MODERATE
TO FRESH WINDS WILL EXTEND AWAY FROM THIS AREA ACROSS THE FAR
OFFSHORE WATERS OF EL SALVADOR AND GUATEMALA MIDWEEK. MODERATE TO
FRESH SOUTHERLY WINDS WILL PULSE SOUTH OF THE MONSOON TROUGH
INTO TONIGHT BEFORE WEAKENING. LARGE SOUTHERLY SWELL WILL IMPACT
WATERS MAINLY FROM ECUADOR TO THE GALAPAGOS ISLANDS THROUGH THE
NEXT SEVERAL DAYS, LARGEST EXPECTED LATER TODAY THROUGH WED.
..REMAINDER OF THE AREA
THE REMNANTS OF HERNAN AND ASSOCIATED WINDS AND SEAS HAVE MOVED
COMPLETELY WEST OF 140W IN THE PAST SEVERAL HOURS. A SURFACE
TROUGH IS OVER THE NORTHWEST WATERS, ANALYZED FROM 23.5N130W TO
18N140W, WITH MODERATE TO FRESH WINDS FROM 17N TO 24N TO THE WEST
OF 130W AND THE TROUGH AS CAPTURED BY VERY RECENT ASCAT
SCATTEROMETER DATA. ASSOCIATED SCATTERED MODERATE ISOLATED STRONG
CONVECTION IS FOUND ON CONVENTIONAL INFRARED SATELLITE IMAGERY
FROM 23.5N TO 28N BETWEEN 125W AND 134W. SOME MODERATE TO FRESH
WINDS ARE ALSO NOTED FROM 09N TO 24N BETWEEN 117W AND 130W NEAR
A TROPICAL WAVE DESCRIBED ABOVE. MODERATE TO FRESH SE TO S WINDS
ARE FOUND SOUTH OF THE MONSOON TROUGH TO THE EAST OF 126W, WHERE
SEAS ARE 7 TO 9 FT IN MIXED SE AND SW SWELLS. WINDS ARE MODERATE
OR WEAKER ACROSS THE REMAINDER OF THE OPEN WATERS, ALONG WITH
SEAS OF 4 TO 7 FT. VERY ACTIVE CONVECTION IS PRESENT ALONG THE
MONSOON TROUGH AND ITCZ AS DESCRIBED ABOVE, POSSIBLY LEADING TO
LOCALLY HIGHER WINDS AND SEAS.
FOR THE FORECAST, AN AREA OF LOW PRESSURE COULD FORM SEVERAL
HUNDRED NAUTICAL MILES SOUTH OF THE COAST OF SOUTHERN MEXICO
AROUND THE MIDDLE PART OF THE WEEK, ASSOCIATED WITH A TROPICAL
WAVE CURRENTLY ANALYZED NEAR 77W. GRADUAL DEVELOPMENT OF THIS
SYSTEM IS POSSIBLE THEREAFTER, AND A TROPICAL DEPRESSION COULD
DEVELOP TOWARDS THE END OF THE WEEK OR NEXT WEEKEND AS THE SYSTEM
MOVES WEST- NORTHWESTWARD WHILE STAYING SOUTH OF MEXICO. IN
ADDITION, A BROAD AREA OF LOW PRESSURE COULD FORM WELL TO THE
SOUTHEAST OF THE HAWAIIAN ISLANDS DURING THE LATTER PART OF THE
WEEK, ASSOCIATED WITH A TROPICAL WAVE CURRENTLY ANALYZED NEAR
124W. ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE FOR GRADUAL
DEVELOPMENT OF THIS SYSTEM, AND A TROPICAL DEPRESSION COULD FORM
TOWARDS THE END OF THE WEEK AND INTO THE WEEKEND AS THE SYSTEM
MOVES GENERALLY WESTWARD ACROSS THE WESTERN PORTION OF THE EAST
PACIFIC AND INTO THE CENTRAL PACIFIC. REGARDLESS OF DEVELOPMENT,
EXPECT SOME INCREASING WINDS AND SEAS WITH THESE AREAS.
LEWITSKY
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