305
AXPZ20 KNHC 212143
TWDEP
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON MAY 21 2018
TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM
THE EQUATOR TO 32N, EAST OF 140W. THE FOLLOWING INFORMATION IS
BASED ON SATELLITE IMAGERY, WEATHER OBSERVATIONS, RADAR, AND
METEOROLOGICAL ANALYSIS.
BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2030 UTC.
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH
THE MONSOON TROUGH EXTENDS FROM 09.5N74W TO 11N94W TO 09.5N115W
TO 08N133W. THE ITCZ EXTENDS FROM 08N134W TO BEYOND 09.5N140W.
SCATTERED MODERATE TO STRONG CONVECTION IS OBSERVED FROM 04.5N
TO 11N BETWEEN THE COAST OF COLOMBIA AND 100W. WIDELY SCATTERED
MODERATE ISOLATED STRONG IS NOTED FROM 05N TO 11.5N BETWEEN 100W
AND 124W. WIDELY SCATTERED MODERATE TO STRONG IS NOTED WITHIN
180 NM N OF THE AXIS BETWEEN 133W AND 140W.
..DISCUSSION
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
EARLY AFTERNOON SCATTEROMETER DATA CONTINUE TO SHOW MODERATE TO
FRESH NW WINDS ACROSS THE OFFSHORE WATERS OF BAJA CALIFORNIA,
WHERE SEAS ARE RUNNING 5-7 FT. STRONG SW CROSS EQUATORIAL SWELL
HAS BEGUN TO MOVE INTO THE REGIONAL WATERS TODAY AND IS
PRODUCING SEAS OF 7-8 FT FROM 21N TO 23N BETWEEN LAS ISLAS TRES
MARIAS AND 112W. THIS SWELL WILL PENETRATE SOUTHERN PORTIONS OF
THE GULF OF CALIFORNIA THIS AFTERNOON THROUGH EARLY WED.
GENERALLY LIGHT TO GENTLE VARIABLE WINDS ARE NOTED OVER THE
SOUTHERN HALF OF GULF OF CALIFORNIA, WHILE MODERATE S TO SW
WINDS PREVAIL ACROSS THE NORTH HALF AS A LOW PRESSURE CENTER HAS
DEVELOPED IN THE FAR N PORTIONS NEAR 31N114.5W. LIGHT NW TO W
WINDS CONTINUE FARTHER SOUTH ACROSS THE MEXICAN COASTAL WATERS.
AS MENTIONED IN RECENT DAYS, THE MAIN MARINE FORECAST ISSUE FOR
THE NEXT COUPLE OF DAYS IS THE ARRIVAL OF LONG PERIOD SW SWELL
MOVING INTO ALL OF THE REGIONAL PACIFIC WATERS TODAY THROUGH MID
WEEK. LARGE SW SWELL WILL BEGIN TO RAISE SEAS IN EXCESS OF 8 FT
ACROSS THE WATERS OF SOUTHERN MEXICO TODAY, AND THE OPEN WATERS
OFF BAJA CALIFORNIA TONIGHT AND TUE, AS IT MIXES WITH NW SWELL
OFF BAJA CALIFORNIA NORTE. OVERNIGHT AND MORNING ALTIMETER DATA
SUGGESTS THAT THE LARGEST AND STRONGEST SWELL IS AIMED FOR
CENTRAL MEXICO BETWEEN TEHUANTEPEC AND MAZATLAN.
IN THE GULF OF TEHUANTEPEC, LIGHT WINDS WILL PERSIST INTO TUE,
THEN MODERATE TO FRESH GAP WINDS WILL PULSE BRIEFLY AS SHARP
TROUGHING SHIFTS SLOWLY NW ACROSS SOUTHEAST MEXICO.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
GULF OF PAPAGAYO: LIGHT TO GENTLE WINDS WILL DOMINATE THE GULF
THE ENTIRE FORECAST PERIOD AS ELONGATED WEAK LOW PRESSURE WILL
PREVAIL ACROSS CENTRAL AMERICA. SEAS OF 5-7 FT THIS AFTERNOON
ARE FORECAST TO BUILD TO 6-9 FT OVER THE GULF AND NEARBY WATERS
THROUGH MID WEEK DUE TO THE STRONG LONG PERIOD SW SWELL ARRIVING
TODAY.
GULF OF PANAMA: GENTLE TO MODERATE S TO SW WINDS ARE FORECAST
THROUGH MID WEEK. SEAS OF 4-6 FT IN LONG PERIOD SW SWELL TODAY
WILL BUILD TO 5-7 FT TONIGHT THROUGH LATE TUE AS THE SW SWELL
REACHES THE COASTS OF PANAMA AND COLOMBIA.
ELSEWHERE, GENTLE TO MODERATE SW WINDS ARE EXPECTED TO THE SOUTH
OF THE MONSOON TROUGH WITH LIGHT TO GENTLE VARIABLE WINDS NORTH
OF TROUGH AS A WEAK PRESSURE PATTERN REMAINS OVER CENTRAL
AMERICA. SEAS OF 6-9 FT IN BUILDING LONG PERIOD SW SWELL WEST OF
THE GALAPAGOS ISLANDS ARE EXPECTED TO PROPAGATE NORTHWARD
TONIGHT THROUGH LATE TUE, BUILDING TO 8 TO 11 FT TO THE WEST AND
NORTHWEST OF THE GALAPAGOS ISLANDS TONIGHT.
ADDITIONALLY, DEEP LAYERED UPPER TROUGHING EXTENDING FROM THE
GULF OF MEXICO SOUTHWARD INTO THE WESTERN CARIBBEAN WILL DRIFT
WESTWARD AND DIG FARTHER SOUTHWARD INTO CENTRAL AMERICA WED AND
THU. THIS MAY INDUCE A BROAD LOW LEVEL CYCLONIC CIRCULATION
ACROSS PORTIONS OF THE YUCATAN AND CENTRAL AMERICA, LEADING TO
PERIODS OF HEAVY RAINFALL ACROSS THE REGION. THIS HEAVY RAIN
COULD EXTEND INTO THE PACIFIC COASTAL ZONES OF THE REGION FROM
WED THROUGH FRI.
REMAINDER OF THE AREA...
A RIDGE EXTENDS FROM 1026 HIGH PRESSURE CENTERED NEAR 31N141W
THROUGH THE REVILLAGIGEDO ISLANDS. AFTERNOON SCATTEROMETER DATA
INDICATED FRESH TO STRONG TRADE WINDS FROM 10N TO 22N TO THE
WEST OF 127W, BETWEEN THE RIDGE AND LOWER PRESSURE ALONG THE
MONSOON TROUGH AND ITCZ. ELSEWHERE THE RIDGE IS MAINTAINING
GENERALLY MODERATE TO FRESH TRADES NORTH OF THE MONSOON TROUGH
AND WEST OF 113W. CONVERGENCE OF THESE WINDS WITH LIGHT TO
MODERATE SW FLOW ON THE SOUTH SIDE OF THE MONSOON TROUGH IS
SUPPORTING CLUSTERS OF SHOWERS AND THUNDERSTORMS NEAR THE
MONSOON TROUGH WEST OF 110W. VARIOUS OVERNIGHT ALTIMETER DATA
ALSO INDICATED 5 TO 7 FT SEAS NORTH OF 20N WHERE WINDS ARE
LIGHTER, AND 7 TO 9 FT SEAS IN THE TRADE WIND BELT BETWEEN THE
MONSOON TROUGH AS FAR NORTH AS 17N AS SW SWELL IS MOVING INTO
THE REGIONAL WATERS.
THE RIDGE WILL BUILD NORTH OF 20N INTO MID WEEK, ENHANCING TRADE
WINDS ESPECIALLY NEAR A DEVELOPING WEAK LOW PRESSURE ALONG THE
MONSOON TROUGH NEAR 11N126W. VARIOUS RECENT ALTIMETER SATELLITE
PASSES CONTINUE TO SHOW SW SWELL IN EXCESS OF 10 FT SOUTH OF
10N, PROPAGATING NORTHWARD. THIS WILL OVERTAKE THE REGION EAST
OF 130W THROUGH TUE. LOOKING AHEAD, THE UPPER PATTERN WILL
AMPLIFY BY MID WEEK, SUPPORTING DEVELOPMENT OF ANOTHER WEAK LOW
ALONG THE MONSOON TROUGH WEST OF 125W.
STRIPLING
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page