710
AXPZ20 KNHC 151606
TWDEP
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE MAY 15 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1415 UTC.
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH
THE MONSOON TROUGH AXIS EXTENDS FROM 07N77W TO 08.5N89W TO
06.5N105W TO LOW PRES NEAR 11.5N116W 1008 MB TO 05N123W, WHERE
LATEST SCATTEROMETER DATA INDICATED THAT IT TRANSITIONS TO THE
ITCZ TO 01.5N135W. SCATTERED MODERATE TO STRONG CONVECTION IS
LOCATED WITHIN 180 NM S AND 210 NM N OF THE TROUGH BETWEEN 86W
AND 122W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS
WITHIN 90 NM OF THE CENTRAL AMERICAN COAST BETWEEN 85W AND 93W.
..DISCUSSION
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
A NW TO SE ORIENTED HIGH PRESSURE RIDGE PREVAILS ACROSS THE
OFFSHORE WATERS WEST OF BAJA CALIFORNIA, PRODUCING FRESH NW
WINDS OVER THOSE WATERS. THESE WINDS WILL REMAIN FRESH TODAY,
THEN INCREASE TO FRESH TO LOCALLY STRONG WED AFTERNOON THROUGH
FRIDAY AS THE RIDGE STRENGTHENS SLIGHTLY. ALTIMETER DATA FROM
LAST NIGHT INDICATED THAT SEAS WERE JUST BELOW 8 FT, IN THE 5-7
FT RANGE. SEAS WILL CHANGE LITTLE THROUGH TONIGHT BEFORE
BUILDING SLIGHTLY ON WED TO 6-8 FT.
GULF OF CALIFORNIA: S TO SW WINDS OF AROUND 15 KT OVER A SMALL
SECTION OF THE NORTHERN GULF OF CALIFORNIA WILL BECOME LIGHT AND
VARIABLE TODAY. GENTLE TO MODERATE NW WINDS WILL CONTINUE ACROSS
THE REMAINDER OF THE GULF THROUGH WED, EXCEPT FOR FRESH NW WINDS
ALONG THE COAST OF MEXICO FROM 24N TO 26N BEGINNING LATE THIS
AFTERNOON THROUGH WED EVENING.
GULF OF TEHUANTEPEC: S TO SW WINDS ARE LIGHT TO GENTLE ACROSS
THE GULF THIS MORNING. WINDS WILL BRIEFLY BECOME MODERATE FRESH
N TO NE TONIGHT INTO WED MORNING, THEN BECOME GENTLE S TO SW
WINDS ON WED AFTERNOON. THIS CYCLE OF CHANGING WINDS WILL REPEAT
THROUGH THU AS A WEAK PRESSURE PATTERN REMAINS OVER 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
MOST OF THE FORECAST PERIOD AS A WEAK PRESSURE REMAINS ACROSS
CENTRAL AMERICA. SEAS OF 5-6 FT PREVAIL THIS MORNING AND WILL
DIMINISH SLIGHTLY TODAY TO 4-5 FT IN LONG PERIOD SW SWELL. A
STRONG PULSE OF CROSS EQUATORIAL SW SWELL WILL MOVE INTO THE
REGIONAL WATERS BEGINNING WED, AND BUILD SEAS TO 5-7 FT THU
THROUGH SAT.
GULF OF PANAMA: GENTLE TO MODERATE S TO SW WINDS ARE FORECAST
DURING THE NEXT SEVERAL DAYS, WITH SEAS OF 4-6 FT IN LONG PERIOD
SOUTHERLY SWELL, BUILDING TO 5-7 FT WED NIGHT THROUGH SAT AS
LONG PERIOD 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 ITS AXIS ROUGHLY ALONG 09N/10N, WITH
LIGHT TO GENTLE VARIABLE WINDS NORTH OF TROUGH AS A WEAK PRESSURE
PATTERN REMAINS OVER CENTRAL AMERICA. SEAS ARE FORECAST TO BUILD
TO 6-7 FT IN LONG PERIOD SW SWELL BETWEEN ECUADOR AND THE
GALAPAGOS ISLANDS BEGINNING ON WED AND CONTINUING THROUGH FRI,
THEN BUILD SLIGHTLY HIGHER TO 6-8 FT SAT.
REMAINDER OF THE AREA...
A RIDGE EXTENDS FROM THE NW WATERS SOUTHEASTWARD TO NEAR THE
REVILLAGIGEDO ISLANDS. THE PRESSURE GRADIENT BETWEEN THE RIDGE
AND THE MONSOON TROUGH AND ITCZ TO THE SOUTH IS PRESENTLY WEAK,
AND YIELDING MODERATE NE-E TRADES BETWEEN ABOUT 10N AND 22N TO
THE WEST OF 112W. SEAS ACROSS THIS AREA OF TRADES ARE 6-8 FT,
AND SHOULD CHANGE LITTLE THROUGH THU. THE RIDGE WILL SHIFT
SLIGHTLY SOUTHEASTWARD THROUGH WED, WITH THE RESULTANT PRESSURE
GRADIENT FORECAST TO INDUCE A SLIGHT INCREASE OF TRADES ACROSS
THE TROPICS. STRONGER HIGH PRESSURE IS THEN FORECAST TO BUILD
SOUTHEASTWARD OVER THE NORTHERN PORTION OF THE DISCUSSION AREA,
WITH AND EVEN TIGHTER GRADIENT EXPECTED TO LEAD TO TRADES
INCREASING TO FRESH TO STRONG SPEEDS. SEAS ARE EXPECTED TO
INCREASE TO 7-9 FT THU INTO FRI.
THE LOW 1008 MB LOW PRESSURE EMBEDDED WITHIN THE MONSOON TROUGH
AS DESCRIBED ABOVE CONTINUES TO SHIFT WESTWARD AT 10-15 KT
ACROSS THE TROPICS THIS MORNING. GLOBAL MODELS DEPICT THE LOW
CONTINUING TO MOVE IN A GENERAL WEST TO SOUTHWEST MOTION THROUGH
FRI WHILE IT WEAKENS. FRESH TO STRONG WINDS WILL REMAIN ACROSS
THE NW QUADRANT OF THE LOW AS IT SHIFTS WESTWARD, WHERE SEAS OF
7-8 FT WILL ACCOMPANY IT.
DECAYING NW SWELL IS PROPAGATING THROUGH THE WATERS NORTH OF 21N
BETWEEN BAJA CALIFORNIA AND 117W, WHERE SEAS PEAKED AT 7-8 FT
OVERNIGHT. THESE SEAS WILL SUBSIDE TO 5-7 LATE TONIGHT AND
CHANGE LITTLE THROUGH THU.
STRIPLING
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