000
AXPZ20 KNHC 031603
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN APR 03 2016

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
1500 UTC.               

...SPECIAL FEATURES...

...GULF OF TEHUANTEPEC GALE WARNING...
A 1024 MB HIGH CENTER LOCATED JUST W OF TAMPICO EXTENDS A RIDGE 
SSE TO OVER SOUTHEASTERN MEXICO. THE ASSOCIATED TIGHT PACKING OF 
ISOBARS OVER THAT PART OF MEXICO AS NOTED ON THE 12 UTC SURFACE 
ANALYSIS SUGGESTS THAT STRONG TO GALE FORCE N-NE WINDS CONTINUE
FUNNELING S THROUGH THE CHIVELA PASS...AND OUT OVER THE GULF OF
TEHUANTEPEC. THE LEADING ARC CLOUD OF THESE WINDS IS SEEN ON
SATELLITE IMAGERY PROPAGATING SW WELL S OF THE GULF TO NEAR 09N.
WIND SPEEDS ARE 30-40 KT WITH SEAS OF 9-15 FT...AND ARE WITHIN
45 NM EITHER SIDE OF A LINE FROM 16N95W TO 15N95W TO 14N95.5W TO
13N96W. N-NE 25-30 KT ARE ELSEWHERE WITHIN 75 NM EITHER SIDE OF A
LINE FROM 16N95W TO 14.5N95W TO 11.5N97W WITH SEAS OF 8-12 FT.
THE 30-40 KT WINDS ARE EXPECTED TO PERSIST TONIGHT WITH SEAS IN
THE 10-15 FT. NE SWELL WILL SPREAD DOWNSTREAM FROM THE GULF
REACHING TO NEAR 09N BETWEEN 93W-100W BY LATE TONIGHT WHERE IT
BEGINS TO MIX WITH THE LEADING EDGE OF A LONG PERIOD NW SWELL
COMPONENT. SEAS WITHIN THIS AREA ARE FORECAST TO BE 8-10 FT.
WITH THE 1024 MB HIGH CENTER WEAKENING ON MON AFTERNOON...THE
TIGHT PRES GRADIENT OVER SOUTHEASTERN MEXICO WILL SLACKEN
ALLOWING FOR THE GALE FORCE WINDS TO DROP TO JUST UNDER 35 KT AT
THAT TIME. THE DOWNSTREAM NE SWELL WILL REACH TO NEAR 08N
BETWEEN 93W-102W AS IT CONTINUES TO MIX WITH THE NW SWELL TO
PRODUCE SEAS OF 8-9 FT THERE. 

ON MON NIGHT...A SLIGHT STRENGTHENING OF THE PRES GRADIENT IS
FORECAST TO BRING ANOTHER ROUND OF GALE FORCE WINDS THROUGH A
NARROW SWATH ACROSS THE GULF WITH SEAS AROUND THE RANGE OF 9-12
FT. A MIX OF NE AND NW SWELL WELL DOWNSTREAM FROM THE GULF WILL
KEEP SEAS OF 8-9 FT FROM 07N-13N BETWEEN 96W-107W. THE GALE
FORCE WINDS THEN DIMINISH TO JUST BELOW GALE FORCE ON TUE
AFTERNOON.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
      
THE ITCZ AXIS EXTENDS FROM 02N115W TO 01N127W TO 02N136W TO
02N140W. NO SIGNIFICANT CONVECTION IS OBSERVED.

...DISCUSSION... 

HIGH PRES OF 1022 MB CENTERED NEAR 28N127W EXTENDS A RIDGE SE TO
NEAR 15N115W. THE PRES GRADIENT BETWEEN THIS AREA OF HIGH PRES
AND LOWER PRES IN THE VICINITY OF THE ITCZ IS MAINTAINING FRESH
NE TRADES OVER THE WATERS FROM 05N TO 17N W OF 120W. A WEAK
SURFACE TROUGH LIES FROM 12N107W TO 02N113W. LOW-LEVEL
CONVERGENCE ASSOCIATED WITH THE TROUGH IS GENERATING SCATTERED
SHOWERS AND ISOLATED TSTMS. STRONGER HIGH FORECAST BY THE GLOBAL
MODELS IS EXPECTED TO BUILD OVER MUCH OF THE CENTRAL AND WESTERN
WATERS LATE MON INTO TUE. THE RESULTANT TIGHT PRES GRADIENT OVER
THE FAR WESTERN WATERS WILL ALLOW FOR STRONG NE TRADES THERE
WITH SEAS OF 8-9 FT. 

NW SWELL IS PROPAGATING THROUGH THE AREA AND MERGING WITH
SHORTER PERIOD NE SWELL WITH SEAS GREATER THAN 8 FT COVERING
MUCH OF THE FORECAST WATERS N OF 06N W OF 120W. THE NW SWELL
WILL SUBSIDE OVER THE FORECAST WATERS OVER THE NEXT COUPLE OF
DAYS. BY EARLY MON COVERAGE OF SEAS GREATER THAN 8 FT WILL
SHRINK TO AN AREA FROM 05N TO 10N W OF ABOUT 120W.

GAP WINDS...HIGH PRES FORECAST TO BUILD OVER THE GULF OF MEXICO
OVER THE NEXT COUPLE OF DAYS WILL ALLOW FOR NE-E 20-25 KT WINDS
OVER THE GULF OF PAPAGAYO BY EARLY MON. WINDS OVER THE GULF OF
PAPAGAYO WILL THEN PULSE TO NEAR 25 KT EACH NIGHT...AND DIMINISH
TO 15-20 KT DURING THE DAYTIME HOURS THROUGH MIDWEEK. 

$$
MCELROY