000 AXPZ20 KNHC 041544 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC MON APR 04 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 1430 UTC. ...SPECIAL FEATURES... ...GULF OF TEHUANTEPEC GALE WARNING...A 1024 MB HIGH CENTER IS LOCATED NEAR TAMPICO WITH A RIDGE EXTENDING S TO OVER SOUTHEASTERN MEXICO. THE ASSOCIATED TIGHT PACKING OF ISOBARS OVER SE MEXICO CONTINUES TO BRING N-NE GALE FORCE WINDS OF UP TO 40 KT TO THE GULF OF TEHUANTEPEC. LATEST SURFACE OBSERVATION AT SALINA CRUZ OAXACA SUGGESTS OFFSHORE GALES ARE CONTINUING. INTERESTINGLY...THE LEADING ARC CLOUD ASSOCIATED WITH THE SURGE REMAINS VISIBLE WELL TO THE SW OF THE GULF FROM 13N93W TO 12N96W. THE GALE FORCE WINDS ARE STILL FORECAST TO DIMINISH TO JUST BELOW GALE FORCE THIS AFTERNOON...THEN INCREASE BACK TO GALE FORCE IN THE RANGE OF 30-35 KT BY EARLY THIS EVENING AND CONTINUE INTO LATE TUE NIGHT PER WIND GUIDANCE FROM THE GFS/UKMET/NAM MODELS. SEAS WITHIN THE GALE WIND AREA ARE FORECAST TO ONLY SUBSIDE SLIGHTLY FROM THE CURRENT RANGE OF 10- 14 FT THROUGH THE NEXT 24-48 HOURS. GIVEN THE LONG DURATION OF THIS EVENT NE SWELL WILL PROPAGATE WELL SW FROM THE GULF TO NEAR 07N104W BY EARLY THIS EVENING...AND TO NEAR 07N103W BY LATE TUE NIGHT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... ITCZ AXIS EXTENDS FROM 04N89W TO 02N104W TO 04N113W WHERE IT IS BRIEFLY INTERRUPTED BY A SURFACE TROUGH THAT EXTENDS FROM 10N114W TO 03N116W. IT RESUMES AT 04N118W TO 03N128W TO 01N140W. ISOLATED MODERATE CONVECTION IS WITHIN 240 NM NORTH OF THE AXIS W OF 125W. ...DISCUSSION... STRONG HIGH PRES OF 1031 MB CENTERED N OF THE AREA AT 37N136W RIDGES SE TO 32N135W TO 25N120W AND TO 18N112W. THE PRES GRADIENT BETWEEN THIS AREA OF HIGH PRES AND LOWER PRES IN THE VICINITY OF THE ITCZ IS MAINTAINING MODERATE TO FRESH NE TRADES OVER THE WATERS FROM 05N-17N W OF 112W. A SHARPENING MID-UPPER LEVEL TROUGH OVER THE NW PORTION OF THE AREA IS FORECAST BY THE GLOBAL MODELS TO SWING EASTWARD THROUGH WED...AND HELP TO INITIATE A SURFACE TROUGH OVER THE S CENTRAL PORTION OF THE AREA. THE INTERACTION BETWEEN THIS NEW TROUGH AND STRONG HIGH PRES THAT BUILDS SE OVER MUCH OF THE AREA BY MID- WEEK WILL INCREASE THE NE TRADES TO THE STRONG CATEGORY FROM 11N- 15N BETWEEN 119W-126W WITH SEAS BUILDING TO AROUND 9 OR 10 FT. DECAYING NW SWELL IN THE FAR WESTERN PORTION WILL ALLOW SEAS THERE TO FALL TO LESS THAN 8 FT BY WED AFTERNOON. AN AREA OF 8 FT N SWELL IS FORECAST TO MOVE INTO THE AREA W OF BAJA CALIFORNIA IN 30 HOURS N OF 29N BETWEEN 123W-127W WITH WINDS 20 KT OR LESS. OTHER GAP WINDS...A TIGHTENING PRES GRADIENT BETWEEN STRONG HIGH PRES OVER SOUTHEASTERN MEXICO AND LOWER PRES OVER CENTRAL AMERICA AND NW COLOMBIA IS INITIATING NE 20-25 KT WINDS OVER THE GULF OF PAPAGAYO THIS MORNING. THESE WINDS WILL DIMINISH TO 15- 20 KT THIS AFTERNOON...THEN PULSE BACK UP TO 20-25 KT TONIGHT...AND CONTINUE TO DO SO DURING THE NEXT 48 HOURS WITH THE ACTUAL AREA OF COVERAGE EXPANDING N TO 12N BY LATE TUE NIGHT WITH SEAS OF 8-9 FT. FOR THE EXTENDED RANGE...CURRENT TEHUANTEPEC SURGE COULD REDEVELOP ON FRIDAY MORNING AND BRING GALES TO THAT REGION. $$ MCELROY