000 AXPZ20 KNHC 201529 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN MAR 20 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... A RATHER STRONG COLD FRONT FOR THIS TIME OF THE YEAR IS MOVING ACROSS THE GULF OF MEXICO AND IS CURRENTLY OVER THE ISTHMUS OF TEHUANTEPEC. STRONG HIGH PRES SURGING S ALONG THE SIERRA MADRE ORIENTAL MOUNTAINS OF EASTERN MEXICO IN THE WAKE OF THE FRONT WILL BRING A GAP WIND EVENT ACROSS THE GULF OF TEHUANTEPEC TODAY. WINDS ARE EXPECTED TO RAPIDLY REACH MINIMAL GALE FORCE EARLY THIS AFTERNOON...THEN WILL FURTHER INCREASE TO 40-45 KT TONIGHT. THESE MAXIMUM WINDS ARE EXPECTED TO PERSIST THROUGH TUE MORNING. SEAS WILL BUILD RAPIDLY IN RESPONSE TO THE WIND FIELD WITH SEAS GREATER THAN 15 FT EXPECTED TONIGHT THROUGH TUE MORNING...PEAKING AROUND 20 FT NEAR 14N96W ON MON AFTERNOON. A LARGE SWATH OF N-NE 20-30 KT WINDS WILL SPREAD S AND SW FROM THE GULF TO BEYOND 100W. SEAS WITHIN THIS AREA WILL BE ROUGHLY IN THE RANGE OF 9-14 FT. WINDS ARE EXPECTED TO DIMINISH BELOW GALE FORCE BY LATE TUE. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFEP2/ FZPN03 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ AXIS EXTENDS FROM 06N100W TO 07N110W TO 04N125W TO 05N135W TO 04N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED FROM 05N TO 07N BETWEEN 107W AND 111W. SCATTERED MODERATE CONVECTION IS FROM 03N TO 05N BETWEEN 113W AND 116W. ...DISCUSSION... A 1020 MB HIGH PRES IS CENTERED NEAR 27N128W WITH A RIDGE AXIS EXTENDING SE TO NEAR THE REVILLAGIGEDO ISLANDS. THE OVERALL PRESSURE GRADIENT BETWEEN THE RIDGE AND LOWER PRES TO THE S WITHIN THE ITCZ REGION IS SUPPORTING MODERATE TO LOCALLY FRESH NE TRADES S OF 18N W OF 130W AND S OF 15N BETWEEN 120W AND 130W. BASED ON A COUPLE OF ALTIMETER PASSES...SEAS WITHIN THE AREA OF THE TRADES ARE IN THE 8 TO 11 FT RANGE IN MIXED NE AND NW SWELL. SIMILAR WIND SPEEDS ARE ALSO NOTED JUST OFF THE BAJA CALIFORNIA PENINSULA DUE TO THE PRES GRADIENT BETWEEN THE RIDGE AND A TROUGH ALONG THE NW COAST OF MAINLAND MEXICO. SEAS ACROSS THE PACIFIC WATERS OF BAJA ARE GENERALLY RANGED 5-8 FT IN NW SWELL. A COLD FRONT IS OVER THE NW CORNER OF THE FORECAST REGION AND EXTEND FROM 30N131W TO 23N140W. GENTLE TO MODERATE WINDS ARE ON EITHER SIDE OF THE FRONT. ADDITIONAL PULSES OF LONG PERIOD NW SWELL ARE EXPECTED IN THE WAKE OF THE FRONT WITH SEAS ONCE AGAIN BUILDING UP TO 16-17 FT ACROSS THE NW WATERS BY LATE TODAY. THIS SWELL EVENT WILL CONTINUE TO PROPAGATE SE WITH THE LEADING EDGE OF THE SWELL TRAIN REACHING MOST OF THE FORECAST WATERS W OF 120W BY TUE MORNING. A GULF OF PAPAGAYO GAP WIND EVENT WITH 20-25 KT NE WINDS IS SUGGESTED BY MODEL GUIDANCE TO TAKE PLACE MON MORNING AS HIGH PRES BUILDS ACROSS THE WESTERN CARIBBEAN AND NORTHERN CENTRAL AMERICA. THE AERIAL EXTENT OF THE FRESH TO STRONG WINDS IN THE 20-30 KT RANGE IS FORECAST TO INCREASE FROM 08.5 TO 12N E OF 91W- 92W BY EARLY TUE MORNING WITH SEAS BUILDING UP TO 10 FT IN AND DOWNSTREAM OF THE GULF TO NEAR 09N81W. NE SWELL GENERATED BY THE COMBINED GAP WIND EVENTS IN TEHUANTEPEC AND PAPAGAYO WILL MERGE DOWNSTREAM TO PRODUCE A LARGE AREA OF SEAS GREATER THAN 8 FT FROM 05N TO 13N BETWEEN 93W AND 105W...AND FROM 06N TO 11N BETWEEN 105W AND 110W. $$ GR