000 AXPZ20 KNHC 021005 RRA TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT APR 02 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...THE NEXT GALE FORCE WIND EVENT IS FORECAST TO DEVELOP LATE THIS AFTERNOON. STRONG HIGH PRES BEHIND A COLD FRONT MOVING ACROSS THE WESTERN GULF OF MEXICO WILL SURGE SWD ALONG THE SIERRA MADRE ORIENTAL MOUNTAINS OF MEXICO. THIS WILL BRING A TIGHT PRES GRADIENT OVER SOUTHEASTERN MEXICO THAT WILL ALLOW FOR GALE FORCE NLY WINDS TO FUNNEL THROUGH THE NARROW CHIVELA PASS...AND OUT INTO THE GULF OF TEHUANTEPEC WHERE VERY WARM (28.5-29 DEG CELSIUS) SEA SURFACE TEMPERATURES ARE PRESENT. MINIMAL GALE FORCE WINDS WILL GRADUALLY INCREASE TO NEAR OR TO 40 KT BY LATE TONIGHT AND INTO SUN MORNING WITH THE AIDED BY NOCTURNAL DRAINAGE. THESE WINDS WILL THEN DIMINISH SLIGHTLY ON SUN AFTERNOON...THEN DIMINISH BRIEFLY TO JUST BELOW GALE FORCE EARLY MON AFTERNOON. THE GFS AND UKEMT MODEL SOLUTIONS SUGGEST THAT WINDS THEN PULSE BACK TO GALE FORCE MON NIGHT. RESULTANT SEAS ARE FORECAST TO BUILD TO 12 FT TONIGHT..TO AROUND 14 FT LATE TONIGHT...AND 15 OR 16 FT ON SUN. SEAS SLOWLY SUBSIDE SUN ...THEN INCREASE SOME MON NIGHT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... ITCZ AXIS EXTENDS FROM 05N94W TO 06N106W TO 04N112W TO 05N119W AND ENDS BRIEFLY AT 05N125W..JUST E OF A TROUGH THAT EXTENDS FROM 10N124W TO 02N128W. THE AXIS RESUMES NEAR 05N130W TO 02N140W. SCATTERED STRONG CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 131W-134W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 112W-117W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF AXIS BETWEEN 117W-120W. ...DISCUSSION... WATER VAPOR IMAGERY SHOWS MAINLY MODERATE TO STRONG SUBSIDENCE WITH DRY CONDITIONS OVER JUST ABOUT THE ENTIRE DISCUSSION AREA EXCEPT FOR THE FAR NW PORTION AND FAR S CENTRAL PORTION IN THE TROPICAL ZONE BETWEEN 102W-122W...WHICH IS IN BETWEEN A LARGE UPPER ANTICYCLONE CENTERED NEAR 09N96W AND A BROAD UPPER TROUGH THAT COVERS THE CENTRAL SECTION OF THE AREA. A RATHER STRONG SHORTWAVE TROUGH ALONG A POSITION FROM 01N117W TO 08N125W IS HELPING TO ENHANCE ITCZ-RELATED CONVECTION BETWEEN 117W-120W. AT THE SURFACE...A 1025 MB HIGH IS CENTERED N OF THE AREA AT 34N127W WITH ONE RIDGE AXIS EXTENDING SW TO 24N133W...AND ANOTHER SE TO 21N118W TO NEAR 15N109W. HIGH PRES COVERS THE AREA N OF 13N W OF 109W. THE PRES GRADIENT BETWEEN THE HIGH AND LOWER PRES IN THE VICINITY OF THE ITCZ IS RESULTING IN MODERATE TO FRESH TRADES ACROSS AN AREA GENERALLY FROM ABOUT 05N-20N W OF 115W WITH SEAS IN THE 8-10 FT RANGE DUE TO A NW SWELL THAT WILL MOVE THROUGH THE WESTERN PORTION INTO EARLY SUN. THE HIGH IS FORECAST TO WEAKEN SOME AS IT MOVE SE TO NEAR 30N126W BY LATE TONIGHT. ANOTHER HIGH CENTER OF 1025 MB IS 31N139W...AND IS FORECAST TO WEAKEN AS IT REACHES NEAR 30N135W BY LATE TONIGHT. A WEAKENING FRONTAL TROUGH EXTENDS FROM A WEAK 1021 MB LOW AT 32N132W SW TO 28N133W TO 25N140W. THIS TROUGH WILL CONTINUE TO SLOWLY MOVE SLOWLY AND DISSIPATE SUN. A LARGE NW SWELL TRAIN AFFECTING THE WESTERN AND PORTION AND MOST OF THE CENTRAL PORTIONS AS WELL IS PRODUCING SEAS IN THE 9-10 FT RANGE. THE SWELL IS FORECAST TO CONTINUE TO PROPAGATE SSE ACROSS MUCH OF THE WESTERN WATERS THROUGH LATE SUN WHILE SHRINKING IN COVERAGE. BY LATE SUN NIGHT...THE ASSOCIATED SEAS ARE FORECAST TO BE 8-9 FT FROM 04N-14N W OF 136W AND FROM 06N-10N BETWEEN 110W-136W. ON MON...SEAS OF 8 FT WILL BE CONFINED FROM 06N-14N W OF 129W. SHORTWAVE IR SATELLITE IMAGERY SHOWS A BROAD AND WEAK SURFACE TROUGH IN THE DEEP TROPICS ROUGHLY ALONG A POSITION FROM NEAR 10N124W TO 02N128W MOVING STEADILY WESTWARD. THE PRES GRADIENT BETWEEN THE AFOREMENTIONED RIDGE TO THE N AND THE TROUGH HAS INITIATED STRONG NE TRADES FROM 08N-10N W OF TROUGH TO 135W WITH SEAS OF 9-10 FT. SCATTERED MODERATE CONVECTION IS OBSERVED WITHIN 120 NM E OF THE TROUGH FROM 03N-05N. BY LATE TONIGHT..THE TROUGH IS FORECAST TO DISSIPATE FROM NEAR 10N129W TO 02N132W. THE GRADIENT WILL RELAX ALLOWING FOR THE STRONG TRADES TO DIMINISH TO FRESH INTENSITY. SEAS WITHIN THE AREA OF THESE TRADES WILL REMAIN HIGH...IN THE 9-10 FT RANGE...DUE TO THE NW SWELL MENTIONED ABOVE. $$ AGUIRRE