000 AXPZ20 KNHC 020313 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON APR 02 2012 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0315 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 05N127W TO 04N140W. NO SIGNIFICANT CONVECTION IS NOTED NEAR THE ITCZ AXIS. A SURFACE TROUGH EXTENDS FROM 10N86W TO 06N91W TO 05N100W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 270 NM S OF THE TROUGH BETWEEN 86W-89W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE TROUGH BETWEEN 89W-97W. ...DISCUSSION... A FAIRLY AMPLIFIED AND WINTER TYPE PROGRESSIVE UPPER PATTERN CONTINUES OVER THE PACIFIC N OF THE DISCUSSION AREA...AND SWD INTO THE FAR NRN SECTOR OF THE AREA. THE LONG WAVE TROUGH HAS SHIFTED TO INLAND THE WRN U.S. AS A LARGE DEEP LAYER RIDGE ADVANCES EWD IN ITS WAKE. WATER VAPOR IMAGERY SHOWS MODERATE SUBSIDENCE BEHIND THE TROUGH E OF 126W. UPPER LEVEL CENTRAL PACIFIC MOISTURE IS RIDING NEWD ACROSS THE CREST OF THE RIDGE...AND SPREADING SEWD INTO THE FAR NRN BOUNDARY OF THE DISCUSSION AREA W OF 123W. THE MOISTURE IS MATERIALIZING INTO SCATTERED TO BROKEN HIGH LEVEL CLOUDS. TO THE SE OF THE RIDGE AND TROUGH...AN UPPER LEVEL SHORT WAVE TROUGH SWINGING EWD ACROSS SRN BAJA CALIFORNIA AND INTO NRN MEXICO BARELY SUSTAINS A RAPIDLY DISSIPATING COLD FRONT THAT STRETCHES FROM FAR NW MEXICO SW ACROSS SRN BAJA CALIFORNIA PENINSULA AND TO 20N128W. BROKEN PATCHES OF STRATOCUMULUS CLOUDS MARKING VERY STABLE AND DRY CONDITIONS BEHIND THE FRONT ARE NW OF THE FRONT W OF 128W...AND ALSO WITHIN 180 NM N OF THE FRONT E OF 128W. A 1032 MB SURFACE HIGH PRES CENTER IS ANALYZED AT 34N130W. THE FRONT WILL DISSIPATE TONIGHT INTO MON...WHILE THE HIGH CENTER SHIFTS EWD. THE ASSOCIATED RIDGE WILL DOMINATE THE AREA N OF ABOUT 15N...BUT WILL WEAKEN THROUGH MON. AN ASCAT PASS FROM NEAR 19 UTC YESTERDAY REVEALED FRESH TO STRONG N TO NE SURFACE WINDS BEHIND THE FRONT INCLUDING THE WATERS ALONG THE BAJA CALIFORNIA PENINSULA W TO A LINE FROM 32N126W TO 21N140W. A BROAD AREA OF FRESH TO STRONG TRADE WINDS IS ALSO NOTED BY THE SAME ASCAT PASS TO EXIST ALONG THE SRN PERIPHERY OF THE RIDGE W OF A LINE FROM 06N131W TO 14N126W TO 21N118W. A FEW SHIP OBSERVATIONS FROM TODAY ALONG WITH EARLIER ALTIMETER DATA NOTED COMBINED SEA HEIGHTS IN THE RANGE OF 13 TO 20 FT OVER THE NE AND N/CENTRAL PORTIONS N OF ABOUT 20N DUE TO AN EXTENSIVE BATCH OF LONG PERIOD NW SWELLS PROPAGATING SE INTO THE AREA BEHIND THE FRONT. COMBINED SEAS TO 9 FT PERSIST S OF 20N IN MIXED SW AND NE SWELL...BUT ARE EXPECTED TO BUILD UP TO 12 FT MON AS THE NW SWELL PRESSES SWD. OVER THE SW PORTION OF THE AREA...A SHARP DEEP LAYER TROUGH CURRENTLY NW OF HAWAII AND WEST OF DEEP LAYER RIDGE MENTIONED ABOVE WILL SHIFT EWD SHUNTING THE RIDGE TOWARDS THE U.S. WEST COAST. AN ASSOCIATED COLD FRONT WILL PUSH THROUGH THE N CENTRAL PACIFIC...REACHING THE NW CORNER OF THE DISCUSSION AREA NEAR 30N140W BY MON AFTERNOON ERODING THE SURFACE HIGH PRES N OF THE AREA. THIS WILL ALLOW THE TRADE WINDS TO THE SOUTH AND THE MORE NORTHERLY FLOW CLOSER TO THE BAJA COAST TO DIMINISH. THE COLD FRONT WILL WEAKEN AS IT MOVES INTO THE NW PART OF THE AREA FROM 32N132W TO 29N140W BY TUE AFTERNOON OR EARLY EVENING. NW SWELLS WILL ALLOW FOR SEAS IN THE RANGE OF 8 TO 11 FT TO BE WITHIN THE AREA BOUNDED FROM 05N TO 20N W OF 105W BY TUE AS YET ANOTHER LARGE BATCH OF NW SWELLS POISES TO SPREAD ACROSS THE FAR NW WATERS BEHIND THE FRONT. WAVEWATCH GUIDANCE SUGGEST THAT THIS BATCH OF SWELLS WILL BUILD SEAS INTO THE RANGE OF 8 TO 11 FT. FURTHER EAST...CLUSTERS OF SHOWERS AND THUNDERSTORMS PERSIST ALONG A STATIONARY TROUGH THAT EXTENDS FROM NEAR NRN COSTA RICA TO 06N91W...AND THEN SW T0 05N100W. THE TROUGH MAY ACTUALLY BE AN INCIPIENT WEAK MONSOON TROUGH...BUT SCATTEROMETER DATA CONTINUE TO SHOW ONLY VERY LIGHT AND OFTEN VARIABLE FLOW S OF THE AXIS. CONVECTIVE GROWTH CONTINUES TO BE AIDED BY A BROAD NEGATIVELY TILTED UPPER TROUGH EXTENDING FROM 09N90W TO 04N87W AND TO 02N80W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 270 NM S OF THE TROUGH BETWEEN 86W-89W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE TROUGH BETWEEN 89W-97W. LARGE CLUSTERS OF SCATTERED STRONG CONVECTION ARE OCCURRING FROM 04N TO 08N BETWEEN 83W AND 86W MAINLY DUE TO CONVERGENCE OF MODERATE NORTHERLY FLOW ACROSS THE PANAMANIAN ISTHMUS AND LIGHT TO MODERATE SW FLOW TO THE SOUTH. ALSO...LONG TERM SATELLITE IMAGERY INDICATES THAT A POSSIBLE WEAK LOW LEVEL PERTURBATION MOVED HAS MOVED INTO THAT PORTION OF THE ERN PACIFIC FURTHER ENHANCING THE DEEP CONVECTION CLUSTERS THERE. GULF OF CALIFORNIA...A DISSIPATING COLD FRONT IS PUSHING SE THROUGH THE SRN WATERS OF THE GULF. A STRONG PRES GRADIENT BETWEEN HIGH PRES BUILDING EWD IN ITS WAKE AND LOW PRES OVER NRN MEXICO HAS LEAD TO NW WINDS OF 20 KT OVER THE FAR NRN GULF. THESE WINDS WILL INCREASE TO 20 TO 25 KT BY EARLY MON AS THE HIGH PRES CENTER N OF THE AREA AND THE ASSOCIATED RIDGE SHIFT EWD. THE HIGH THEN WEAKENS LATER MON INTO TUE ALLOWING FOR THE PRES GRADIENT TO SLACKEN...AND THUS DIMINISHING THE WINDS TO LESS THAN 20 KT BY EARLY TUE. $$ AGUIRRE