000 AXPZ20 KNHC 250905 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON APR 25 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 0900 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A TROUGH AXIS EXTENDS FROM 11N86W TO 10N96W TO 06N105W. THE ITCZ AXIS EXTENDS FROM 06N105W TO 05N120W TO 04N140W. SCATTERED MODERATE CONVECTION IS FROM 10N TO 12N E OF 88W...FROM 09N TO 11N BETWEEN 93W AND 97W...FROM 04N TO 07N BETWEEN 102W AND 112W...AND ALSO WITHIN 45 NM NW OF A LINE FROM 10N113W TO 04N123W. ...DISCUSSION... N OF 15N E OF 120W... A COLD FRONT IS MOVING ACROSS THE CALIFORNIA CHANNEL ISLANDS WHILE A TROUGH EXTENDS FROM THE CALIFORNIA/ARIZONA BORDER SOUTHWARD INTO THE NORTHERN GULF OF CALIFORNIA. RECENT SCATTEROMETER PASSES OVER THIS AREA SHOWED FRESH TO STRONG SW WINDS AHEAD OF THIS TROUGH IN THE NORTHERN GULF. WINDS ARE FORECAST TO DIMINISH LATER THIS MORNING AS THE COLD FRONT TEMPORARILY DISTURBS THE PRESSURE GRADIENT IN THE AREA. THE FRONT WILL CLIP ACROSS NW MEXICO TONIGHT WITH FRESH TO NEAR GALE FORCE WINDS JUST AHEAD OF IT...AND ALSO BEHIND IT...QUICKLY DIMINISHING TO 20 KT OR LESS BY TUE MORNING. THE NEXT COLD FRONT IS FORECAST TO MOVE THROUGH SOUTHERN CALIFORNIA AND INTO NW MEXICO WED NIGHT THROUGH THU...BRINGING SIMILAR CONDITIONS THAT ARE OCCURRING WITH THE FIRST FRONT. SURFACE HIGH PRESSURE AT 1032 MB IS LOCATED TO THE NW NEAR 36N136W WITH A RIDGE AXIS EXTENDING SE FROM THE HIGH CENTER THROUGH 28N125W TO NEAR CABO CORRIENTES MEXICO. THE PRESSURE GRADIENT BETWEEN THIS RIDGING AND LOW PRESSURE ALONG THE COLD FRONT MOVING THROUGH SOUTHERN CALIFORNIA IS SUPPORTING GALE FORCE NW WINDS OFFSHORE OF SOUTHERN CALIFORNIA. ASSOCIATED FRESH TO STRONG OUTER WINDS ARE SPREADING SOUTHWARD INTO THE WATERS N OF 28N BETWEEN 117W AND 126W. FRESH NW SWELLS OF 9-12 FT ALSO COVER THIS AREA...WHILE A SURROUNDING AREA OF LONGER PERIOD NW SWELL IS PROPAGATE SOUTHEASTWARD CURRENTLY W OF 110W. THE WINDS WILL GRADUALLY DIMINISH TO 20 KT OR LESS BY TUE NIGHT AS THE PRESSURE GRADIENT WEAKENS. ANOTHER SURGE OF FRESH TO STRONG NORTHERLY WINDS IS POSSIBLE BEHIND THE NEXT COLD FRONT MENTIONED ABOVE WHICH WILL MOVE ACROSS THE AREA WED NIGHT THROUGH THU...WITH ADDITIONAL NW SWELLS PROPAGATING ACROSS THE WATERS W OF 110W THROUGH THE END OF THE WEEK. OTHERWISE...MAINLY MODERATE TO OCCASIONALLY FRESH ONSHORE FLOW IS EXPECTED ALONG AND OFFSHORE OF CENTRAL AND SOUTHERN MEXICO THROUGH THE WEEK. S OF 15N E OF 110W... MAINLY LIGHT TO MODERATE ONSHORE WINDS ARE EXPECTED THROUGH THE WEEK...EXCEPT WINDS WILL SHIFT TO OFFSHORE WITH NOCTURNAL DRAINAGE FLOW IN THE GULF OF PAPAGAYO DURING THE OVERNIGHT HOURS. CROSS-EQUATORIAL SW SWELLS WITH LEADING WAVE PERIODS OF 19-21 SECONDS AND WAVE HEIGHTS OF 6-9 FT WILL PROPAGATE IN FROM THE SW WED NIGHT THROUGH THE END OF THE WEEK...REACHING THE SW FACING PORTIONS OF THE GALAPAGOS ISLANDS THU AFTERNOON AND EVENING...THEN REACHING THE PACIFIC COAST OF CENTRAL AMERICA ON FRI. ELSEWHERE FROM THE EQUATOR TO 32N E OF 140W... THE RIDGING MENTIONED ABOVE IS SUPPORTING MODERATE TO FRESH TRADES WITH COMBINED SEAS OF 6-9 FT ACROSS THE REMAINDER OF THE AREA. THE PARENT HIGH OF THE RIDGE WILL SHIFT SW REACHING NEAR 31N140W BY WED MORNING AS THE NEXT COLD FRONT DROPS IN FROM THE N. THAT FRONT WILL MOVE THROUGH THE NORTHERN WATERS WED NIGHT AND WILL WEAKEN THROUGH THU...WITH REINFORCING HIGH PRESSURE BUILDING IN ITS WAKE FOR THE END OF THE WEEK. $$ LEWITSKY