000 AXPZ20 KNHC 100236 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI APR 10 2015 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE PRIMARY ITCZ AXIS WAS ANALYZED FROM 04N90W TO 05N96W TO 03N108W TO 05N135W. ISOLATED MODERATE CONVECTION WAS WITHIN 150 NM EITHER SIDE OF THE PRIMARILY AXIS E OF 130W WITH SCATTERED MODERATE CONVECTION BETWEEN 150 NM AND 270 NM N OF THE PRIMARY AXIS BETWEEN 124W-130W. A TROUGH WAS ANALYZED ON THE W END OF THE ITCZ FROM 12N136W TO 05N139W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN 390 NM E AND 300 NM W OF THE TROUGH FROM 06N-12N. THE SECONDARY ITCZ AXIS WAS ANALYZED FROM 02S91W TO 03S98W TO 02S110W TO 02S120W. SCATTERED MODERATE CONVECTION WAS WITHIN 60 NM N AND 150 NM S OF THE SECONDARY AXIS BETWEEN 95W-103W. ...DISCUSSION... A SURFACE RIDGE AXIS EXTENDS FROM A 1018 MB HIGH CENTER NEAR 28N122W THROUGH 18N112W TO 12N96W. RECENT ASCAT DATA SHOW AN AREA OF MODERATE TO FRESH TRADE WINDS SW OF THE RIDGE AXIS. THE SUBTROPICAL HIGH IS EXPECTED TO WEAKEN FURTHER AND SHIFT SE FRI BEFORE DISSIPATING SAT AS A PROGRESSIVE COLD FRONT OVER THE NW PART OF THE AREA ENCROACHES UPON IT. THIS SHOULD KEEP TRADE WINDS BELOW THE ADVISORY CRITERIA OF 20-25 KT THROUGH THE END OF THE FORECAST PERIOD SAT AFTERNOON. HOWEVER...WINDS SHOULD REMAIN A SOLID FRESH BREEZE OVER W WATERS THROUGH TOMORROW AS A SURFACE TROUGH ENHANCES THE PRESSURE GRADIENT. THIS TROUGH CURRENTLY LIES FROM 12N136W TO 05N139W AND IS FORECAST TO SHIFT W OF THE AREA FRI. THE FRESH BREEZE HERE SHOULD HELP MAINTAIN SEAS TO 9 FT OVER WATERS W OF 130W THROUGH FRI WHERE NW...NE AND SW SWELL ARE COMBINING. SEAS ARE EXPECTED TO SUBSIDE BELOW 8 FT BY THE END OF THE FORECAST PERIOD SAT EVENING. THE COLD FRONT ENCROACHING ON THE SUBTROPICAL HIGH STRETCHES FROM 32N131W TO 26N140W. SHOWERS LIE PRIMARILY WITHIN 150 NM SE OF THE FRONT. THE 1924 UTC ASCAT-B PASS SHOWED SW WINDS TO ADVISORY CRITERIA LIE WITHIN 120 NM AHEAD OF THE FRONT N OF 29N. SEAS ABOVE 8 FT WILL BUILD S OF 30N BEHIND THE FRONT OVERNIGHT TONIGHT. ALOFT...THE TROUGH SUPPORTING THIS COLD FRONT IS CUTTING OFF FROM THE NORTHERN STREAM. A DEEP LAYERED LOW WILL MOVE INTO WATERS N OF 30N BETWEEN 130W-135W TONIGHT INTO FRI. THUNDERSTORMS WILL ACCOMPANY THE LOW. WINDS W OF THE LOW WILL INCREASE TO A STRONG BREEZE AS SEAS BUILD AS HIGH AS 15 FT. THE SYSTEM WILL BREAK DOWN AT THE SURFACE...WITH THE WINDS DIMINISHING AND THE FRONT AND LOW DISSIPATING...BY SAT. SPLIT FLOW OVER THE CENTRAL PACIFIC HAS DIRECTED A 100 KT JET ACROSS THE AREA FROM 18N140W THROUGH 23N120W TO GUAYMAS MEXICO. THIS JET IS PROPELLING WANING TROPICAL MOISTURE ALOFT ACROSS THE FORECAST AREA. A BAND OF CIRRUS LIES WITHIN 510 NM SE OF THE JET AXIS FROM THE OUTFLOW ASSOCIATED WITH THE SURFACE TROUGH OVER SW WATERS NORTHEASTWARD INTO THE SOUTHERN GULF OF CALIFORNIA AND BEYOND INTO NW MEXICO. THIS UPPER JET IS EXPECTED TO BECOME MORE ZONAL AS THE TROUGH ASSOCIATED WITH THE COLD FRONT OVER NW WATERS PUSHES SE. THIS SHOULD FURTHER LIMIT THE MOISTURE ALOFT PROPELLED INTO MEXICO BY THE JET. GAP WINDS... GULF OF PAPAGAYO...THE PRESSURE GRADIENT BETWEEN RIDGING OVER THE WESTERN CARIBBEAN AND THE ITCZ TO THE S IS STRONG ENOUGH TO SUPPORT A PULSING FRESH TO STRONG NE BREEZE IN THE GULF OF PAPAGAYO WITH THE ASSISTANCE OF NOCTURNAL DRAINAGE FLOW. THE WINDS ARE BELOW ADVISORY CRITERIA AT THE MOMENT...BUT ARE EXPECTED TO RETURN IN THE EARLY MORNING HOURS FRI. WINDS WILL DROP OFF AGAIN FRI AFTERNOON AND RETURN TO ADVISORY CRITERIA SAT MORNING...EXCEPT HUG CLOSER TO THE COAST...BEFORE DROPPING OFF AGAIN SAT AFTERNOON. $$ SCHAUER