000 AXPZ20 KNHC 150301 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON APR 15 2013 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 0300 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS IS ANALYZED FROM 07N78W TO 06N87W TO 06N96W. ITCZ AXIS EXTENDS FROM 06N96W TO 05N104W TO 07N111W. IT RESUMES AT 07N115W TO 06N126W TO 05N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 82W AND 87W...AND ALSO WITHIN 60 NM N OF THE AXIS BETWEEN 132W AND 136W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM S OF AXIS BETWEEN 109W AND 112W. ...DISCUSSION... A MID/UPPER TROUGH EXTENDS FROM NEAR 03N92W NWWD TO 14N106W. ZONAL WESTERLY FLOW DOMINATES THE AREA W OF THE TROUGH. THIS FLOW BEGINS TO DIVERGE AROUND THE TROUGH E OF 115W WHICH CONTINUES TO ENHANCE THE VERTICAL MOTION FROM THE ITCZ TO 10N AND BETWEEN 106W AND 110W WHERE DEEP ATMOSPHERIC MOISTURE AND INSTABILITY IS EVIDENT. EARLIER DEEP CONVECTION OBSERVED NEAR THE TROUGH IN THE MONSOON TROUGH AREA IS RAPIDLY DISSIPATING ..BUT SHOULD REDEVELOP LATE TONIGHT AND MON. UPPER LEVEL DIFFLUENCE ASSOCIATED WITH A HIGHLY AMPLIFIED RIDGE THAT STRETCHES FROM NW COLOMBIA NWWD ACROSS CENTRAL AMERICA AND TO NEAR 13N96W IS CONTRIBUTING TO LIFT NEAR AN AREA OF POOLED LOW TO MID-LEVEL MOISTURE ALONG AND WITHIN 120 NM N OF THE MONSOON TROUGH BETWEEN 82W AND 87W WHERE CONVECTION IS OCCURRING AS DESCRIBED ABOVE UNDER ITCZ/MONSOON TROUGH. DEBRIS BLOWOFF MOISTURE...IN THE FORM OF SCATTERED TO BROKEN CIRRUS CLOUDS RELATED TO THIS CONVECTION...IS BEING CHANNELED NWD AROUND THE WRN PERIPHERY OF THE RIDGE TO ACROSS SE MEXICO...AND FROM HONDURAS SWD TO PANAMA. TO THE NE OF THE DISCUSSION AREA OVER THE WRN CONUS REGION...A MEAN UPPER TROUGH STRETCHES SWWD OVER FAR NRN BAJA CALIFORNIA SW TO NEAR 28N121W. THIS TROUGH IS BEING ENERGIZED WITH NRN STREAM ENERGY...WITH A STRONGER SHORTWAVE SYSTEM EXPECTED TO AMPLIFY THE TROUGH SIGNIFICANTLY BEGINNING ON MON THIS WILL HELP AMPLIFY THE UPPER RIDGE OVER THE FAR WRN PART OF THE AREA AS IT SHIFTS EWD. AN UPPER LOW NOTED ON SATELLITE WATER VAPOR TO BE JUST W OF THE AREA AT 27N142W WILL SLOWLY MOVE NE INTO THE FAR NW CORNER OF THE AREA THROUGH TUE. HOWEVER...A RATHER DRY AND STABLE SURROUNDING ENVIRONMENT WILL INHIBIT THE DEVELOPMENT OF ANY CONVECTION WITH THIS LOW. A DEEP LAYER TROUGH OVER THE CENTRAL PACIFIC IS ATTENDANT BY A JET STREAM BRANCH THAT ENTERS THE DISCUSSION AREA THROUGH 17N140W...AND REACHES TO NEAR 17N132W BEFORE IT BECOMES ILL-DEFINED. SCATTERED TO BROKEN CIRRUS CLOUDS ALONG AND S OF THIS JET STREAM BRANCH ARE STREAMING EWD INTO THE FAR WRN PART OF THE AREA FROM 13N TO 18N AND W OF 126W. AT THE SURFACE...A RIDGE EXTENDS SEWD INTO THE AREA THROUGH 32N133W AND TO NEAR 22N123W. HIGH PRES COVERS THE AREA N OF 16N AND W OF 123W. THE OSCAT PASS FROM 2032 UTC SUN ALONG WITH A PREVIOUS ASCAT PASS REVEALED MAINLY LIGHT TO MODERATE NE TRADE WINDS TO THE W OF THE RIDGE AXIS. THE SAME OSCAT PASS REVEALED N TO NE 20 KT WINDS N OF 28N BETWEEN 122W AND 130W. THESE WINDS ARE S OF A TIGHT PRES GRADIENT JUST N OF THE AREA WHERE NW TO N GALE FORCE WINDS ARE PRESENT OFF THE COAST OF SOUTHERN CALIFORNIA. N SWELLS ARE PROPAGATING S FROM THIS REGION INTO NE FORECAST WATERS...WITH SEAS TO 8 FT OVER THE AREA BOUNDED FROM N OF 27N BETWEEN 120W AND 130W. A WEAK SURFACE TROUGH MOVING W ABOUT 15 KT EXTENDS FROM 10N114W TO 05N115W. TOTAL PRECIPITABLE WATER (TPW) MOISTURE COMPOSITE ANIMATION INDICATES THAT THE TROUGH IS WITHIN AN AREA OF CONCENTRATED DEEP ATMOSPHERIC MOISTURE. LATEST IR SATELLITE IMAGERY SHOWS WIDELY SCATTERED SHOWERS AND TSTMS WITHIN 180 NM W OF THE TROUGH FROM 08N TO 10N. MODELS SUGGEST THAT THE RIDGE WILL GRADUALLY SHIFT EWD THROUGH TUE. ONLY LITTLE CHANGES CANE BE EXPECTED WITH CURRENT WIND REGIME AND SPEEDS ACROSS THE AREA THROUGH THEN. A TIGHT PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES OVER THE INTER- MOUNTAIN U.S. WILL KEEP GALE FORCE WINDS ALONG THE CALIFORNIA COAST THROUGH TUE. THE ASSOCIATED NORTHERLY SWELLS WILL CONTINUE TO PROPAGATE INTO NE FORECAST WATERS...WITH SEAS EXPECTED TO BUILD AS HIGH AS 11 FT OR 12 FT N OF ABOUT 28N MON AND TUE. MARINE...CROSS-EQUATORIAL SWELLS WITH PERIODS IN EXCESS OF 20 SECONDS ON ITS LEADING EDGE HAS MADE ITS WAY TO THE ENTIRE CENTRAL AMERICAN AND MAINLAND MEXICAN COAST AS WELL AS THE BAJA CALIFORNIA PENINSULA S OF 26N. THESE SWELLS WILL CONTINUE TO STRETCH N ALONG THE BAJA CALIFORNIA PENINSULA OVERNIGHT TONIGHT WHILE DAMPENING ALONG THE REMINDER OF THE COASTLINE. SEAS OF 8 FT ARE CONFINED TO W OF THE GALAPAGOS ISLANDS S OF 09N BETWEEN 92W AND 107W AS DETECTED BY A JASON ALTIMETER PASS FROM LATE SUN AFTERNOON. THESE SEAS ARE FORECAST BY WAVEWATCH MODEL GUIDANCE TO GRADUALLY SUBSIDE TO LESS THAN 8 FT THROUGH MON MORNING. THE 8 FT SEAS OVER THE FAR ERN PART OF THE S OF 07N BETWEEN 82W AND 98W WILL SUBSIDE TO LESS THAN 8 FT EARLY ON MON. $$ AGUIRRE