000 AXPZ20 KNHC 030319 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN MAR 03 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 0130 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 06N77W TO 06N87W TO 03N92W TO 03N105W. THE ITCZ AXIS WAS ANALYZED FROM 03N105W TO 03N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 180 NM N OF THE AXIS BETWEEN 85W AND 89W. ...DISCUSSION... GULF OF TEHUANTEPEC...STORM FORCE WINDS ARE BELIEVED TO BE CURRENTLY FOUND IN THE GULF OF TEHUANTEPEC. THERE HAVE BEEN NO RECENT SCATTEROMETER PASSES IN THE GULF...BUT SHIP 9V7955 REPORTED 42 KT NE WINDS NEAR 15N96W TO THE W OF THE USUAL AREA OF STRONGEST WINDS. SEA SURFACE TEMPERATURES HAVE COOLED TO THE MID 60 DEGREES FAHRENHEIT...LIMITING THE AMOUNT OF VERTICAL MIXING EXPECTED. THIS SHOULD KEEP THE EVENT AT MINIMAL STORM FORCE. WINDS SHOULD DIMINISH TO A STRONG GALE AGAIN AROUND MIDDAY SUN...FALL BELOW GALE FORCE MON MORNING...AND DIMINISH BELOW 25 KT BY MON AFTERNOON. MOST IMPRESSIVE IS THE LARGE AREA OF N SWELL PROPAGATING S FROM THE TEHUANTEPEC COAST WHICH WILL RESULT IN SEAS 8 FT OR GREATER EVENTUALLY COVERING THE PACIFIC WATERS FROM S OF 15N BETWEEN 95W AND 117W BY MON EVENING...WITH SEAS OVER 8 FT ALSO EXPECTED FARTHER E DUE TO SWELL FROM THE GULFS OF PAPAGAYO...FONSECA...AND PANAMA. GULFS OF PAPAGAYO AND FONSECA...LAND OBSERVATIONS AROUND THE GULF OF FONSECA SHOW N-NE WINDS AT 20 KT THIS EVENING. WINDS ARE LIKELY TO BE STRONGER OFFSHORE...AND THE NUMERICAL GUIDANCE SUGGESTS A STRONG BREEZE HAS COMMENCED. THESE WINDS SPREAD SOUTHWARD THROUGH THE GULF OF PAPAGAYO TONIGHT WHERE THEY WILL REACH 30 KT. THE STRONG BREEZE IN THE GULF OF FONSECA WILL DIMINISH SUN...BUT IT WILL REMAIN IN THE GULF OF PAPAGAYO. A BRIEF GALE IS EXPECTED IN THE GULF OF PAPAGAYO IN THE MORNING HOURS ON MON DURING THE PERIOD OF PEAK DRAINAGE FLOW OFF THE LAND. WIND WAVES AND SWELL HERE WILL MIX WITH SWELL FROM TEHUANTEPEC AS WELL AS CROSS EQUATORIAL SW SWELL TO BRING SEAS TO 12-13 FT ON SUN. SOME OF THE GUIDANCE SUGGESTS THE DEVELOPMENT OF A LOW PRESSURE SYSTEM ALONG THE MONSOON TROUGH S OF PAPAGAYO. FOR NOW...CONFIDENCE IS LOW IN THIS SCENARIO. WINDS AND MAXIMUM SEAS DOWNWIND OF PAPAGAYO WILL BEGIN TO DIMINISH ON MON. GULF OF PANAMA...A FRESH TO STRONG NORTHERLY BREEZE WILL COMMENCE IN THE GULF OF PANAMA BY EARLY SUN MORNING. SEAS WILL GRADUALLY BUILD OVER 8 FT AND PROPAGATE AS FAR S AS 04N BY MON EVENING. THE UPPER PATTERN OVER THE AREA FEATURES TWO POSITIVELY TILTED UPPER TROUGHS...ONE ACROSS NORTHERN MEXICO AND ONE CLIPPING NW WATERS...BOOKENDING AN UPPER RIDGE ALONG 120W. THE REAR RIGHT QUADRANT OF THE UPPER JET ON THE LEADING EDGE OF THE EASTERN TROUGH IS TAPPING INTO MOSITURE POOLED ALONG THE MONSOON TROUGH AXIS NEAR 100W AND PULLING IT NORTHWARD. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 120 NM EITHER SIDE OF A LINE FROM 15N102W TO 06N100W AS A RESULT. THIS JET SHOULD REMAIN IN PLACE...MAKING THIS A FAVORABLE REGION FOR CONVECTION OVER THE NEXT FEW DAYS. LOW-LEVEL MOISTURE IS ALSO POOLED ALONG THE ITCZ OVER WATERS W OF 130W. MULTIPLE LAYERS OF CLOUDS AND SOME SHOWERS LIKELY LIE IN THE AREA W OF 133W S OF 20N...BUT NO SIGNIFICANT DEEP CONVECTION IS NOTED. THE WESTERN UPPER TROUGH IS EXPECTED TO WEAKEN OVER THE NEXT FEW DAYS...MAKING THE UPPER FLOW MORE ZONAL OVER THE FORECAST WATERS AND DAMPENING THE RIDGE TO ITS E. THE FORMER SUBTROPICAL HIGH HAS BEEN DIMINISHED BY A COLD FRONT APPROACHING FROM THE W AND HAS BEEN REPLACED BY 1030 MB HIGH PRESSURE CENTER FARTHER NW BEHIND THE FRONT NEAR 42N138W. THIS HIGH IS EXPECTED TO MOVE OFF TO THE NE OVER THE NEXT FEW DAYS. THE DEEP LAYER RIDGE IS EXPECTED TO REMAIN WEAK OVER THE FORECAST AREA. TRADE WINDS ARE CURRENTLY A MODERATE TO FRESH BREEZE OVER THE FORECAST AREA AND ARE EXPECTED TO REMAIN THAT WAY THROUGH AT LEAST MON EVENING. NW SWELL WITH PERIODS TO 21 SECONDS IS CURRENTLY PROPAGATING THROUGH MUCH OF THE AREA W OF 115W AS WELL AS SOUTHWARD ALONG THE PACIFIC COAST OF BAJA CALIFORNIA SUR. THE LEADING EDGE OF THIS SWELL WILL MEET UP WITH NE SWELL FROM THE GULF OF TEHUANTEPEC BY SUN EVENING. BY MON EVENING...THIS AREA OF NW SWELL OVER 8 FT WILL SHRINK TO W OF 133W FROM 04N-18N AS THE SWELL DAMPENS. A NEW NW SWELL TRAIN WILL ENTER FAR NW WATERS MON EVENING AND QUICKLY BRING SEAS TO THE 8-10 FT RANGE. $$ SCHAUER