000 AXPZ20 KNHC 040234 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SAT APR 04 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 0215 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...A TIGHTENING PRESSURE GRADIENT WILL SET UP 20-25 KT NORTHERLY FLOW DURING MAXIMUM DRAINAGE LATE TONIGHT. THE NORTHERLY WINDS WILL GRADUALLY INCREASE THROUGHOUT THE DAY ON SAT REACHING 30-35 KT MINIMAL GALE FORCE ON SAT EVENING. THE GALE WILL PERSIST THROUGH SAT NIGHT WITH SEAS BUILDING TO 13 FT. THE WINDS WILL DIMINISH BELOW GALE FORCE ON SUN AFTERNOON. THE NORTHERLY FLOW WILL GRADUALLY DIMINISH SUN NIGHT...WITH N WINDS AT 15-20 KT BY MON AFTERNOON. EXPECT 20 KT NORTHERLY WINDS TO DEVELOP ON MON NIGHT AND 20-25 KT NORTHERLY CONDITIONS ON TUE NIGHT AND WED NIGHT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A SOUTHERN HEMISPHERE ITCZ IS ANALYZED FROM 01S82W TO 01S91W. SCATTEROMETER WINDS INDICATE THAT THE NORTHERN HEMISPHERE ITCZ DEVELOPS NEAR 04N105W AND EXTENDS SW TO 00N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED ALONG THE SOUTHERN HEMISPHERE ITCZ WITHIN 75 NM OF 02S87W. SIMILAR CONVECTION IS NOTED ALONG THE NORTHERN HEMISPHERE ITCZ WITHIN 90 NM EITHER SIDE OF A LINE FROM 06.5N105W TO 03N120W...AND WITHIN 60 NM OF 05N127W. ISOLATED MODERATE CONVECTION FLARES INTERMITTENTLY ALONG A SURFACE TROUGH EXTENDING SW ALONG THE PACIFIC COAST OF COLOMBIA...BUT IS CURRENTLY ISOLATED MODERATE AT BEST. ...DISCUSSION... AN UPPER TROUGH EXTENDING S TO BASE OVER THE DEEP TROPICS AT 11N133W. AN UPPER ANTICYCLONE IS OVER NW COLOMBIA WITH AN UPPER RIDGE EXTENDING NW THROUGH ANOTHER UPPER ANTICYCLONE AT 13N92W TO A CREST NEAR 33N125W...JUST E OF THE PREVIOUSLY MENTIONED UPPER TROUGH. A 120 NM WIDE BAND OF UPPER MOISTURE EXTENDS NE ALONG THE RIDGE CREST FROM THE UPPER CYCLONE TO ACROSS SOUTHERN CALIFORNIA AND THE NORTHERN BAJA CALIFORNIA PENINSULA...AND CONTINUES ENE ACROSS NEW MEXICO AND ARIZONA. UPPER DEBRIS MOISTURE CONTINUES ACROSS THE DISCUSSION AREA FROM 17-29N BETWEEN 122W-100W. AT THE LOW LEVELS A SURFACE RIDGE EXTENDS FROM 32N137W TO 16N102W. ALTHOUGH THE NORTHERLY FLOW N OF THE RIDGE IS AT 15-20 KT...COMBINED SEAS ARE 7-11 FT IN MIXED S AND NW SWELL ACROSS THE DISCUSSION WATERS FROM 26-32N BETWEEN 117-132W. THESE ENHANCED SEAS WILL PROPAGATE E REACHING ALONG THE PACIFIC COAST OF THE NORTHERN BAJA PENINSULA ON SUN NIGHT...THEN SUBSIDE TO 5- 7 FT ON MON. THE GRADIENT SW OF THE RIDGE HAS RELAXED WITH NE TRADES OF 15-20 KT ACROSS THE DISCUSSION WATERS W OF 125W BETWEEN THE ITCZ AND THE RIDGE. LONG PERIOD NE...S AND NW SWELL ARE MIXING WITH COMBINED SEAS OF 7-9 FT ACROSS THE DISCUSSION WATERS FROM 07-27N BETWEEN 133-140W. THESE SWELLS WILL GRADUALLY SUBSIDE THROUGH EARLY NEXT WEEK. GULF OF PAPAGAYO...EXPECT NOCTURNAL DRAINAGE OF ENE 20-25 KT WINDS TONIGHT INTO EARLY SAT MORNING WITH SEAS BUILDING TO 8 FT. EXPECTING THESE NOCTURNAL DRAINAGE EVENTS TO BECOME STRONGER BEGINNING ON SAT NIGHT CONTINUING EACH NIGHT THROUGH THE MIDDLE OF NEXT WEEK...WITH THE WESTERN EXTENT REACHING AS FAR W AS 09N91W. THE ASSOCIATED SEAS WILL BUILD TO ABOUT 9 FT. MON NIGHTS EVENT MAY REACH A MAXIMUM OF 30 KT. GULF OF PANAMA...MODERATE TO FRESH NORTHERLY WINDS ARE EXPECTED ACROSS THE GULF OF PANAMA AND DOWNWIND TO ABOUT 06N OVER THE NEXT COUPLE OF DAYS WITH BUILDING SEAS OF 5-7 FT. $$ NELSON