000 AXPZ20 KNHC 070230 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE APR 07 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... SCATTEROMETER WINDS INDICATE THAT THE ITCZ FORMS NEAR 05N94W AND EXTENDS WSW TO 02N116W THEN TURNS NW TO 05N140W. ISOLATED MODERATE CONVECTION IS OBSERVED E THE ITCZ WITHIN 60 NM EITHER SIDE OF A LINE FROM 00N85W TO 04N92W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED ALONG THE ITCZ WITHIN 90 NM EITHER SIDE OF A LINE FROM 04.5N98W TO 01N111W. SIMILAR CONVECTION IS OBSERVED OVER AND TO THE N OF THE ITCZ WITHIN 210 NM EITHER SIDE OF A LINE FROM 04N120W TO 13N122W AND WITHIN 90 NM OF LINE FROM 09N126W TO 08N140W. ...DISCUSSION... AN UPPER LONG WAVE TROUGH DOMINATES THE WESTERN PORTION OF THE DISCUSSION AREA...AND IS CURRENTLY BEING REINFORCED BY AN EMBEDDED SHORTWAVE TROUGH EXTENDING SW FROM 32N130W TO 19N140W. UPPER MOISTURE CONTINUES TO SWING E THROUGH THE TROUGH TO THE N OF 31N ACROSS CALIFORNIA TO THE N OF 34N. THE ITCZ IS CONVECTIVELY ACTIVE W OF 120W TO AT LEAST 160W...WITH THE RESULTANT DEBRIS MOISTURE ADVECTED NE AHEAD OF THE UPPER TROUGH WITHIN 360 NM EITHER SIDE OF A LINE FROM 11N127W TO ACROSS THE SOUTHERN GULF OF CALIFORNIA...CONTINUING NE ACROSS NORTHERN MEXICO AND TEXAS...THEN TURNING E ACROSS THE SOUTHERN CONUS. A 480 NM WIDE BAND OF UPPER DRY AIR SEPARATES THESE TWO MOISTURE PLUMES...AND EXTENDS FROM 18N140W TO ACROSS THE NORTHERN GULF OF CALIFORNIA AND ACROSS NEVADA. AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 12N109W WITH ITS ANTICYCLONIC ENVELOPE OF DRY UPPER AIR COVERING THE DISCUSSION AREA FROM 04-17N BETWEEN 106-75W WITH ONLY THE SMALL AREAS OF CONVECTION PREVIOUSLY DESCRIBED ALONG THE SOUTHERN EDGE OF THE UPPER SUBSIDENCE. AT THE LOW LEVELS A SURFACE RIDGE EXTENDS FROM 29N140W TO 16N105W. THE RIDGE WILL SHIFT SOUTHWARD ON TUE ALLOWING A COLD FRONT TO SWEEP RAPIDLY E ACROSS THE DISCUSSION AREA TO THE N OF 29.5N...WITH THE FRONT PASSING ACROSS THE NORTHERN GULF OF CALIFORNIA EARLY WED. THE RIDGE WILL THEN REORIENTED FROM 32N127W TO 15N100W. THE POST-FRONTAL NW FLOW IS EXPECTED TO INCREASE TO 20-25 KT ALONG THE NW COAST OF THE BAJA CALIFORNIA PENINSULA BRIEFLY ON WED. THE GRADIENT CURRENTLY SW OF THE RIDGE IS SUPPORTING NE TRADES OF 15-20 KT ACROSS THE DISCUSSION WATERS BETWEEN THE ITCZ AND 22N. LONG PERIOD NE...S AND NW SWELL ARE MIXING WITH COMBINED SEAS OF 7-9 FT ACROSS THE DISCUSSION WATERS FROM 08-14N BETWEEN 132-140W. THE N SWELL COMPONENT WILL GRADUALLY SUBSIDE THROUGH THE MIDDLE OF THE WEEK AS THE INCREASING NE TRADE SWELL MIXES WITH CROSS EQUATORIAL SOUTHERLY AND BUILDS THE COMBINED SEAS TO 7-8 FT ACROSS THE TROPICS N OF THE ITCZ AND W OF 118W. GULF OF CALIFORNIA...GUIDANCE IS SUGGESTING THAT THE NW FLOW WILL INCREASE TO 20-25 KT ACROSS THE SOUTHERN GULF OF CALIFORNIA LATE WED. GULF OF TEHUANTEPEC...EXPECT A NORTHERLY 20-25 KT DRAINAGE SURGE LATE TONIGHT AND AGAIN ON TUE NIGHT. GULF OF PAPAGAYO...EXPECT ENE 20-30 KT NOCTURNAL DRAINAGE TONIGHT INTO EARLY TUE ACROSS THE PACIFIC WATERS FROM 09-13N BETWEEN 86-93W...WITH SEAS BUILDING TO 10 FT. ANOTHER STRONG EVENT IS EXPECTED TUE NIGHT...THEN ONLY BRIEF 20-25 KT SURGES EXPECTED ON WED AND THU NIGHTS. GULF OF PANAMA...STRONG NORTHERLY WINDS WILL SOON EXTEND FROM THE WESTERN GULF OF PANAMA S TO 05N82W...BUT DIMINISH BY SUNRISE TUE. MODERATE TO FRESH NORTHERLY WINDS ARE THEN EXPECTED ACROSS THE GULF OF PANAMA AND DOWNWIND TO ABOUT 06N THROUGH EARLY WED. $$ NELSON