000 AXPZ20 KNHC 021553 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC MON JUL 02 2012 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE PANAMA/COLOMBIAN BORDER AT 08N77W WESTWARD TO NEAR 08N90W...THEN BECOMES DISTORTED BY A TROPICAL WAVE ALONG 100W DESCRIBED BELOW. SCATTEROMETER DATA DETECTS SOUTHWESTERLY LOW LEVEL FLOW HAS BECOME STRONGER W OF THE TROPICAL WAVE A SECOND LEG OF THE MONSOON TROUGH IS ANALYZED FROM 11N112W TO 07N128W WHERE THE LOW LEVEL WINDS INDICATE A TRANSITION TO AN ITCZ WHICH THEN CONTINUES SW TO BEYOND 04N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED FROM 04N TO 13N BETWEEN 79W AND 94W WITH LIGHTNING DATA INDICATING THE HEAVIEST ACTIVITY WITHIN 30 NM OF 12.5N92W WHERE THE CONVECTION SHOULD BEGIN TO WEAKEN. THUNDERSTORM CELLS ALONG 06N TO 07N BETWEEN 81W AND 88W APPEAR TO BE STRENGTHENING. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS ALSO NOTED WITHIN 90 NM EITHER SIDE OF A LINE FROM 04N107W TO 11N124W. ...TROPICAL WAVE... A TROPICAL WAVE EXTENDS FROM 12N98W TO 07N101W WITH AN EMBEDDED LOW PRES NEAR 10N99W AND ESTIMATED AT 1009 MB. SCATTERED MODERATE TO STRONG CONVECTION IS NOTED FROM 04W TO 12N BETWEEN 94W AND 102W. THE LOW PRES IS EXPECTED TO MOVE W NW FOR THE NEXT FEW DAYS AND SLOWLY STRENGTHEN...REACHING NEAR 11N104W ON TUE AND 12N107W ON WED. ...DISCUSSION... A SECONDARY UPPER LEVEL TROUGH EXTENDS SW FROM NORTHERN CALIFORNIA THROUGH AN EMBEDDED CYCLONE AT 35N126W AND 34N137W AND 34N143W. THIS SECONDARY TROUGH WILL DIP A LITTLE FURTHER S...TO PERHAPS ALONG 32.5N TONIGHT...BUT NOT REINFORCE AN UPPER TROUGH CURRENTLY STALLING ACROSS THE AREA FROM SOUTHERN CALIFORNIA TO 29N120W TO 26N140W. AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 24N126W WITH A RIDGE EXTENDING E TO A CREST AT 25N116W AND EXTENDING W TO A CREST AT 24N138W. AN UPPER CYCLONE IS JUST S OF THE WESTERN RIDGE AT 18N139W AND WILL W OF THE AREA TONIGHT. THESE FEATURES COMBINE TO DRY OUT THE UPPER LEVELS OF THE DISCUSSION AREA W OF A LINE FROM 32N113W TO 12N140W. AN UPPER CYCLONE IS OVER NW OLD MEXICO AT 27N107W AND MOVING SLOWLY W WITH TIME. AN UPPER TROUGH EXTENDS SW FROM THE CYCLONE TO A SECOND UPPER CYCLONE BARELY EVIDENT AT 14.5N122W WHICH IS ALSO SHIFTING WESTWARD WITH TIME. ISOLATED CONVECTION IS FLARING E OF THE TROUGH ALONG THE MEXICAN COAST NEAR THE BANDERAS BAY AND CAPE CORRIENTES ANCHORAGES. CONVECTION WAS ENHANCED LAST NIGHT OVER NW MEXICO NEAR 28N110W...AND IS NOW DISSIPATING OVER THE GULF OF CALIFORNIA NEAR 26.5N111W. UPPER MOISTURE IS WRAPPING AROUND THIS CYCLONE OVER THE AREA N OF 20N BETWEEN 102W AND 113W. ANOTHER UPPER CYCLONE IS OVER MEXICO AT 18N95W AND IS MOVING WESTWARD WITH AN UPPER TROUGH EXTENDING S TO BASE OVER THE EPAC AT 13N97W. THIS IS NEAR THE NORTHERN EXTENT THE LOW LEVEL INVERTED TROUGH/TROPICAL WAVE PREVIOUSLY DESCRIBED. A SMALL UPPER ANTICYCLONE IS ESTIMATED NEAR 10N98W...AND IS VENTILATING THE UPPER LEVELS OVER THE CONVECTION PREVIOUSLY DESCRIBED NEAR THE TROPICAL WAVE AND ITS EMBEDDED SURFACE LOW. AT THE LOW LEVELS A BROAD RIDGE DOMINATES THE AREA N OF 12N W OF 115W WITH A RIDGE AXIS EXTENDING ROUGHLY FROM 30N140W TO 13N117W. LOW LEVEL WINDS NE OF THE RIDGE CONTINUE AT 15 TO 20 KT IN THE AREA N OF 26N BETWEEN 120W AND THE BAJA PENINSULA WITH SEAS 6 TO 7 FT IN LONG PERIOD NW SWELL. THE GRADIENT IS RELAXING IN THIS AREA AND EXPECT THE NW WINDS TO DIMINISH TO 15 KT LATE TODAY. GUIDANCE IS FLUCTUATING SLIGHTLY...BUT EXPECT THE NE TRADES TO INCREASE SW OF THIS RIDGE IN THE AREA FROM 07N TO 12N TODAY...BUT THEN SHIFT N TO THE AREA BOUNDED BY 17N TO 23N W OF 130W ON TUE AND WED. GAP WINDS...E WINDS AT 15 TO 20 KT WILL CONTINUE TO SURGE THROUGH THE GULF OF PAPAGAYO AND DOWNSTREAM ACROSS THE AREA FROM 10N TO 12N E OF 90W THROUGH WED. GULF OF CALIFORNIA...SE WINDS WILL PULSE AT 15 TO 20 KT OVER THE WATERS S OF 27N TODAY...THEN SHIFT N TO ACROSS THE WATERS N OF 29N LATE TONIGHT AND EARLY WED BEFORE DIMINISHING BELOW 20 KT LATE WED. $$ NELSON