000 AXPZ20 KNHC 280956 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU JUL 28 2011 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS WESTWARD FROM PANAMA AT 09N83W TO DEVELOPING LOW PRES AT 09N92W...WITH THE TROUGH AXIS CONTINUING SW TO 08N87W...THEN TURNS NW TO 13N114W...THEN TURNS ABRUPTLY SW TO 06N122W WHERE LOW LEVEL WINDS INDICATE THAT THE ITCZ AXIS BEGINS AND CONTINUES W TO BEYOND 07N140W. OVERCAST MULTILAYERED CLOUDS ARE OBSERVED OVER THE ENTIRE AREA E OF 95W. NUMEROUS STRONG WITHIN 30 NM OF 06N78W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS EMBEDDED ELSEWHERE WITHIN THE DENSE CLOUDINESS TO THE NE OF LINE EXTENDING FROM 02N79W TO 09N96W. SIMILAR CONVECTION IS NOTED WITHIN 30 NM OF 13.5N113W. ISOLATED SMALL CLUSTERS ARE ALSO FLARING ALONG 13N BETWEEN 120W AND 128W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED OVER THE GULF OF CALIFORNIA FROM 24N TO 28N. ...DISCUSSION... AN UPPER RIDGE EXTENDS SW FROM THE TEXAS PANHANDLE TO A CREST AT 32N124W AND HAS HALTED THE EASTWARD ADVANCE OF A DEEP LAYERED TROUGH EXTENDING FROM CENTRAL CALIFORNIA TO 32N126W TO 23N130W TO A BASE AT 17N134W...WITH INDICATION OF AN UPPER CYCLONE DEVELOPING AT 22.5N130W AS EXPECTED. NORTHERLY SURFACE WINDS ARE EXPECTED TO INCREASE TO 20 KT TONIGHT WITH SEAS BUILDING TO 9 FT W OF THE TROUGH. AN UPPER ANTICYCLONE IS W OF THE DEEP LAYERED TROUGH AT 24N142W. AN UPPER ANTICYCLONE IS E OF THE DEEP LAYERED TROUGH AT 18N118W...WITH A RIDGE EXTENDING SW TO A CREST AT 12N141W...AND AN UPPER RIDGE ALSO EXTENDS SE TO A CREST AT 16N109W. A SMALL UPPER CYCLONE IS DEVELOPING JUST NE OF THE RIDGE AT 22N113W. ANOTHER SMALL UPPER CYCLONE IS OVER THE DEEP TROPICS AT 05N134W. AN UPPER RIDGE EXTENDS E TO W ALONG THE EQUATOR W OF 105W. THIS SETS UP AN AREA OF UPPER DIFFLUENCE OVER THE MONSOON TROUGH AND ITCZ WITH TINY CLUSTERS OF CONVECTION CONTINUOUSLY ENHANCED ALONG 13N BETWEEN 112W AND 138W. THE RESULTANT DEBRIS MOISTURE IS FANNING OUT FROM 07N TO 17N BETWEEN 110W AND 140W. DEBRIS MOISTURE...ORIGINATING FROM AFTERNOON CONVECTION THAT FLARED ALONG THE MEXICAN SIERRA MADRE RIDGE...IS ADVECTED W OVER THE PACIFIC TO THE N OF 24N E OF 116W. OTHERWISE ALL THE FEATURES DESCRIBED COMBINE TO DRY OUT THE UPPER LEVELS N OF 16N W OF 116W. THE SW CONUS RIDGE WILL BUILD A LITTLE FURTHER W AND PUSH THE UPPER CYCLONE NEAR 22N130W A LITTLE FURTHER W OVER THE NEXT DAY OR SO. THE UPPER CYCLONE NEAR 18N118W IS EXPECTED TO DEEPEN AND MOVE TO NEAR 21N114W BY EARLY FRI. THE UPPER FLOW IS NORTHEASTERLY OVER THE DEEP TROPICS E OF 100W. CONVECTION HAS BEEN ENHANCED OVER CENTRAL AMERICA WITH THE DEBRIS MOISTURE SPREADING W COVERING THE AREA E OF 95W. SOUTHWESTERLY MONSOONAL FLOW HAS INCREASED TO 15-20 KT ACROSS THE WATERS TO THE S OF 07N BETWEEN 79W AND 92W...WITH COMBINED SEAS TO 11 FT IN SW SWELL. CROSS EQUATORIAL SW SWELL...SEAS TO 9 FT...SURROUNDS THIS AREA OF ENHANCED MONSOON FLOW...GENERALLY TO THE S OF 15N E OF 109W. STATIONARY LOW PRESSURE IS FORMING ALONG THE MONSOON TROUGH NEAR 10N90W ANS IS EXPECTED TO SLOWLY DEEPEN THROUGH SAT AS CROSS EQUATORIAL SWELL CONTINUES OVER THE WATERS S OF 11N BETWEEN 80W AND 100W. $$ NELSON