000 AXPZ20 KNHC 270954 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT AUG 27 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 AXIS EXTENDS NW AND INLAND CENTRAL AMERICA FROM THE PANAMA AND COLOMBIA BORDER AT 08N76W TO 17N97W... THEN MOVES OFFSHORE TURNING W INTO THE 1008 MB LOW PRES AT 19N117W...THEN TURNS ABRUPTLY SW TO 10N125W THEN CONTINUING W TO NEAR 09N140W WHERE LOW LEVEL WINDS SUGGEST THE ITCZ BEGINS. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED N OF 03N E OF 80W WITH NUMEROUS LIGHTNING STRIKES DETECTED. SIMILAR CONVECTION IS NOTED WITHIN 60 NM EITHER SIDE OF A LINE FROM 11N87W TO 15N95W TO 15N107W TO 10N120W...AND ALSO WITHIN 30 NM OF 08N89W. ...DISCUSSION... AN UPPER LONG WAVE TOUGH DOMINATES THE NE PACIFIC E OF 160W. A COUPLE OF EMBEDDED SHORTWAVE TROUGHS ARE MOVING THROUGH THE LONG WAVE PATTERN INT THE DISCUSSION AREA BETWEEN 120W AND 130W. THE EASTERNMOST SHORT WAVE TROUGH HAS ITS MEAN AXIS FROM 32N129W TO A BASE AT 22N133W. THE WESTERNMOST TROUGH EXTENDS SW FROM 35N134W INTO AN UPPER CYCLONE AT 32N140W WITH THE TROUGH CONTINUING S TO A BASE AT 28N140W. SOME UPPER MOISTURE IS NOTED WITHIN 120 NM OF THE WESTERN TROUGH. AN UPPER ANTICYCLONE IS ANCHORED OVER WESTERN NEW MEXICO WITH AN UPPER RIDGE EXTENDING SW TO A FAIRLY SHARP CREST AT 25N124W...AND EFFECTIVELY BLOCKS THE EASTWARD ADVANCE OF THE EASTERN UPPER TROUGH WHICH SHOULD FILL IN LATER TODAY WHILE THE WESTERN TROUGH STALLS AND BEGINS TO DRIFT W. INTENSE CONVECTION ACCOMPANIED BY NUMEROUS LIGHTNING STRIKES...WAS ENHANCED ALONG THE SIERRA MADRE OCCIDENTAL. THIS SCATTERED MODERATE TO STRONG CONVECTION IS CURRENTLY MOVING W OVER THE PACIFIC WITHIN 30 NM OF THE COAST 21.5N106.5W...AND OVER THE GULF OF CALIFORNIA TO THE S OF 28N. THE DEBRIS MOISTURE IS SPREADING W ACROSS THE BAJA CALIFORNIA PENINSULA TO OVER THE PACIFIC TO THE N OF 20N E OF 122W. AN UPPER ANTICYCLONE CENTERED JUST NE OF THE HAWAIIAN ISLANDS HAS AN UPPER RIDGE EXTENDING E TO A SHARP CREST AT 19N131W. DRY UPPER AIR IS INDICATED ELSEWHERE N OF 15N W OF 125W. AN UPPER TROUGH DISSECTS THE SOUTHERN GULF OF MEXICO FROM E TO W...AND CONTINUES W ACROSS CENTRAL OLD MEXICO AND OVER THE E PACIFIC ALONG 22N...THEN TURNS SW THROUGH UPPER CYCLONES AT 19N118W AND 13N125W AND 03N138W. AN UPPER RIDGE...ORIENTATED FROM NE TO SW...IS NOTED OVER THE TROPICS...EXTENDING THROUGH UPPER ANTICYCLONES AT 20N89W AND 16N107W AND 06N124W. THE UPPER FLOW IS GENERALLY NE OVER THE TROPICS TO THE S OF 20N BETWEEN 113W AND 80W...AND IS ADVECTING DEBRIS MOISTURE S TO ALONG THE EQUATOR BETWEEN 80W AND 117W. AN UPPER TROUGH WILL BUILD SW ACROSS THE CARIBBEAN SEAS TO NEAR PANAMA...OTHERWISE EXPECT THE NORTHEASTERLY UPPER FLOW TO CONTINUE THROUGH SUN. AT THE SURFACE...WEAK RIDGING DOMINATES THE SUBTROPICS W OF 125W. A 1008 MB SURFACE LOW PRES IS AT 19N117W WITH THE LATEST SCATTEROMETER DATA INDICATING THE GRADIENT IS SUPPORTING E-SE WINDS 15-20 KT WITHIN 240 NM OVER THE NE QUADRANT. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 30 NM OF 19N117W. MONSOONAL SOUTHWESTERLY FLOW AT 20-25 KT...SEAS 9-13 FT...IS OBSERVED IN THE SCATTEROMETER DATA WITHIN ABOUT 360 NM SE OF LINE FROM 07N123W TO 17N104W. ANOTHER AREA OF SW-W WINDS AT 15-20 KT...SEAS TO 9 FT...IS OBSERVED FROM 10N TO 12N BETWEEN 92W AND 98W. SOUTHERLY SWELLS ARE MAINTAINING COMBINED SEA HEIGHTS TO 10 TO 10 FT ELSEWHERE FROM 07N-14N BETWEEN 88W-100W...AND FROM 04N-18N BETWEEN 100W-122W. REINFORCING SW SWELL WILL REACH THE EQUATOR BETWEEN 110W AND 140W ON MON...REACHING THE CENTRAL AMERICAN COAST BY TUE NIGHT. $$ NELSON