000 AXPZ20 KNHC 290947 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON AUG 29 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 ALONG THE PACIFIC COAST OF CENTRAL AMERICA FROM THE PANAMA AND COLOMBIA BORDER AT 08N77W TO 11N86W TO 18N103W...THEN MOVES OFFSHORE CONTINUING W ALONG 17N INTO AN EMBEDDED SURFACE LOW PRESSURE AT 18N123W...THEN TURNS ABRUPTLY SW TO BEYOND 11N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED FROM 02N TO 07N E OF 80W WITH NUMEROUS LIGHTNING STRIKES DETECTED. SIMILAR CONVECTION HAS MOVED W OFF THE COAST OF CENTRAL AMERICA WITHIN 90 NM EITHER SIDE A LINE FROM 10N88W TO 16N95W...AND A LINE FROM 15N99W TO 20N106W...AND YET ANOTHER LINE FROM 15N112W TO 11N120W. ...DISCUSSION... AN UPPER LONG WAVE TOUGH DOMINATES THE NE PACIFIC E OF 160W WITH ITS MEAN AXIS ALONG 35N144W INTO AN UPPER CYCLONE AT 29N150W... WITH THE UPPER TROUGH CONTINUING S TO BASE AT 18N150W. AN UPPER ANTICYCLONE IS ANCHORED OVER NEW MEXICO WITH AN UPPER RIDGE EXTENDING SW ACROSS THE NORTHERN BAJA CALIFORNIA PENINSULA THROUGH 18N130W...TO A CREST AT 12N140W. A SMALL UPPER CYCLONE IS EMBEDDED IN THE LONG WAVE RIDGE AT 22N125W...WITH AN ASSOCIATED 1008 MB SURFACE LOW AT 18N123W. SMALL CLUSTERS OF CONVECTION FLARED OVER THE BAJA CALIFORNIA PENINSULA ON SUN... WITH THE DEBRIS MOSITURE NOW EVAPORATING WITHIN 60 NM EITHER SIDE OF A LINE FROM 21N108W TO 29N115W. OTHERWISE...SOUTHERLY FLOW DOMINATES THE UPPER LEVELS N OF 20N BETWEEN 115W AND 140W WITH DRY UPPER AIR INDICATED OVER THE ENTIRE AREA N OF 14N W OF 116W. AN UPPER TROUGH DISSECTS THE GULF OF MEXICO FROM NE TO SW...AND CONTINUES W ACROSS OLD MEXICO AND OVER THE E PACIFIC ALONG 19N INTO AN UPPER CYCLONE AT 16N120W. AN UPPER ANTICYCLONE IS OVER THE YUCATAN PENINSULA AT 16N89W WITH A RIDGE EXTENDING SW OVER THE E PACIFIC INTO ANOTHER ILL DEFINED UPPER ANTICYCLONE NEAR 14N108W. AN UPPER TROUGH IS DIGGING SW ACROSS THE CENTRAL CARIBBEAN INTO A SMALL UPPER CYCLONE OVER THE PACIFIC AT 05N85W. THIS SMALL CYCLONE DOES NOT SEEM TO INTERRUPT THE NORTHEASTERLY UPPER FLOW DOMINATING MOST OF TROPICS TO THE S OF 20N BETWEEN 110W AND 80W...WHICH IS ADVECTING DEBRIS MOISTURE S TO ALONG 05N BETWEEN 80W AND 125W. A SURFACE HIGH PRESSURE IS NEAR 35N138W WITH A BROAD RIDGE OVER THE PACIFIC WATERS N OF 20N W OF 125W. THE PERSISTENT SURFACE LOW PRES AT 18N123W IS EXPECTED TO DRIFT SW AND REMAIN WITHIN THE MONSOON TROUGH REGIME THROUGH MID WEEK. THE MONSOONAL SOUTHWESTERLY FLOW HAS WEAKENED TO A 15 KT MAXIMUM THIS MORNING. CROSS EQUATORIAL SOUTHWESTERLY SWELL CONTINUES... RESULTING IN SEAS TO 9 FT WITHIN THE AREA BOUNDED BY 10N TO 15N BETWEEN 93W AND 105W. A NEW BOUT OF CROSS EQUATORIAL SWELL...COMBINED SEAS TO 8 FT... HAS MOVED INTO THE N PACIFIC WATERS...S OF 05N BETWEEN 115W AND 135W...ACCOMPANIED BY SE WINDS AT 15 TO 20 KT. THESE SOUTHERLY SWELLS WILL PROPAGATE NE TO ALONG 15N BETWEEN 98W AND 130W BY TUE NIGHT...REACHING THE CENTRAL AMERICAN COAST BETWEEN 105W AND 85W ON WED AND REACHING THE NORTHERN BAJA PENINSULA BY THU. A SURFACE LOW PRESSURE IS EXPECTED TO FORM ALONG THE MONSOON TROUGH NEAR 16N103W ON TUE NIGHT. SOUTHWESTERLY WINDS ARE EXPECTED TO INCREASE OVER THE WATERS S OF 13N W OF 90W BY MID WEEK. $$ NELSON