000 AXPZ20 KNHC 311547 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC WED AUG 31 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1515 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION EIGHT-E IS CENTERED NEAR 18.0N 102.7W AT 31/1500 UTC OR 65 NM WNW OF ZIHUATANEJO MEXICO MOVING NW AT 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. THE DEPRESSION REMAINS UNDER A FAVORABLE MIDDLE TO UPPER LEVEL ENVIRONMENT DUE TO AN UPPER LEVEL ANTICYCLONE NOTED ON WATER VAPOR IMAGERY CENTERED OVER SOUTHERN MEXICO NEAR 19N98W. THE UPPER LEVEL RIDGE AXIS EXTENDS WESTWARD OVER THE DEPRESSION TO NEAR 18N112W. THIS IS ENHANCING SCATTERED MODERATE AND ISOLATED STRONG CONVECTION OCCURRING WITHIN 150 NM OF THE CENTER. WHILE THE DEPRESSION IS FORECAST TO REACH COAST LATER TODAY...RAINFALL ASSOCIATED WITH THE DEPRESSION MAY PRODUCE LIFE-THREATENING FLASH FLOODING AND MUD SLIDES IN AREAS OF STEEP TERRAIN. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/ WTNT23 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 11N86W TO 16N95W TO TROPICAL DEPRESSION EIGHT-E THEN TO 18N124W TO 10N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 03N TO 08N BETWEEN 77W AND 79W. SCATTERED MODERATE CONVECTION IS FROM 11N TO 14N BETWEEN 93W AND 97W. ...DISCUSSION... AN UPPER LEVEL TROUGH IS SWINGING SOUTHEASTWARD INTO THE NW PORTION OF THE DISCUSSION AREA WITH AXIS ALONG 32N130W TO 28N139W. AN UPPER LEVEL ANTICYCLONE CENTERED OVER SE OKLAHOMA EXTENDS AN UPPER LEVEL RIDGE AXIS SW ACROSS NW MEXICO AND THE BAJA CALIFORNIA PENINSULA THROUGH 21N120W. WHILE THE RIDGING IS DISRUPTED ALOFT BECAUSE OF THE UPPER LEVEL TROUGH SWINGING SOUTHEASTWARD...AN UPPER LEVEL ANTICYCLONIC IS CENTERED NEAR 16N137W. THE UPPER LEVELS APPEAR VERY DRY ON WATER VAPOR IMAGERY NW OF A LINE FROM 10N140W TO 24N112W. AN UPPER LEVEL TROUGH ALONG THE SE CONUS SEABOARD STRETCHES SW ACROSS THE NORTHERN GULF OF MEXICO THROUGH AN UPPER CYCLONE AT 28N92W AND THROUGH AN UPPER CYCLONE OVER MEXICO AT 24N105W EXTENDING TO AN UPPER CYCLONE OVER THE TROPICAL PACIFIC AT 23N113W. IMMEDIATELY SE OF THIS TUTT IS UPPER LEVEL RIDGING... ORIENTATED NE TO SW WHICH AS MENTIONED ABOVE IS LOCATED ALOFT OVER TROPICAL DEPRESSION EIGHT-E. AT THE SURFACE...A RIDGE DOMINATES THE NW CORNER OF THE FORECAST AREA WITH N TO NE WINDS AT 15 TO 20 KT SPREADING SE OVER THE PACIFIC WATERS W OF A LINE FROM 32N120W TO 10N140W. THE ASSOCIATED NORTHERLY SWELL IS MIXING WITH CROSS EQUATORIAL SOUTHERLY SWELL RESULTING IN COMBINED SEAS TO 9 FT. THE NORTHERLY WINDS WILL DIMINISH BELOW 20 KT S OF 32N ON THU...BUT OPPOSING SWELL WILL CONTINUE OVER THE ENTIRE WATERS N OF 20N...AND FROM 12N TO 20N TO THE W OF 130W THROUGH THU NIGHT. THESE LONG PERIOD CROSS EQUATORIAL SOUTHERLY SWELLS WILL ALSO SPREAD NE TO THE CENTRAL AMERICAN COAST S OF 20N WITH SEAS TO 11 FT IN THE AREAS OF ENHANCED SOUTHWESTERLY MONSOON FLOW...JUST TO THE S OF TROPICAL DEPRESSION EIGHT-E. $$ HUFFMAN