000 AXPZ20 KNHC 251555 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN AUG 25 2013 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. ...SPECIAL FEATURES... TROPICAL DEPRESSION IVO IS CENTERED NEAR 25.1N 114.9W OR 165 MILES W OF CABO SAN LAZARO MEXICO AT 1500 UTC...MOVING N-NW OR 340 DEG AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB. MAXIMUM SUSTAINED WINDS ARE 30 KT WITH GUSTS TO 40 KT. CURRENTLY SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 60 NM EITHER SIDE OF A LINE FROM 28N114W TO 24N115W. IVO IS EXPECTED TO WEAKEN TO REMNANT LOW TONIGHT AND THEN STALL LATE MON WITH THE REMNANTS DRIFTING S MON NIGHT INTO TUE WHILE GRADUALLY DISSIPATING. CYCLONIC WINDS OF 15-20 KT...WITH SEAS OF 8-11 FT...SURROUND IVO ACROSS THE WATERS FROM 20-27N BETWEEN 109- 117W. THE AFFECTED AREA OF 20-25 KT WINDS WILL SHRINK TO WITHIN 90 NM OF THE REMNANT CENTER ON MON AND WITHIN 60 NM ON TUE. SE WINDS AT 15-20 KT OBSERVED ACROSS THE GULF OF CALIFORNIA WILL DIMINISH TO 10-15 THIS EVENING. SEE THE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/ WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. ...TROPICAL LOW/TROPICAL WAVE... A SURFACE LOW PRESSURE AT 14N95W IS ESTIMATED AT 1009 MB AND IS ASSOCIATED WITH A TROPICAL WAVE. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 210 NM OVER THE E SEMICIRCLE OF THE LOW CENTER WHERE BANDING FEATURES APPEAR TO BE FORMING... AND ALSO IN A LARGE CLUSTER W OF THE CENTER WITHIN 90 NM OF 15N99W. CURRENTLY 15-20 KT WINDS ARE OBSERVED WITHIN 120 NM OVER N SEMICIRCLE WITH SEAS 6-8 FT PRIMARILY DUE TO LONG PERIOD CROSS- EQUATORIAL SW SWELL. THE LOW IS EXPECTED TO MOVE W-NW TO NEAR 13.5N 98.5W EARLY MON AND NEAR 15N102W EARLY TUE. BY MID DAY TUE E-SE WINDS SHOULD BE INCREASING TO 20-30 KT WITHIN 150 NM OVER THE NE SEMICIRCLE. ATMOSPHERIC AND OCEANOGRAPHIC CONDITIONS WILL BE FAVORABLE FOR TROPICAL CYCLONE DEVELOPMENT IN A COUPLE OF DAYS. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS W ACROSS THE SW CARIBBEAN ALONG 09- 10N FROM THE NW COAST OF COLOMBIA AT 76W...TURNING SW OVER THE PANAMA AND COSTA RICA BORDER...THEN TURNING NW PARRELLING THE PACIFIC COAST OF CENTRAL AMERICA FROM 10N85W TO THE EMBEDDED SURFACE LOW PRESSURE CENTER PREVIOUSLY DESCRIBED AT 14N95W...THEN TURNING SW TO 09N107W WHERE THE TROUGH LOSES IDENTITY. THE MONSOON TROUGH IS EVIDENT AGAIN NEAR 17N121W AND CONTINUES SW THROUGH ANOTHER EMBEDDED SURFACE LOW PRESSURE NEAR 14.5N126W...AND THEN CONTINUES SW TO BEYOND 11N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WELL S OF THE MONSOON TROUGH WITHIN 90 NM EITHER SIDE OF A LINE FROM 04.5N80W TO 08N86W TO 08N91W. SIMILAR CONVECTION IS NOTED ALONG THE TROUGH WITHIN 120 NM EITHER SIDE OF A LINE FROM 12N95W TO 08N110W...WITHIN 30 NM OF LINE FROM 15N105W TO 15N112W TO 16N116W...AND ALONG THE WESTERN SEGMENT OF THE MONSOON OF THE TROUGH WITHIN 60 NM EITHER SIDE OF A LINE FROM 13.5N129W TO 10N140W. ...DISCUSSION... AN UPPER LEVEL NEGATIVE TILT TROUGH EXTENDS FROM 32N126W TO 23N122W. AN AREA OF UPPER MOISTURE IS NOTED WITHIN THE TROUGH AND IS CURRENTLY SWINGING NE AND WILL LIKELY REACH THE CALIFORNIA PENINSULA N OF 34N THIS EVENING. A LARGE UPPER ANTICYCLONE IS CENTERED W OF THE AREA AT 23N150W WITH A RIDGE EXTENDING E TO A CREST AT 21N136W. THESE TWO UPPER FEATURES COMBINE TO DRY OUT THE UPPER LEVELS W OF A LINE FROM THE NW BAJA PENINSULA TO 20N117W TO 13N140W. AN UPPER LEVEL ANTICYCLONE IS OVER OLD MEXICO AT 27N106W WITH AN UPPER RIDGE EXTENDING S TO GENTLE CREST ALONG 08N BETWEEN 104- 115W. AN UPPER TROUGH IS OVER OLD MEXICO ALONG 100W AND THROUGH AN EMBEDDED UPPER CYCLONE NOTED NEAR 19N101W. A SMALL UPPER ANTICYCLONE IS OVER THE YUCATAN PENINSULA. THE RESULT IS AN AREA OF UPPER DIFFLUENCE OVER THE TROPICAL PACIFIC TO THE N OF 08N BETWEEN 92-103W...AND IS ENHANCING THE CONVECTION AS PREVIOUSLY DESCRIBED NEAR THE LOW PRESSURE/TROPICAL WAVE MOVING THROUGH THE GULF OF TEHUANTEPEC AREA. $$ NELSON