000 AXPZ20 KNHC 241547 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC WED AUG 21 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 STORM IVO IS CENTERED NEAR 22.5N 113.4W OR 225 MILES W OF CABO SAN LUCAS MEXICO AT 1500 UTC...MOVING N-NW OR 340 DEG AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 998 MB. MAXIMUM SUSTAINED WINDS ARE 40 KT WITH GUSTS TO 50 KT. CURRENTLY SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 90 NM EITHER SIDE OF A LINE FROM 24N114W TO 21N112W TO 17N112W. IVO IS EXPECTED TO REMAIN A TROPICAL STORM FOR THE NEXT 24 HOURS THEN WEAKEN TO A TROPICAL DEPRESSION AS THE CENTER BEGINS TO TRACK ACROSS COOLER SEA SURFACE WATERS. THE DEBRIS MOISTURE FROM IVO IS ADVECTED N TO ALONG 29N BETWEEN 16W-115W AND WILL LIKELY CONTINUE TO SUPPORT CONVECTION ALONG THE THE MEXICAN COAST NEAR 27N110W. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. A LONG FETCH OF SOUTHWESTERLY WINDS ASSOCIATED WITH THE TROPICAL CYCLONE IS NOTED FROM 20-25N BETWEEN 105-115W...AND IS PRODUCING COMBINED SEAS TO 16 FT WITH THE MAXIMUM SEAS NEAR THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA. LARGE SURF WILL IMPACT THE PACIFIC COAST OF THE CENTRAL AND SOUTH BAJA CALIFORNIA PENINSULA THROUGH TONIGHT...AS WELL AS THE SOUTHERN GULF OF CALIFORNIA. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS W ALONG 11N FROM THE NW COAST OF COLOMBIA AT 76W ACROSS THE SW CARIBBEAN TURNING NW ACROSS SOUTHERN NICARAGUA AND ALONG THE PACIFIC COAST OF SAN SALVADOR AND GUATEMALA TO 14.5N92W...THEN TURNS ABRUPTLY SW TO THE PACIFIC AT 09N104W...THEN NW TO 13N106W WHERE THE TROUGH LOSES IDENTITY IN THE BROAD CYCLONIC CIRCULATION ASSOCIATED WITH TROPICAL CYCLONE IVO. THE MONSOON TROUGH IS EVIDENT IN THE SCATTEROMETER DATA SW OF IVO NEAR 17N116W AND CONTINUES SW THROUGH AN EMBEDDED SURFACE LOW PRESSURE AT 14N126W...THEN CONTINUES SW TO BEYOND TO 11N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED ALONG THE COAST OF COLOMBIA TO THE N OF 03N AND E OF 80W. SIMILAR CONVECTION IS NOTED WELL S OF THE MONSOON TROUGH AXIS WITHIN 60 NM EITHER SIDE OF A LINE FROM 09.5N89W TO 07N99W TO 10N100W... AND ALONG THE MONSOON TROUGH AXIS WITHIN 120 NM EITHER SIDE OF A LINE FROM 12N90W TO 14N95W TO 10N105W. SMALL CLUSTERS OF SCATTERED MODERATE ISOLATED STRONG CONVECTION IS ALSO NOTED ALONG THE WESTERN SEGMENT OF THE MONSOON TROUGH WITHIN 15 NM EITHER SIDE OF A LINE FROM 15N113W TO 16.5N120W...AND WITHIN 60 NM EITHER SIDE OF A LINE FROM 09N130W TO 12N134W TO 11N140W. THE ILL-DEFINED EMBEDDED SURFACE LOW AT 14N126W IS UNDER THE CREST OF AN UPPER RIDGE...WITH DRY UPPER AIR CONTINUING TO ENTRAIN AROUND THE WESTERN PERIPHERY OF THE LOWER LEVEL CYCLONE. LITTLE CHANGE IS EXPECTED FOR THE NEXT 24 HOURS. ...DISCUSSION... AN UPPER LEVEL NEGATIVE TILT TROUGH EXTENDS FROM 32N124W TO 26N123W. SOME UPPER MOISTURE IS SWINGING E THROUGH THE TROUGH AND WILL MOVE ACROSS THE CALIFORNIA PENINSULA N OF 34N IN A FEW HOURS. A LARGE UPPER ANTICYCLONE IS CENTERED W OF THE AREA AT 23N147W WITH A RIDGE EXTENDING E TO A CREST AT 24N129W. THESE TWO UPPER FEATURES COMBINE TO DRY OUT THE UPPER LEVELS W OF A LINE FROM SOUTHERN ARIZONA TO 14N130W. AN UPPER LEVEL ANTICYCLONE IS OVER OLD MEXICO AT 24N104W WITH ITS ANTICYCLONIC ENVELOPE EXTENDING SE TO AN ILL-DEFINED CREST AT 12N90W...RESULTING IN UPPER LEVEL NE FLOW ACROSS THE DEEP TROPICS BETWEEN 88-114W...AND ADVECTING THE DEBRIS MOISTURE FROM THE PREVIOUSLY DESCRIBED MONSOON TROUGH CONVECTION S TO ALONG 05N BEFORE IT EVAPORATES. $$ NELSON