000 AXPZ20 KNHC 130853 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SUN OCT 13 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0830 UTC. ...SPECIAL FEATURES... RECENTLY UPGRADED TROPICAL STORM OCTAVE NEAR 17.1N 111.0W AT 13/0900 UTC OR 352 NM S OF THE SOUTHERN TIP OF BAJA CALIFORNIA MOVING NW AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE 1002 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS WITHIN 60 NM IN THE E SEMICIRCLE...AND ALSO FROM 14N TO 21N BETWEEN 110W AND 113W. FAVORABLE UPPER LEVEL WINDS AND WARM SSTS SHOULD ALLOW FOR CONTINUED DEVELOPMENT DURING THE NEXT 24 HOURS AS OCTAVE MOVES TO THE NW-N. AFTER THAT...OCTAVE WILL BE MOVING OVER COOLER SSTS AND WILL ENCOUNTER INCREASING VERTICAL WIND SHEAR AND DRIER AIR CAUSING OCTAVE TO WEAKEN TO A REMNANT LOW BY TUE NIGHT WHILE MOVING MORE TO THE N-NE...DISSIPATING COMPLETELY BY THU NIGHT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 09N80W TO 13N103W...THEN RESUMES FROM LOW PRES NEAR 13N117W TO 12N133W TO BEYOND 08N140W. NO ITCZ IS PRESENT E OF 140W. SCATTERED MODERATE CONVECTION IS FROM 11N TO 13N BETWEEN 98W AND 100W...FROM 07N TO 11N BETWEEN 101W AND 109W...AND ALSO WITHIN 120 NM IN THE NW SEMICIRCLE OF THE LOW PRES NEAR 13N117W. ...DISCUSSION... AN UPPER LEVEL TROUGH REMAINS IN PLACE FROM SOUTHERN CALIFORNIA THROUGH 32N120W TO 14N130W...MAKING LITTLE EASTWARD PROGRESS AS A BROAD AND DOMINANT UPPER LEVEL ANTICYCLONE OVER CENTRAL MEXICO NEAR 24N100W HOLDS IN PLACE. THE UPPER LEVEL TROUGH CONTINUES TO MAINTAIN A VERY DRY...STABLE...AND SUBSIDING AIR MASS OVER THE BASIN W OF ITS AXIS. TIGHT SOUTHERLY FLOW ALOFT BETWEEN THE TROUGH AND ANTICYCLONE IS ADVECTING MOIST AIR AND CONVECTIVE DEBRIS OVER THE SOUTHERN PORTION OF THE BAJA CALIFORNIA PENINSULA AS WELL AS OVER MAINLAND MEXICO. CONVECTION IS FANNING OUT ON THE S-SW PERIPHERY OF THE ANTICYCLONE ACROSS THE WATERS S OF 20N E OF 120W. ELSEWHERE AT THE SURFACE...A RIDGE IS OVER THE NW PORTION EXTENDING FROM 32N137W TO JUST NW OF OCTAVE NEAR 20N113W. MODERATE NORTHERLY WINDS AND 4-6 FT SEAS DOMINATE THE WATERS UNDER THE RIDGE N OF 20N W OF THE BAJA CALIFORNIA PENINSULA. 1010 MB LOW PRES...THE REMNANTS OF NARDA...IS EMBEDDED IN THE MONSOON TROUGH NEAR 13N135W. FRESH TO STRONG WINDS ARE OCCURRING WITHIN 180 NM IN THE N QUADRANT ALONG WITH 9-11 FT SEAS...WHILE A SET OF N-NE SWELL WITH HEIGHTS OF 8-9 FT OVERLAP THE LOW WITHIN 360 NM IN THE NW SEMICIRCLE. THE LOW IS FORECAST TO CONTINUE TO MOVE WESTWARD WHILE DISSIPATING TO A TROUGH BY MON AFTERNOON AS IT APPROACHES 140W. 1006 MB LOW PRES IS EMBEDDED IN THE MONSOON TROUGH SW OF OCTAVE NEAR 13N117W. AN AREA OF FRESH TO STRONG WINDS AND 8-10 FT SEAS IS OCCURRING SE-S OF THIS LOW WITH A SMALL AREA OF DISORGANIZED DEEP CONVECTION NEAR THE LOW. THE LOW IS FORECAST TO SLOWLY LIFT TO THE N-NE THROUGH THE NEXT 48 HOURS AND WILL LIKELY BE IMPACTED BY THE OUTER CIRCULATION OF OCTAVE HINDERING ANY SIGNIFICANT DEVELOPMENT. GULF OF TEHUANTEPEC...THE REMNANTS OF A TROPICAL WAVE OVER WESTERN CENTRAL AMERICA IS FORECAST TO HELP USHER IN FRESH TO STRONG NORTHERLY WINDS AND RESULTANT SEAS TO 8 FT IN THE GULF OF TEHUANTEPEC LATER THIS MORNING. THESE CONDITIONS WILL PERSIST THROUGH MON...DIMINISHING BY MON NIGHT. $$ LEWITSKY