000 AXPZ20 KNHC 140917 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON OCT 14 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 0900 UTC. ...SPECIAL FEATURES... TROPICAL STORM OCTAVE NEAR 21.6N 113.9W AT 14/0900 UTC OR 213 NM SSW OF CABO SAN LAZARO MEXICO MOVING NNW AT 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE 995 MB. MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS WITHIN 120 NM IN THE NE QUADRANT. SCATTERED MODERATE CONVECTION IS ELSEWHERE WITHIN 180 NM IN THE N AND NE QUADRANTS. OCTAVE IS FORECAST TO WEAKEN AS IT MOVES OVER COOLER SEA SURFACE TEMPERATURES WHILE ALSO ENCOUNTERING INCREASING SHEAR ALOFT WITH THE OFFICIAL FORECAST BRINGING OCTAVE DOWN TO A TROPICAL DEPRESSION BY TUE AFTERNOON...THEN TO A REMNANT LOW BY LATE TUE NIGHT. EVEN THOUGH OCTAVE IS FORECAST TO WEAKEN AS IT MOVES CLOSER THE SOUTHERN BAJA CALIFORNIA PENINSULA...LOCALLY HEAVY RAINFALL IS SPREADING ACROSS THE SOUTHERN PENINSULA AND WILL CONTINUE TO DO SO DURING THE NEXT DAY OR TWO. NEWLY NAMED TROPICAL STORM PRISCILLA NEAR 14.3N 115.7W AT 14/0900 UTC OR 613 NM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MOVING NNE AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE 1001 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS WITHIN 150 NM IN THE SW QUADRANT. SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 12N TO 14N BETWEEN 116W AND 119W. PRISCILLA IS FORECAST TO MOVE TO THE N-NE WHILE STRENGTHENING SLIGHTLY DURING THE NEXT 24 HOURS...THEN IS FORECAST TO WEAKEN AS IT ENCOUNTERS COOLER SEA SURFACE TEMPERATURES AND A MORE STABLE AIRMASS. THE OFFICIAL FORECAST HAS OCTAVE WEAKENING TO A TROPICAL DEPRESSION BY WED NIGHT...THEN TO REMNANT LOW BY THU NIGHT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 09N84W TO LOW PRES NEAR 10N100W TO 14N106W...THEN RESUMES FROM 12N120W TO 09N119W. THE ITCZ EXTENDS FROM 09N119W TO BEYOND 09N140W. NO SIGNIFICANT CONVECTION DIRECTLY RELATED TO THE MONSOON TROUGH OR ITCZ IS NOTED...HOWEVER SCATTERED MODERATE CONVECTION IS N OF 03N E OF 80W...INCLUDING THE GULF OF PANAMA...AS WELL AS N OF 11N BETWEEN 88W AND 92W. ...DISCUSSION... AN UPPER LEVEL TROUGH REMAINS IN PLACE FROM SOUTHERN CALIFORNIA THROUGH 32N118W TO 12N137W WITH LITTLE TO NO EASTWARD PROGRESS BEING MADE DUE TO A DOMINATE UPPER LEVEL ANTICYCLONE WHICH REMAINS ANCHORED OVER CENTRAL MEXICO NEAR 23N100W. DRY AND STABLE AIR IS BETWEEN 116W AND 130W IN THE VICINITY OF THE TROUGH AXIS WHILE THE ANTICYCLONE CONTINUES TO PROVIDE UPPER LEVEL SUPPORT FOR BOTH OCTAVE AND PRISCILLA WHICH ARE ON THE SW- W PERIPHERY OF IT. ADDITIONAL CONVECTIVE DEBRIS IS BEING ADVECTED BY THE ANTICYCLONE ACROSS THE WATERS FROM 04N TO 20N BETWEEN 102W AND 122W...AS WELL AS ACROSS THE SOUTHERN BAJA CALIFORNIA PENINSULA...GULF OF CALIFORNIA AND NW MEXICO. AN UPPER LEVEL RIDGE IS OVER THE NW PORTION W OF THE UPPER TROUGH EXTENDING FROM 17N134W TO 32N133W. TROPICAL MOISTURE IS MOVING UP FROM THE DEEP TROPICS NEAR AND S OF THE HAWAIIAN ISLANDS TO THE NE AROUND THE RIDGE W OF ITS AXIS. ELSEWHERE AT THE SURFACE...A RIDGE EXTENDS FROM 32N133W TO NW OF OCTAVE NEAR 25N120W. MODERATE TO FRESH WINDS AND 4-7 FT SEAS DOMINATE THE WATERS N OF 10N W OF 120W...EXCEPT FROM 14N TO 18N W OF 136W WHERE LINGERING 8 FT SEAS IN NE SWELL ARE GRADUALLY DECAYING IN THE WAKE OF THE REMNANTS OF NARDA WHICH HAVE FINALLY SHIFTED W OF 140W. WINDS ARE FORECAST TO INCREASE TO MODERATE TO FRESH IN THE NORTHERN GULF OF CALIFORNIA WITH SEAS BUILDING TO 4-6 FT AFTER OCTAVE DISSIPATES WITH A TIGHTENING PRES GRADIENT SETTING UP ACROSS THE NW MEXICO REGION. GULF OF TEHUANTEPEC...THE REMNANTS OF A TROPICAL WAVE ALONG WITH HIGH PRES RIDGING OVER THE FAR W GULF OF MEXICO ARE SUPPORTING FRESH TO STRONG NORTHERLY WINDS AND RESULTANT SEAS TO 8 FT IN THE GULF OF TEHUANTEPEC TONIGHT. WHILE A BRIEF LULL IN THESE CONDITIONS IS FORECAST LATER TODAY...EXPECT ANOTHER ROUND OF FRESH TO STRONG WINDS AND SEAS TO 8 FT IN THE IMMEDIATE GULF OF TEHUANTEPEC WATERS IN 24 HOURS BEFORE DIMINISHING DURING THE DAY ON TUE. $$ LEWITSKY