000 AXPZ20 KNHC 100936 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON OCT 10 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0745 UTC. ...SPECIAL FEATURES... HURRICANE JOVA CENTERED NEAR 16.3N 107.2W AT 10/0900 UTC MOVING E OR 085 DEG AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 960 MB. MAXIMUM SUSTAINED WIND SPEED IS 105 KT WITH GUSTS TO 130 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. NUMEROUS MODERATE TO STRONG CONVECTION LIES WITHIN 90 NM OF CENTER WITH SCATTERED MODERATE TO STRONG CONVECTION ELSEWHERE WITHIN 150 NM EXCEPT 180 NM NE QUADRANT...240 NM SW QUADRANT AND 120 NM NW QUADRANT. LATEST NHC ADVISORY FORECASTS JOVA TO INTENSIFY TODAY AS IT CONTINUES ON AN E-NE MOTION AND THEN TURN MORE NE AS IT APPROACHES CENTRAL MEXICO...WITH LANDFALL ANTICIPATED OVERNIGHT TUE NIGHT. LARGE AND DANGEROUS WAVES ASSOCIATED WITH JOVA WILL BEGIN TO REACH THE COASTLINE TODAY. INTERESTS IN AND NEAR W CENTRAL MEXICO SHOULD CAREFULLY MONITOR THE LATEST NHC ADVISORY INFORMATION FOR RELATED WATCHES AND WARNINGS AFFECTING MEXICO. TROPICAL STORM IRWIN CENTERED NEAR 14.9N 118.5W AT 10/0900 UTC MOVING E OR 085 DEG AT 5 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. SCATTERED MODERATE CONVECTION LIES WITHIN 120 NM N AND S QUADRANTS OF IRWIN. THE LATEST NHC ADVISORY FORECASTS IRWIN TO REMAIN GENERALLY ON A E-NE TRACK THROUGH THE NEXT 120 HRS WITH LITTLE CHANGE IN INTENSITY. A 1006 MB LOW LOCATED NEAR 11N95W IS DRIFTING E. THE CONVECTION ASSOCIATED WITH THE SYSTEM IS DISPLACED TO THE W...WITH SCATTERED MODERATE AND ISOLATED STRONG CONVECTION N OF 06N BETWEEN 95W AND 100W. BUOY 43301 NEAR 08N95W REPORTED 23 KT SW WINDS AT 0800 UTC AND THE 0256 UTC AND 0436 UTC ASCAT PASSES SHOW A LARGE AREA OF FRESH TO STRONG WINDS SPANNING MUCH OF THE REGION S OF THE MONSOON TROUGH. FORECAST GUIDANCE SUGGESTS THAT THE UPPER LEVEL WINDS CURRENTLY SHEARING THE CONVECTION AWAY FROM THE LOW LEVEL CENTER SHOULD BECOME WEAKEN...ALLOWING FOR SLOW DEVELOPMENT OF THE LOW DURING THE NEXT 48 HOURS AS THE LOW MOVES E-NE. THE LOW MAY BECOME A TROPICAL CYCLONE DURING THIS TIME. INTERESTS ALONG THE PACIFIC COASTS OF SOUTHERN MEXICO...GUATEMALA...EL SALVADOR...HONDURAS...AND NICARAGUA SHOULD MONITOR THE PROGRESS OF THIS SYSTEM. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS IS ANALYZED FROM 11N86W TO 12N91W TO LOW PRES NEAR 11N95W THEN CONTINUES FROM 14N121W TO 11N133W TO 09N138W. ITCZ AXIS IS ANALYZED FROM 09N138W TO 09N140W. NUMEROUS MODERATE TO STRONG CONVECTION LIES WITHIN 180 NM S OF THE AXIS BETWEEN 84W AND 88W. SCATTERED MODERATE CONVECTION IS ELSEWHERE WITHIN 60 NM EITHER SIDE OF THE AXIS E OF 91W. ...DISCUSSION... THE 1026 MB SUBTROPICAL HIGH PRES IS CENTERED W OF THE AREA NEAR 30N150W WITH A RIDGE AXIS EXTENDING E-SE TO NEAR 25N115W. TO THE SE LIES A BROAD AREA OF LOW PRES THAT SPANS ACROSS MEXICO AND CENTRAL AMERICAN INTO THE ADJACENT GULF OF MEXICO...CARIBBEAN AND PACIFIC INCLUDING TROPICAL STORM IRWIN AND HURRICANE JOVA. THIS RIDGE CONTINUES TO BE ERODED AS IRWIN AND JOVA MAKE THEIR WAY TO THE E-NE. FRESH TRADES OVER FAR E WATERS WILL DIMINISH TODAY AS A RESULT OF THE WEAKENED RIDGE. HOWEVER...THE PRES GRADIENT BETWEEN THIS RIDGE AND INCREASINGLY LOWER PRES OVER NW MEXICO IS GENERATING A SMALL AREA OF FRESH N WINDS OVER N CENTRAL FORECAST WATERS AS REPORTED BY SHIP A8EH5 NEAR 25N130W AND SHIP ZCDA9 NEAR 28N131W AT 0600 UTC. AS HURRICANE JOVA APPROACHES THE COAST...EXPECT THE PRES GRADIENT TO ALSO TIGHTEN OVER THE GULF OF CALIFORNIA WHERE FRESH N TO NW WINDS ARE EXPECTED TO BEGIN TONIGHT AND PERSIST THROUGH EARLY THU...BECOMING STRONG NEAR THE END OF THAT TIME PERIOD. FRESH SOUTHWESTERLY MONSOON FLOW DOMINATES THE AREA S OF THE THREE SPECIAL FEATURES NOTED ABOVE. THE PRES GRADIENT IS STRONGEST BETWEEN HIGH PRES OVER THE EASTERN SOUTH PACIFIC AND THE AFOREMENTIONED BROAD LOW PRES OVER CENTRAL AMERICA EXTENDING W TO ENCOMPASS IRWIN AND JOVA. BUOY 43301 NEAR 08N95W REPORTED 23 KT SW WINDS AT 0800 UTC AND THE 0256 UTC AND 0436 UTC ASCAT PASSES SHOW A LARGE AREA OF FRESH TO STRONG WINDS SPANNING MUCH OF THE REGION S OF THE MONSOON TROUGH. THESE WINDS ARE EXPECTED TO MERGE WITH THE LOW PRES DISCUSSED IN THE SPECIAL FEATURES SECTION AS PRESSURES FALL ALONG THE MONSOON TROUGH AND AROUND THIS LOW. THE STRENGTHENING SW FLOW OVER EASTERN WATERS WILL MAINTAIN LOW LEVEL CONFLUENCE AND CONTINUE TO PRODUCE ACTIVE CONVECTION NEAR THE MONSOON TROUGH. SEAS CONTINUE TO REMAIN CHAOTIC OVER CENTRAL WATERS WHERE NW SWELL FROM THE FRONTAL SYSTEMS TO THE N...CROSS-EQUATORIAL SW SWELL...AND NE SWELL FROM THE DIMINISHING TRADE WINDS ARE MERGING IN THE VICINITY OF HURRICANE JOVA AND TROPICAL STORM IRWIN. A NEW PULSE OF NW SWELL IS CURRENTLY PROPAGATING INTO THE FORECAST AREA AND WILL HELP KEEP SEAS TO 9 FT OVER N CENTRAL WATERS WHERE THE AFOREMENTIONED FRESH N WINDS ARE IN PLACE. MEANWHILE...A NEW BATCH OF SW SWELL IS FORECAST TO MOVE INTO SOUTHERN WATERS TUE AND WILL RAISE SIGNIFICANT WAVE HEIGHTS TO 8 TO 10 FT IS AREAS S OF THE MONSOON TROUGH WHERE WINDS ARE NOT FRESH OR STRONGER. $$ SCHAUER