000 AXPZ20 KNHC 090312 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN OCT 09 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC. ...SPECIAL FEATURES... TROPICAL STORM IRWIN CENTERED NEAR 14.7N 120.3W AT 09/0300 UTC MOVING NE OR 050 DEG AT 3 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. OUTFLOW FROM THE WIDESPREAD CONVECTION ASSOCIATED WITH HURRICANE JOVA TO THE E HAS CONTINUED TO PRODUCE EASTERLY WIND SHEAR IMPINGING UPON IRWIN...LEAVING A COMPLETELY EXPOSED LOW LEVEL CIRCULATION VOID OF DEEP CONVECTION. IN FACT...VERY LIMITED DEEP CONVECTION REMAINS AND WHAT DOES REMAIN IS WELL REMOVED FROM THE CENTER. ISOLATED TO SCATTERED MODERATE CONVECTION IS FROM 11.5N TO 15N BETWEEN 122W AND 127W. IRWIN IS EXPECTED TO MOVE LITTLE OVER THE NEXT 24 HOURS...BUT THEREAFTER IS FORECAST TO MOVE E-NE IN THE GENERAL DIRECTION OF W CENTRAL MEXICO THROUGH 120 HOURS. IRWIN IS FORECAST TO FLUCTUATE LITTLE IN INTENSITY THROUGH 72 HOURS WITH SLIGHTLY STRENGTHENING POSSIBLE THEREAFTER. HURRICANE JOVA CENTERED NEAR 16.0N 109.6W AT 09/0300 UTC MOVING E OR 090 DEG AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 989 MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH GUSTS TO 80 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. DEEP CONVECTION CONTINUES TO SURROUND JOVA WITH NUMEROUS MODERATE TO STRONG CONVECTION WITHIN 60-90 OF THE CENTER...AND SCATTERED MODERATE CONVECTION ELSEWHERE FROM 11.5N TO 18N BETWEEN 108W AND 115W. JOVA IS EXPECTED TO CONTINUE MOVING E-NE TOWARD W CENTRAL MEXICO WITH THE CURRENT FORECAST INDICATING JOVA WILL MAKE LANDFALL ON TUE AFTERNOON. ADDITIONAL STRENGTHENING IS FORECAST UNTIL LANDFALL WITH THE CURRENT FORECAST HAVING JOVA REACHING MAJOR HURRICANE STRENGTH JUST PRIOR TO LANDFALL. 1007 MB LOW PRES EMBEDDED IN THE MONSOON TROUGH CENTERED NEAR 11N96.5W IS BECOMING BETTER ORGANIZED AND THERE IS A HIGH CHANCE THAT IT COULD BECOME A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. THIS LOW IS DRIFTING W AROUND 5 KT. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE LOW CENTER. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 11N86W TO 1007 MB LOW PRES NEAR 11N96W TO 12N98W WHERE THERE IS A BREAK IN THE TROUGH DUE TO THE CIRCULATION AROUND TROPICAL STORM IRWIN AND HURRICANE JOVA. THE MONSOON TROUGH THEN RESUMES FROM 13N124W TO 08N136W. THE ITCZ AXIS EXTENDS FROM 08N136W TO 08N140W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE LOW CENTER AND ALSO FROM 07N TO 11N BETWEEN 97W AND 103W. SIMILAR CONVECTION IS FROM 16N TO 18N BETWEEN 103W AND 106W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 06N TO 10N E OF 85W. ...DISCUSSION... 1027 MB HIGH PRES IS CENTERED N OF THE AREA NEAR 33N137W WITH A RIDGE AXIS EXTENDING SE TO NEAR 22N116W. THE PRES GRADIENT BETWEEN THIS RIDGE AND LOWER PRES ASSOCIATED WITH TROPICAL STORM IRWIN AND HURRICANE JOVA CONTINUES TO PRODUCE FRESH NE TRADES FROM 17N TO 22N W OF 130W WITH SEAS OF 9 TO 11 FT IN MIXED NE AND NW SWELL. THESE TRADES WILL DIMINISH IN 24 HOURS AS THE PRES GRADIENT WEAKENS SLIGHTLY WITH THE HIGH MOVING SW AND IRWIN AND JOVA MOVING E. IN ADDITION...THE PRES GRADIENT BETWEEN THE RIDGE AND TROUGHING OVER INLAND MEXICO IS MAINTAINING FRESH NW TO N WINDS OVER THE GULF OF CALIFORNIA FROM 26N TO 30N WHICH WILL ALSO DIMINISH BY 24 HOURS AS THE HIGH RETREATS. MONSOONAL FLOW DOMINATES THE REMAINDER OF THE SOUTHERN HALF OF THE WATERS WITH THE THREE SPECIAL FEATURES NOTED ABOVE ORIGINATING WITHIN THE MONSOON TROUGH. IRWIN AND JOVA REMAIN EMBEDDED WITHIN THE WESTERN END OF THIS MONSOONAL CIRCULATION...WHILE THE LOW CENTER SW OF THE GULF OF TEHUANTEPEC IS EMBEDDED WITHIN THE W PORTION OF A MONSOONAL GYRE WHICH IS ANCHORED BY A BROAD AND WEAK LOW LEVEL CYCLONIC CIRCULATION ACROSS THE EXTREME SW CARIBBEAN. SW TO W 20 TO 25 KT FLOW IS EXPECTED FROM THE MONSOON TROUGH S TO ABOUT 04N E OF 100W TO PANAMA AND COLOMBIA...WHICH WILL MAINTAIN LOW LEVEL CONFLUENCE AND CONTINUE TO PRODUCE ACTIVE CONVECTION ACROSS THIS ZONE. NW SWELL IS CONTINUING TO PROPAGATE THROUGH THE NORTHERN FORECAST WATERS AND IS MERGING WITH THE 15-17 PERIOD CROSS-EQUATORIAL SW SWELL OVER THE CENTRAL WATERS INCLUDING THE AREAS NEAR JOVA AND IRWIN...WHERE COMBINED SEAS ARE AS HIGH AS 12 FT. THIS MERGING SWELL COMBINED WITH FRESHLY GENERATED WIND WAVES IS CREATING A VERY CONFUSED AND CHAOTIC SEA STATE ACROSS THE CENTRAL WATERS THAT IS EXPECTED TO PERSIST THROUGH MON. A NEW PULSE OF NW SWELL WILL PROPAGATE INTO THE FORECAST SUN NIGHT INTO MON WITH FRESH N TO NE WINDS DEVELOPING N OF 20N BETWEEN 120W AND 130W IN 48 HOURS AS THE PRES GRADIENT TIGHTENS A BIT. $$ LEWITSKY