000 AXPZ20 KNHC 210323 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON NOV 21 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 0300 UTC. ...SPECIAL FEATURE... TROPICAL STORM KENNETH NEAR 12.2N 107.0W AT 21/0300 UTC OR 505 MI S OF MANZANILLO MEXICO MOVING W-NW AT 12 KT. KENNETH SHOULD MOVE ON A GENERAL W TO W-NW HEADING THROUGH THE NEXT 48 HOURS UNDER THE W EXTENSION OF MID-LEVEL RIDGING REACHING W-SW FROM THE GULF OF MEXICO. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...AND KENNETH IS EXPECTED TO BECOME A HURRICANE IN ABOUT 36 HOURS. NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS WITHIN 120 NM IN THE W SEMICIRCLE OF THE CENTER OF KENNETH. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS ELSEWHERE FROM 10N TO 16N BETWEEN 103W AND 110W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ33 FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 10N86W TO 07N91W TO 10N102W THEN RESUMES NEAR 10N108W TO 09N115W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N115W TO 07N127W TO 09N132W THEN RESUMES FROM 09N134W TO 09N140W. ISOLATED TO SCATTERED MODERATE CONVECTION IS FROM 08N TO 10N BETWEEN 108W AND 115W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 07N TO 10N BETWEEN 130W AND 133W. SIMILAR CONVECTION IS WITHIN 45 NM EITHER SIDE OF ITCZ W OF THE 137W. ...DISCUSSION... AN UPPER LEVEL TROUGH ENTERS THE FORECAST REGION THROUGH 32N120W EXTENDING SW-W THROUGH 25N125W TO BEYOND 23N140W. SW FLOW AHEAD OF THIS TROUGH IS ADVECTING ABUNDANT MID TO UPPER LEVEL MOISTURE FROM THE DEEP TROPICS TO THE N WATERS AND ACROSS BAJA CALIFORNIA AND NW MEXICO. AN ASSOCIATED SURFACE COLD FRONT REACHES FROM 32N119W TO 26N130W...THEN IS DISSIPATING TO 29N140W. NW-N 20 KT WINDS ARE NOTED BEHIND THE FRONT TO 130W AS CONFIRMED BY AN EARLIER ASCAT SCATTEROMETER PASS...WITH BUILDING SEAS TO 15 FT IN NW SWELL ALONG THE N CENTRAL BORDER. THIS SWELL WILL CONTINUE TO PROPAGATE SE ACROSS THE DISCUSSION AREA COVERING MAINLY THE AREA N OF 15N AND W OF 110W WHILE ENCOUNTERING THE SEAS ASSOCIATED WITH KENNETH. THE FRONT WILL WEAKEN AS IT CONTINUES TO THE E-SE...DISSIPATING BY 24 HOURS...WITH THE NW SWELL GRADUALLY DECAYING TO 12 FT BY 48 HOURS. A PAIR OF UPPER LEVEL ANTICYCLONES ARE CENTERED SW OF CENTRAL MEXICO...ONE NEAR 15N100W AND THE OTHER NEAR 16N109W. UPPER LEVEL RIDGING EXTENDS FROM THESE ANTICYCLONES NE TO ACROSS THE GULF OF MEXICO AND SW-W TO NEAR 10N140W. UPPER LEVEL DIFFLUENCE ALONG THE RIDGE IS ENHANCING CONVECTION ALONG THE ITCZ AS IS DESCRIBED IN THE SECTION ABOVE. IN ADDITION...THE RIDGING IS HELPING TO SUSTAIN THE DEVELOPING CONVECTION ASSOCIATED WITH TROPICAL STORM KENNETH. ELSEWHERE AT THE SURFACE...BROAD HIGH PRES EXISTS S OF THE COLD FRONT WITH A TIGHT PRES GRADIENT IS PRESENT BETWEEN THE FRONT... THE HIGH...AND LOWER PRES ASSOCIATED WITH THE ITCZ...RESULTING IN AN AREA OF FRESH TRADES FROM 11N TO 20N W OF 130W ALONG WITH 8-10 FT SEAS IN MIXED NE AND NW SWELL. A SURFACE TROUGH IS ALSO ANALYZED IN THIS AREA FROM 13N130W TO 08N133W WITH ASSOCIATED CONVECTION DESCRIBED IN THE SECTION ABOVE. THE TROUGH WILL APPROACH 140W BY 48 HOURS. MEANWHILE...THE TRADES WILL EXPAND EASTWARD DURING THE NEXT 24-48 HOURS AS TROPICAL STORM KENNETH DRAWS CLOSER TO THE AREA ALONG WITH BUILDING HIGH PRES ARRIVING BEHIND THE DISSIPATING COLD FRONT. SW 15-20 KT WINDS ARE IN THE FAR NORTHERN GULF OF CALIFORNIA AHEAD OF THE APPROACHING COLD FRONT. FRESH NORTHERLY WINDS WILL ARRIVE BEHIND THE FRONT BY EARLY MON MORNING...THEN WILL DISSIPATE AS THE GRADIENT WEAKENS IN THE EARLY AFTERNOON. A NEW ROUND OF FRESH NORTHERLY WINDS WILL COMMENCE ACROSS THE MAJORITY OF THE GULF MON NIGHT AND TUE AS THE PRES GRADIENT TIGHTENS OVER THE REGION. A NEW AND EVEN STRONGER COLD FRONT WILL APPROACH THE NW CORNER OF THE DISCUSSION AREA BY 48 HOURS WITH SW 20-25 KT WINDS AHEAD OF IT...AND BUILDING NW SWELL TO 10 FT PROPAGATING OUT AHEAD OF IT. GAP WINDS...AN EARLIER ASCAT PASS CAPTURED N-NE 20 KT WINDS IN THE GULF OF TEHUANTEPEC. THESE WINDS ARE FORECAST TO DIMINISH TO LESS THAN 20 KT DURING THE NEXT 24 HOURS. MEANWHILE...NE-E 20 KT WINDS WILL PULSATE IN AND DOWNWIND OF THE GULF OF PAPAGAYO OFF AND ON DURING THE NEXT 48 HOURS...MAINLY DURING THE LATE NIGHT AND EARLY MORNING HOURS DURING PEAK DRAINAGE FLOW. $$ LEWITSKY