000 AXPZ20 KNHC 202202 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SUN NOV 20 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2100 UTC. ...SPECIAL FEATURE... TROPICAL STORM KENNETH NEAR 11.5N 105.6W AT 20/2100 UTC OR 525 MI S OF MANZANILLO MEXICO MOVING W-NW AT 11 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 EXTENDING W-SW FROM THE GULF OF MEXICO. ESTIMATED MINIMUM CENTRAL PRESSURE 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. KENNETH BECOMES THE LATEST-FORMING NAMED STORM IN THE EASTERN NORTH PACIFIC SINCE HURRICANE WINNIE FORMED ON 4 DECEMBER 1983. SLOW STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS. NUMEROUS MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 240 NM IN THE N SEMICIRCLE OF KENNETH. SCATTERED MODERATE CONVECTION IS WITHIN 90-180 NM IN THE SE AND S QUADRANTS OF KENNETH. 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 08N92W TO 09N96W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N96W TO 11N102W THEN RESUMES FROM 09N107W TO 08N125W TO 09N129W THEN RESUMES FROM 10N132W TO 09N140W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM N OF THE ITCZ BETWEEN 111W AND 114W. SIMILAR CONVECTION IS FROM 08N TO 10 BETWEEN 127W AND 132W. ...DISCUSSION... AN UPPER LEVEL TROUGH ENTERS THE FORECAST REGION THROUGH 32N121W EXTENDING SW-W TO BEYOND 25N140W. SW FLOW AHEAD OF THIS TROUGH IS ADVECTING ABUNDANT MID TO UPPER LEVEL MOISTURE ACROSS THE N WATERS INTO BAJA CALIFORNIA AND NW MEXICO. AN ASSOCIATED COLD FRONT REACHES FROM 30N123W TO 28N133W...THEN DISSIPATING TO 30N140W. NW-N 20 KT WINDS ARE NOTED BEHIND THE FRONT AS CONFIRMED BY A 1800 UTC 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. MEANWHILE...THE FRONT WILL MOVE SE WHILE WEAKENING...REACHING FROM 29N115W TO 25N120W TO 23N130W IN 24 HOURS...THEN DISSIPATING BY 48 HOURS. A PAIR OF UPPER LEVEL ANTICYCLONES ARE CENTERED SW OF CENTRAL MEXICO...ONE NEAR 14N99W AND THE OTHER NEAR 15N109W. UPPER LEVEL RIDGING EXTENDS FROM THESE ANTICYCLONES NE TO THE YUCATAN PENINSULA 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...1021 MB HIGH PRES IS NEAR 25N135W AHEAD OF THE ABOVE MENTIONED COLD FRONT. A TIGHT PRES GRADIENT EXISTS BETWEEN THE FRONT...HIGH...AND LOWER PRES ASSOCIATED WITH THE ITCZ...RESULTING IN AN AREA OF FRESH TRADES FROM 11N TO 20N W OF 130W WITH SEAS TO 9 FT. A SURFACE TROUGH IS ALSO ANALYZED IN THIS AREA FROM 12N130W TO 08N132W 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 DRAWERS CLOSER TO THE AREA ALONG WITH BUILDING HIGH PRES ARRIVING BEHIND THE DISSIPATING COLD FRONT. SW 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 ON MON MORNING...THEN WILL DISSIPATE AS THE GRADIENT WEAKENS IN THE EARLY AFTERNOON...WITH A NEW ROUND OF FRESH NORTHERLY WINDS ACROSS THE MAJORITY OF THE GULF MON NIGHT AND TUE AS THE PRES GRADIENT TIGHTENS OVER THE REGION. GAP WINDS...A HIGH RESOLUTION 1622 UTC 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