000 AXPZ20 KNHC 040332 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE NOV 04 2008 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0300 UTC. ...ITCZ... AXIS FROM 09N85W TO 06N90W TO 09N115W TO 10N110W TO 07N120W TO 09N135W TO 08N140W. SCATTERED MODERATE CONVECTION WITHIN 90 NM S OF AXIS W OF 137W. ...SPECIAL FEATURE... TROPICAL STORM POLO CENTERED AT 9.5N 115.5W OR ABOUT 860 NM SSW OF SOUTHERN TIP OF BAJA CALIFORNIA AT 2100 UTC MOVING WNW OR 285 DEG AT 12 KT. ESTIMATED MINIMUM CENTRAL PRES 1005 MB. MAXIMUM SUSTAINED WINDS 35 KT GUSTS 45 KT. SATELLITE PICTURES INDICATE A TROPICAL CYCLONE IN A MODERATE WESTERLY SHEAR ENVIRONMENT. HOWEVER...SHIPS MODEL VALUES SHOW NO MORE THAN 10 KT OF VERTICAL SHEAR...WHICH ROUGHLY IS IN AGREEMENT WITH LATEST CIMSS SHEAR ANALYSES. PERHAPS THE LOWER-LEVEL SHEAR IS HIGHER THAN THE SHEAR OVER THE DEPTH OF THE STANDARD MEASURES OF SHEAR OVER THE TROPOSPHERE. PUFFS OF CONVECTION HAVE INTERMITTENTLY BEEN FORMING IMMEDIATELY E OF THE CENTER...WITH A ONCE HEALTHIER BAND LOCATED ROUGHLY 90 NM FROM THE CENTER OVER THE SE SEMI- CIRCLE NOW BECOMING LESS DEFINED AND MORE DISJOINTED FROM THE SYSTEMS CENTRAL FEATURES. POLO COULD NOMINALLY STRENGTHEN OVER THE NEXT DAY OR SO BEFORE LIKELY WEAKENING BEFORE IT ENCOUNTERS EVEN STRONGER WIND SHEAR. SEE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPEP3/WTPZ33 KNHC AND FULL FORECAST /ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC FOR MORE DETAILS. ...DISCUSSION... ELSEWHERE OVER THE TROPICAL EAST PACIFIC...A LOW-LEVEL TROUGH AND ASSOCIATED WEAK SURFACE LOW ALONG 138W/139W IS MOVING RAPIDLY E AT 20 TO 25 KT WITHIN THE ITCZ. AN EARLIER QUIKSCAT PASS REVEALED SCATTERED 20 TO 25 KT NE TO E WINDS IN ASSOCIATION WITH THIS SYSTEM...WHICH EXPAND FARTHER N IN AN AREA RUNNING FROM 10N TO 17N W OF 122W. IN ADDITION TO STRONG WINDS...RELATED BUT DISORGANIZED CONVECTIVE ACTIVITY SURROUNDS THE ITCZ BETWEEN 136W AND 140W... THOUGH THERE ARE NO SIGNS OF ORGANIZATION. CIMSS SHEAR ANALYSES CONTINUE TO SHOW THIS WEATHER SYSTEM ON THE CUSP OF A HIGH WESTERLY SHEAR ENVIRONMENT...WITH THE SHEAR PERHAPS LIKELY HIGH ENOUGH TO PREVENT ANY FURTHER DEVELOPMENT. ASIDE FROM THAT... CLIMATOLOGY DOES NOT FAVOR DEVELOPMENT SO FAR WEST THIS TIME OF YEAR. OTHERWISE...LONG PERIOD NW SWELL WHICH CAME OUT OF THE NE PACIFIC THE LAST FEW DAYS CONTINUES TO FLOOD MOST OF THE NW HALF OF THE AREA TONIGHT. LATEST SEA STATE ANALYSES INDICATE NW SWELL OF 8 TO 10 FT GENERALLY NW OF A LINE EXTENDING FROM 25N112W TO 10N124W TO 05N140W. THE NW SWELL IS COMBINING WITH NE WIND WAVES BEING GENERATED BY ENHANCED TRADES FROM 10N TO 17N W OF 122W TO MAKE FOR A LARGE AREA OF ROUGH AND CONFUSED SEAS WITH WAVE HEIGHTS UP TO 11 FT. OVER THE NEXT FEW DAYS...THE ENHANCED TRADES SHOULD GRADUALLY TAPER OFF...AND THE NW SWELL COMING OUT OF THE NE PACIFIC SHOULD CONTINUE DISPERSING AND SUBSIDING AS IT OVERSPREADS MUCH OF THE AREA W OF 110W. FINALLY...A GULF OF TEHUANTEPEC GALE/STORM EVENT NEARLY A WEEK AGO HAS FINALLY COME TO A CLOSE...MAKING IT THE SECOND LONGEST GULF OF TEHUANTEPEC GAP WIND EVENT SINCE THE LATE 1990S. THERE IS SOME SUGGESTION IN THE MODEL DATA THAT N TO NE WINDS HAVE FURTHER DIMINISHED TO 20 TO 25 KT WITHIN ABOUT 45 NM EITHER SIDE OF A LINE FROM 16.594.5W TO 14N95.5W...AND THIS IS CORROBORATED BY A 0026 UTC QUIKSCAT PASS. OUTSIDE OF THIS AREA...N TO NE SWELL FROM THE LONG-LIVED WIND EVENT ARCS WELL SW TO W THROUGH 11N98W TO NEAR 08N110W. INTERESTINGLY...A COMBINATION OF IR SATELLITE IMAGERY AND OTHER SEA SURFACE TEMPERATURE DATA SUGGEST THAT THE STRONG GAP WINDS AND SUBSEQUENT SURFACE EVAPORATION HAVE COOLED WATER TEMPERATURES FROM 1 TO NEARLY 3C IN AREAS DOWNSTREAM OF THE GULF OF TEHUANTEPEC. WITH LOWERING SURFACE PRESSURE NOW SPREADING INTO THE CENTRAL PLAINS MEXICO...THE PATTERN WHICH LED TO THIS LONG-LIVED GAP WIND EPISODE IS BEGINNING TO DISAPPEAR. AS A RESULT...EXPECT WINDS TO CONTINUE TO GRADUALLY DIMINISH AND SEAS SUBSIDE THROUGH THE NEXT 48 HOURS. $$ KIMBERLAIN