000 AXPZ20 KNHC 200915 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SUN AUG 20 2006 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 0845 UTC. ...SPECIAL FEATURES... HURRICANE HECTOR AT 19.4N 132.6W 980 MB AT 0900 UTC AUG 20 MOVING WNW OR 305 DEG AT 9 KT. MAXIMUM SUSTAINED WINDS 75 KT GUSTS 90 KT. SOLID AREA OF STRONG CONVECTION IS NOTED WITHIN 90 NM NW QUADRANT OF CENTER. NUMEROUS MODERATE TO STRONG CONVECTION IN A BAND SE OF THE CENTER FOR 125 NM. HECTOR IS ENCOUNTERING NW SHEAR AND DRY AIR ENTRAINMENT OVER ITS SW QUAD. A STEADY WEAKENING TREND IS FORECAST TODAY AS HECTOR MOVES OVER COOLER SEA SURFACE WATERS. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE ALONG 98W MOVING W AT 10 TO 15 KT. SOME CYCLONIC ROTATION NOTED IN MID CLOUDS NEAR WAVE AXIS. SCATTERED MODERATE CONVECTION WITHIN 4 DEGREES OF AXIS BUT NO ORGANIZATION. A TROPICAL WAVE ALONG 121W MOVING W AT 10 TO 15 KT. SCATTERED MODERATE CONVECTION ALONG THE ITCZ BUT NO ORGANIZATION. ...ITCZ... THE ITCZ AXIS ALONG 7N77W 13N98W 8N108W 9N121W 15N130W 11N140W. SCATTERED STRONG CONVECTION WITHIN 90 NM OF 5N78W AND 7N88W. SCATTERED MODERATE/ISOLATED STRONG WITHIN 30 NM OF A LINE FROM 9N98W TO 8N110W TO 9N123W. ISOLATED MODERATE NEAR 13N136W. SCATTERED STRONG CONVECTION NEAR 10N88W 13N91W 15N93W 15N95W 15N100W AND 14N102W. ...DISCUSSION... AT MID LEVELS TONIGHT A STRONG RIDGE REMAINS OVER THE SRN PLAINS WITH IT'S AXIS EXTENDING WSW TO 14N126W. THE WESTERLIES REMAIN N OF 30N WITH A SHORTWAVE TROUGH ALONG 132W MOVING E TONIGHT. ON THE SURFACE TONIGHT A WEAKENED PACIFIC RIDGE REMAINS OVER THE AREA FROM 30N132W SE TO 15N110W. HRCN HECTOR CONTINUES ON A WNW COURSE AND IS PUSHING INTO THE RIDGE CREATING AN AREA OF STRONG NE WINDS OF 25 KT BETWEEN 15N AND 26N W OF 130W. THE RIDGE IS ALSO PRODUCING NW WINDS TO 20 KT ALONG THE BAJA COAST TONIGHT THANKS IN PART TO WEAK LOW PRESSURE OVER THE GULF OF CALIFORNIA. GAP WINDS ALONG THE CENTRAL AMERICAN COAST REMAIN LIGHT WHILE CROSS EQUATORIAL SLY WINDS TO 20 KT ARE MAINLY BETWEEN 90W AND 110W S OF 8N ACCORDING TO QUIKSCAT AND SSMI. LATER DAY 1 WHILE THE MID LEVEL RIDGE REMAINS IN PLACE A WEAK INVERTED TROUGH WORKS IT'S WAY W ALONG 107W. THE TROUGH IS EMBEDDED IN THE TROPICAL EASTERLIES. THE SHORTWAVE TROUGH IN THE WESTERLIES BEGINS TO LIFT NE ALONG 125W N OF 30N WITH THE FLOW BECOMING MORE ZONAL BEHIND THE TROUGH. ON THE SURFACE LATER DAY 1 LITTLE CHANGE TO THE NE TRADES AS HECTOR CONTINUES WNW. WINDS ALONG THE BAJA COAST WILL REMAIN NWLY TO 20 KT WITH NW SWELL TO 8 FT. GAP WINDS WILL REMAIN LIGHT. THE GFS MODEL WANTS TO DEVELOP A WEAK LOW PRES CENTER NEAR 10N100W BUT AS OF NOW LITTLE EVIDENCE CAN BE FOUND FOR IT IN IR IMAGERY OR MICROWAVE IMAGERY. CROSS EQUATORIAL SLY WINDS S OF 8N SHOULD BE STRONGEST BETWEEN 95W AND 110W WITH SLY SWELL TO 8 FT. FOR DAY 2 THE MID LEVEL RIDGE OVER THE SRN US SHOWS SIGNS OF WEAKENING BUT THE OVERALL CONFIGURATION CHANGES LITTLE. A RIDGE AXIS WILL STILL EXTEND SW TO NEAR 20N128W. THE INVERTED TROUGH IN THE EASTERLIES MOVES TO 110W. THE WESTERLIES BECOME MORE SWLY W OF 135W WITH A STRONG MID LEVEL TROUGH MOVING BY THE REGION ALONG 132W AND A WEAKER ONE APPROACHING THE NW CORNER OF THE AREA ALONG 142W. ON THE SURFACE DAY 2 HECTOR WEAKENS RAPIDLY AS IT MOVES TO THE EDGE OF THE REGION NEAR 22N140W. THE PACIFIC RIDGE REMAINS OVER THE REGION FROM 30N132W TO 20N125W WITH NE TRADES CONFINED TO AN AREA N OF HECTOR TO 30N AND W OF 130W. SOME INCREASE IN NLY WINDS TO 20 KT N OF 22N BETWEEN 118W AND 130W FOR DAY 2. WINDS ALONG THE BAJA COAST WILL WEAKEN SLIGHTLY TO 10 TO 15 KT AS THE PRES GRADIENT WEAKENS. GAP WINDS REMAIN LIGHT WHILE CROSS EQUATORIAL WINDS SHOULD BE STRONGEST S OF 10N BETWEEN 95W AND 120W WITH SLY SWELL TO 8 FT. THESE WINDS WILL DEPEND ON DEVELOPMENT OF LOW PRESSURE NEAR 11N102W AS THE GFS MODEL CONTINUES TO SHOW. $$ RRG