000 AXPZ20 KNHC 030943 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU OCT 02 2008 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...SPECIAL FEATURES... TROPICAL STORM MARIE IS CENTERED NEAR 17.8N 121.7 W AT 03/0900 UTC...OR ABOUT 725 NM WEST-SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. MARIE IS MOVING WEST OR 270 DEG AT 06 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 65 KT. PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC AND THE INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPEP4/WTPZ34 KNHC FOR MORE DETAILS. THE CONVECTIVE PATTERN ASSOCIATED WITH MARIE CONTINUES TO IMPROVE...WITH A PROMINENT BANDING FEATURE WRAPPING NEARLY TWO- THIRDS OF THE WAY AROUND THE CENTER. THE CIMSS SHEAR ANALYSES SUGGEST ABOUT 10 KT OF NORTHERLY SHEAR OVER MARIE...WHICH MATCHES THE STORM STRUCTURE AS REVEALED IN A LATE EVENING SSMIS PASS FROM YESTERDAY. MARIE IS FORECAST TO STRENGTHEN SLIGHTLY OVER THE NEXT DAY OR SO BEFORE IT ENCOUNTERS COOLER WATERS. A BROAD AREA OF LOW PRESSURE LOCATED NEAR 14N100W...OR A LITTLE LESS THAN 200 MILES S OF ACAPULCO...HAS BEEN MOVING SLOWLY WNW TO NW THE PAST FEW DAYS. A STRONG LOW- TO MID-LEVEL TURNING... NOT COINCIDENT WITH THE ESTIMATED SURFACE CENTER...IS LOCATED NW OF THE DEEPEST CONVECTIVE TOPS EARLY THIS MORNING. THIS CONVECTION MAKES OUT WHAT MAY BE A PRIMITIVE BANDING FEATURE... THOUGH THE CONVECTION COMPRISING IT HAS BEEN INTERMITTENT. EARLIER QUIKSCAT DATA INDICATED NOTHING MORE THAN AN ELONGATED BUT SHARP TROUGH AXIS RUNNING ROUGHLY E-W ALONG 14N. CIMSS SHEAR ANALYSES DO INDICATE IN EXCESS OF 10 KT OF EASTERLY SHEAR...BUT THE SYSTEM STILL HAS A MEDIUM POTENTIAL (20-50%) TO BECOME A TROPICAL DEPRESSION WITHIN THE NEXT 48 HOURS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 12N85W TO 14N100W TO 12N118W TO 06N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 150 NM N AND 240 NM S OF AXIS BETWEEN 85W AND 110W. ...DISCUSSION... W OF 110W... WATER VAPOR IMAGERY AND CLOUD-TRACKED WINDS INDICATE AN ENHANCED PACIFIC JET WELL N OF THE AREA...WHICH SHOULD SEND A VIGOROUS SHORTWAVE TROUGH INTO THE WEST COAST BY SAT AFTERNOON. STRONG NW FLOW IN THE WAKE OF THE ASSOCIATED SURFACE CYCLONE IS FORECAST TO GENERATE SIGNIFICANT NW SWELL...WHICH SHOULD BEGIN ARRIVING OVER THE FAR NW WATERS SAT AFTERNOON. THIS SWELL SHOULD REINFORCE THE 7 TO 9 FT NW SWELL CURRENTLY MOVING THROUGH THE NW HALF OF THE AREA...ROUGHLY NW OF A LINE RUNNING FROM 27N114W TO 09N140W. EXPECT SEAS TO REBUILD OVER THE FAR NW AND N CENTRAL WATERS TO 8 TO 12 FT LATE IN THE WEEKEND...WITH THE PEAK SWELL REACHING THE WEST COAST OF BAJA CALIFORNIA LATE MON. ENHANCED WESTERLY FLOW PEELING OFF FROM THE NORTH PACIFIC JET RUNS FROM THE NW WATERS THROUGH BAJA CALIFORNIA AS FAR S AS 23N. TO THE SOUTH A WELL-DEFINED MID- TO UPPER-LEVEL RIDGE AXIS EXTENDS FROM THE CENTRAL NORTH PACIFIC TO N OF TROPICAL STORM MARIE...WHICH IS KEEPING THE MARIE ON A MOSTLY WESTERLY PATH. WATER VAPOR IMAGERY SHOWS NOTHING BUT STRONG SUBSIDENCE UNDERNEATH THE ANTICYCLONIC FLOW OVER THE WESTERN PART OF THE BASIN...WITH EVEN STRONGER SUBSIDENCE NOTED IN THE UPPER-LEVEL WESTERLY FLOW W OF THE BAJA PENINSULA. E OF 110W.. BROAD CYCLONIC FLOW AT MID- TO UPPER-LEVELS IS NOTED OVER MEXICO AS FAR S AS 19N IN ASSOCIATION WITH A DEEP TROUGH OF LOW PRESSURE EXTENDING FROM THE EASTERN U.S. THROUGH NE MEXICO. IN THE WAKE OF THE TROUGH...SURFACE HIGH PRESSURE DOMINATES THE GULF OF MEXICO AND NE MEXICO SOUTHWARD TO THE GULF OF TEHUANTEPEC. MEANWHILE...ENHANCED SURFACE LOW PRESSURE EXISTS FROM CENTRAL AMERICA THROUGH THE MAIN DEVELOPMENT REGION OF THE EASTERN PACIFIC. AS A RESULT...GAP WINDS DOWNSTREAM OF THE GULF OF TEHUANTEPEC CONTINUE THIS MORNING...WITH A COMBINATION OF MODEL AND QUIKSCAT DATA INDICATING N TO NE WINDS OF 20 TO 25 KT. THESE WINDS HAVE CAUSED SEAS TO PEAK AROUND 9 TO 10 FT WITHIN ABOUT 120 NM S OF THE GULF OF TEHUANTEPEC. WITH THE MEAN TROUGH POSITION FORECAST TO ONLY GRADUALLY LIFT OUT THIS WEEKEND...GAP WINDS SHOULD CONTINUE DOWNSTREAM OF THE GULF OF TEHUANTEPEC AT LEAST THROUGH SAT OR EARLY SUN BEFORE ABATING. OTHERWISE...A NEAR CONTINUAL SUPPLY OF SW SWELL CONTINUES TO ARRIVE OVER THE TROPICAL EAST PACIFIC E OF 110W...WITH MAXIMUM SEAS OF 9 TO 11 FT FORECAST TO LINGER GENERALLY N OF 10N THROUGH EARLY THIS WEEKEND. $$ KIMBERLAIN