000 AXPZ20 KNHC 112206 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC TUE AUG 11 2009 CORRECTION FOR CLARIFICATION IN GAP WIND SECTION... TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2130 UTC. ...SPECIAL FEATURES... AT 200 PM PDT...2100 UTC...THE CENTER OF TROPICAL DEPRESSION NINE-E WAS LOCATED NEAR LATITUDE 15.1 NORTH...LONGITUDE 128.8 WEST OR ABOUT 1345 MILES...2165 KM...WEST-SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. THE DEPRESSION WAS MOVING TOWARD THE WEST...270 DEGREES...NEAR 14 MPH...OR 23 KM/HR...AND THIS GENERAL MOTION SHOULD CONTINUE FOR THE NEXT COUPLE OF DAYS. MAXIMUM SUSTAINED WINDS WERE NEAR 35 MPH...55 KM/HR...WITH HIGHER GUSTS. ESTIMATED MINIMUM CENTRAL PRESSURE WAS 1006 MB...29.71 INCHES. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. CONVECTION CONTINUES TO BE LIMITED WITH THE DEPRESSION AS IT IS PASSING THROUGH THE BASE OF A SHARP UPPER LEVEL TROUGH...AND ENCOUNTERING UPPER LEVEL CONVERGENCE. SCATTERED MODERATE CONVECTION WAS NOTED OCCURRING 25-120 NM FROM THE CENTER IN THE NW QUADRANT. SLOW STRENGTHENING IS POSSIBLE ON WEDNESDAY AND THURSDAY...AND THE DEPRESSION COULD BECOME A TROPICAL STORM DURING THAT TIME AS IT MOVES AWAY FROM THE UPPER TROUGH AND BEGINS TO MOVE UNDERNEATH AN UPPER LEVEL RIDGE. A 1008 MB LOW PRES CENTER NEAR 12N111W HAS MOVED LITTLE TODAY...AND IN FACT MAY BE BECOMING ABSORBED BY A LARGE POSITIVELY TILTED TROPICAL WAVE DIRECTLY BEHIND IT COVERING AN AREA BETWEEN 113W AND 108W. THIS SYSTEM WAS PRODUCING A LARGE AREA OF SCATTERED TO NUMEROUS MODERATE TO STRONG CONVECTION SPREAD ACROSS THIS AREA...BEING VENTILATED BY DIFFLUENT ANTICYCLONIC FLOW OVERHEAD. LATEST SATELLITE IMAGERY SUGGESTS THE BEST CYCLONIC TURNING OF THE WAVE IS OCCURRING WITH AND JUST TO THE EAST OF THE SURFACE LOW...AND THIS WAVE MAY BE GAINING BETTER ORGANIZATION. TPW ANIMATIONS INDICATE A LARGE AREA OF ABUNDANT MOISTURE ENTRAINED WITHIN THE ELONGATED CIRCULATION OF THE TROPICAL WAVE...AND WAS PULLING ADDITIONAL MOISTURE OFF THE W COAST OF MEXICO. UPPER-LEVEL CONDITIONS ARE EXPECTED TO BECOME MORE FAVORABLE FOR DEVELOPMENT OF THIS SYSTEM DURING THE NEXT COUPLE OF DAYS AS IT MOVES GENERALLY WESTWARD AROUND 15 MPH. THERE IS A MEDIUM CHANCE...30 TO 50 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE WAS ENTERING THE EPAC FORECAST AREA...EXITING NW S AMERICA...ALONG 78/79W MOVING W 10 TO 15 KT. SCATTERED MODERATE CONVECTION WAS OCCURRING ALONG AND TO THE S OF THE ITCZ AHEAD OF THIS WAVE...IN LOW LEVEL SWLY CONVERGENCE. A TROPICAL WAVE WAS ANALYZED ALONG 98/99W N OF 05N MOVE W 10 TO 15 KT. ONLY ISOLATED MODERATE CONVECTION IN THE ITCZ WAS NEAR THE WAVE AXIS. THIS WAVE HAS BEEN DIFFICULT TO LOCATE DECISIVELY TODAY...AND ADJUSTMENT TO ITS LOCATION MAY BECOME NECESSARY. A LARGE TROPICAL WAVE WAS POSITIVELY TILTED FROM 113W TO 108W FROM 07N TO 19N MOVING W 15 KT. THE WAVE AND AN EMBEDDED 1008 MB LOW ARE MENTIONED ABOVE UNDER SPECIAL FEATURES. A TROPICAL WAVE WAS EXITING THE FORECAST AREA...AND WAS STRONGLY NEGATIVELY TILTED FROM NEAR 16N136W TO 09N141W MOVING W 10 TO 15 KT. CONVECTION HAS DIMINISHED WITH THIS WAVE TODAY...WITH ISOLATED MODERATE CONVECTION OCCURRING ACROSS THE NORTHERN PERIPHERY OF THIS WAVE. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED ALONG THE LINE 07N78W TO 08N100W TO 13N112W TO 08N125W TO 12N140W. SCATTERED MODERATE WITHIN 120 NM OF N OF AXIS AND WITHIN 120 NM S OF AXIS BETWEEN 120W AND 125W. ...DISCUSSION... EXTENDING FROM WEST TO EAST...A RIDGE-TROUGH-RIDGE-TROUGH UPPER PATTERN COVERS THE TROPICAL EASTERN PACIFIC THIS AFTERNOON... STARTING FROM AN ANTICYCLONE JUST SE OF THE BIG ISLAND OF HAWAII. THE TWO NARROW UPPER TROUGHS WERE NORTH TO SOUTH ALIGNED...ONE QUASISTATIONARY ALONG 124/125W...AND THE OTHER A TUTT LIKE LOW WITH BROAD TROUGH EXTENDING NE INTO THE ERN GULF OF MEXICO...SHIFTING W ALONG 93/94W. EAST TO NORTHEASTERLY UPPER FLOW S OF THE RIDGES AND THE WRN MOST UPPER TROUGH WAS BLOWING ACROSS THE EQUATOR...AND WAS ACTING TO PRODUCE A LARGE AREA OF UPPER DIFFLUENCE BETWEEN 105W AND 130W...VENTING AND ENHANCING ITCZ CONVECTION ACROSS THIS REGION. AT THE SURFACE...THE EASTERN PACIFIC SEMIPERMANENT HIGH WAS CENTERED NEAR 33N141W WITH RIDGE EXTENDING SE TO BAJA CALIFORNIA. THE MODERATE TO STRONG GRADIENT ALONG THE W COAST OF THE U.S. AND TO BAJA CALIFORNIA OF RECENT WEEKS HAS WEAKENED IN THE PAST FEW DAYS...AND WINDS ALONG THE SRN CALIFORNIA AND THE BAJA HAVE DROPPED BELOW 20 KT. S OF THE RIDGE...MODERATE SIZED ZONES OF 20 KT WINDS WITH POCKETS TO 25 KT...WERE OCCURRING ACROSS THE NRN PERIPHERY OF EACH OF THE TROPICAL WAVES. GAP WINDS... NE TO E WINDS OF 20 KT CONTINUE TO FUNNEL THROUGH THE GULF OF PAPAGAYO RAISING SEAS TO 8 FT. THIS WAS OCCURRING BEHIND AN ELONGATED LOW TO MID LEVEL JET ASSOCIATED WITH THE TROPICAL WAVE BETWEEN 113W AND 108W...AND WAS ALSO CONTRIBUTING TO NLY GAP FLOW OF 20-30 KT THROUGH THE GULF OF TEHUANTEPEC. THE GAP WINDS THROUGH PAPAGAYO ARE FORECAST TO CONTINUE THROUGH THE NEXT COUPLE OF DAYS...WITH THE TEHUANTEPEC PLUME WILL LIKELY CONTINUE NEAR 20 KT OR GREATER FOR THE NEXT 24 TO 36 HOURS. CROSS-EQUATORIAL SE SWELLS CONTINUE TO AFFECT THE SOUTHERN PORTION OF THE FORECAST AREA. THESE CONDITIONS ARE EXPECTED TO GRADUALLY SUBSIDE DURING THE NEXT 24 TO 48 HOURS. $$ STRIPLING