000 AXPZ20 KNHC 141609 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC FRI AUG 14 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1530 UTC. ...SPECIAL FEATURES... AT 1500 UTC...HURRICANE GUILLERMO AT 17.8N 127.3W OR ABOUT 1180 NM W-SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA...MOVING TOWARD THE WEST OR 280 DEG AT 13 KT. MAXIMUM SUSTAINED WINDS ARE 70 KT WITH GUSTS TO 85 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS ESTIMATED AT 984 MB. OVERNIGHT MICROWAVE PASSES HAVE INDICATED AN IMPROVED BANDING AND ORGANIZATION. CURRENTLY NUMEROUS STRONG CONVECTION IS OBSERVED WITHIN 90 NM OVER THE N SEMICIRCLE AND WITHIN 125 NM OVER THE S SEMICIRCLE OF CENTER. GUILLERMO IS EXPECTED TO REMAIN A MINIMAL HURRICANE FOR ABOUT A DAY AND THEN WEAKEN BACK TO A TROPICAL STORM AS IT MOVES OVER COOLER WATERS. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. THE REMNANT LOW PRES OF TROPICAL DEPRESSION NINE-E WAS LOCATED NEAR 11N138.5W AND WAS ESTIMATED AT 1009 MB. THE CENTER APPEARS TO BE MOVING VERY SLOWLY W...AND EMBEDDED WITHIN THE ITCZ. SCATTERED MODERATE TO STRONG CONVECTION HAS INCREASED ACROSS THE W SEMICIRCLE AND EXTENDS OUT 225 NM W OF THIS LOW. A CONTINUED W TO W-SW MOTION IS EXPECTED WITH THIS LOW...WHICH WILL KEEP IT OVER WARM WATERS. THERE IS A MEDIUM CHANCE...30 TO 50 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE AGAIN DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE IS ANALYZED N OF 05N ALONG 88W WITH WESTWARD MOTION ESTIMATED AT 20 KT. BROAD CYCLONIC FLOW IN THE LOWER LEVELS DOMINATING THIS REGION...AND THE DOMINANCE OF THE S AMERICAN MONSOON CIRCULATION ARE LIKELY GIVING THIS WAVE A MORE POSITIVE TILT THAN EARLIER INDICATED...WITH THE N PORTION OF THE WAVE LIKELY APPROACHING THE GULF OF TEHUANTEPEC REGION...WHERE CLUSTERS OF DEEP CONVECTION HAVE DEVELOPED THIS MORNING. A TROPICAL WAVE IS ANALYZED 103W AND HAS BEEN MOVING W AT 20 KT OVER THE PAST 24 HOURS. THIS WAVE HAS BEEN VERY DIFFICULT TO TRACK THE PAST DAYS DUE TO ITS PROXIMITY AND SYNCHRONOUS MOTION WITH THE UPPER CYCLONE OFF THE W COAST OF MEXICO. NUMEROUS MODERATE TO STRONG CONVECTION IS CONCENTRATED WITHIN 240 NM OF THE ITCZ BETWEEN THIS WAVE AND THE WAVE TO THE E OF THE WAVE AXIS. LOW TO MID LEVEL CYCLONIC TURNING WAS INDICATED UPSTREAM OF THIS WAVE...S OF 13N AND ALONG 106W. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED ALONG 08N81W TO 07N92W TO 09N106W TO 17N124W TO 11N140W. SCATTERED MODERATE ISOLATED STRONG N OF 02N BETWEEN 78W AND 82W. SCATTERED MODERATE FROM 05N TO 10N BETWEEN 82W AND 89W. SCATTERED MODERATE ISOLATED STRONG FROM 05N TO 13N BETWEEN 93W AND 109W. SCATTERED MODERATE FROM 06N TO 14N BETWEEN 113W AND 121W. SCATTERED MODERATE FROM 06N TO 11N BETWEEN 122W AND 136W. ...DISCUSSION... ANTICYCLONIC FLOW ASSOCIATED WITH AN UPPER ANTICYCLONE AT 22N123W IS DOMINATING MOST OF THE UPPER LEVELS FROM 115W TO 133W...BUT AN APPROACHING UPPER TROUGH IS BEGINNING TO ERODE THE NW PERIPHERY OF THE ASSOCIATED RIDGE NEAR 27N138W. CURRENT UPPER DIFFLUENCE IS SUPPORTING OUTFLOW OVER HURRICANE GUILLERMO... WITH GOOD OUTFLOW IN ALL BUT THE SW QUADRANT. DEBRIS MOISTURE IS NOTED REMAINING S OF 23N BETWEEN 121W AND 132W. AN NARROW AND ELONGATED TUTT AXIS MEANDERS IN AN "S" LIKE FASHION FROM NE ARIZONA ACROSS NORTHERN BAJA CALIFORNIA THEN WESTWARD ALONG 27N EXTENDING S-SW TO THE W OF GUILLERMO...WHERE VERY DRY INDICATED IN WATER VAPOR INDICATES SINKING MOTION AND SUBSIDENCE INTO THE MIDDLE LEVELS. HURRICANE GUILLERMO MAY BEGIN TO ENTRAIN SOME OF THIS DRY STABLE AIR IN ABOUT A DAY OR SO AS IT ENTERS THIS ENVIRONMENT...AND BEGINS TO MOVE OVER COOLER WATER. A SECOND UPPER ANTICYCLONE IS OVER EASTERN MEXICO NEAR 20N98W AND DOMINATES THE UPPER LEVELS OF THE TROPICAL PACIFIC TO THE E OF 100W. THE ASSOCIATED UPPER DIFFLUENCE CONTINUES TO ENHANCE CONVECTION ALONG THE ITCZ E OF 100W. A NARROW UPPER LEVEL TROUGH EXTENDS INTO THE AREA FROM THE W CENTRAL GULF OF MEXICO WESTWARD INTO CENTRAL MEXICO NORTH OF THE ABOVE RIDGE...AND TURNS SW INTO AN UPPER CYCLONE AT 19N109W...WITH THE TROUGH THEN CONTINUING S ACROSS THE EQUATOR AT 111W. THIS UPPER CYCLONE CONTINUES TO DRIFT SLOWLY W...AND ENHANCE CONVECTION ALONG THE ITCZ TO ITS S AND SE. AT LOW LEVELS A SURFACE RIDGE EXTENDS INTO THE AREA AT 36N143W TO 28N118W...WITH A STATIONARY FRONT DRAPED ACROSS IT. A SURFACE TROUGH IS NOW ANALYZED WITHIN THE ITCZ BELT MOVING QUICKLY W-SW NEAR 115W...AND HAS LIKELY BEEN INDUCED IN ASSOCIATION WITH SOME TYPE OF LOW TO MID LEVEL WIND SURGE RELATED TO THE UPPER CYCLONE OFF OFF THE W COAST OF MEXICO. GAP WINDS...AN OVERNIGHT SSMI PASS...AND MORNING QUIKSCAT PASS REVEAL THAT 20-25 KT NLY WINDS CONTINUE THROUGH THE GULF OF TEHUANTEPEC. THESE CONDITIONS ARE EXPECTED TO PERSIST THROUGH TODAY AND THEN BEGIN TO GRADUALLY DIMINISH. ALSO...THE LATEST MORNING QUIKSCAT PASS SUGGESTS THAT THE NE TO E WINDS SURGING THROUGH THE GULF OF PAPAGAYO HAVE DIMINISHED JUST BELOW 20 KT. EASTERLY TRADES ARE FAIRLY STRONG UPSTREAM IN W CARIBBEAN SO EXPECT LITTLE CHANGE...WITH MODEST PULSES IN WIND SPEED UP AND DOWN FOR THE FEW DAYS. $$ STRIPLING