000 AXPZ20 KNHC 160351 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN AUG 16 2009 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. ...SPECIAL FEATURES... HURRICANE GUILLERMO CENTERED AT 19.5N 135.3W AT 0300 UTC...OR ABOUT 1450 NM W OF THE SOUTHERN TIP OF BAJA CALIFORNIA...MOVING WNW OR 290 DEG AT 14 KT. MAXIMUM SUSTAINED WINDS WERE 95 KT WITH GUSTS TO 115 KT. ESTIMATED MINIMUM CENTRAL PRESSURE WAS ESTIMATED AT 958 MB. GUILLERMO HAS REACHED ITS PEAK INTENSITY TODAY AND APPEARS TO HAVE BEGUN THE SLOW AND GRADUAL WEAKENING PROCESS AS IT IS BEGINNING TO MOVE OVER GRADUALLY COOLER WATERS...AND SOME DRIER MORE STABLE AIR IS SLOWLY BECOMING ENTRAINED INTO THE SW AND S SIDES OF THE CIRCULATION SYSTEM. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE IS ANALYZED ALONG 85W...MOVING ACROSS COSTA RICA AND THE ADJACENT PACIFIC WATERS...EXTENDING N-NW INTO THE WRN CARIBBEAN...WITH WESTWARD MOTION ESTIMATED AT 20 KT THROUGH THE WESTERN CARIBBEAN. SMALL CLUSTERS OF MODEST CONVECTION WERE NOTED OFF THE PACIFIC COAST OF COSTA RICA. A TROPICAL WAVE WAS ANALYZED ALONG 97/98W AND HAS BEEN MOVING W AT 20 KT OVER THE PAST 48 HOURS. SCATTERED MODERATE CONVECTION WAS ACTIVE WITHIN 120 NM EITHER SIDE OF THE WAVE AXIS. A TROPICAL WAVE WAS ANALYZED ALONG 112W AND HAS BEEN MOVING W NEAR 20 KT OVER THE PAST 48 HOURS. THE WAVE IS FOLLOWING THE SE EXTENSION OF AN UPPER LOW CENTERED NEAR 20N115W. SCATTERED MODERATE CONVECTION WAS OCCURRING AT THE BASE OF THE WAVE NEAR THE ITCZ BETWEEN 110W AND 115W. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED ALONG 10N86W TO 12N115W TO 13N120W TO 11N140W TO 11N140W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS NOTED WITHIN 150 NM S OF THE ITCZ AXIS BETWEEN 103W AND 107W...AND WITHIN 90 NM N OF AXIS BETWEEN 110W AND 115W. ...DISCUSSION... E OF 115W...A BROAD ANTICYCLONE IS CENTERED OVER CENTRAL MEXICO NEAR 20N104W. FAIRLY DRY SUBSIDENT FLOW IS PUSHING SOUTHWARD ON THE SIDE OF THIS FEATURE...OVER SOUTHERN MEXICO AND NORTHERN CENTRAL AMERICA. THIS SAME PATTERN WAS SETTING UP LAST NIGHT...AND ALLOWED ENOUGH RADIATIONAL COOLING OVER LAND TO INITIATE A LARGE BAND OF DRAINAGE FLOW INDUCED CONVECTION OFF THE COAST FROM THE GULF OF FONSECA TO NORTH OF TEHUANTEPEC. THIS WILL LIKELY REOCCUR BY LATE MORNING. WINDS THROUGH THE GULF OF TEHUANTEPEC HAVE PROBABLY DIED DOWN TODAY IN THE WAKE OF TROPICAL WAVE THAT PASSED SOUTH OF THE AREA EARLIER. WINDS MAY INCREASE SLIGHTLY BY EARLY MONDAY BUT REMAIN LESS THAN 20 KT AS ANOTHER TROPICAL WAVE MOVES WESTWARD TO THE SOUTH OF THE AREA. WINDS THROUGH THE GULF OF PAPAGAYO MAY SURGE TO 20 KT IN THE WAKE OF THE TROPICAL WAVE ON SUNDAY. NW WINDS MAY ALSO SPORADICALLY REACH 20 KT OFF THE PACIFIC COAST OF THE BAJA PENINSULA AS SURFACE HIGH PRES BUILDS TO THE WEST IN THE WAKE OF THE EXITING HURRICANE GUILLERMO. AN UPPER LOW IS CENTERED NEAR 20N115W. DIVERGENT FLOW ALOFT BETWEEN THE UPPER LOW AND THE UPPER ANTICYCLONE IS ENHANCING MODEST CONVECTION BETWEEN 110W AND 115W. SLIGHTLY STRONGER SOUTHERLY CROSS-EQUATORIAL FLOW WILL ENHANCE CLUSTERS OF CONVECTION ALONG THE ITCZ SUNDAY INTO MONDAY. W OF 115W...UPPER DIVERGENCE ON THE SW SIDE OF AN UPPER ANTICYCLONE CENTERED OVER 27N123W IS ENHANCING CONVECTION ASSOCIATED WITH HURRICANE GUILLERMO ON THE SW SIDE OF THE UPPER RIDGE. DRY SUBSIDENT NORTHERLY FLOW BETWEEN THE EAST SIDE OF THE UPPER ANTICYCLONE AND AN UPPER LOW TO THE EAST IS CLEARING MUCH OF THE CLOUDINESS AND CONVECTION AS FAR SOUTH AS THE ITCZ BETWEEN 115W AND 125W. SURFACE HIGH PRES RELATED TO THE UPPER ANTICYCLONE IS CENTERED N OF THE AREA. AN ASCAT PASS FROM 18Z SHOWED A BROAD AREA OF 20 TO 30 KT WINDS BETWEEN GUILLERMO AND THIS SURFACE HIGH. A PAIR OF ALTIMETER PASSES FROM ROUGHLY THE SAME TIME SHOWED LARGE AREAS OF SEAS FROM 8 TO 12 FT MAINLY N OF 20N W OF 125W. THIS IS A BIT HIGHER THAN INDICATED IN WW3 GUIDANCE. A WEAK 1010 MB LOW IS CENTERED SW OF GUILLERMO NEAR 12N139W AND IS EMBEDDED WITHIN THE ITCZ. THIS IS THE REMNANT LOW OF TROPICAL DEPRESSION NINE-E...AND IT IS EXPECTED TO DRIFT VERY SLOWLY TO THE NNE OVER THE NEXT 24 TO 48 HOURS IN RESPONSE TO THE MOVEMENT OF GUILLERMO TO THE NORTH. $$ CHRISTENSEN