000 AXPZ20 KNHC 230245 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SAT JUL 23 2011 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0300 UTC. ...SPECIAL FEATURE... EARLY TONIGHT...A NOAA AIRCRAFT FOUND THAT DORA HAS WEAKENED TO A TROPICAL STORM. AT 23/0300 UTC IT IS CENTERED NEAR 20.4N 110.5W MOVING NW OR 315 DEGREES AT 7 KT. ON THIS TRACK...DORA WOULD BE MOVING NEARLY PARALLEL TO THE WEST COAST OF SOUTHERN BAJA CALIFORNIA. MAXIMUM SUSTAINED WINDS ARE 60 KT WITH GUSTS TO 75 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB. PLEASE SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. DORA IS CROSSING THE 26C ISOTHERM INTO MUCH COOLER WATERS. WITH SOME NELY SHEAR AND A MORE STABLE AIR MASS EXPECTED...A CONTINUED WEAKENING OF DORA IS FORECAST...AND THE CYCLONE WILL LIKELY BECOME A TROPICAL DEPRESSION BY SUNDAY. LARGE SWELLS GENERATED BY DORA WILL AFFECT THE COAST OF SOUTHWESTERN MEXICO AND BAJA CALIFORNIA DURING THE NEXT COUPLE OF DAYS. THESE SWELLS WILL LIKELY CAUSE LIFE- THREATENING SURF AND RIP CURRENT CONDITIONS. ...ITCZ/MONSOON TROUGH... MONSOON TROUGH 10N86W TO 14N100W TO 17N105W. ITCZ AXIS FROM 13N112W TO 10N125W TO 09140W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE ITCZ BETWEEN 118W AND 122W. ...DISCUSSION... PRES GRADIENT REMAINS WEAK OVER NW PORTION OF THE DISCUSSION AREA N OF 15N W OF 120W...WITH NE TRADE WINDS 10-15 KT AND SEAS GENERALLY 6-7 FT IN MIXED N AND SE SWELL. FURTHER SOUTH...THE ITCZ HAS RE-ESTABLISHED ITSELF W OF AROUND 110W AS LARGE SCALE MONSOON FLOW WEAKENS. SATELLITE IMAGERY SHOWS MULTIPLE WEAK VORTICES ALONG THE ITCZ...AND NONE OF THEM ARE EXPECTED TO DEVELOP INTO DISTINCT AREAS OF LOW PRES. SATELLITE AND SURFACE DATA INDICATE A WEAK MONSOON TROUGH CROSSING COSTA RICA INTO THE EPAC ALONG 10N THEN CONTINUES W AND NW TO NEAR T.S. DORA. ISOLATED CONVECTION IS NOTED IN THE SW MONSOONAL FLOW E OF 95W. A CLUSTER OF MODERATE TO STRONG CONVECTION HAS DEVELOPED N OF 06N E OF 79W TO THE COASTS OF COLOMBIA AND PANAMA. A WEAK TO MODERATE PAPAGAYO GAP WIND EVENT WILL PULSE THE NEXT SEVERAL DAYS WITH WINDS REACHING 20 KT IN THE EARLY MORNING... AND FADING BY LATE AFTERNOON. CROSS-EQUATORIAL SE SWELLS CONTINUES TO PROPAGATE NW ACROSS THE EQUATOR AFFECTING MAINLY THE SW PORTION OF THE FORECAST AREA. THESE SWELLS ARE MIXING WITH NE TRADE SWELL ALONG 10N BETWEEN 130W AND 140W. SOUTHERLY SWELL PREVAILS OVER THE TROPICAL WATERS E OF 125W. N TO NW SWELL WILL REACH N WATERS IN ABOUT 18-24 HOURS RAISING SEAS TO 8 FT N OF 25N E OF 125W. THESE SWELLS WILL BE ASSOCIATED WITH STRONG NWLY WINDS EXPECTED TO DEVELOP OFF THE CALIFORNIA COAST...AND WILL MIX WITH SE SWELL GENERATED BY TROPICAL CYCLONE DORA. $$ GR