000 AXPZ20 KNHC 270451 CCA TWDEP TROPICAL WEATHER DISCUSSION...CORRECTION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN JUN 27 2010 CORRECTION FOR SPECIAL FEATURES 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 0115 UTC. ...SPECIAL FEATURES.... THE CENTER OF TROPICAL STORM CELIA WAS NEAR 15.8N 122.7W AT 0300 UTC MOVING W OR 280 DEG AT 06 KT. THE MAXIMUM SUSTAINED WIND SPEED HAS DIMINISHED TO 55 KT WITH GUSTS TO 65 KT...AND THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 994 MB. NUMEROUS MODERATE CONVECTION IS WITHIN 150 NM N SEMICIRCLE OF CELIA. SOUTHERLY SHEAR AND COOLER WATER TEMPERATURES HAVE WEAKENED CELIA TO A TROPICAL STORM. A WEAKENING TREND IS EXPECTED TO CONTINUE...WITH CELIA DIMINISHING TO A POST-TROPICAL REMNANT LOW BY THE END OF THE FORECAST PERIOD ON MON EVENING. A JASON-2 ALTIMETER PASS AT 1500 UTC CONFIRMED THAT THE AREA OF SEAS GREATER THAN 12 FEET HAS SHRUNK OVER THE PAST 12 HOURS. PLEASE REFER TO THE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPEP4/WTPZ24 KNHC FOR MORE DETAILS. TROPICAL STORM DARBY WAS CENTERED NEAR 13.5N 103.0W AT 0300 UTC MOVING W OR 270 DEG AT 02 KT. THE MAXIMUM SUSTAINED WIND SPEED IS 60 KT WITH GUSTS TO 75 KT...AND THE ESTIMATED MINIMUM CENTRAL PRESSURE WAS 992 MB. NUMEROUS MODERATE TO STRONG CONVECTION IS WITHIN 120 NM NW QUADRANT OF DARBY WHILE NUMEROUS MODERATE CONVECTION LIES ELSEWHERE WITHIN 180 NM NW QUADRANT OF DARBY. SATELLITE IMAGERY INDICATES THAT DARBY HAS ENCOUNTERED SOUTHEASTERLY SHEAR. THIS SHEAR IS FORECAST TO STRENGTHEN IN ABOUT 24 HOURS. DARBY IS FORECAST TO GRADUALLY DIMINISH OVER THE NEXT FEW DAYS...DROPPING BELOW TROPICAL STORM STRENGTH BY MON NIGHT. REFER TO THE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPEP5/WTPZ25 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE N OF 07N ALONG 91W IS MOVING W AT ABOUT 13 KT. NUMEROUS MODERATE TO STRONG CONVECTION IS OVER FORECAST WATERS WITHIN 180 NM W OF THE WAVE N OF 12N WHILE SCATTERED MODERATE CONVECTION LIES ELSEWHERE WITHIN 240 NM EITHER SIDE OF THE WAVE N OF 11N. MOST OF THE HEAVY RAIN ON THE WESTERN PORTION OF CENTRAL AMERICA HAS MOVED OFFSHORE OVER THE PAST FEW HOURS...BUT MODERATE TO STRONG CONVECTION CAN BE FOUND IN BANDS ASSOCIATED WITH ATLANTIC TROPICAL STORM ALEX OVER NORTHERN COSTA RICA AND EASTERN NICARAGUA AND HONDURAS AS WELL AS OVER MUCH OF THE YUCATAN PENINSULA. THIS CONVECTION COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUDSLIDES. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE AXIS WAS ANALYZED FROM 11N92W TO 08N105W TO 12N117W TO 07N132W TO 08N140W. SCATTERED MODERATE BETWEEN 60 NM AND 120 NM N OF AXIS BETWEEN 113W AND 115W. ...DISCUSSION... ASIDE FROM HURRICANES CELIA AND DARBY...THE FEATURE IMPACTING THE LARGEST PORTION OF THE DISCUSSION AREA IS THE CROSS EQUATORIAL SW SWELL WITH SEAS IN THE 8 TO 10 FT RANGE FOUND S OF 26N BETWEEN 110W AND 130W AND OVER FORECAST WATERS FROM 05N TO 23N BETWEEN 93W AND 110W. THIS SWELL WILL DAMPEN AS IT TREKS NORTHWARD OVER THE NEXT TWO DAYS. A NEW SURGE OF SOUTHERLY SWELL...WITH PERIODS IN THE 17-19 SECOND RANGE...WILL MOVE INTO SE WATERS SUN AFTERNOON AND RAISE SIGNIFICANT WAVE HEIGHTS ONCE AGAIN TO THE 8 TO 10 FT RANGE. THIS SWELL WILL APPROACH THE COAST OF WESTERN PANAMA AND COSTA RICA BY THE END OF THE FORECAST PERIOD ON MON EVENING. SURFACE RIDGING EMANATING FROM A 1028 MB HIGH PRES CENTER NEAR 36N141W DOMINATES MUCH OF THE AREA N OF 20N AND STRONG SUBSIDENCE IS IN PLACE THERE ASIDE FROM THE CONVECTIVE BLOW OFF ASSOCIATED WITH CELIA. THE STRENGTHENED PRES GRADIENT BETWEEN THIS RIDGING AND TROUGHING OVER THE SW U.S. AND GULF OF CALIFORNIA HAS BROUGHT NW TO N WINDS TO 20 KT ALONG THE W COAST OF BAJA CALIFORNIA. SEVERAL SHIP REPORTS EARLIER THIS EVENING CONFIRMED THESE CONDITIONS ALONG WITH THE 1754 UTC ASCAT PASS. THE AREA OF 20 KT WINDS IS EXPECTED TO SHIFT S ALONG THE COAST OF BAJA CALIFORNIA SUN WHEN THE RIDGE WILL BE FORCED SOUTHWARD BY A COLD FRONT ENCROACHING UPON IT FROM THE N. THE RELATIVELY WEAK HIGH PRES OVER THE FORECAST AREA HAS REDUCED THE EASTERLY TRADE WINDS TO LESS THAN 20 KT. TRADES ARE EXPECTED TO REMAIN WEAK THROUGH THE PERIOD. THE EARLIER 1616 UTC ASCAT PASS SHOWED 20-25 KT NW WINDS SIPHONING THOUGH THE GULF OF TEHUANTEPEC AND CONVERGING WITH 20 KT SW TO W FLOW S OF THE GULF CENTERED AROUND 10N. THIS LOW LEVEL CONVERGENCE IS SUPPLYING LOW LEVEL MOISTURE TO THE TROPICAL WAVE ALONG 90W. WINDS ARE EXPECTED TO REMAIN AROUND 20 KT AHEAD OF THE TROPICAL WAVE AS IT CONTINUES W THROUGH THE PERIOD. $$ SCHAUER/NELSON