000 AXPZ20 KNHC 271555 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC THU JUN 27 2013 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1530 UTC. ...SPECIAL FEATURES... TROPICAL STORM COSME WAS CENTERED NEAR 20.4N 120.9W 1003 MB AT 1500 UTC JUN 27 MOVING WNW OR 285 DEGREES AT 14 KT. MAXIMUM SUSTAINED WINDS ARE 35 KT WITH GUSTS TO 45 KT. LATEST SATELLITE IMAGERY SHOW THAT COSME HAS LOST ALL OF ITS DEEP CONVECTION AS IT CONTINUES TO BE AFFECTED BY VERTICAL SHEAR AND WHILE AT THE SAME TIME IT MOVES OVER COOLER OCEAN TEMPERATURES. THE REMAINING CIRCULATION CONSISTING OF LOW AND MID-LEVEL CLOUDS REMAINS QUITE LARGE AS IS EVIDENT IN THE SATELLITE IMAGERY...AND AS WAS CAPTURED BY AN ASCAT PASS FROM 0600 UTC LAST NIGHT. THE LATEST NHC FORECAST HAS COSME WEAKENING TO POST-TROPICAL REMNANT LOW PRES BY EARLY THIS EVENING...AND CONTINUING AS ONE THROUGH THE NEXT 48 HRS. SEE THE LATEST FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTNT23 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS W FROM COLOMBIA AT 09N76W TO ACROSS CENTRAL PANAMA TO 08N92W TO AN EMBEDDED LOW PRES AT 11N102W TO 12N108W WHERE THE TROUGH LOSES IDENTITY IN BROAD CYCLONIC CIRCULATION ASSOCIATED WITH DISSIPATING TROPICAL CYCLONE COSME. THE MONSOON TROUGH RESUMES WELL SSW OF COSME NEAR 12N122W...AND CONTINUES WSW TO BEYOND 07N140W. SCATTERED STRONG CONVECTION IS WITHIN 60 NM OF TROUGH E OF 86W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM S OF THE TROUGH BETWEEN 90W-100W. AN AREA OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS NOTED FROM 07N TO 12N BETWEEN 100W-114W. SCATTERED MODERATE TO STRONG CONVECTION EXISTS WITHIN 45 NM OF LINE FROM 12N115W TO 10N121W. SCATTERED STRONG CONVECTION IS N OF THE MONSOON TROUGH WITHIN 30 NM OF 13N102W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ALSO N OF THE MONSOON TROUGH WITHIN 30 NM OF 15N96W. ...DISCUSSION... AN UPPER LEVEL ANTICYCLONE AT 26N128W HAS A RIDGE EXTENDING NNE TO N OF THE AREA AT 34N127W WHERE IT IS BLOCKING THE FORWARD ADVANCE OF AN APPROACHING SHORTWAVE TROUGH THAT IS IN TURN ACCOMPANIED BY FAIRLY DENSE UPPER MOISTURE. OTHERWISE SATELLITE WATER VAPOR IMAGERY SHOWS A VERY DRY ATMOSPHERE ALOFT W OF A LINE FROM THE NRN BAJA CALIFORNIA PENINSULA TO 20N128W TO 10N130W. AN UPPER RIDGE ALSO EXTENDS SW FROM THE ANTICYCLONE TO NEAR 13N139W. THIS FEATURE WILL CONTRIBUTE TO THE STEERING OF THE RAPIDLY WEAKENING CYCLONE COSME TODAY. AT THE SURFACE...A SCATTERED TO BROKEN LOW CLOUDS OVER THE FAR NW CORNER WITHIN 60 NM EITHER SIDE OF A LINE FROM 32N134W TO 28N140W DEFINE WHAT REMAINS OF THE DECAYING FRONTAL TROUGH. OVER THE ERN PORTION OF THE AREA...AN UPPER ANTICYCLONE CENTERED W OF BAJA CALIFORNIA NEAR 26N115W HAS A RIDGE AMPLIFYING N TO A CREST AT 30N115W...AND A RIDGE SW FROM IT THROUGH 22N121W TO 13N126W. THE SRN AND SW SIDES OF THE RIDGE ARE PROVIDING THE UPPER DIFFLUENCE AIDING DEEP CONVECTION IN THE TROPICS BETWEEN 100W-114W AS DESCRIBED ABOVE. HIS CONVECTION CONTINUES TO CONTRIBUTE TO EXTREMELY DENSE UPPER MOISTURE OBSERVED S OF 14N BETWEEN 99W-120. S OF THIS MOISTURE IS NOW ADVECTED NE ACROSS EXTREME SE MEXICO AND ACROSS GUATEMALA TO THE E OF AN UPPER TOUGH DIGGING S TO A BASE OVER THE GULF OF TEHUANTEPEC. ELSEWHERE AT THE SURFACE...A 1019 MB SURFACE HIGH IS ANALYZED JUST N OF THE AREA AT 33N127W WITH A RIDGE SE TO NEAR 29N118W. CROSS EQUATORIAL SOUTHERLY SWELL CONTINUES TO PROPAGATE N ACROSS THE DISCUSSION AREA BETWEEN 100W-130W...AND WAS REINFORCED BY SWELL GENERATED BY TROPICAL CYCLONE COSME. THESE SOUTHERLY SWELLS ARE FORECAST TO CROSS 30N DURING TODAY THEN SUBSIDE BELOW 8 FT ACROSS THE DISCUSSION WATERS W OF 115W ON FRI. THE SOUTHERLY SWELLS... RESULTING IN COMBINED SEAS OF UP TO 10 FT...ACROSS THE GULF OF CALIFORNIA TO THE S OF 23N SHOULD SUBSIDE TO BELOW 8 FT THIS AFTERNOON. BROAD CYCLONIC TURNING IS NOTED ALONG THE W EDGE OF THE MONSOON TROUGH WITH AN ESTIMATED WEAK AND DISORGANIZED LOW PRES CNTR NEAR 11N104W. NWP MODELS CONTINUE TO SUGGEST THAT A MORE DEFINITIVE LOW PRES IS EXPECTED TO FORM OVER THE NEXT 49 HRS AS UPPER LEVEL WINDS BECOME MORE FAVORABLE FOR ORGANIZATION. THE GENERAL EXPECTED FORECAST TRACK OF THIS FEATURE IS IN A GENERAL NNW MOTION THROUGH THE NEXT COUPLE OF DAYS WHILE POSSIBLY STRENGTHENING. $$ AGUIRRE