000 AXPZ20 KNHC 142224 CCA TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC FRI SEP 13 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2115 UTC. ...SPECIAL FEATURE... TROPICAL STORM MANUEL CENTERED NEAR 16.8N 102.5W AT 2100 UTC... OR ABOUT 78 NM SW OF ZIHUATENEJO MEXICO...MOVING NORTH-NORTHWEST OR 345 DEG AT 6 KT. MAXIMUM SUSTAINED WINDS 45 KT GUSTS 55 KT. ESTIMATED MINIMUM PRESSURE IS 994 MB. TROPICAL STORM FORCE WINDS ARE OCCURRING WITHIN 70 NM NE...210 NM SE...50 NM SW...AND 60 NM NW OF CENTER. THE LATEST SATELLITE IMAGERY SHOWS STRONG TSTORMS INCREASING ACROSS THE S AND SW QUADRANTS OUT TO 90 NM...WHILE CONVECTION HAS DECREASED TO THE NW OF MANUEL. MANUEL REMAINS EMBEDDED WITHIN A CYCLONIC GYRE ALIGNED NE TO SW THAT EXTENDS ACROSS S CENTRAL MEXICO INTO THE SW GULF OF MEXICO...WHERE TROPICAL STORM INGRID REMAINS EMBEDDED WITHIN THE NE END OF THE GYRE. THIS ALIGNMENT CONTINUES TO PRODUCE A VERY LONG FETCH OF STRONG SOUTHWESTERLY WINDS FROM NEAR 09N112W NORTHEASTWARD TO THE MEXICAN COAST BETWEEN PUERTO ANGEL AND ZIHUATENEJO. THIS SOUTHWESTERLY FLOW OF MOIST TROPICAL AIR WILL CONTINUE TO SLAM AGAINST THE SOUTHERN SLOPES OF THE SIERRA MADRES DEL SUR DURING THE NEXT FEW DAYS TO PRODUCE TREMENDOUS RAINFALL ACCUMULATIONS LEADING TO LIFE THREATENING FLASH FLOODING AND MUDSLIDES. TROPICAL STORM FORCE WINDS HAS BEEN EXTENDED CONSIDERABLY ACROSS THE SE QUADRANT WITH THE MOST RECENT BULLETIN...BASED ON AN AFTERNOON ASCAT PASS SHOWING GALE FORCE WINDS EMBEDDED WITHIN THE ZONE OF STRONG SOUTHWESTERLY FLOW...LOCATED WELL TO THE SE OF THE MAIN CIRCULATION OF MANUEL. THE LARGE AREA OF SEAS ASSOCIATED WITH THIS ZONE OF SOUTHWEST WINDS HAS ALSO SPREAD TO VERY NEAR MANUEL...AND THE TROPICAL STORM FORCE WINDS AND 12 FT SEA RADII WERE EXPANDED TO TAKE THIS MERGER INTO ACCOUNT. MANUEL IS EXPECTED TO MOVE ASHORE ACROSS SOUTHWEST MEXICO SUNDAY MORNING...AND INLAND THROUGHOUT THE DAY. WIDESPREAD RAINFALL WILL DOMINATE SOUTHERN MEXICO...INCLUDING INTERIOR PORTIONS FUR THE NEXT FEW DAYS AS THIS BROAD CYCLONIC CIRCULATION DRIFTS N- NW. PLEASE SEE WMO HEADER/AWIPS HEADERS WTPZ23 KNHC/MIATCMEP3 FOR ADDITIONAL DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH AXIS EXTENDS FROM COLOMBIA NEAR 08N73W AND MEANDERS THROUGH 15N87W...AND HAS FRACTURED FROM T.S. INGRID IN THE BAY OF CAMPECHE. THE TROUGH RESUMES TO THE SW OF T.S. MANUEL NEAR 14N105W TO LOW PRES NEAR 11.5N116W 1006 MB TO 10N137W... WHERE IT TRANSITIONS TO ITCZ...CONTINUING BEYOND 10N140W. SCATTERED TO LOCALLY NUMEROUS STRONG CONVECTION NOTED FROM 12.5N TO 18N BETWEEN 96.5W AND 104W. SCATTERED STRONG FROM 10.5N TO 17N BETWEEN 104W AND 111W. ...DISCUSSION... AN UPPER LOW MIGRATING W FROM THE WESTERN GULF OF MEXICO OVER N CENTRAL MEXICO IS COMING INTO PHASE WITH A SHARP MID LATITUDE TROUGH EXTENDING FROM THE GREAT BASIN TO N CENTRAL MEXICO. THIS COMBINED UPPER TROUGH STRETCHES SWD TO NEAR 16N110W. WHILE THIS SET-UP CONTINUES TO ENHANCE CONVECTION E OF 106W...NORTHERLY FLOW ALOFT BETWEEN THE UPPER TROUGH AND A BROAD ANTICYCLONE CENTERED W OF THE AREA NEAR 23N123W IS SUPPRESSING CONVECTION W OF 105W EXCEPT S OF 15N WHERE FRESH TO STRONG SW FLOW IS ALLOWING CONVECTION TO PULSE ALONG THE MONSOON TROUGH WITHIN 200 NM W OF MANUEL. FARTHER NORTH...ASCAT DATA FROM LAST NIGHT ALONG WITH ALTIMETER PASSES FROM THIS MORNING HAVE CONTINUED TO SHOW NW TO N WINDS UP TO 20 KT WITH SEAS TO 7 FT OFF THE COAST OF BAJA CALIFORNIA SUR OUT TO 115W...BETWEEN THE LOWER PRES OFF CENTRAL MEXICO AND WEAK HIGH PRES OVER THE FAR WESTERN PART OF THE AREA. SURFACE ANALYSIS REVELAS THAT A WEAK PRES PATTERN PREVAILS ACROSS THE AREA W OF ABOUT 110W AND E OF 95W WITH LIGHT TO MODERATE WINDS AND SLIGHT SEAS PREVAILING. LOOKING AHEAD...GLOBAL MODELS INDICATE THAT THE GYRE WILL WEAKEN THROUGH MID WEEK WITH THE STRONG SW FLOW DIMINISHING INTO THE MONSOON TROUGH BETWEEN 95W AND 115W. SEAS WILL GRADUALLY DIMINISH AS WELL. UNTIL THEN...EXPECT THE COMBINED MARINE HAZARDS OF ROUGH SEAS AND DANGEROUS RIP CURRENTS ALONG THE COAST OF MEXICO FROM WESTERN OAXACA THROUGH GUERRERO THROUGH EARLY NEXT WEEK. $$ STRIPLING