000 AXPZ20 KNHC 201605 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC THU SEP 20 2007 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1515 UTC. ...SPECIAL FEATURES... THE CENTER OF HURRICANE IVO AT 20/1500 UTC IS NEAR 17.1N 112.8W...OR ABOUT 400 NM SOUTH-SOUTHWEST OF CABO SAN LUCAS MEXICO...MOVING NORTH-NORTHWEST 6 KT. THE MAXIMUM SUSTAINED WINDS ARE 65 KT WITH GUSTS TO 80 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 987 MB. PLEASE READ THE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS FROM 16N TO 19N BETWEEN 111W AND 114W. A TROUGH EXTENDS FROM A DEEP LAYER CUTOFF CYCLONIC CIRCULATION CENTER NEAR 36N123W TO 28N124W AND 25N133W. DRY AIR/SUBSIDENCE IS NORTHWEST OF 31N116W 27N120W 22N130W 20N140W. SOME INTENSIFICATION OF IVO IS POSSIBLE... BECAUSE THE WATER AROUND IVO IS WARM AND THE WIND SHEAR IS LOW. RESIDENTS AND BUSINESS OWNERS IN SOUTHERN BAJA CALIFORNIA SHOULD MONITOR THE PROGRESS OF IVO CLOSELY DURING THE NEXT FEW DAYS...AND KEEP IN MIND THAT THERE IS GREAT UNCERTAINTY IN THE FORECASTS FOR DAY 4 AND DAY 5. THE CENTER OF TROPICAL DEPRESSION THIRTEEN-E AT 20/1500 UTC IS NEAR 17.9N 130.2W...MOVING WEST-NORTHWEST 5 KT. THE MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC FOR MORE DETAILS. ONE LONELY CELL OF DEEP CONVECTIVE PRECIPITATION REMAINS NEAR THE CENTER OF THE CYCLONE. THE DVORAK ESTIMATES HAVE DROPPED TO 25 KT AT THIS TIME. THE VERTICAL SHEAR FROM THE SOUTHEAST IS WEAK. IT APPEARS THAT THE COMBINED EFFECT OF COOL SEA SURFACE TEMPERATURES AND A STABLE ATMOSPHERE ARE CONTRIBUTING TOWARD THE CYCLONE'S DEMISE. THE INTENSITY FORECAST IS FOR NO RE-DEVELOPMENT AND DECAY TO A REMNANT LOW WITHIN 36 HR. THIS WEAKENING WILL OCCUR SOONER IF DEEP CONVECTIVE PRECIPITATION DOES NOT RESUME SHORTLY. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 91W SOUTH OF 21N MOVING WEST 10 TO 15 KT. THIS WAVE STRETCHES FROM THE NORTHWESTERN CORNER OF THE YUCATAN PENINSULA OF MEXICO SOUTHWARD INTO WESTERN GUATEMALA... AND INTO THE EASTERN PACIFIC OCEAN. SHOWERS AND THUNDERSTORMS ALONG THE COASTS OF EL SALVADOR AND GUATEMALA MAY BE MORE RELATED TO A MIDDLE LEVEL TROUGH. THIS PARTICULAR TROUGH STRETCHES FROM THE EASTERN GULF OF MEXICO CYCLONIC CIRCULATION CENTER TO THE YUCATAN PENINSULA TO 90W ALONG THE COASTS OF CENTRAL AMERICA. ...ITCZ... 8N78W 10N80W 10N93W 10N100W 16N108W 11N116W 17N127W 15N132W 12N140W. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS WITHIN A 30 NM RADIUS OF 13.5N123W...FROM 14N TO 15N BETWEEN 129W AND 133W...AND WITHIN A 60 NM RADIUS OF 13N134.5W. SCATTERED MODERATE TO ISOLATED STRONG SHOWERS AND THUNDERSTORMS FROM 5N TO 9N BETWEEN 81W AND 85W...FROM 9N TO 14N BETWEEN 93W AND 103W...FROM 9N TO 12N BETWEEN 106W AND 108W. ISOLATED TO WIDELY SCATTERED MODERATE SHOWERS AND THUNDERSTORMS FROM 10N TO 13N BETWEEN 115W AND 121W...AND FROM 11N TO 14N BETWEEN 136W AND 140W. ...DISCUSSION... BROAD UPPER LEVEL ANTICYCLONIC FLOW COVERS CENTRAL AMERICA FROM 12N TO 19N. AN UPPER LEVEL RIDGE EXTENDS FROM 17N140W TO THE AREA OF HURRICANE IVO TOWARD THE MEXICO COAST NEAR 23N107W. AN UPPER LEVEL RIDGE EXTENDS FROM AN ANTICYCLONIC CIRCULATION CENTER NEAR 15N142W TO 26N139W. A MIDDLE TO UPPER LEVEL INVERTED TROUGH BETWEEN HURRICANE IVO AND TROPICAL DEPRESSION 13-E ALONG 117W IS PRODUCING AN AREA OF MODERATE TO STRONG SUBSIDENCE NORTH OF 15N BETWEEN 110W AND 122W. THE SURFACE RIDGE IS FAIRLY STRONG NORTH OF THE AREA AND IS ALLOWING FOR THE ADVECTION OF A LARGE AREA OF STABLE STRATOCUMULUS CLOUDS ACROSS THE SUBTROPICAL WATERS NORTH OF 20N WEST OF 115W. $$ MT