000 AXPZ20 KNHC 250247 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN MAY 25 2014 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 0215 UTC. ...SPECIAL FEATURE... HURRICANE AMANDA IS CENTERED NEAR 11.6N 110.7W...OR ABOUT 665 MILES SW OF MANZANILLO MEXICO AT 0300 UTC MAY 25 AND HAS RAPIDLY INTENSIFIED OVER THE PAST FEW HOURS. MINIMUM CENTRAL PRESSURE IS 966 MB. AMANDA IS MOVING WNW...OR 295 DEG... AT 04 KT. MAXIMUM SUSTAINED WINDS ARE 100 KT WITH GUSTS TO 120 KT. AMANDA NOW HAS 15 NM DIAMETER EYE WITH NUMEROUS STRONG CONVECTION OBSERVED WITHIN 90 NM SE AND WITHIN 45 NM NW SEMICIRCLES. SCATTERED MODERATE TO STRONG CONVECTION IS NOTED ELSEWHERE WITHIN 120 NM EITHER SIDE OF A LINE FROM 15.5N109.5W TO 08N110W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED IN AN OUTER BAND WITHIN 45 NM EITHER SIDE OF A LINE FROM 14N112W TO 11N113W. AMANDA IS FORECAST TO STRENGTHEN TO A 110 KT MAJOR HURRICANE EARLY SUN NEAR 11.8N 111.0W AND MAINTAIN THAT STRENGTH FOR ABOUT 12 HOURS. THEREAFTER...AMANDA WILL BEGIN TO ENCOUNTER SOUTHERLY SHEAR AND IS EXPECTED TO WEAKEN A TROPICAL STORM ON WED NEAR 16N111.5W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS OFF THE COAST OF CARIBBEAN COAST OF COLOMBIA AT 08.5N77W TO ACROSS NE PANAMA AND EASTERN COSTA RICA EXITING THE COAST OF COSTA RICA AT 09N84W. THE TROUGH CONTINUES SE TO 08N94W...THEN TURNS NW TO 11N103W WHERE THE MONSOON TROUGH LOSES IDENTITY IN THE BROAD CYCLONIC CIRCULATION ASSOCIATED WITH STRENGTHENING HURRICANE AMANDA. THE MONSOON TROUGH THEN RESUMES SW OF AMANDA NEAR 06N112W TO 07N122W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ. THE ITCZ THEN WIGGLES WESTWARD TO BEYOND 06N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED OVER AND ALONG THE EASTERN SEGMENT OF THE MONSOON TROUGH WITHIN 120 NM EITHER SIDE OF LINES FROM 09N84W TO 02N99W AND FROM 11N93W TO 07N105W. ISOLATED MODERATE TO STRONG CONVECTION IS OBSERVED ELSEWHERE FROM 02-15N E OF 105W. SCATTERED MODERATE ISOLATED STRONG IS OBSERVED ALONG THE WESTERN SEGMENT OF THE MONSOON TROUGH WITHIN 45 NM OF 06N115W. SCATTERED MODERATE CONVECTION IS NOTED OVER AND TO THE S OF THE ITCZ WITHIN 75 NM EITHER SIDE OF A LINE FROM 05N133W TO 04N138W. ...DISCUSSION... AN UPPER ANTICYCLONE IS CENTERED NEAR 32N130W WITH DRY UPPER AIR INDICATED WITHIN ITS ENVELOPE AND COVERING THE DISCUSSION AREA N OF 26N TO THE W OF 123W. AN UPPER CYCLONE HAS BEEN QUASI- STATIONARY NEAR 21N135W FOR THE PAST DAY WITH AN UPPER TROUGH EXTENDING SE TO A BASE OVER THE TROPICS AT 13N128W. A SMALL UPPER ANTICYCLONE IS OVER THE DEEP TROPICS AT 04N136W...AND IS ENHANCING ONLY SCATTERED MODERATE CONVECTION ALONG THE ITCZ AS PREVIOUSLY DESCRIBED. DEBRIS MOISTURE FROM THIS CONVECTION SPREADS N AND MERGES WITH A DENSE MOISTURE...ORIGINATING FROM ITCZ CONVECTION W OF THE AREA...AND CONCENTRATES INTO A TROPICAL PLUM THAT CONTINUES NE WITHIN 120 NM EITHER SIDE OF A LINE FROM 13N133W TO 22N113W. THIS MOISTURE WILL LIKELY MERGE WITH THE DEBRIS MOISTURE FROM HURRICANE AMANDA LATER TONIGHT NEAR THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA. AN UPPER CYCLONE IS CENTERED OVER WESTERN NEW MEXICO WITH AN UPPER TROUGH EXTENDING SSW TO A BASE OVER THE PACIFIC AT 23N114W. UPPER MOISTURE IS ROTATING CYCLONICALLY AROUND THE WESTERN SEMICIRCLE OF THE CYCLONE AND IS NOW SPREADING S ACROSS THE NORTHERN BAJA CALIFORNIA PENINSULA. AN UPPER ANTICYCLONE IS E OF HURRICANE AMANDA NEAR 13N102W WITH AN UPPER RIDGE EXTENDING SW ACROSS THE HURRICANE TO A SHARP CREST AT 10N123W. DEBRIS MOISTURE FROM AMANDA...AND OTHER CONVECTION UNDER THE UPPER RIDGE BETWEEN 89-116W...IS ADVECTED NE ALONG THE W PERIPHERY OF THE ANTICYCLONE AND ACROSS CENTRAL MEXICO FROM 13-25N...AND CONTINUES NE ACROSS THE CENTRAL GULF OF MEXICO. AN UPPER TROUGH CONTINUES SW ACROSS THE WESTERN CARIBBEAN TO A BASE OVER PANAMA. CONVECTION IS ENHANCED ALONG THE BASE OF THIS UPPER TROUGH AND ALONG THE LOWER LEVEL MONSOON TROUGH AS PREVIOUSLY MENTIONED. ALTHOUGH SOME OF THE DEBRIS MOISTURE IS ADVECTED NE ACROSS EXTREME NW COLOMBIA...MOST OF THE DEBRIS MOISTURE IS ADVECTED S...CURRENTLY REACHING THE EQUATOR BETWEEN 87-97W. A 1026 MB SURFACE HIGH IS CENTERED NEAR 33N136W WITH A RIDGE EXTENDING SE TO 17N105W PER LATEST SCATTEROMETER WINDS. ANTICYCLONIC SURFACE WINDS ARE FORECAST AT 10-15 KT AROUND THE SOUTHERN PERIPHERY OF THIS RIDGE THROUGH THE MIDDLE OF NEXT WEEK...WITH ASSOCIATED SEAS OF 5-7 FT. THE GRADIENT IS EXPECTED TO TIGHTEN NE OF THE RIDGE ON SUN NIGHT...INCREASING THE NW-N WINDS TO 15-20 KT AND DRIVING A TONGUE OF 7-9 FT SEAS INTO THE DISCUSSION WATERS N OF 25N BETWEEN 120-132W ON MON AND TUE. THE N WINDS ARE EXPECTED TO INCREASE TO 20-25 KT ACROSS THE WATERS N OF 30N ON WED...WITH SEAS BUILDING 8-12 FT IN MIXED N AND S SWELL ACROSS THE WATERS N OF 25N W OF 117W. $$ NELSON