000 AXPZ20 KNHC 252148 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 UTC. ...SPECIAL FEATURE... HURRICANE AMANDA IS CENTERED NEAR 12.3N 111.3W...OR ABOUT 740 MILES S OF THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA... AT 2100 UTC MAY 25 AND IS BEGINNING TO WEAKEN. MINIMUM CENTRAL PRESSURE IS 935 MB. AMANDA IS MOVING N...OR 350 DEG...AT 04 KT. MAXIMUM SUSTAINED WINDS ARE 130 KT WITH GUSTS TO 160 KT. AMANDA HAS A 10 NM DIAMETER EYE WITH SCATTERED STRONG CONVECTION OBSERVED WITHIN 120 NM E AND WITHIN 45 NM W SEMICIRCLES OF CENTER. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED ELSEWHERE WITHIN 120 NM EITHER SIDE OF A LINE FROM 16N112W TO 09N110W...AND ALONG AN OUTER BAND WITHIN 30 NM EITHER SIDE OF A LINE FROM 09N112W TO 12N114W. AMANDA IS FORECAST TO GRADUALLY WEAKEN TO A TROPICAL STORM ON WED. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS NW OFF THE COAST OF COAST OF COLOMBIA AT 06N77W TO 11N93W...THEN TURNS W TO 11N106W WHERE THE MONSOON TROUGH LOSES IDENTITY IN THE BROAD CYCLONIC CIRCULATION ASSOCIATED WITH HURRICANE AMANDA. THE MONSOON TROUGH THEN RESUMES SW OF AMANDA NEAR 09N114W AND CONTINUES SW TO 08N125W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ. THE ITCZ THEN CONTINUES SW TO BEYOND 06N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED OVER AND TO THE S OF THE MONSOON TROUGH WITHIN 150 NM EITHER SIDE OF A LINE FROM 03N77W TO 08N95W TO 07N103W. SIMILAR CONVECTION IS OBSERVED OVER AND TO THE N OF THE MONSOON TROUGH WITHIN 90 NM EITHER SIDE OF A LINE FROM 10N88W TO 17N102W...AND ALSO WITHIN 150 NM EITHER SIDE OF A LINE FROM 05N110W TO 04N118W...AND ALONG THE ITCZ WITHIN 90 NM EITHER SIDE OF A LINE FROM 05N125W TO 06N135W. ...DISCUSSION... AN UPPER ANTICYCLONE IS CENTERED NEAR 31N131W WITH DRY UPPER AIR INDICATED WITHIN ITS ENVELOPE WHICH IS COVERING THE DISCUSSION AREA N OF 26N TO THE W OF 118W. AN UPPER CYCLONE HAS BEEN QUASI- STATIONARY NEAR 22N135W FOR THE PAST TWO DAYS DAY...WITH AN UPPER TROUGH CURRENTLY EXTENDING SE TO A BASE OVER THE TROPICS AT 11N120W. A SMALL UPPER ANTICYCLONE IS OVER THE DEEP TROPICS AT 05N138W...AND IS ENHANCING THE CONVECTION ALONG THE ITCZ AS PREVIOUSLY DESCRIBED. SOME OF THE DEBRIS MOISTURE FROM THIS CONVECTION SPREADS N AND MERGES WITH ANOTHER MOISTURE PLUME...THAT ORIGINATES FROM ITCZ CONVECTION W OF THE AREA...WITH THE MERGED PLUME CONTINUING NE WITHIN 180 NM EITHER SIDE OF A LINE FROM 12N130W TO 23N110W WHERE IT MERGES WITH THE DEBRIS MOISTURE FROM HURRICANE AMANDA. AN UPPER CYCLONE IS CENTERED OVER CENTRAL NEW MEXICO WITH AN UPPER TROUGH EXTENDING SW TO A BASE OVER THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA. SEVERAL UPPER ANTICYCLONES ARE OBSERVED E OF HURRICANE AMANDA WITH A COMBINED UPPER RIDGE EXTENDING W ACROSS THE HURRICANE TO A GENTLE RIDGE ALONG POINTS 11N117W...18N116W AND 22N110W. DEBRIS MOISTURE FROM AMANDA...AND OTHER CONVECTION UNDER THE UPPER RIDGE BETWEEN 88-115W...IS ADVECTED NE ALONG THE W PERIPHERY OF THE ANTICYCLONE...AND ACROSS CENTRAL MEXICO FROM 14- 25N...AND CONTINUES E ACROSS THE WESTERN GULF OF MEXICO. AN UPPER TROUGH CONTINUES SW ACROSS THE WESTERN CARIBBEAN TO A BASE OVER PANAMA. FOR THE THIRD DAY 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 OCCASIONALLY ADVECTED NE ACROSS EXTREME NW COLOMBIA...MOST OF THE DEBRIS MOISTURE IS CURRENTLY ADVECTED S...REACHING THE EQUATOR BETWEEN 80-100W. A 1026 MB SURFACE HIGH IS CENTERED NEAR 34N136W WITH A RIDGE EXTENDING SE TO 20N110W PER LATEST SCATTEROMETER WINDS. ANTICYCLONIC SURFACE WINDS ARE FORECAST AT 10-15 KT AROUND THE SOUTHERN PERIPHERY OF THIS RIDGE THROUGH THE NEXT WEEKEND... WITH ASSOCIATED SEAS OF 5-7 FT. THE GRADIENT IS EXPECTED TO TIGHTEN NE OF THE RIDGE AS AMANDA CONTINUES NORTHWARD. THIS WILL INCREASE THE NW-N WINDS TO 15-20 KT TONIGHT AND MON...AND PUSH A TONGUE OF 7-9 FT SEAS INTO THE DISCUSSION WATERS N OF 26N BETWEEN 122-132W ON MON AND TUE. N-NE WINDS ARE EXPECTED TO INCREASE TO 20-25 KT ACROSS THE WATERS N OF 30N...AND 15-20 KT FROM 25-30N ON WED...WITH SEAS BUILDING 8-12 FT IN MIXED N AND S SWELL ACROSS THE WATERS N OF 25N W OF 117W. $$ NELSON