000 AXPZ20 KNHC 071005 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SUN OCT 07 2012 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...SPECIAL FEATURE... TROPICAL STORM OLIVIA NEAR 14.4N 120.9W 998 MB AT 07/0900 UTC MOVING WNW OR 295 DEGREES AT 07 KT. MAXIMUM SUSTAINED WIND SPEED HAS INCREASED SLIGHTLY TO 50 KT WITH GUSTS TO 60 KT. THE LARGE MASS OF CONVECTION EARLIER NOTED THAT WAS ASSOCIATED WITH A TIGHT BANDING FEATURE AROUND THE CENTER HAS BROKEN UP DURING THE PAST FEW HRS. LATEST SATELLITE IMAGERY SHOWS THE REMAINING BANDS IN FRACTURED FORM. THEY CONSIST OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 45 NM OF A LINE FROM 10N122W TO 09N126W...ALSO WITHIN 30 NM OF LINE FROM 15N121W TO 16N120W AND WITHIN 30 NM OF A LINE FROM 14N117W TO 11N119W. SCATTERED STRONG CONVECTION IS WITHIN 60 NM N OF THE CENTER. LATEST NHC ADVISORY FORECASTS OLIVIA TO CONTINUE IN A WNW TACK THROUGH LATE TUE NIGHT. THROUGH MON THE CYCLONE WILL BE UNDER AN UPPER LEVEL RIDGE FAVORABLE FOR IT TO BRIEFLY STRENGTHEN INTO A MINIMAL HURRICANE BY LATE MON NIGHT BEFORE IT BEGINS TO MOVE ACROSS COOLER SEA SURFACE TEMPERATURES AND AT THE SAME TIME COME UNDER THE INFLUENCE OF SW SHEAR. THIS WILL CAUSE OLIVIA TO RAPIDLY BEGIN TO WEAKEN AFTER MON NIGHT AND THROUGH THE MIDDLE OF NEXT WEEK. FOR FURTHER DETAILS SEE AWIPS/WMO HEADERS MIATCMEP5 AND WTPZ25 KNHC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS W ACROSS THE SOUTHERN CARIBBEAN ALONG 11N FROM EXTREME N COLOMBIA TO ACROSS THE NORTHERN COSTA RICA TO 09N99W AND TO 11N111W WHERE IT ENDS. IT THEN RESUMES TO THE SW OF TROPICAL STORM OLIVIA AT 11N124W TO 08N134W WHERE IT TRANSITIONS TO THE ITCZ AXIS TO 09N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM S OF THE TROUGH BETWEEN 85W-90W ...AND WITHIN 60 NM OF THE TROUGH W OF 124W. ...DISCUSSION... AN UPPER LEVEL ANTICYCLONE IS IDENTIFIED ON WATER VAPOR IMAGERY TO BE LOCATED NE OF TROPICAL STORM OLIVIA NEAR 17N116W WITH UPPER RIDGES EXTENDING N BEYOND 32N116W...SE TO A CREST AT 11N99W AND W TO A CREST AT 15N134W. AN UPPER 50-90 KT JET IS DETECTED BY CLOUD MOTION VECTORS ALONG THE NW PERIPHERY OF THE ANTICYCLONE THROUGH POINTS 24N140W NE TO BEYOND THE AREA AT 32N123W AND E FROM THERE TO ACROSS FAR SRN CALIFORNIA AND THEN SE TO OVER THE SW U.S. IT IS ADVECTING A 120 NM WIDE PLUME OF UPPER MOISTURE NE AND E ACROSS THE NORTHERN RIDGE CREST AND SEWD TO OVER THE SW AND S CENTRAL PORTIONS OF THE U.S. THE DEBRIS MOISTURE FROM OLIVIA IS ADVECTED NE TO 21N116W WHERE IT TURNS SEWD...AND EVAPORATES IN THE DRY SUBSIDENT AIR ALOFT. AN UPPER TROUGH EXTENDS FROM THE CENTRAL U.S. SW TO ACROSS THE WESTERN GULF OF MEXICO...AND TO OVER CENTRAL MEXICO WHERE IT THEN STRETCHES S TO SW OF THE GULF OF TEHUANTEPEC WHERE A COL REGION IS NOTED. AN INVERTED TROUGH EXISTS S OF THIS COL REGION ROUGHLY ALONG 93W. THIS TROUGH CONTINUES TO SPLIT THE UPPER FLOW OVER THE TROPICAL PACIFIC. AN UPPER ANTICYCLONE OVER THE EASTERN GULF OF HONDURAS HAS ITS ANTICYCLONIC ENVELOPE EXTENDING S OVER THE DISCUSSION AREA TO THE N OF 06N AND E OF 93W. THE ASSOCIATED UPPER DIFFLUENCE CONTINUES TO AID IN THE DEVELOPMENT OF CONVECTIVE ACTIVITY ALONG THE EASTERN SEGMENT OF THE LOWER LEVEL MONSOON TROUGH AS PREVIOUSLY DESCRIBED. SOME OF THE UPPER DEBRIS MOISTURE FROM THE CONVECTIVE ACTIVITY...IN THE FORM OF HIGH CLOUDS...IS BEING CHANNELED NNE TOWARDS CENTRAL AMERICA AND THE GULF OF HONDURAS. ELSEWHERE AT THE LOW LEVELS...SURFACE HIGH PRESSURE OF 1020 MB IS ANALYZED AT 29N130W WITH RIDGING COVERING THE DISCUSSION AREA N OF 20N W OF THE BAJA PENINSULA. NW WINDS OF 20-25 KT ARE PRESENT IN THE FAR NE PART OF THE AREA N OF 27N E OF 118W TO THE NORTHERN BAJA CALIFORNIA PENINSULA DUE TO THE PRES GRADIENT BETWEEN THE RIDGE AND THE GULF OF CALIFORNIA THERMAL TROUGH. THE GRADIENT RELAXES ON MON AFTERNOON ALLOWING FOR THESE WINDS TO DIMINISH TO 20 KT OR LESS INTO TUE WITH SEAS SUBSIDING FROM AN 8 FT MAXIMUM TO 6-7 FT ON MON AND INTO TUE IN THAT PART OF THE AREA. GAP WINDS...N-NE WINDS OF 20-25 KT ARE EXPECTED TO AGAIN PULSE THROUGH THE GULF OF TEHUANTEPEC BEGINNING LATE TONIGHT AND CONTINUING THROUGH THE MIDDLE OF NEXT WEEK...INCREASING TO 20-30 KT ON THU. THE STRONGEST DRAINAGE FLOW WILL OCCUR LATE EACH NIGHT THROUGH A COUPLE OF HOURS AFTER DAYBREAK EACH MORNING. $$ AGUIRRE