000 AXPZ20 KNHC 080947 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU NOV 08 2007 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N77W 9N85W 6N91W 10N127W 9N140W. SCATTERED MODERATE CONVECTION NOTED IN THE GULF OF PANAMA. SCATTERED MODERATE ISOLATED STRONG CONVECTION OBSERVED WITHIN 60 NM OF AXIS W OF 126W. ...DISCUSSION... AN UPPER CUT-OFF CYCLONE CONTINUES QUASI-STATIONARY N OF AREA NEAR 34N126W WITH A TROUGH EXTENDING SW THROUGH A WEAK UPPER CYCLONE DEVELOPING AT 25N131W WITH THE TROUGH CONTINUING S TO A BASE AT 17N135W. DRY UPPER AIR IS NOTED OVER THE DISCUSSION AREA W OF THE TROUGH WITHIN 120 NM EITHER SIDE OF LINE 32N128W 18N140W. TO THE SW OF THIS UPPER TROUGH...AN ERODING UPPER RIDGE PUSHES INTO THE SW CORNER OF AREA WITH AN ILL-DEFINED CREST ALONG 18N140W 10N130W TO THE EQUATOR AT 133W. UPPER MOISTURE... ORIGINATING FROM ITCZ CONVECTION ENHANCED UNDER THIS RIDGE BETWEEN 130W AND 145W...IS STREAMING N ALONG THE W PERIPHERY OF A LARGE UPPER RIDGE DESCRIBED BELOW...WITHIN 180 NM EITHER SIDE OF LINE 13N136W 20N126W TURNING EASTWARD BEYOND 32N117W. AN UPPER ANTICYCLONE IS ESTIMATED NEAR 15N93W WITH AN UPPER RIDGE EXTENDING NW CRESTING ALONG POINTS 16N121W 30N121W 37N112W 30N90W. A DECAYING FRONTAL TROUGH OVER THE W CARIBBEAN LIES UNDER THIS UPPER RIDGE WITH SCATTERED CONVECTION ENHANCED NEAR 14N81W. CONVECTION ALONG THE E PAC ITCZ IS ALSO ENHANCED ALONG 9N BETWEEN 93W AND 100W. THE RESULTANT DEBRIS MOISTURE FROM THESE AREAS OF WEAK CONVECTION IS ADVECTED NW WITHIN 120 NM EITHER SIDE OF LINE 9N99W TO 24N108W. A LOW LEVEL RIDGE EXTENDS FROM 32N137W TO 17N115W AND IS EXPECTED TO CHANGE LITTLE THROUGH 48 HOURS THEN SHIFT SLIGHTLY S HIGH A SURFACE HIGH NEAR 27N138W 1022 MB. THIS WILL EFFECTIVELY BLOCK THE SOUTHERN ADVANCE OF A COLD FRONT STALLING IT ALONG 30N W OF 123W IN ABOUT 72 HOURS. THE GRADIENT S OF RIDGE WILL CONTINUE TO SUPPORT NE TO E WINDS IN 20 KT RANGE THROUGH 48 HOURS. N WINDS ALONG W COAST BAJA PENINSULA IN THE 15 KT RANGE...EXCEPT TO NEAR 20 KT NEAR SOUTHERN TIP OF THE BAJA PENINSULA AT THE MOMENT...BUT MODELS AGAIN SUGGEST THE GRADIENT WILL WEAKEN AND SUPPORT MOSTLY 15 KT LATER TODAY THE TIGHTEN AGAIN IN 48 HOURS WITH NW WINDS INCREASING TO 20 KT IN THE SAME AREA. GAP WINDS...GALE WINDS IN AND JUST S OF THE GULF OF TEHUANTEPEC ARE NOW EXPECTED TO PERSIST THROUGH 36 HOURS WITH MODELS FLUCTUATING A LITTLE ON THE DURATION OF GALE FORCE. NLY WINDS 20 KT IN THE GULF OF FONSECA AND GULF OF PAPAGAYO THROUGH 48 HOURS. $$ NELSON