000 AXPZ20 KNHC 242156 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SUN OCT 24 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 UTC. ...ITCZ... THE ITCZ AXIS EXTENDS FROM 10N85W TO 08N90W TO 08N140W. ISOLATED MODERATE CONVECTION IS OBSERVED NE OF A LINE FROM 03N79W TO 12N93W TO THE COAST OF CENTRAL AMERICA. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 60 NM EITHER SIDE OF A LINE FROM 11.5N112W TO 09N121W AND ALSO WITHIN 75 NM OF 08N132W AND 08N138W. ...DISCUSSION... AN UPPER TROUGH FROM 32N100W TO 22N110W TO 16N130W. AN UPPER ANTICYCLONE IS CENTERED AT 30N153W WITH A RIDGE BUILDING E ALONG 29N TO A CREST AT 29N115W. UPPER MOISTURE IS INDICATED N OF THE RIDGE AXIS...ALONG 29N...WITH THE MOISTURE EXTENDING E ACROSS MOST OF THE SW CONUS. OTHERWISE THE UPPER LEVELS ARE VERY DRY ACROSS THE SUBTROPICS...N OF 23N. THE UPPER TROUGH IS EXPECTED TO LEAVE CUT OFF AN UPPER CYCLONE NEAR 18N135W BY TUE WITH AN UPPER ANTICYCLONE DEVELOPING 19N114W. AN UPPER CYCLONE IS OBSERVED NEAR 07N127W AND IS PROGRESSING W WITH TIME. AN UPPER TROUGH EXTENDS E FROM THE CYCLONE TO NEAR 14N111W. THIS CYCLONE AND TROUGH EFFECTIVELY SEPARATE THE UPPER FLOW OVER THE TROPICAL E PACIFIC. TO THE W AN UPPER ANTICYCLONE IS CENTERED AT 12N142W WITH A RIDGE EXTENDING E TO A SHARP CREST AT 13N131W. UPPER DIFFLUENCE S OF THIS RIDGE IS ENHANCING THE TWO CONVECTIVE CLUSTERS NEAR 08N132W AND 08N138W WITH THE DEBRIS MOISTURE SPREADING OUT FROM 07N TO 11N BETWEEN 130W AND 142W. THE UPPER TROUGH IS ENHANCING CONVECTION ALONG THE ITCZ ALONG THE LINE FROM 11.5N112W TO 09N121W...BUT THE DEBRIS MOISTURE REMAINS WITHIN A FEW DEGREES OF THE CONVECTION AS THE UPPER LEVELS APPEAR VERY DRY OVER THE ENTIRE AREA S OF 23N W OF 95W. THE UPPER ANTICYCLONE ASSOCIATED WITH HURRICANE RICHARD IN THE NW CARIBBEAN HAS ITS ENVELOPE OF ANTICYCLONIC FLOW EXTENDING ACROSS CENTRAL AMERICA WITH A RIDGE EXTENDING W TO A CREST OVER THE TROPICAL PACIFIC AT 15N106W. THE UPPER DIFFLUENCE IS ENHANCING CONVECTION OVER MOST OF THE WESTERN CARIBBEAN AND CENTRAL AMERICA...AND THE ISOLATED CONVECTION OVER THE PACIFIC WATERS AS PREVIOUSLY DESCRIBED. THE DEBRIS MOISTURE IS SPREADING W OVER THE DISCUSSION AREA N OF 07N E OF 95W. ELSEWHERE AT THE SURFACE...HIGH PRES CENTERED NEAR 25N143W HAS A RIDGE EXTENDING E TO NEAR 15N107W. A VERY DRY COLD FRONT IS RACING ACROSS THE PACIFIC WATERS N OF THIS RIDGE BUT THE ASSOCIATED WIND SHIFT IS VERY MINOR PER GUIDANCE WITH THE RIDGE EXPECTED TO REBUILD GRADUALLY IN THE WAKE OF THE FRONT. THE STRONG N WINDS DO NOT ARRIVE ALONG 31N TILL LATE MON REACHING ALONG 24N E OF 125W LATE TUE NIGHT ACCOMPANIED BY SEAS TO 15 FT NEAR 30N120W. IN THE MEANTIME THE PRES GRADIENT S OF THE RIDGE AND N OF THE ITCZ IS PRODUCING AN AREA OF FRESH NE TRADE WINDS BETWEEN 10N AND 20N W OF 120W. EXPECT THIS AREA TO SHIFT N AS THE RIDGE AXIS SHIFT N TO ALONG 31N MON NIGHT. MONSOONAL SW FLOW CONTINUES S OF 10N E OF 105W WITH SW WINDS 15 TO 20 KT FROM 05N TO 12N E OF 110W. $$ NELSON