000 AXPZ20 KNHC 020955 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT MAY 02 2009 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 0915 UTC. ...ITCZ... ITCZ AXIS IS ALONG 08N83W TO 07N104W TO 03N135W TO 05N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED AND CONFIRMED BY LIGHTNING DATA WITHIN 240 NM EITHER SIDE OF LINE FROM 05N77W TO 06N95W AND WITHIN 60 NM EITHER SIDE OF LINE FROM 07N114W TO 10N130W AND ALSO FROM 04N TO 10N BETWEEN 136W AND 142W. SCATTERED MODERATE WITHIN 45 NM OF 03.5N130.5W. ...DISCUSSION... ALOFT...AN UPPER TROUGH OVER THE WESTERN SEABOARD OF THE CONUS CONTINUES SW INTO THE DISCUSSION AREA FROM 32N115W TO 15N140W. AN UPPER ANTICYCLONE NEAR HAWAII HAS AN UNSTABLE UPPER RIDGE COLLAPSING SE ALONG 27N140W TO FAIRLY SHARP CREST AT 27N126W. A QUASI STATIONARY UPPER ANTICYCLONE IS CENTERED AT 14N118W WITH A RIDGE EXTENDING N TO WELL BEYOND 32N106W. UPPER DEBRIS MOISTURE IS TRAPPED WITHIN THIS WESTERN RIDGE COVERING THE DISCUSSION AREA NW OF A LINE FROM 32N115W TO 20N140W...WHILE DRY UPPER AIR IS INDICATED WITHIN 180 NM OF THE UPPER TROUGH AXIS TO THE S OF 24N. UPPER DIFFLUENCE UNDER THE RIDGE ENHANCED CONVECTION ALONG THE ITCZ BETWEEN 120W AND 132W...WITH THE DEBRIS MOISTURE ADVECTED NE AS A DENSE TROPICAL PLUME ALONG THE W PERIPHERY OF THE EASTERN RIDGE...ALL ROUGHLY WITHIN 150 NM EITHER SIDE OF LINE FROM 10N132W TO 30N106W. THE MOISTURE THEN FANS OUT OVER THE UPPER LEVELS OF THE SW CONUS WITH SOME OF THE MOISTURE NOW SPILLING SE ACROSS THE RIDGE OVER NORTHERN OLD MEXICO. A SECOND UPPER TROUGH OVER THE EASTERN SEABOARD OF THE CONUS EXTENDS DISSECTING THE GULF OF MEXICO INTO A DEEP LAYERED CYCLONE AT 17N103W AND CONTINUING S INTO A SECOND MID TO UPPER CYCLONE AT 07N104W...WITH THE TROUGH CONTINUING S ACROSS THE EQUATOR AT 109W. A STATIONARY UPPER RIDGE EXTENDS W NW ACROSS COLOMBIA AND THE NW CARIBBEAN CRESTING OVER THE BAY OF CAMPECHE. UPPER DIFFLUENCE E OF THE UPPER TROUGH ENHANCED CONVECTION EARLIER OVER OLD MEXICO ALONG 17N TO THE E OF 100W...AND ALSO ALONG THE PACIFIC ITCZ BETWEEN 83W AND 107W. THE RESULTANT UPPER DEBRIS MOISTURE IS SPREADING NE ACROSS THE NW CARIBBEAN AND THE SE GULF OF MEXICO...BUT APPEARS TO BE MOSTLY THIN OVERCAST CIRRUS. OTHERWISE VERY DRY UPPER AIR IS OBSERVED OVER THE AREA FROM 10N TO 20N BETWEEN 100W AND 118W AND IS SUPPRESSING CONVECTION. AT THE SURFACE...A 1022 MB HIGH PRES IS QUASI STATIONARY NEAR 26N126W WITH A RIDGE EXTENDING SW TO BEYOND 21N140W...AND A RIDGE ALSO EXTENDS SE TO NEAR 13N102W. SOUTHERLY SURFACE WINDS WELL TO THE N OF THE RIDGE ARE IN THE 20 KT RANGE IN ADVANCE OF A SERIES OF WEAK COLD FRONTS THAT WILL BRUSH THE EXTREME N BOUNDARY OF THE DISCUSSION AREA OVER THE NEXT FEW DAYS. NORTHERLY WINDS TO 20 KT ALONG THE PACIFIC COAST OF NORTHERN BAJA WILL INCREASE TO 20 TO 25 KT AND SPREAD S ALONG THE ENTIRE BAJA PENINSULA SUN REACHING AS FAR S AS 19N BETWEEN 110W AND 118W MON. EASTERLY TRADES TO THE SW OF THE LOW LEVEL RIDGE ARE MOSTLY IN THE 15 TO 20 KT RANGE AND NOT EXPECTED TO CHANGE MUCH THROUGH THE WEEKEND. $$ NELSON