000 AXPZ20 KNHC 212221 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC WED MAR 21 2007 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 2345 UTC. ...ITCZ... ITCZ IS CENTERED ALONG...6N77W 74N110W 6N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 30 NM 5N77W AND WITHIN 30 NM EITHER SIDE OF LINE 4N92W 5N123W. ...DISCUSSION... A MID TO UPPER LEVEL TROUGH LIES ALONG 32N118W 23N130W 21N140W WITH AN EMBEDDED UPPER CYCLONE DEVELOPING NEAR 32N121W. JUST TO THE W OF THE DISCUSSION AREA AN UPPER ANTICYCLONE IS CENTERED NEAR 30N147W WITH A RIDGE AMPLIFYING NE TO BEYOND 40N136W WITH THE UPPER FLOW NOW SPILLING SE ACROSS THE RIDGE INTO THE DISCUSSION AREA N OF 25N W OF 135W ACCOMPANIED BY DRY UPPER AIR. AN UPPER LEVEL ANTICYCLONE IS NEAR 5N118W WITH A RIDGE W TO NEAR 7N136W AND A RIDGE AMPLIFYING N OVER THE CENTRAL CONUS BEYOND 38N104W. ANOTHER UPPER TROUGH EXTENDS SW ACROSS THE E PORTION OF THE AREA...ROUGHLY ALONG 26N83W 19N90W 8N97W. A MOISTURE PLUME...ORIGINATING FROM ITCZ CONVECTION BETWEEN 128W AND 155W...LIES ALONG THE W PERIPHERY OF THE UPPER RIDGE...WITHIN 300 NM EITHER SIDE OF LINE FROM 12N137W 20N117W TO NEAR 34N104W WHERE THE MOISTURE ABRUPTLY EVAPORATES. DRY UPPER AIR IS TRAPPED ELSEWHERE UNDER THE UPPER RIDGE...AND EXTENDS E ACROSS THE REMAINDER OF THE DISCUSSION AREA. UPPER DIFFLUENCE OVER THE DEEP TROPICS E OF 110W IS ENHANCING CONVECTION ALONG THE ITCZ WITH DEBRIS ADVECTED ONLY A SHORT DISTANCE NE BEFORE EVAPORATING. ONLY A THIN MOISTURE PLUME IS NOTED MOVING NE ACROSS W PANAMA. AT THE SURFACE...A RIDGE EXTENDS SE INTO THE AREA ALONG 32N136W 20N110W. SCATTERED TO LOCALLY BROKEN LOW CLOUDS AND ISOLATED SHOWERS ARE NOTED OVER THE DISCUSSION AREA NW OF A LINE ALONG 20N140W 20N130W 28N115W. GAP WINDS...SURFACE OBSERVATIONS REPORT N WINDS AT 15-20 GUSTS TO 25KT SURROUNDING THE GULF OF TEHUANTEPEC. HIGH RESOLUTION MODELS SUGGEST NLY SURGES 20 TO 25 KT THROUGH 36 HOURS THEN AN INCREASE TO 20-30 KT. TIGHT PRES GRADIENT OVER THE W CARIBBEAN IS SPILLING ACROSS CENTRAL AMERICA AT 20-25 KT INTO AND DOWNSTREAM OF THE GULF OF PAPAGAYO. MODELS AREA FLUCTUATING ON DURATION OF THESE SURGES AND SW CARIBBEAN WINDS IN 20-30 KT RANGE W OF 75W...SO WILL FORECAST LITTLE CHANGE THROUGH 48 HOURS. $$ NELSON