000 AXPZ20 KNHC 012151 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT APR 01 2006 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 2145 UTC. ...ITCZ... ITCZ AXIS ALONG 6N77W 4N85W 4N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 90 NM EITHER SIDE OF LINE 7N85W 4N94W. SCATTERED MODERATE WITHIN 30 NM EITHER SIDE OF LINE 8N99W 3N117W 5N123W 10N124W. ...DISCUSSION... THE NE PAC IS DOMINATED BY A LONGWAVE TROUGH. AN UPPER CYCLONE IS NEAR THE BASE OF THE LONGWAVE TROUGH NEAR 5N121W AND MAY POSSIBLY CUT OFF AS THE TROUGH AXIS SHIFTS E. UPPER DIFFLUENCE IS ENHANCING CONVECTION NEAR THE CYCLONE CENTER AND WITHIN 180 NM NW OF CENTER. AN EMBEDDED SHORTWAVE RIDGE ORIGINATES FROM AN ANTICYCLONE NEAR 3N164W AND EXTENDS NE ALONG 17N150W TO A CREST IN THE DISCUSSION AREA NEAR 28N132W. THIS RIDGE SEPARATES TWO EMBEDDED SHORTWAVE TROUGHS WITHIN THE LARGER PATTERN. THE FIRST TROUGH HAS MOVED INLAND THE WESTERN CONUS AND EXTENDS S INTO THE DISCUSSION AREA ALONG 32N116W 20N118W. THE SECOND SHORTWAVE IS APPROACHING THE NW PORTION AND IS CURRENTLY 36N145W 28N144W. A BAND OF DRY AIR IS NOTED WITHIN THE LONGWAVE TROUGH WITHIN 90 NM EITHER SIDE OF LINE 32N107W 26N113W 25N120W 30N132W 29N140W. A BAND OF UPPER MOISTURE RIDES ACROSS THE SHORTWAVE RIDGE THEN CYCLONICALLY NE THROUGH THE LONGWAVE TROUGH...ROUGHLY WITHIN 240 NM EITHER SIDE OF LINE 20N140W TO 18N124W WHERE THE PLUME NARROWS TO 90 NM WIDE THROUGH 24N110W 32N102W. AN UPPER ANTICYCLONE IS CENTERED OVER VENEZUELA WITH A RIDGE EXTENDING NW ACROSS THE W CARIBBEAN AND THE CENTRAL GULF OF MEXICO AND CONTINUING N ACROSS THE CENTRAL CONUS. UPPER DIFFLUENCE UNDER THIS RIDGE IS ENHANCING CONVECTION WITHIN 90 NM EITHER SIDE OF LINE 7N85W 4N94W. OTHERWISE DRY UPPER AIR DOMINATES THE DISCUSSION AREA WITHIN 540 NM EITHER SIDE OF LINE 4N128W 21N80W. AT THE SURFACE...HIGH PRES 1019 MB IS QUASI STATIONARY NEAR 26N120W AND IS BLOCKING THE E PROGRESS OF A WEAKENING FRONTAL TROUGH THAT LIES ALONG 32N125W THROUGH A WEAK LOW PRES 27N133W 1016 MB WITH THE TROUGH CONTINUING SW TO 22N140W. GULF OF PAPAGAYO...LATEST QSCAT WINDS AND SSMI INDICATE NE WINDS 20 KT WITHIN 90 NM EITHER SIDE LINE 12N87W 10N91W. THESE NE 20 KT WINDS EXPECTED TO CONTINUE THROUGH 48 HOURS. $$ NELSON