000 AXPZ20 KNHC 111551 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC TUE APR 11 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1545 UTC. ...ITCZ... ITCZ AXIS ALONG 9N83W 5N94W 3N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 30 NM EITHER SIDE OF AXIS FROM 82W TO 102W AND WITHIN 180 NM OF 6N118W. ...DISCUSSION... THE NE PAC IS DOMINATED BY A LONGWAVE TROUGH WITH A DEEP LAYERED CYCLONE NEAR 38N132W WITH A MEAN TROUGH AXIS S TO NEAR 15N135W. ONE EMBEDDED SHORTWAVE HAS MOVED INLAND THE CONUS ALONG 36N122W 30N109W. A SECOND SHORTWAVE ENTERS THE DISCUSSION AREA ALONG 32N130W 18N131W. A BAND OF DRY AIR IS NOTED WITHIN 60 NM EITHER SIDE OF LINE 32N108W 24N119W THEN COVERING THE DISCUSSION AREA FROM 16N TO 26N W OF 122W. AN UPPER ANTICYCLONE IS ESTIMATED NEAR 7N117W AND ANOTHER NEAR 16N107W. A COMBINED UPPER RIDGE EXTENDS NNE ALONG 22N108W TO BEYOND 32N102W WITH THIS SHORTWAVE RIDGE AMPLIFYING NE AND MERGING WITH A NE TO SW LONGWAVE RIDGE THAT DOMINATES EASTERN N AMERICA. UPPER DIFFLUENCE UNDER THE RIDGE IS ENHANCING CONVECTION ALONG A COUPLE OF INVERTED LOW LEVEL TROUGHS EMBEDDED IN THE ITCZ. ONE TROUGH IS NEAR 136W AND THE OTHER NEAR 117W. THE UPPER DEBRIS MOISTURE FROM THESE CONVECTIVE AREAS SPREADS N ALONG THE RIDGE AXIS BECOMING A 480 NM WIDE MOISTURE PLUME CENTERED ALONG 14N119W TO BEYOND 32N102W. E OF THE LONGWAVE RIDGE OVER EASTERN N AMERICA A SHARP POSITIVE TILT UPPER TROUGH IS NOW SHIFTING E ACROSS THE W ATLC. A SHORTWAVE TROUGH EXTENDS SW INTO THE DISCUSSION AREA FROM 32N78W TO 17N90W THEN THROUGH A SMALL UPPER CYCLONE NEAR 7N102W AND CONTINUING S TO ANOTHER CYCLONE STATIONARY OVER THE EQUATOR AT 100W. DRY UPPER AIR IS INDICATED ON MOISTURE CHANNEL ROUGHLY WITHIN 420 NM EITHER SIDE OF LINE 32N78W 1N108W. AN ILL-DEFINED UPPER ANTICYCLONE IS NOTED OVER VENEZUELA NEAR 7N62W. THE ASSOCIATED RIDGE CRESTS ALONG POINTS 10N92W 20N71W. UPPER DIFFLUENCE UNDER THE RIDGE IS ENHANCING SMALL CONVECTIVE BURSTS ALONG THE ITCZ E OF 102W. DEBRIS MOISTURE IS ADVECTED NE ACROSS CENTRAL AMERICA AND ACROSS THE CENTRAL CARIBBEAN. AT THE SURFACE...HIGH PRES 1016 MB IS NEAR 26N126W. A COLD FRONT LIES ALONG 32N129W 28N140W. GAP WINDS...GULF OF TEHUANTEPEC...A QSCAT PASS THIS MORNING AGAIN SHOWS THE DIURNAL 12Z MAX OF 30 KT. AGAIN MODEL GUIDANCE FLUCTUATE THE NLY WINDS FROM 15-25 KT THROUGH WED NIGHT THEN HIGH PRES OVER THE SE CONUS WILL SURGE THROUGH THE GAP AT GALE FORCE AND THUS A WARNING HAS BEEN POSTED FOR 12 UTC THU. A ELY SURGE THROUGH GULF OF PAPAGAYO WILL CONTINUE THROUGH 48 HOURS. $$ NELSON