000 AXPZ20 KNHC 101552 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC MON APR 10 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 7N78W 4N94W 7N120W 4N132W 6N140W. SCATTERED MODERATE TO STRONG WITHIN 60 NM OF 5N83W AND 8N121W. SCATTERED MODERATE ISOLATED STRONG WITHIN 30 NM EITHER SIDE OF LINE 5N87W 4N98W AND LINE 4N110W 7N119W AND ELSEWHERE FROM 3N TO 9N BETWEEN 120W AND 126W. ...DISCUSSION... THE NE PAC AND W COAST OF CONUS IS DOMINATED BY A LONGWAVE TROUGH. THE MOST SIGNIFICANT EMBEDDED SHORTWAVE ENTERS THE DISCUSSION AREA ALONG 32N125W 18N134W. A BAND OF DRY AIR IS NOTED WITHIN 30 NM EITHER SIDE OF LINE 32N117W 28N120W THEN WIDENS TO 210 NM EITHER SIDE OF POINTS 22N130W 21N140W. AN UPPER ANTICYCLONE IS ESTIMATED NEAR 8N122W AND ANOTHER NEAR 14N105W. A COMBINED UPPER RIDGE EXTENDS NNE ALONG 23N112W TO BEYOND 38N103W WITH THIS SHORTWAVE RIDGE AMPLIFYING NE AND MERGING WITH A LONGWAVE RIDGE THAT DOMINATES N AMERICA ROUGHLY ALONG 90W. UPPER DIFFLUENCE UNDER THE RIDGE IS ENHANCING CONVECTION ALONG AN INVERTED LOW LEVEL TROUGH THAT EXTENDS FROM 2N127W TO 10N120W. THE UPPER DEBRIS MOISTURE FROM THIS CONVECTION SPREADS N ALONG THE RIDGE AXIS MERGING WITH A 630 NM WIDE MOISTURE PLUME AXIS THAT ENTERS THE DISCUSSION AREA NEAR 9N140W...AND CONTINUES NE AND NARROWS THROUGH 22N120W...THEN TURNS ANTICYCLONICALLY E CROSSING THE UPPER RIDGE OVER NORTHERN OLD MEXICO AND THE DESERT SW OF CONUS...THEN SPILLING SE TO ALONG 98W WHERE IT EVAPORATES IN DRIER UPPER AIR. A POSITIVE TILT UPPER TROUGH DOMINATES THE ENTIRE EASTERN SEABOARD OF N AMERICA WITH VIGOROUS SHORTWAVES EFFECTIVELY ANCHORING THE LONGWAVE AXIS. ONE SHORTWAVE EXTENDS SW INTO THE DISCUSSION AREA FROM 32N87W TO 16N90W THEN THROUGH A SMALL UPPER CYCLONE NEAR 6N102W AND CONTINUING S TO ANOTHER CYCLONE OVER THE EQUATOR AT 101W. DRY UPPER AIR IS INDICATED ON MOISTURE CHANNEL ROUGHLY WITHIN 960 NM EITHER SIDE OF LINE 32N84W 3N110W. AN ILL-DEFINED UPPER ANTICYCLONE IS NOTED OVER VENEZUELA NEAR 8N66W. TOGETHER THEY CREST SE OF THE UPPER TROUGH ALONG POINTS 7N95W 22N74W 22N60W. UPPER DIFFLUENCE UNDER THE RIDGE IS ENHANCING CONVECTION ALONG THE ITCZ E OF 98W...WITH A THIN BAND OF DEBRIS MOISTURE ADVECTED NE ACROSS CENTRAL AMERICA BECOMING ZONAL OVER THE CENTRAL CARIBBEAN. AT THE SURFACE...HIGH PRES 1018 MB IS NEAR 25N123W AND IS RETARDING THE E PROGRESS OF A WEAKENING FRONTAL TROUGH THAT LIES ALONG 32N118W 25N131W. THE TROUGH IS EXPECTED TO MOVE E ALONG 30N AND E OF AREA LATER TODAY. THE INVERTED LOW LEVEL TROUGH ALONG 125W IS QUITE WEAK AND EMBEDDED IN THE ITCZ AND MAY SOON BE DROPPED FROM THE SURFACE ANALYSIS. GAP WINDS...GULF OF TEHUANTEPEC...A QSCAT PASS THIS MORNING SHOWS MAX OF 30 KT. MODELS FLUCTUATE THE NLY WINDS FROM 15-25 KT THROUGH WED THEN HIGH PRES OVER THE SE CONUS WILL SURGE THROUGH THE GAP AT GALE FORCE. $$ NELSON