000 AXPZ20 KNHC 300304 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE MAR 30 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0130 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED ALONG 03N78W TO 05N95W TO 02N105W TO 05N128W TO 04N140W. SCATTERED MODERATE TO STRONG CONVECTION WAS WITHIN 30 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 82W AND 84W. SCATTERED MODERATE CONVECTION WAS WITHIN 120 NM N AND 45 NM S OF THE ITCZ AXIS BETWEEN 90W AND 95W AS WELL AS WITHIN 90 NM N OF THE ITCZ AXIS BETWEEN 129W AND 136W. TWO TROUGHS ARE EMBEDDED IN THE ITCZ AXIS. THE EASTERN TROUGH WAS FROM 07N96W TO 01N98W AND HAD SCATTERED MODERATE CONVECTION WITHIN 330 NM W OF THE TROUGH. THE WESTERN TROUGH WAS FROM 09N113W TO 03N128W AND HAD ISOLATED MODERATE CONVECTION WITHIN 45 NM EITHER SIDE OF THE TROUGH. ...DISCUSSION... SUBTROPICS... A NEW COLD FRONT CURRENTLY FOUND JUST NW OF THE AREA WILL DISSIPATE BEFORE REACHING FORECAST WATERS TUE...BUT WILL BRING A NEW BATCH OF NW SWELL WITH SIGNIFICANT WAVE HEIGHTS TO 18 FT AND WAVE PERIODS REACHING 17-18 SECOND AS THE SWELL PROPAGATES SE. THE PRES GRADIENT BETWEEN THE ITCZ AND 1031 MB HIGH PRES BEHIND THE COLD FRONT NEAR 32N161W WITH A RIDGE EXTENDING EAST-SOUTHEASTWARD TO SOCORRO ISLAND IS MAINTAINING A BROAD AREA OF FRESH TO STRONG TRADE WINDS FROM 07N TO 23N W OF 127W ACCORDING TO THE 1840 UTC ASCAT PASS. THE STRENGTH AND POSITION OF THIS HIGH PRES CENTER WILL VARY LITTLE OVER THE NEXT TWO DAYS BUT THE EASTWARD EXTENDING RIDGE AXIS WILL LIFT N AFTER THE COLD FRONT TO ITS N WEAKENS AND THEN BE FORCED S ON WED AS A SECONDARY COLD FRONT DROPS S OFF THE CALIFORNIA COAST. THE AREA OF FRESH TO STRONG TRADE WINDS WILL CREEP NORTHWARD TOMORROW AND THEN SLIGHTLY S ON WED...BUT THE WIND STRENGTH WILL REMAIN UNCHANGED. THE PRES GRADIENT BETWEEN THE EASTERN EDGE OF THE SURFACE RIDGE AND A LEE SIDE TROUGH ALONG THE NW SLOPES OF THE SIERRA MADRE OCCIDENTAL HAS SLACKENED ENOUGH FOR WINDS IN THE CENTRAL GULF OF CALIFORNIA TO DROP BELOW 20 KT BUT THE GRADIENT IS STILL GENERATING NW TO N WINDS TO 20 KT ALONG THE W COAST OF BAJA CALIFORNIA. LITTLE CHANGE IS EXPECTED IN THESE CONDITIONS ON TUE...BUT LOOK FOR THE SECONDARY COLD FRONT TO EXPAND THE 20 KT WIND AREA W OF 135W N OF 29N ON WED EVENING. TROPICS... AN UPPER LOW LIES NEAR 01S125W AND AN ANTICYCLONE LIES TO ITS N NEAR 09N123W. A SURFACE TROUGH REFLECTION OF THE LOW ALOFT IS EMBEDDED IN THE ITCZ FROM 09N113W TO 03N128W. CONVECTION NEAR THE TROUGH HAS BECOME MORE ISOLATED OVER THE LAST 6 HOURS AS THE FLOW HAS BECOME MORE CONFLUENT ALOFT. FARTHER E...UPPER LEVEL DIFFLUENCE ASSOCIATED WITH A RIDGE AXIS THAT PASSES OVER ANOTHER SURFACE TROUGH EMBEDDED IN THE ITCZ ALONG 97W/98W IS SPARKING CONVECTION WITHIN 300 NM W OF THE SURFACE TROUGH AND E OF THE TROUGH ALONG THE ITCZ. THE STRONGEST CONVECTION OF THE EVENING IS ALONG THE ITCZ NEAR 83W WHERE PRECIPITABLE WATERS VALUES ON THE RISE UNDER INCREASINGLY MORE SOUTHERLY FLOW AHEAD OF THE DEEP LAYER TROUGH EXTENDING FROM THE NW CARIBBEAN INTO THE EASTERN U.S. THIS CONVECTION IS ALSO SUPPORTED BY BROAD UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE BROAD RIDGE AXIS OVER SE WATERS. GAP WINDS... WHILE THE 1520 UTC AND 1658 UTC ASCAT PASSES MISSED THE GULF OF TEHUANTEPEC...THE VISIBLE SATELLITE IMAGERY SHOWS THE TELL-TALE ROPE CLOUD ON THE EDGE OF THE ENHANCED GAP WIND REGION AND THE 1244 UTC WINDSAT PASS HAD CONFIRMED GALE FORCE WINDS MON MORNING. WINDS IN THE GULF OF TEHUANTEPEC ARE BELIEVED TO BE AS STRONG AS 40 KT AT THE MOMENT...AND THEY WILL DIMINISH BELOW GALE FORCE BY TUE MORNING. THIS SAME COLD FRONT WILL ALSO BRING 20 KT WINDS THROUGH THE GULF OF FONSECA EARLY TUE THAT WILL DIMINISH IN THE AFTERNOON. SHIP DHEE NEAR 10N88W AT 1800 UTC REPORTED 22 KT NE WINDS DOWNWIND OF THE GULF OF PAPAGAYO. STATION MRLB AT LIBERIA COSTA RICA SAW WINDS INCREASE FROM 9 KT TO 19 KT FROM 1600 UTC TO 23000 UTC...BUT HAS SINCE SEEN WINDS DIMINISH TO 13 KT. WHILE THE MODELS DO NOT SHOW THE WINDS INCREASING HERE UNTIL THE FRONT REACHES THE AREA OVERNIGHT...THERE IS EVIDENCE THAT THE WINDS HAVE ALREADY BEGUN TO FUNNEL THROUGH THE GULF OF PAPAGAYO AND HAVE REACHED 20 KT. WINDS HERE WILL INCREASE OVERNIGHT AS THE FRONT PASSES THROUGH AND WILL SPREAD DOWNSTREAM TO 93W OVER THE NEXT FEW DAYS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SCHAUER