000 AXPZ20 KNHC 062142 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SUN APR 06 2008 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2115 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 5N77W 3N85W 4N96W 5N105W 2N118W 3N130W 4N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE AXIS BETWEEN 134W-139W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 130W-134W. ISOLATED MODERATE CONVECTION EXISTS FROM 3N-6N BETWEEN 104W-115W. ...DISCUSSION... W OF 105W... A LARGE MID/UPPER LEVEL CYCLONIC CIRCULATION W OF THE REGION MOVING SLOWLY SSW IS NEAR 25N148W WITH A TROUGH EXTENDING SSE THROUGH 18N145W TO 15N140W TO 10N135W AND TO NEAR 2N128W. TO ITS E BROAD MID/UPPER LEVEL RIDGING COVERS THE AREA TO THE N OF 18N WITH THE ASSOCIATED MID/UPPER LEVEL ANTICYCLONE ANCHORED NEAR 12N113W. THE MEAN RIDGE AXIS EXTENDS FROM THE ANTICYCLONE NW THROUGH 18N118.5W TO 24N126W TO NW OF THE REGION AT 32N131W. SINCE BOTH THE CYCLONIC CIRCULATION AND THE ANTICYCLONE HAVE BEEN RATHER PERSISTENT OVER THE PAST FEW DAYS IN SHOWING VERY LITTLE MOVEMENT...THE SWLY FLOW PATTERN BETWEEN BOTH THESE FEATURES HAS BEEN TRANSPORTING ABUNDANT MID/UPPER LEVEL MOISTURE FROM THE DEEP CENTRAL TROPICAL PACIFIC NEWD INTO THE DISCUSSION AREA AND UP AND OVER THE NRN PERIPHERY OF THE RIDGE N OF 19N WITH A GENERAL TRAJECTORY TOWARDS BAJA AND CENTRAL MEXICO. HOWEVER...SINCE AN AREA OF MODERATE SUBSIDENCE LEFT BEHIND A MID/UPPER LEVEL TROUGH THAT MOVED INLAND THE WRN UNITED STATES A FEW DAYS REMAINS OVER THE GULF OF CALIFORNIA ...AND TO WITHIN 200 NM W OF BAJA CALIFORNIA THIS MOISTURE HAS BEEN ERODING BEFORE IT SPREADS ACROSS BAJA CALIFORNIA. CIMSS SATELLITE DERIVED WINDS WERE IN THE RANGE OF 70-90 KT OVER THE AREA FROM 19N-24N E OF 115W. OVER THE DEEP TROPICS...WATER VAPOR IMAGERY DEPICTS STRONG SUBSIDENCE DUE TO THE ANTICYCLONE AND RIDGE COVERING THE AREA FROM 5N TO 20N BETWEEN 100W AND 125W...AND IS RESPONSIBLE FOR MAINTAINING RATHER STABLE CONDITIONS OVER THIS AREA. UPPER LEVEL DIFFLUENCE OCCURRING TO THE SW OF THE ANTICYCLONE NEAR THE SE TIP OF THE MID/UPPER LEVEL TROUGH IS AIDING ITCZ CONVECTION BETWEEN 131W-134W. NWP MODELS SUGGEST LITTLE OVERALL CHANGE TO THIS PATTERN THROUGH TUE...THEN THE ANTICYCLONE TRANSLATES EWD AND LOSES ITS IDENTITY AS HEIGHTS LOWER OVER MUCH OF THE ERN PORTION OF THE AREA. THE MID/UPPER LEVEL FLOW THEN BECOMES ZONAL OVER JUST ABOUT THIS ENTIRE AREA N OF 15N...EXCEPT THE FAR NW CORNER WHERE IT WILL BE MORE NWLY DUE TO AN UPPER LEVEL HIGH THAT STRADDLES THE NRN BOUNDARY WED AND THU. AT THE SURFACE...THE COMBINATION OF A STATIONARY 1012 MB LOW W OF THE REGION NEAR 24N149W AND A HIGH CENTER OF 1027 MB NEAR 32N133W IS RESULTING IN A TIGHT PRES GRADIENT OVER THE NW SECTION OF THE AREA PRODUCING SE WINDS OF 20-25 KT N OF 18N AND 135W WITH SEAS IN THE RANGE OF 8-10 FT. QUIKSCAT DATA FROM 1500 UTC THIS MORNING SHOWED SE WINDS OF 20-25 KT FROM 20N-28N W OF 135W. THE LOW AND HIGH ARE FORECAST TO DISSIPATE WITHIN THE NEXT 24 HOURS ALLOWING FOR THESE WINDS TO DIMINISH TO 20 KT. QUIKSCAT DATA FROM 1322 UTC THIS MORNING REVEALED N-NE WINDS TO 20 KT OVER THE ERN PART OF THE AREA PRIMARILY N OF 20N AND E OF 121W. LITTLE CHANGE IS EXPECTED WITH THESE WINDS THROUGH THE MIDDLE PORTION OF NEXT WEEK...THEN THE AREAL COVERAGE SHIFTS TO THE FAR NE PORTION BY THE END OF THE WEEK AS LOW PRES OVER THE WRN UNITES STATES BECOMES ESTABLISHED FURTHER ...AND THE HIGH PRES OVER THE NE PACIFIC WEAKENS. A WEAK SURFACE TROUGH MOVING W 5-10 KT EXTENDS FROM 9N104W TO 4N105W. ISOLATED SHOWERS AND TSTMS ARE ALONG THE TROUGH...BUT MAINLY ATTRIBUTED TO THE ITCZ IN THE VICINITY. A QUIKSCAT PASS FROM 1315 UTC THIS MORNING SHOWED RELATIVELY LIGHT WINDS ASSOCIATED WITH THE TROUGH...WITH RAIN FLAG VECTORS IN ITCZ CONVECTION INDICATING MUCH STRONGER WINDS. THE TROUGH IS FORECAST TO TRACK WWD OVER THE NEXT 48-7W HOURS BEFORE DISSIPATING. ANOTHER SURFACE TROUGH IS LOCATED FROM 8N134W TO 3N139W MOVING W 15 KT. TSTM ACTIVITY WITH THIS TROUGH IS CURRENTLY INCREASING AS IT INTERACTS WITH THE ITCZ AND GETS ADDITIONAL SUPPORT FROM THE UPPER LEVEL DIFFLUENT REGION AT THE TIP OF THE MID/UPPER LEVEL TROUGH MENTIONED ABOVE. E OF 105W... THE TAIL END OF AN UPPER LEVEL TROUGH OVER THE WRN CARIBBEAN SEA EXTENDS SWWD ACROSS HONDURAS AND NICARAGUA TO A BASE OVER THE FAR E PACIFIC NEAR 9N93W. MID/UPPER LEVEL RIDGING EXTENDS WWD FROM THE NRN PORTION OF S AMERICA WWD TO E OF THE TROUGH AND N OF 4N. THE TROUGH IN COMBINATION WITH HEATING OF THE DAY IS ENHANCING SCATTERED TSTMS ACTIVITY OVER COSTA RICA AND PANAMA. THE TROUGH IS FORECAST TO PULL OFF TO THE E AND AWAY FROM THE FAR E PACIFIC THROUGH THE END OF NEXT WEEK. OUTSIDE THE ITCZ...MODERATE SUBSIDENCE PREVAILS OVER THE REMAINDER OF THE TROPICAL E PACIFIC WITH BROAD ANTICYCLONIC FLOW NOTED S OF THE ITCZ BETWEEN 105W-88W. $$ AGUIRRE