000 AXPZ20 KNHC 070339 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON APR 07 2008 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 0315 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 5N77W 4N85W 4N94W 5N105W 4N115W 4N131W 3N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 180 NM N OF THE AXIS BETWEEN 125W-139W. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 110W-115W. ...DISCUSSION... W OF 105W... A NEARLY STATIONARY LARGE MID/UPPER LEVEL CYCLONIC CIRCULATION W OF THE REGION IS NEAR 25N147W WITH A TROUGH EXTENDING SSE 17N145W TO SE TO 16N140W TO 12N135W TO 8N130W TO NEAR 2N125W. 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 12N112W. THE MEAN RIDGE AXIS EXTENDS FROM THE ANTICYCLONE NW THROUGH 15N117W TO 25N125W 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...THIS MOISTURE HAS BEEN ERODING BEFORE IT SPREADS ACROSS BAJA CALIFORNIA DUE TO AN AREA OF MODERATE SUBSIDENCE LEFT BEHIND A MID/UPPER LEVEL TROUGH THAT MOVED INLAND THE WRN UNITED STATES A FEW DAYS REMAINING OVER THE GULF OF CALIFORNIA AND ALSO WITHIN 150 NM W OF 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 NEARLY STATIONARY 1011 MB LOW W OF THE REGION NEAR 24N149W AND A HIGH CENTER OF 1032 MB N OF THE AREA NEAR 40N145W 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 W OF 135W WITH SEAS UP TO 9 FT. THE LOW IS FORECAST TO DISSIPATE WITHIN THE NEXT 24 HOURS ALLOWING FOR THESE WINDS TO DIMINISH TO 20 KT. NW-N WINDS TO 20 KT OVER THE ERN PART OF THE AREA PRIMARILY N OF 24N AND E OF 122W TO THE COAST OF BAJA CALIFORNIA ARE EXPECTED TO CHANGE LITTLE THROUGH THE NEXT 24 HRS...THEN INCREASE TO 20-25 KT IN ABOUT 48 HRS AS HIGH PRES NW OF THE REGION SHIFTS E AND INTERACTS WITH LOW PRES OVER THE SW UNITED STATES TO INCREASE THE PRES GRADIENT ALONG AND OFFSHORE THE CALIFORNIA AND BAJA COASTS. A WEAK SURFACE TROUGH MOVING W 10 KT EXTENDS ALONG 106W FROM 5N-10N. ISOLATED SHOWERS ARE ALONG THE TROUGH...BUT MAINLY ATTRIBUTED TO THE ITCZ. A QUIKSCAT PASS FROM EARLY THIS EVENING SHOWED RELATIVELY LIGHT WINDS ASSOCIATED WITH THE TROUGH. THE TROUGH IS FORECAST TO TRACK WWD OVER THE NEXT 48-72 HOURS BEFORE DISSIPATING. ANOTHER SURFACE TROUGH IS LOCATED ALONG 139W FROM 3N TO 6N AND MOVING W 17 KT. SCATTERED STRONG TSTM ACTIVITY HAS MARKEDLY INCREASED WITH THIS OVER THE PAST FEW HOURS AS IT INTERACTS WITH THE ITCZ...AND GETS UPPER LEVEL SUPPORT FROM UPPER LEVEL DIFFLUENCE AT THE BASE OF THE MID/UPPER LEVEL TROUGH MENTIONED ABOVE. EXPECT THIS CONVECTION TO PERSIST OVER THE NEXT 12 HRS. 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 10N92W. MID/UPPER LEVEL RIDGING EXTENDS WWD FROM THE NRN PORTION OF S AMERICA WWD TO E OF THE TROUGH AND N OF 4N. SCATTERED TSTMS THAT EARLIER FIRED UP OVER COSTA RICA AND PANAMA HAVE RECENTLY DISSIPATED...BUT SHOULD FLARE UP ONCE AGAIN ON MONDAY WITH THE HEATING OF THE DAY. 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