000 AXPZ20 KNHC 201629 CCA TWDEP TROPICAL WEATHER DISCUSSION...CORRECTED NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN APR 20 2008 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1600 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 07N78W 06N86W 03N94W 06N106W 06N115W 04N130W TO 03140W. SCATTERED MODERATE TO STRONG CONVECTION WITHIN 120 NM S OF THE AXIS BETWEEN 81W-86W...87W-91W AND E OF 79W TO THE COLOMBIAN COAST. SCATTERED MODERATE CONVECTION IS WITHIN 240 NM N OF THE AXIS BETWEEN 110W-129W. ...DISCUSSION... W OF 105W... A MID/UPPER LEVEL TROUGH MOVING QUICKLY EWD ENTERS THE AREA THROUGH 32N126W...AND EXTENDS SW THROUGH 27N134W TO A MID/UPPER LEVEL CYCLONIC CIRCULATION NEAR 25N138W...AND CONTINUES SW TO W OF THE REGION TO ANOTHER MID/UPPER LEVEL CYCLONIC CIRCULATION TO NEAR 22N145W. ANOTHER TROUGH EXTENDS FROM 17N116W SE TO 11N109W. THE CYCLONIC CIRCULATION NEAR 25N138W WILL CONTINUE TO MOVE NE THROUGH MON MORNING AND BECOME ABSORBED INTO ITS ASSOCIATED TROUGH MENTIONED ABOVE. SATELLITE WATER VAPOR IMAGERY SHOWS MODERATE SUBSIDENCE N OF 25N E OF 130W...AND ALSO NW OF A LINE FROM 17N140W TO 25N130W. A VERY PRONOUNCED SUBTROPICAL JET STREAM BRANCH EXTENDS FROM 16N140W TO 25N130W...AND THEN ENE TO ACROSS SRN BAJA CALIFORNIA WHERE IT BEGINS TO ROUND THE BASE OF LONGWAVE LOCATED OVER THE WRN UNITED STATES. SATELLITE-DERIVED WINDS ARE INDICATED TO BE IN THE RANGE OF 60-80 KT OVER THE NE PART OF THE AREA WHERE THE UPPER LEVEL FLOW BECOMES CONFLUENT AROUND THE NRN PERIPHERY OF ANTICYCLONIC FLOW COVERING THE AREA TO THE S OF THE JET STREAM ROUGHLY BETWEEN 100W-138W. THIS ANTICYCLONIC FLOW MARKS..ALTHOUGH RATHER PERSISTENT THE PAST FEW DAYS...HAS RECENTLY BECOME A LITTLE AMPLIFIED AS THE MID/UPPER LEVEL TROUGH TO THE N BROADENS WITH TIME. A SMALL UPPER LEVEL ANTICYCLONE MOVING NE 15 KT IS OBSERVED NEAR 13N104W. EXTENSIVE UPPER LEVEL MOISTURE IN THE FORM OF HIGH CIRRUS CLOUDS IS BEING CHANNELED BY THE JET STREAM NEWD TOWARDS BAJA...NRN MEXICO AND THE SW UNITED STATES. A QUASI-STATIONARY MID TO UPPER LEVEL CYCLONIC CIRCULATION HAS BECOME CUT-OFF NEAR 4N103W. TO ITS E...THE UPPER LEVEL FLOW BECOMES DIFFLUENT AND IS AIDING IN THE DEVELOPMENT OF ITCZ CONVECTION TO THE E OF 100W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OCCURRING N OF THE ITCZ WITHIN 75 NM EITHER SIDE A LINE FROM 11N111W TO 8N116W. AT THE SURFACE...HIGH PRES RIDGING ENTERS THE REGION THROUGH 32N135W AND EXTENDS SE TO 26N126W AND TO 19N116W. HIGH PRES COVERS THE AREA N OF 15N W OF 115W. A SURFACE TROUGH MOVING W 15 KT IS ALONG 115W/116W FROM 5N-10N...AND IS ENHANCING ITCZ CONVECTION WITHIN 240 NM TO ITS E WHILE REMAINS UNDER A POCKET OF LEVEL DIFFLUENT FLOW. NWP MODELS SUGGEST THAT WEAK LOW PRES MAY BECOME EVIDENT ON THE TROUGH AXIS LATER TODAY OR ON MONDAY. SCATTERED TO BROKEN MOSTLY STRATOCUMULUS CLOUDS MOVING SW WITH ISOLATED SHOWERS IN NE FLOW ARE SEEN W OF 130W. E OF 105W... A SMALL AND WEAK UPPER LEVEL CYCLONIC CIRCULATION MOVING NNW 10-15 KT IS NEAR 3N87W. THIS FEATURE IS ENHANCING ITCZ CONVECTION PRIMARILY BETWEEN IT AND THE COLOMBIAN COAST. THE SURFACE PRES ANALYSIS FROM 12 UTC THIS MORNING SHOWED A 1007 MB LOW NEAR 7N87W. THIS LOW IS FORECAST BY BOTH MOST OF THE GLOBAL MODELS TO MOVE TOWARDS THE WNW OVER THE NEXT 24-48 HOURS. WITH THE PRES GRADIENT OVER THIS AREA BEING RATHER WEAK AND VERY GOOD COVERAGE TAKING PLACE ALONG THE ITCZ AS SEEN IN A MORNING QUIKSCAT PASS FROM JUST PAST 12 UTC...EXPECT BURSTS OF MODERATE TO STRONG CONVECTION TO CONTINUE NEAR AND AROUND BOTH THE SURFACE AND UPPER LEVEL LOWS THROUGH THE NEXT 48-72 HRS. MODERATE SUBSIDENCE IS NOTED OVER JUST ABOUT THE ENTIRE AREA OUTSIDE THE ITCZ. A MID/UPPER LEVEL RIDGE RUNS FROM COLOMBIA NW TO ACROSS COSTA RICA. A SMALL UPPER LEVEL ANTICYCLONE IS OVER SE MEXICO NEAR 19N96W...AND IS EMBEDDED IN AREA OF UPPER LEVEL RIDGING THAT COVERS ALL OF SE MEXICO AND THE NRN PORTION OF OF CENTRAL AMERICA. CONVECTION HERE REMAINS NON-EXISTENT AS DRY CONDITIONS PREVAIL. ONLY ISOLATED SHOWERS AND TSTMS ARE SEEN ALONG THE COAST OF COSTA RICA AND NRN PANAMA AT THIS TIME. GAP WINDS...NE 20 KT WINDS ACROSS THE GULF OF PAPAGAYO ARE EXPECTED TO CONTINUE IN BRIEF SURGES THROUGH THE NEXT 36 HOURS AT WHICH TIME STRONG TRADES IN THE SW CARIBBEAN WILL BE WEAK. A SMALL SWATH OF N WINDS OF 20 KT THROUGH THE GULF OF TEHUANTEPEC IS EXPECTED TO DIMINISH IN ABOUT 12 HOURS. $$ AGUIRRE