000 AXPZ20 KNHC 102204 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED MAR 10 2010 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 2030 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED ALONG A LINE FROM 05N77W TO 06N85W TO 05N95W TO 06N118W TO 04N140W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION LIED WITHIN 120 NM N OF THE ITCZ AXIS BETWEEN 82W AND 96W. SCATTERED MODERATE CONVECTION WAS FOUND WITHIN 150 NM S OF THE ITCZ AXIS BETWEEN 84W AND 88W. THERE IS A TROUGH EMBEDDED IN THE ITCZ FROM 09N116W TO 07N120W TO 04N121W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION COULD BE FOUND WITHIN 300 NM W OF THE TROUGH FROM 05N TO 08N AND ELSEWHERE WITHIN 90 NM EITHER SIDE OF THE TROUGH. ...DISCUSSION... AN UPPER LEVEL TROUGH AXIS EXTENDS FROM W TEXAS THROUGH NW MEXICO TO 22N140W. A STRONG UPPER JET LIES TO THE S OF THIS TROUGH AXIS WITH A CORE OF WESTERLY WINDS IN EXCESS OF 150 KT E OF 125W. SOUTHWESTERLY UPPER LEVEL WINDS CONTINUE TO ADVECT MOISTURE NORTHEASTWARD WHICH IS MANIFESTED IN THE FORM OF BROKEN CIRRUS CLOUDS BETWEEN 150 NM AND 510 NM S OF THE TROUGH AXIS. MODERATE TO STRONG SUBSIDENCE AND DRY STABLE AIR IS NOTED ON WATER VAPOR IMAGERY ALONG AND NORTH OF THE TROUGH AXIS...WITH ONLY THE SCATTERED TO BROKEN STRATOCUMULUS DECK EVIDENT ON VISIBLE IMAGERY. THIS TROUGH WILL SHIFT E OVER THE NEXT FEW DAYS...MAKING WAY FOR RIDGING BEHIND IT THROUGH THU NIGHT. BY FRI...A DEEP LAYERED TROUGH WILL MOVE INTO NW WATERS. THE COLD FRONT ASSOCIATED WITH THIS NEW TROUGH IS EXPECTED TO BE WEAK. A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 07N114W INFLUENCES THE REMAINDER OF THE DISCUSSION AREA. A RIDGE AXIS EXTENDS FROM THE ANTICYCLONE NE INTO NORTHERN NICARAGUA WHILE A SECOND RIDGE AXIS EXTENDS W OF THE ANTICYCLONE TO 06N140W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION IS FOUND ASSOCIATED WITH A SURFACE TROUGH EMBEDDED IN THE ITCZ UNDER THE MODERATE UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THIS RIDGE. PLEASE SEE THE SECTION ABOVE FOR DETAILS. FARTHER E...CONVECTION ALONG THE ITCZ BETWEEN 82W AND 96W LIES IN A POOL OF 2.25 TO 2.50 INCH PRECIPITABLE WATER VALUES BUT ALSO UNDER A REGION OF WEAK UPPER LEVEL CONFLUENCE. THEREFORE...THE CONVECTION HERE IS EXPECTED TO BE SHORT LIVED. AT THE SURFACE...STRONG 1032 MB HIGH PRES LIES W OF THE AREA NEAR 31N142W WHILE CONTINUED TROUGHING LIES OVER THE SW U.S. WITH A 1015 MB LOW NEAR 34N119W DROPPING S ALONG THE COAST AND DRAGGING A COLD FRONT BEHIND IT. THE STRONG PRES GRADIENT BETWEEN THIS TROUGHING AND THE SURFACE RIDGE AXIS...WHICH EXTENDS SOUTHEAST FROM THE HIGH TO NEAR 15N105W...IS GENERATING 20 TO 25 NW WINDS OFF THE NORTHERN BAJA CALIFORNIA COAST. THE ASCAT PASS FROM 1652 UTC CONFIRMED THESE WINDS ARE IN PLACE OFF THE W COAST OF BAJA CALIFORNIA. THE BROAD UPPER LEVEL TROUGHING OVER THE SW U.S. WILL MOVE E OVER THE NEXT TWO DAYS AND WINDS WILL BEGIN TO DIMINISH AND SHRINK IN AREA. SIGNIFICANT WAVE HEIGHTS HAVE PEAKED AT 16 FT IN THE NW SWELL OFF THE NORTHERN BAJA CALIFORNIA COAST AND WILL GRADUALLY SUBSIDE AS THE SWELL PROPAGATES SOUTHWARD. LOW PRES AT THE SURFACE ASSOCIATED WITH THE LEADING EDGE OF THE BROAD TROUGH ALOFT HAS SHIFTED SOUTHEASTWARD INTO EASTERN MEXICO. THE PRES GRADIENT ALONG THE MEXICAN PACIFIC COAST NEAR 20N HAS STRENGTHENED BETWEEN THIS LOWER PRES TO THE E AND THE RIDGE TO THE W. NW TO N WINDS ARE EXPECTED TO HOVER NEAR 20 KT HERE FOR THE NEXT TWO DAYS. SOUTH OF THE SURFACE RIDGE AXIS LIES A BROAD AREA OF STRONG NE TRADE WINDS. THE 1502 UTC WINDSAT PASS SHOWED 20 TO 25 KT WINDS FROM 05N TO 24N OVER W WATERS. TONIGHT...THE HIGH PRES JUST W OF NW WATERS IS FORECAST TO MOVE SE AHEAD OF THE APPROACHING COLD FRONT INTO FORECAST WATERS...SHIFTING THE RIDGE AXIS FARTHER SOUTH. THIS WILL COMPRESS THE TRADES SLIGHTLY SOUTHWARD TOMORROW AND THE AREA OF 20 TO 25 KT WINDS WILL SHRINK W FRI AS THE HIGH PRES TO THE N WEAKENS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN/SCHAUER