AXPZ20 KNHC 110244 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC THU MAR 11 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 0115 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED ALONG A LINE FROM 05N77W TO 07N90W TO 05N104W TO 07N120W TO 04N140W. SCATTERED MODERATE TO STRONG CONVECTION LIED WITHIN 90 NM N OF THE ITCZ AXIS E OF 78W ALONG THE COLOMBIAN COAST AS WELL AS WITHIN 150 NM S OF THE ITCZ AXIS BETWEEN 87W AND 96W. A TROUGH IS EMBEDDED IN THE ITCZ FROM 10N120W TO 03N123W. SCATTERED MODERATE CONVECTION WAS FOUND WITHIN 210 NM W OF THE TROUGH FROM 05N TO 08N AND WITHIN 300 NM E OF THE TROUGH FROM 05N TO 10N. ...DISCUSSION... AN UPPER LEVEL TROUGH AXIS EXTENDS FROM W TEXAS THROUGH NW MEXICO TO 20N140W. 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 120W. SOUTHWESTERLY UPPER LEVEL WINDS CONTINUE TO ADVECT TROPICAL MOISTURE NORTHEASTWARD ALOFT WHICH IS MANIFESTED IN THE FORM OF A BROKEN BAND OF CIRRUS CLOUDS BETWEEN 150 NM AND 550 NM S OF THE TROUGH AXIS. MODERATE TO STRONG SUBSIDENCE AND DRY STABLE AIR IS NOTED ON WATER VAPOR IMAGERY NORTH OF THE TROUGH AXIS. A SCATTERED TO BROKEN STRATOCUMULUS DECK CAN BE SEEN IN INFRARED IMAGERY IN THIS REGION. 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 08N116W INFLUENCES THE REMAINDER OF THE DISCUSSION AREA. A RIDGE AXIS EXTENDS FROM THE ANTICYCLONE NE INTO THE GULF OF FONSECA WHILE A SECOND RIDGE AXIS EXTENDS W OF THE ANTICYCLONE TO 08N140W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS OBSERVED NEAR THE SURFACE TROUGH EMBEDDED IN THE ITCZ NEAR 120W UNDER THE MODERATE UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THIS WESTERN RIDGE AXIS ALOFT. PLEASE SEE THE SECTION ABOVE FOR DETAILS. FARTHER E...SCATTERED MODERATE TO STRONG CONVECTION ALONG THE ITCZ BETWEEN 87W AND 96W LIES IN A POOL OF 2.25 TO 2.50 INCH PRECIPITABLE WATER VALUES BUT ALSO UNDER A REGION OF INCREASING UPPER LEVEL CONFLUENCE. THEREFORE...THE CONVECTION HERE IS EXPECTED TO DISSIPATE OVER THE NEXT 24 HOURS. AT THE SURFACE...1029 MB HIGH PRES LIES OVER FAR NW WATERS NEAR 29N140W WHILE CONTINUED TROUGHING LIES OVER THE SW U.S. WITH A DISSIPATING STATIONARY FRONT FOUND OFF THE NORTHERN BAJA AND CALIFORNIA COAST FROM 31N117W TO 33N126W. 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 SOUTHWARD. SIGNIFICANT WAVE HEIGHTS 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 WITH 996 MB LOW PRES ANALYZED NEAR 22N98W. THE PRES GRADIENT ALONG THE MEXICAN PACIFIC COAST NEAR 20N HAS STRENGTHENED BETWEEN THIS LOW PRES TO THE E AND THE RIDGE TO THE W. NW TO N WINDS ARE EXPECTED TO HOVER NEAR 20 KT THERE AND INTO THE SOUTHERN GULF OF CALIFORNIA FOR THE NEXT TWO DAYS. SOUTH OF THE SURFACE RIDGE AXIS LIES A BROAD AREA OF STRONG NE TRADE WINDS. THE 1652 AND 1834 UTC ASCAT PASSES SHOWED 20 TO 25 KT WINDS W OF 115W FROM 05N TO 24N WITH SOME RETRIEVALS AS HIGH AS 30 KT. TONIGHT...THE HIGH PRES OVER NW WATERS IS FORECAST TO MOVE SE AHEAD OF THE APPROACHING COLD FRONT...SHIFTING THE RIDGE AXIS FARTHER SOUTH. THIS WILL COMPRESS THE TRADES SOUTHWARD TOMORROW AND THE AREA OF 20 TO 25 KT WINDS WILL SHRINK WESTWARD FRI AS THE HIGH PRES TO THE N WEAKENS. GAP WINDS... 20 KT N WINDS ARE EXPECTED TO FUNNEL FROM THE GULF OF MEXICO SOUTHWARD INTO THE GULF OF TEHUANTEPEC BY THE END OF THE FORECAST PERIOD ON FRI EVENING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SCHAUER