000 AXPZ20 KNHC 112204 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC THU MAR 11 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 06N77W TO 07N90W TO 05N105W TO 07N118W TO 01N140W. SCATTERED MODERATE TO STRONG CONVECTION WAS WITHIN 180 NM S OF THE ITCZ AXIS BETWEEN 83W AND 88W AS WELL AS WITHIN 300 NM S OF THE ITCZ AXIS BETWEEN 110W AND 115W. SCATTERED MODERATE CONVECTION WAS WITHIN 150 NM S OF THE ITCZ AXIS BETWEEN 88W AND 103W AS WELL AS WITHIN 120 NM N OF THE ITCZ AXIS BETWEEN 99W AND 103W. ...DISCUSSION... A PROGRESSIVE PATTERN OVER N WATERS WILL SEE THE BROAD UPPER TROUGH OVER THE SW U.S. FINALLY PUSH EASTWARD AS THE NEXT DEEP LAYERED TROUGH MOVES INTO NW WATERS TOMORROW. A W-SW UPPER JET IN EXCESS OF 130 KT WILL REMAIN CENTERED ALONG 25N E OF 120W THROUGH TOMORROW NIGHT WHEN THE JET WILL PUSH E ALONG THE LEADING EDGE OF THE DEEP LAYERED TROUGH. THE W-SW UPPER LEVEL WINDS FEEDING INTO THE JET CONTINUE TO ADVECT TROPICAL MOISTURE NORTHEASTWARD ALOFT WHICH IS MANIFESTED IN THE FORM OF A BROKEN BAND OF CIRRUS CLOUDS BETWEEN 300 NM AND 600 NM S OF THE TROUGH AXIS WHICH LIES FROM W TEXAS THROUGH NW MEXICO TO 25N120W. MODERATE TO STRONG SUBSIDENCE AND DRY STABLE AIR IS NOTED ON WATER VAPOR IMAGERY ALONG AND NORTH OF THE TROUGH AXIS. THIS TROUGH MOVE E TO MAKE WAY FOR THE DEEP LAYERED TROUGH TOMORROW WITH THE COLD FRONT ASSOCIATED WITH THIS NEW TROUGH EXPECTED TO BE WEAK INITIALLY. THE LARGEST IMPACT FROM THIS COLD FRONT TOMORROW WILL BE A NEW SURGE OF NW SWELL PUSHING INTO THE AREA WITH ITS ARRIVAL...WITH SIGNIFICANT WAVE HEIGHTS INCREASING TO 13 FT. THE FRONT WILL DISSIPATE AS IT MOVES INTO SOUTHERN CALIFORNIA AND NE WATERS ON SAT...BUT THE PRES GRADIENT IS EXPECTED TO BUILD BETWEEN THE FRONT AND HIGH PRES TO ITS W ALLOWING FOR NW TO N WINDS TO BUILD ABOVE 20 KT OVER NE WATERS W OF THE FRONT BY SAT AFTERNOON. A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 09N110W INFLUENCES THE REMAINDER OF THE DISCUSSION AREA. A RIDGE AXIS EXTENDS FROM THE ANTICYCLONE NE INTO EL SALVADOR WHILE A SECOND RIDGE AXIS EXTENDS SW OF THE ANTICYCLONE TO 07N135W. SCATTERED MODERATE TO STRONG CONVECTION IS OBSERVED S OF THE ITCZ BETWEEN 110W AND 115W IN THE REGION OF MODERATE UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE ANTICYCLONE ALOFT. PLEASE SEE THE SECTION ABOVE FOR DETAILS. FARTHER E...SCATTERED MODERATE TO STRONG CONVECTION ALSO LIES S OF THE ITCZ BETWEEN 83W AND 88W. THIS AREA LIES IN A POOL OF 2.25 TO 2.50 INCH PRECIPITABLE WATER VALUES AND UNDER MODERATE UPPER LEVEL DIFFLUENCE. THE DIFFLUENT REGION ALOFT IS EXPECTED TO SHIFT W OVER THE NEXT FEW DAYS. THEREFORE...LOOK FOR THE STRONGEST CONVECTION TO SHIFT W AS WELL. AT THE SURFACE...1027 MB HIGH PRES LIES OVER NW WATERS NEAR 27N134W WITH A RIDGE AXIS EXTENDING SE TO SOCORRO ISLAND WHILE LOW PRES AT THE SURFACE ASSOCIATED WITH THE LEADING EDGE OF THE BROAD TROUGH ALOFT OVER THE U.S. HAS SHIFTED EASTWARD INTO THE WESTERN GULF OF MEXICO WITH 1002 MB LOW PRES ANALYZED NEAR 23N94W. 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 THROUGH FRI. SOUTH OF THE SURFACE RIDGE AXIS LIES A BROAD AREA OF STRONG NE TRADE WINDS. THE 1440 UTC WINDSAT AND 1814 ASCAT PASSES SHOWED 20 TO 25 KT WINDS W OF 120W FROM 05N TO 23N 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... THE NEXT TEHUANTEPEC GAP WIND EVENT IS FORECAST TO BEGIN IN ABOUT TOMORROW EVENING AS A COLD FRONT MOVES ACROSS THE GULF OF MEXICO. WINDS OF 20 TO 30 KT ARE EXPECTED THROUGH SAT AFTERNOON. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SCHAUER