000 AXPZ20 KNHC 130340 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SAT MAR 13 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 0130 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED FROM 06N77W TO 04N100W TO 06N110W TO 07N120W TO 04N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 180 NM N AND 90 NM S OF THE ITCZ AXIS W OF 132W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN 240 NM S OF THE ITCZ AXIS BETWEEN 91W AND 98W. ...DISCUSSION... A PROGRESSIVE PATTERN IS IN PLACE OVER N WATERS. THE WESTERLY UPPER JET WITH WINDS IN EXCESS OF 120 KT CENTERED ALONG 25N IS BEGINNING TO SHIFT MORE SOUTHWESTERLY W OF 120W AS A DEEP LAYERED TROUGH OVER NW FORECAST WATERS PUSHES EASTWARD. THE COLD FRONT ASSOCIATED WITH THIS DEEP LAYERED TROUGH IS RELATIVELY WEAK. THE LARGEST IMPACT FROM THIS COLD FRONT OVERNIGHT TONIGHT IS THE NEW SURGE OF NW SWELL PUSHING SE THROUGH THE AREA...WITH SIGNIFICANT WAVE HEIGHTS INCREASING TO 14 FT NW OF THE FRONT AS IT TRAVERSES N WATERS. THE FRONT WILL DISSIPATE AS IT MOVES INTO NORTHERN BAJA CALIFORNIA AND NE WATERS SAT...BUT THE PRES GRADIENT IS EXPECTED TO BUILD BETWEEN THE FRONTAL TROUGH AND HIGH PRES FOLLOWING CLOSELY BEHIND IT AS THE NORTHERN STREAM PATTERN BECOMES MORE AMPLIFIED. THIS WILL ALLOW FOR NW TO N WINDS TO INCREASE ABOVE 20 KT OVER NE WATERS OFF THE W COAST OF BAJA CALIFORNIA AND INTO THE NORTHERN GULF OF CALIFORNIA OVER THE WEEKEND. A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 08N105W HAS A RIDGE AXIS THAT EXTENDS FROM ITS CENTER NE INTO THE GULF OF PAPAGAYO. SCATTERED MODERATE CONVECTION WAS SEEN WITHIN 30 NM OF THE COAST OF PANAMA W OF 81W IN THE DIFFLUENT REGION ON THE EASTERN SIDE OF THIS RIDGE AXIS. A SECOND RIDGE AXIS EXTENDS W OF THE ANTICYCLONE TO 02N128W. JUST TO THE W LIES A WEAK UPPER LOW NEAR 02N133W. SCATTERED MODERATE CONVECTION CAN BE FOUND NEAR THE ITCZ W OF 132W IN THE DIFFLUENT REGION BETWEEN THE UPPER LOW AND SW FLOW ASSOCIATED WITH THE AFOREMENTIONED JET TO THE N. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS OBSERVED S OF THE ITCZ BETWEEN 91W AND 98W. THIS AREA LIES IN A POOL OF 2.25 TO 2.50 INCH PRECIPITABLE WATER VALUES AND UNDER WEAK UPPER LEVEL DIFFLUENCE. THIS DIFFLUENT REGION ALOFT HAS SHIFTED W OVER THE LAST 24 HOURS AND IS EXPECTED TO MOVE SW TO THE EQUATOR NEAR 100W OVER THE NEXT 24 HOURS. LOOK FOR THIS AREA OF CONVECTION TO CONTINUE TO SHIFT W AND BECOME LESS ORGANIZED. AT THE SURFACE...THE HIGH PRES CENTER THAT WAS E OF THE COLD FRONT OVER NW WATERS AT 1800 UTC HAS NOW MERGED WITH THE HIGH NW OF THE FRONT. A 1026 MB HIGH PRES LIES NEAR 33N140W WITH A RIDGE AXIS EXTENDING SE TO SOCORRO ISLAND. THE PRES GRADIENT ALONG THE MEXICAN PACIFIC COAST NEAR 20N HAS STRENGTHENED BETWEEN THIS RIDGE AND TROUGHING INDUCED BY A COLD FRONT PASSING THROUGH SOUTHERN MEXICO AND GUATEMALA AS WELL AS THE INVERTED TROUGHING ON THE WESTERN SLOPE OF THE SIERRA MADRE OCCIDENTAL. NW TO N WINDS ARE CURRENTLY IN PLACE N OF 19N E OF 111W...INCLUDING IN THE GULF OF CALIFORNIA. THE PRES GRADIENT BETWEEN THE INVERTED TROUGH AND THIS RIDGE IS ALSO ENHANCING WINDS OFF THE W COAST OF BAJA CALIFORNIA N OF 24N. SHIP 9HJB9 REPORTED 19 KT WINDS AS IT TRAVELED FROM 28N115W TO 19N116W BETWEEN 2100 AND 0000 UTC. SOUTH OF THE SURFACE RIDGE AXIS LIES A BROAD AREA OF STRONG NE TRADE WINDS. THE 1934 AND 1752 UTC ASCAT PASSES SHOWED 20 TO 25 KT WINDS W OF 120W FROM 06N TO 21N. LITTLE CHANGE IS EXPECTED IN THE AREA AND STRENGTH OF THE TRADES THROUGH THE WEEKEND. GAP WINDS... THE COLD FRONT IN SOUTHERN MEXICO HAS BROUGHT 20 TO 30 KT NORTHERLY WINDS THROUGH THE ISTHMUS OF TEHUANTEPEC THIS EVENING. WINDS MAY BRIEFLY REACH GALE FORCE WITH THE ASSISTANCE OF MORNING DRAINAGE FLOW SAT MORNING...BUT THE EVENT IS EXPECTED TO BE SHORT LIVED DUE TO THIS INCREASINGLY MORE PROGRESSIVE LARGE SCALE PATTERN. THE FORECAST CALLS FOR WINDS TO QUICKLY DROP BELOW 20 KT BY SUN MORNING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SCHAUER