000 AXPZ20 KNHC 160244 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE MAR 16 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 ALONG 04N77W TO 03N85W TO 06N100W TO 03N115W TO 05N140W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN 120 NM N OF THE ITCZ AXIS BETWEEN 81W AND 85W AS WELL AS BETWEEN 90 NM AND 210 NM N OF THE ITCZ AXIS BETWEEN 98W AND 101W. SCATTERED MODERATE CONVECTION WAS WITHIN 180 NM S OF THE ITCZ AXIS W OF 138W. ...DISCUSSION... SUBTROPICS... A STRONG UPPER LOW LIES OVER TEXAS NEAR 33N101W. A TROUGH EXTENDS SW FROM THE LOW THROUGH NW MEXICO TO A STRONG SHORTWAVE SYSTEM NEAR 20N117W AND THEN TO 12N116W. A 1007 MB SURFACE LOW LIES OVER NORTHERN MEXICO NEAR 25N104W ASSOCIATED WITH THIS UPPER LOW. THE INCREASED PRES GRADIENT BETWEEN HIGH PRES OVER THE GREAT BASIN AS WELL AS THE 1026 MB SUBTROPICAL HIGH CENTERED NEAR 32N125W AND THIS LOW OVER NORTHERN MEXICO IN ADDITION TO THE LOW PRES OVER THE W SLOPES OF THE SIERRA MADRE OCCIDENTAL HAS INDUCED 20 TO 25 KT NORTHERLY WINDS IN THE GULF OF CALIFORNIA. SHIP ZCDG7 NEAR 23N109W CONFIRMED THESE WINDS AT 0000 UTC AND THE 1646 UTC ASCAT PASS SAW WINDS TO 25 KT OVER THE CENTRAL PORTION OF THE GULF OF CALIFORNIA. THESE WINDS ARE EXPECTED TO DIMINISH BELOW 20 KT WED AFTERNOON AS THE NEXT COLD FRONT MOVES INTO THE GREAT BASIN...DECREASING THE PRES GRADIENT. ALOFT...THE SOUTHWESTERLY JET JUST S OF THE UPPER TROUGH AXIS WITH WINDS IN EXCESS OF 70 KT IS TRANSPORTING TROPICAL MOISTURE ALOFT NORTHEASTWARD INTO W CENTRAL AND NE MEXICO...WITH A SHRINKING BAND OF SCATTERED TO BROKEN CIRRUS CLOUDS FOUND WITHIN 300 NM EITHER SIDE OF A LINE FROM 15N112W TO 22N100W. THE AFOREMENTIONED SHORTWAVE ENERGY ALOFT IS ATTEMPTING TO DECOUPLE FROM THE N PORTION OF THE TROUGH THAT EXTENDS NE TO THE ANCHOR LOW. HOWEVER...THE BROAD DEEP-LAYERED TROUGH CURRENTLY OVER NW WATERS WILL SEND ITS LEADING EDGE EASTWARD INTO CALIFORNIA AND NE FORECAST WATERS OVERNIGHT TUE NIGHT. THIS WILL CAUSE THE RIDGE TO ITS E TO PROGRESS INTO THE WESTERN U.S. AND NW MEXICO WHICH WILL HELP SHOVE MOST OF THE SHORTWAVE ENERGY LINGERING OVER NE WATERS EASTWARD. THE SUBTROPICAL SURFACE HIGH HAS WEAKENED AND WILL MERGE TOMORROW WITH THE HIGH PRES W OF THE COLD FRONT...CURRENTLY FOUND FROM 30N136W TO 26N140W...ASSOCIATED WITH THIS DEEP LAYERED TROUGH. THE STRONG TRADE WINDS THAT HAD BEEN IN PLACE FOR DAYS HAVE WEAKENED TO FRESH TRADES OVER WATERS W OF 125W ACCORDING TO THE 1830 UTC ASCAT PASS. THE AREA OF TRADES WILL CONTINUE TO SHRINK W TOMORROW AS HIGH PRES SHIFTS NW AND WILL MIGRATE SOUTH ON WED AS THE PATTERN THE NORTH BECOMES MORE AMPLIFIED...MOVING THE STRONGEST PRES GRADIENT S. THIS COLD FRONT HAS NW WINDS BEHIND AROUND 20 KT BASED ON INTERPOLATION OF THE 1826 AND 2006 UTC ASCAT PASSES. THE COLD FRONT HAS USHERED IN A NEW BATCH OF NW SWELL. SIGNIFICANT WAVE HEIGHTS ARE EXPECTED TO REACH AS HIGH AS 17 FT OVER THE NW WATERS TUE EVENING. DEEP TROPICS... A SERIES OF WEAK SHORTWAVE SYSTEMS ARE PASSING SOUTHWESTWARD FROM THE N COAST OF COLOMBIA. THE CONVECTION ASSOCIATED WITH THE WESTERN SHORTWAVE NEAR 03N94 HAS WANED OVER THE PAST 6 HOURS...BUT SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION CAN STILL BE FOUND WITHIN 120 NM N OF THE ITCZ AXIS BETWEEN 81W AND 85W ASSOCIATED WITH THE EASTERN SHORTWAVE. A TROUGH IS EMBEDDED IN THE ITCZ FROM 10N103W TO 03N106W. WHILE THERE IS LITTLE CONVECTION ASSOCIATED WITH THIS TROUGH. JUST TO ITS E...THERE IS SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION N OF THE ITCZ BETWEEN 98W AND 101W. THIS CONVECTION APPEARS TO BE ASSISTED BY DIFFLUENCE ALOFT ASSOCIATED WITH THE REAR RIGHT QUADRANT OF THE UPPER LEVEL JET. ELSEWHERE...A BROAD ANTICYCLONIC CIRCULATION FROM 02N106W TO NICARAGUA IS SEPARATED FROM A WEAK ANTICYCLONE NEAR 01N124W BY AN UPPER TROUGH ALONG 116W S OF 08N. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 180 NM S OF THE ITCZ AXIS W OF 138W UNDER THE DIFFLUENT NW FLOW ALOFT MOVING AROUND THE WESTERN ANTICYCLONE DOWNSTREAM. GAP WINDS... ASIDE FROM THE WINDS IN THE GULF OF CALIFORNIA...LOOK FOR N WINDS IN THE GULF OF TEHUANTEPEC TO INCREASE TO GALE FORCE OVERNIGHT TUE NIGHT AS THE DEEP LAYER TROUGH ASSOCIATED WITH THE UPPER LOW CURRENTLY OVER TEXAS FINALLY SWINGS THROUGH THE WESTERN GULF OF MEXICO. WINDS WILL REACH JUST BELOW STORM FORCE ON WED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SCHAUER