000 AXPZ20 KNHC 100330 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC WED MAR 10 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 AN AXIS FROM 01N79W TO 07N89W TO 04N105W TO 05N120W TO 03N140W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION LIED WITHIN 150 NM S OF THE ITCZ AXIS BETWEEN 92W AND 95W AND BETWEEN 120 NM AND 240 NM SW OF THE ITCZ AXIS BETWEEN 86W AND 88W. SCATTERED MODERATE CONVECTION LIED WITHIN 180 NM N OF THE ITCZ AXIS W OF 126W. A TROUGH IS EMBEDDED IN THE ITCZ FROM 09N117W TO 02N118W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS FOUND WITHIN 90 NM W OF THE TROUGH AXIS FROM 05N TO 07N. ...DISCUSSION... AN UPPER LEVEL TROUGH AXIS EXTENDS FROM A STRONG CYCLONIC CIRCULATION NEARING THE FOUR CORNERS OF ARIZONA...UTAH... COLORADO AND NEW MEXICO SOUTHWESTWARD THROUGH THE NORTH PORTION OF THE FORECAST AREA TO 25N140W. AT THE SURFACE...STRONG 1032 MB HIGH PRES LIES NORTH OF THE AREA NEAR 32N139W WHILE A COLD FRONT ASSOCIATED WITH THE DEEP LAYERED LOW OVER THE SOUTHWESTERN U.S. STRETCHES INTO THE NE MEXICO FROM THE ARIZONA/NEW MEXICO BORDER. THE STRONG PRES GRADIENT BETWEEN THE LOW PRES OVER THE SOUTHWEST AND THE SURFACE RIDGE AXIS...WHICH EXTENDS SOUTHEAST FROM THE HIGH TO NEAR SOCORRO ISLAND...IS GENERATING NW WINDS UP TO 30 KT AND SEAS TO 14 FT OFF THE NORTHERN BAJA CALIFORNIA COAST AS COLD AIR ADVECTION CONTINUES ACROSS THE FAR NE PORTION OF THE DISCUSSION AREA. THE ASCAT PASS FROM 1710 UTC SHOWED WINDS TO 30 KT WITHIN 120 NM OF SHORE N OF 28N WHILE THE 1850 UTC PASS SHOWED 20 TO 25 KT WINDS ELSEWHERE AS MUCH AS 600 NM W OF SHORE. SEVERAL SHIP OBSERVATIONS AT 0000 UTC ARE IN THIS AREA AND CONFIRM THE ASCAT MEASURED CONDITIONS. THESE SHIPS REPORTED SEAS IN THE 8 TO 12 FT RANGE. THE UPPER LEVEL IMPETUS FOR THIS SYSTEM IN THE SW U.S. WILL MOVE E OVER THE NEXT TWO DAYS AND WINDS WILL BEGIN TO SUBSIDE AND SHRINK IN AREA. HOWEVER...MEAN TROUGHING IS EXPECTED TO REMAIN OVER THE SW U.S. AS NEW NORTHERN STREAM ENERGY MOVES FROM THE PACIFIC NW INTO THE BACKSIDE OF THE TROUGH ALOFT WED. SIGNIFICANT WAVE HEIGHTS ARE EXPECTED TO PEAK AT 16 FT IN THE NW SWELL OFF THE NORTHERN BAJA CALIFORNIA COAST TOMORROW AND GRADUALLY SUBSIDE AS THE SWELL PROPAGATES SOUTHWARD. LOW PRES AT THE SURFACE IS SHIFTING SOUTHEASTWARD AHEAD OF THE FRONT INTO EASTERN MEXICO. THIS IS ALSO BUILDING THE PRES GRADIENT ALONG THE MEXICAN COAST NEAR 20N BETWEEN THE INCREASINGLY 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. SHIP VREX8 REPORTED 21 KT NEAR 19N106W AT 0100 UTC. SOUTH OF THE SURFACE RIDGE AXIS LIES A BROAD AREA OF STRONG NE TRADE WINDS. THE 1854 UTC ASCAT PASS SHOWED 20 TO 25 KT WINDS FROM 06N TO 24N AT LEAST AS FAR E AS 127W. THE TRADES ARE EXPECTED TO REMAIN RELATIVELY UNCHANGED UNTIL LATE WED WHEN THE HIGH IS FORECAST TO MOVE SOUTHWARD INTO FORECAST WATERS...SHIFTING THE RIDGE AXIS FARTHER SOUTH. THIS WILL COMPRESS THE TRADES SLIGHTLY SOUTHWARD AND EXPAND THE FRESH TO STRONG TRADE WINDS EASTWARD TO 113W. A BROAD UPPER RIDGE LIES TO THE SE OF THE TROUGH OVER N WATERS AND COVERS MUCH OF THE REMAINDER OF THE DISCUSSION AREA. IT IS ANCHORED BY AN ANTICYCLONIC CIRCULATION CENTERED NEAR 09N105W. BETWEEN THIS TROUGH AND THE RIDGE...MOIST W-SW FLOW ALOFT CONTINUES TO ADVECT MOISTURE FROM THE DEEP TROPICS NORTHEASTWARD ALONG AN AXIS FROM 15N140W INTO MEXICO NEAR 26N108W. THIS AREA IS MARKED BY A BAND OF CIRRUS CLOUDS. THE TRANSPORTING MECHANISM IS A STRONG SUBTROPICAL JETSTREAM WITH WINDS CORE WINDS IN EXCESS OF 150 KT. ELSEWHERE S OF 10N...AN EAST TO WEST UPPER LEVEL RIDGE AXIS EXTENDS FROM THE AFOREMENTIONED ANTICYCLONE TO WESTERN COLOMBIA NEAR 04N76W. DIFFLUENCE ASSOCIATED WITH THIS RIDGE IS HELPING INDUCE SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION IN THE AREA SOUTH OF THE ITCZ BOUNDED FROM 02N TO 06N BETWEEN 86W AND 95W. FARTHER W...THE TROUGH EMBEDDED IN THE ITCZ DISCUSSED IN THE SECTION ABOVE IS WEDGED IN A DIFFLUENT REGION ALOFT BETWEEN THE ANTICYCLONE NEAR 09N105W AND A BROAD ANTICYCLONE TO THE W CENTERED ALONG 07N BETWEEN 125W AND 135W. THIS BROAD ANTICYCLONE IS ALSO HELPING THE CASE FOR CONVECTION ALONG THE ITCZ W OF 126W. GAP WINDS... WINDS HAVE DROPPED BELOW 20 KT IN THE GULF OF PANAMA ACCORDING TO THE 2300 UTC WINDSAT PASS. UNFORTUNATELY...A NEW PASS WAS NOT AVAILABLE FOR THE GULF OF PAPAGAYO WHERE WINDS ARE BELIEVED TO HAVE DROPPED BELOW 20 KT AS WELL. THE PRES GRADIENT OVER THE AREA IS WEAKENING NOW THAT LOW PRES IS BUILDING TO THE N OVER EASTERN MEXICO AND WINDS IN THE SW CARIBBEAN ARE LESS THAN 10 KT NEAR THE EAST COAST OF COSTA RICA/NICARAGUA ACCORDING TO THE 2300 UTC WINDSAT PASS. WINDS MAY PULSE TO 20 KT WITH THE DRAINAGE FLOW IN THE MORNING HOURS IN PAPAGAYO...BUT THESE WINDS WOULD BE SHORT LIVED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SCHAUER