000 AXPZ20 KNHC 100910 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU FEB 10 2011 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0730 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED FROM 08N82W TO 04N90W TO 04N115W TO 07N120W TO 07N140W. SCATTERED MODERATE CONVECTION LIES FROM 60 NM TO 210 NM N OF THE ITCZ AXIS BETWEEN 132W AND 139W. ...DISCUSSION... ALOFT...THE REX BLOCK PATTERN IN PLACE OVER THE PAST WEEK HAS BROKEN DOWN LEAVING AN AMPLIFIED UPPER TROUGH FROM 32N125W TO 16N140W. THE SUBTROPICAL JET E OF THE TROUGH IS ADVECTING ABUNDANT MOISTURE ALOFT INTO THE SOUTHERN BAJA CALIFORNIA PENINSULA AND NW MEXICO WITH CORE SPEEDS NEAR 80 KT. THIS AMPLIFIED UPPER PATTERN APPEARS TEMPORARY AS MODEL GUIDANCE SUGGESTS THE UPPER RIDGE TO THE W OF THIS TROUGH CURRENTLY EXTENDING NE FROM HAWAII TO NEAR 40N135W WILL ENCROACH UPON THE POSITIVELY TILTED UPPER TROUGH...PINCHING OFF AN ANTICYCLONE NEAR 35N130W ON FRI AND ALLOWING THE TROUGH TO LEAVE BEHIND AN UPPER LOW NEAR 25N133W. SURFACE...1035 MB HIGH PRES CONTINUES TO BE STATIONARY NEAR 46N130W AND EXTENDS A RIDGE SOUTHWESTWARD TO JUST S OF THE HAWAIIAN ISLANDS. THE PRES GRADIENT REMAINS TIGHT ENOUGH BETWEEN THE RIDGE AND A SURFACE TROUGH JUST OFF THE CALIFORNIA COAST TO GENERATE 20 TO 25 KT WINDS OVER N WATERS W OF 125W. SHIP GBQV REPORTED 20 KT WINDS JUST W OF THE AREA NEAR 25N141W AT 0400Z WHILE SHIP ZCDG7 CONFIRMED STRONG NE WINDS AND 12 FT SEAS NEAR 28N131W AT 0600Z. ALTIMETER PASSES FROM JASON1 AT 0336Z AND JASON2 AT 0428Z SHOWED SEAS IN THE 9 TO 13 FT RANGE IN THIS AREA. HIGH PRES WILL WEAKEN AND REORGANIZE FARTHER S TODAY...ALLOWING WINDS TO DROP BELOW 20 KT OVER N WATERS. ASSOCIATED NORTHERLY SWELLS ARE FORECAST TO SPREAD SOUTHWARD W OF 115W AND SUBSIDE TO 8 TO 10 FT BY EARLY FRI MORNING. MEANWHILE...20 KT NE TRADE WINDS LIE FROM 06N TO 16N OVER W WATERS AND ARE EXPECTED TO REMAIN THERE INTO FRI. ON SAT...LOOK FOR THIS AREA OF FRESH TRADES TO SHIFT E AS THE HIGH PRES RIDGE IS FORCED EASTWARD BY AN ADVANCING COLD FRONT W OF THE AREA. GAP WINDS... GULF OF TEHUANTEPEC...A COLD FRONT SWEEPING THROUGH THE WESTERN GULF OF MEXICO AND SLIDING SWD ALONG THE SIERRA MADRE WILL USHER IN GAP WIND FLOW THROUGH THE ISTHMUS OF TEHUANTEPEC WITH GALE FORCE WINDS EXPECTED TO BEGIN THIS AFTERNOON AND TAPER OFF FRI MORNING. A SECONDARY COLD FRONT WILL DEVELOP AS SOME OF THE SHORTWAVE ENERGY ASSOCIATED WITH THE AFOREMENTIONED AMPLIFIED UPPER TROUGH OVER NW FORECAST WATERS MOVES INTO THE BACKSIDE OF LONGWAVE TROUGH OVER NORTH AMERICA AND PASSES THROUGH NORTHERN MEXICO. THIS SECONDARY SURGE OF COLD DRY AIR WILL BRING GALE FORCE WINDS TO TEHUANTEPEC AGAIN BY EARLY SAT MORNING. GULF OF PAPAGAYO...EASTERLY TRADE WINDS IN THE SOUTHWESTERN CARIBBEAN ARE SPILLING ACROSS THE MOUNTAINS OF COSTA RICA WITH WINDS TO 25 KT REPORTED BY SHIPS PDGE AND PDGS. WINDS ARE FORECAST TO DIMINISH TO 20 KT LATER TODAY WITH STRONGEST WINDS EXPECTED IN THE EARLY MORNING HOURS WHEN DRAINAGE FLOW IS AT A MAXIMUM. GULF OF PANAMA...THE 0304Z ASCAT PASS ALONG WITH SHIP 9HOB8 CONFIRM WINDS ABOVE ADVISORY CRITERIA LIE WITHIN THE GULF OF PANAMA THIS MORNING. WINDS TO 20 KT ARE EXPECTED TO CONTINUE HERE THROUGH AT LEAST SAT MORNING. GULF OF CALIFORNIA...A TIGHT GRADIENT BETWEEN HIGH PRES OVER THE ROCKIES AND GREAT BASIN AND SURFACE TROUGHING OVER WESTERN MEXICO HAS GENERATED NW WINDS WHICH ARE FUNNELING THROUGH THE GULF AT SPEED IN THE 20 TO 25 KT RANGE. SHIP PDAN NEAR 27N111W AT 0800Z REPORTED NW WINDS AT 23 KT. WINDS WILL DIMINISH TO 20 KT HERE TODAY AND THROUGH THE REMAINDER OF THE FORECAST PERIOD AS THE PRES GRADIENT GRADUALLY WEAKENS. $$ SCHAUER