000 AXPZ20 KNHC 131004 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT MAR 13 2010 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 0945 UTC. ...ITCZ... THE ITCZ AXIS WAS CENTERED ALONG 7N79W 3N93W 6N109W 6N120W 5N131W 5N140W. SCATTERED MODERATE CONVECTION IS WITHIN 130-150 NM S OF AXIS BETWEEN 88W AND 98W. SCATTERED MODERATE CONVECTION WITHIN 135 NM N OF AXIS W OF 135W. ...DISCUSSION... A DEEP LAYER TROUGH EXTENDED FROM THE WRN U.S. SW THROUGH 30N122W TO 25N130W TO 21N140W WHERE IT BECOMES A SHEAR AXIS WELL TO THE VICINITY OF HAWAIIAN ISLANDS. THE ASSOCIATED COLD FRONT HAS EXTENDED FROM SRN CALIFORNIA SW TO 30N128W WHERE IT BECAME STATIONARY TO NEAR 28N138W. TO THE E AND SE OF THE TROUGH... BROAD SCALE RIDGING WAS EVIDENT WITH A MEAN AXIS FROM CENTRAL MEXICO TO WELL N ACROSS THE CENTRAL U.S. THE ASSOCIATED MID/UPPER ANTICYCLONE WAS OBSERVED ON SATELLITE WATER VAPOR TO BE NEAR 7N105W WITH ANOTHER RIDGE EXTENDING W TO NEAR 126W AND E TO THE WRN CARIBBEAN SEA. MODERATE TO STRONG UPPER LEVEL EASTERLIES ARE S OF THE RIDGE E OF 90W. A JET STREAM BRANCH WITH JET CORE WINDS IN THE RANGE OF 60-130 KT ROUNDED THE BASE OF THE TROUGH WITH ITS ENTERING POINT INTO THE DISCUSSION AREA NEAR 18N140W...THEN CONTINUED NE TO 24N123W TO ACROSS CENTRAL BAJA CALIFORNIA AND UP AND OVER THE RIDGE AXIS OVER CENTRAL MEXICO. UPPER CONFLUENT FLOW INTO THE BACK SIDE OF THE TROUGH WAS NOTED AS DRY AND STABLE CONDITIONS WITHIN ABOUT 390 NM W OF THE TROUGH S OF 28N...AND 120 NM W OF THE TROUGH N OF 28N. A 150 NM WIDE SWATH OF MODERATE ALSO INDICATIVE OF DRY...STABLE AIR IS WITHIN 120 NM TO THE SE OF THE TROUGH. THE TROUGH IS FORECAST TO MOVE INLAND THE WESTERN U.S. IN ABOUT 24 HOURS WHILE THE COLD FRONT WEAKENS. THE MAIN IMPACT FROM THE COLD FRONT WILL BE SEEN AS A NEW SURGE OF NW SWELLS SPREADING ACROSS MUCH OF THE ERN PORTION OF THE AREA INDUCING SIGNIFICANT WAVE HEIGHTS POSSIBLY UP TO 14 FT WITHIN THE NEXT 24-36 HRS. THE RIDGING OVER THE SRN PORTION OF THE AREA HAD EARLIER HELPED SUSTAIN ITCZ CONVECTION BETWEEN 118W-125W...BUT INCREASING DRY AIR ALOFT HAS REPLACED THE MOSITURE HERE NOT ALLOWING FOR DEEP CONVECTION TO FORM. THE ANTICYCLONE IS EXPECTED TO CHANGE LITTLE OVER THE NEXT 24 HRS...THEN BEGIN TO SHIFT E IN 36-48 HRS. AT THE SURFACE...A 1026 MB HIGH IS ANALYZED N OF THE AREA NEAR 33N126W WITH A RIDGE SE TO NEAR 21N114W. HIGH PRES COVERS THE AREA N OF 14N AND W OF 111W. THE HIGH CENTER IS FORECAST TO MOVE ESE ABOUT 10 KT TO NEAR 32N129W IN 24 HRS...AND TO NEAR 30N130W IN 48 HRS AS THE NEXT COLD FRONT APPROACHES THE FAR NW CORNER OF THE AREA. UNDER THIS WEATHER PATTERN...EXPECT LITTLE CHANGE TO THE AREA OF NE 20-25 KT TRADE WINDS FROM 6N-22N THROUGH THE NEXT 36 HRS ...THEN DIMINISH SOME IN 48 HRS AS THE COLD FRONT ADVANCES FURTHER IN THE NW CORNER OF THE AREA AND THE HIGH CENTER TRANSLATES EASTWARD. THE FRONT IS FORECAST TO USHER IN YET ANOTHER NW SWELL TRAIN CONSISTING OF LARGE SEA STATE EARLY NEXT WEEK. GAP WINDS... A 0318 UTC HIGH RESOLUTION ASCAT PASS REVEALED NW-N WINDS OF UP TO 30 KT WITH A FEW WIND VECTORS INDICATING MINIMAL GALE FORCE WINDS. BASED ON THIS...IT APPEARS THAT THIS GAP EVENT HAS PEAK...AND WILL BEGIN TO SUBSIDE THROUGH THE REMAINDER OF THE DAY WITH WINDS FORECAST TO DROP TO LESS THAN 20 KT BY 24 HRS. SEAS UP TO 10 FT ARE FORECAST BY ALL OF THE WAVEWATCH GUIDANCE TO DECREASE TO LESS THAN 8 FT ALSO IN 24 HRS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ AGUIRRE