000 AXPZ20 KNHC 220347 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE OCT 21 2008 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 0315 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 8N84W 10N92W 11N102W 10N110W 8N122W 9N131W 9N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 97W-103W... AND WITHIN 60 NM S OF THE AXIS BETWEEN 134W-138W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 103W-110W. ...DISCUSSION... N-NE WINDS OF 20-30 KT ARE ESTIMATED THROUGH THE GULF OF TEHUANTEPEC WITH SEAS UP TO NEAR 11 FT. NE-E WINDS IN THE 20-25 KT RANGE DOWNSTREAM FROM GULF AS FAR W AS 102W FROM 11N-14N AND E TO 96W. MODELS ARE IN PRETTY GOOD AGREEMENT THAT THESE WINDS WILL DIMINISH FURTHER THROUGH THU...HOWEVER A COLD FRONT MOVING SSE THROUGH THE WESTERN AND CENTRAL GULF OF MEXICO FRI AND SAT WILL BE FOLLOWED BY SWD SURGING HIGH PRES WHICH IS EXPECTED TO INDUCE GALE FORCE WINDS ONCE AGAIN POSSIBLY ON FRI AND SAT. TIMING AND MAGNITUDE OF THIS NEXT EVENT WILL BE DEPENDENT ON THE INTERACTION OF THIS HIGH WITH LOWER PRES OVER THE SOUTHERN YUCATAN PENINSULA AND HONDURAS. WEAK 1011 MB SURFACE LOWS ARE EMBEDDED WITHIN THE ITCZ NEAR 10N105W...AND ANOTHER ONE AT 9N119W. BROAD MID/UPPER RIDGING EXTENDS FROM THE CARIBBEAN SEA W TO 110N FROM 10N TO 22N. THIS IS PROVIDING UPPER DIFFLUENCE WHICH IS ENHANCING CONVECTION WITHIN THE ITCZ MOSTLY E OF THE SURFACE LOW. BROAD UPPER ANTICYCLONE IS CENTERED JUST N OF THE ITCZ NEAR 13N132W WITH ITS ASSOCIATED ENVELOPE OF RIDGING COVERING THE AREA S OF 21N W OF 120W. AN UPPER TROUGH IS RAPIDLY MOVING SE OVER THE SW UNITED STATES...AND EXTENDING SW TO ACROSS CENTRAL BAJA CALIFORNIA...THEN W TO 26N126W. UPPER LEVEL MOISTURE IN THE FORM OF SCATTERED CIRRUS CLOUDS MOVING NE IS WITHIN 150 NM SE OF THE TROUGH. THIS TROUGH IS FORECAST TO MOVE EASTWARD AS IT SHARPENS AND REACH THE CENTRAL UNITED STATES THROUGH THE END OF THE WEEK. A WELL PRONOUNCED UPPER LEVEL ANTICYCLONE IS LOCATED N OF THE AREA NEAR 34N127W...AND IS SHIFTING E WITH TIME. AT THE SURFACE...A RIDGE EXTENDS THROUGH 32N131W TO 24N122W TO 21N118W. THE HIGH IS FORECAST TO SHIFT E TOWARDS CALIFORNIA OVER THE NEXT 48 HOURS AS A STRONG STRONG DEEP LAYERED TROUGH MOVES INTO THE NW SECTION LAT WED/EARLY THU. A CUT-OFF LOW WILL DEVELOP ON THIS TROUGH AND DROP S ALONG 140W THU AND FRI THEN LIFT NE ACROSS THE FAR NW CORNER OF THE AREA SAT AND SUN. THE ASSOCIATED SURFACE COLD FRONT IS EXPECTED TO ENTER THE FAR NW PORTION OF THE AREA EARLY ON THU...THEN WEAKEN THROUGH FRI. WAVEWATCH MODEL GUIDANCE INDICATES THAT A LARGE SWELL TRAIN WITH SEAS UP TO 10 FT WILL MOVE SE INTO THE NW PORTION ON FRI...WITH YET ANOTHER SWELL TRAIN CONSISTING OF HIGHER SEAS PERHAPS UP TO 12 FT MOVING INTO THE NW PORTION SAT THROUGH EARLY SUN BEFORE SPREADING E TO THE N CENTRAL PORTION ON SUN. MID/UPPER LEVEL RIDGING FROM 24N-29N W OF 130W IS PRECEDES THE ABOVE MENTIONED TROUGH CURRENTLY W OF THE AREA. AN INCREASING PRES GRADIENT OVER THE FAR SW UNITED STATES RESULTING AS STRONG HIGH PRES BUILDS S AND SE OVER THE GREAT PLAINS WED AND THU AND INTERACTS WITH LOWER PRES IN THE VICINITY OF THE GULF OF CALIFORNIA SHOULD BRING 20-30 KT NW WINDS TO THE NORTHERN GULF OF CALIFORNIA BEGINNING IN ABOUT 18 HOURS...THEN DIMINISHING TO 20 KT N OF 26N WITHIN ABOUT 48 HOURS. LONG PERIOD CROSS-EQUATORIAL SOUTHERLY SWELLS (ABOUT 8-10 FT) WILL CONTINUE TO EXIST OVER MUCH OF THE SOUTHERN PORTION OF THE AREA THROUGH FRI BEFORE SUBSIDING TO NEAR 8 FT. $$ AGUIRRE