000 AXPZ20 KNHC 181015 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON JAN 18 2010 UPDATED FOR LATEST WIND FORECASTS TO AFFECT GAP WIND AREA AND FOR GULF OF CALIFORNIA 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 0915 UTC. ...ITCZ... AXIS WAS ANALYZED ALONG 05N77W TO 06N83W TO 05N101W TO 07N110W TO 06N126W TO 06.5N133W TO 06N140W. ISOLATED MODERATE TO STRONG CONVECTION WAS WITHIN 90 NM S OF AXIS E OF 88W. SCATTERED MODERATE TO STRONG CONVECTION WAS WITHIN 60 NM N AND 90 NM S OF THE AXIS W OF 114W. ...DISCUSSION... THE PREVAILING UPPER PATTERN WAS OBSERVED TO CONSIST OF STRONG AND DEEP WESTERLY FLOW PRIMARILY OCCURRING TO THE N OF 25N OVER THE TOP OF LARGE SCALE RIDGING...CENTERED WITHIN 5 DEG SW OF THE HAWAIIAN ISLANDS...AND EXTENDING E TO NEAR 17N132W. A SERIES OF SHORTWAVE TROUGHS WERE EMBEDDED WITHIN THE FAST WESTERLY FLOW AND WERE QUICKLY MOVING EASTWARD TOWARDS THE WESTERN U.S. AND NORTHERN BAJA CALIFORNIA REGIONS. TO THE E OF THIS UPPER RIDGE...AND E OF THE SERIES OF SHORTWAVES WAS A LONGER WAVE TROUGH ENTERING THE SRN PLAINS EXTENDING S ACROSS NW PORTIONS OF OLD MEXICO THROUGH THE FAR SOUTHERN GULF OF CALIFORNIA...THEN SW TO NEAR 12N120W...THEN CONTINUES WSW AS A TUTT LIKE AXIS TO 05N150W. FAVORABLE UPPER LEVEL SPEED DIVERGENCE ON THE S SIDE OF THIS TROUGH W OF 110W WAS AIDING IN ISOLATED TO SCATTERED MODERATE TO STRONG CONVECTION WITHIN THE ITCZ. SE OF THIS UPPER TROUGH WAS AN UPPER RIDGE CENTERED OVER THE CENTRAL CARIBBEAN EXTENDING W TO 95W. THE BULK OF DEEP LEVEL MOISTURE ASSOCIATED WITH FAST WESTERLY FLOW OVER THE CENTRAL AND NW PACIFIC WAS N OF THE AREA...BUT A LARGE SWATH OF MOISTURE HAS MOVED E INTO THE NE PORTION OF THE AREA TO THE N OF 26N AND HAD SPREAD E INTO SOUTHERN CALIFORNIA AND THE NRN BAJA PENINSULA. MID/UPPER LEVEL FORCING DUE TO THE SHORTWAVE TROUGHS WILL RESULT IN ABUNDANT PRECIPITATION JUST SKIRTING THE NE PORTION OF THE AREA AND AFFECTING THE WESTERN U.S OVER THE NEXT 48 HRS. WATER VAPOR IMAGERY SHOWED ABUNDANT MODERATE SUBSIDENCE WITH ASSOCIATED STABLE ENVIRONMENT CONDITIONS COVERING THE JUST ABOUT THE ENTIRE AREA SW OF A LINE FROM 32N140W TO 26N130W TO 23N119W. A SURFACE COLD FRONT RELATED TO A RATHER VIGOROUS SHORTWAVE N OF THE AREA NEAR 135W HAD REACHED 32N136W. SW TO W WINDS OF 20 TO 25 KT ARE OCCURRING AHEAD OF THE FRONT N OF 28N AND 130W. AS THE TIGHT PRES GRADIENT E OF THE COLD FRONT SHIFTS E IN TANDEM WITH THE FRONT AND LOW PRES REMAINS OVER SOUTHERN CALIFORNIA... EXPECT THESE WINDS TO BEGIN TO IMPACT THE FAR NORTHERN WATERS OF THE GULF OF CALIFORNIA N OF ABOUT 29N BEGINNING TONIGHT WITH LITTLE CHANGE THROUGH TUE. ALTHOUGH UPPER LEVEL IMPULSES WILL MAINLY STAY TO THE N INTO MON...ENOUGH OF THAT ENERGY WILL MAKE IT JUST S OF 32N TO PROVIDE IMPETUS FOR W TO NW FLOW BEHIND THE FRONT THIS AFTERNOON TO SUPPORT WINDS OF 25 TO 30 KT WITH POSSIBLE HIGHER GUSTS TO NEAR GALE FORCE INTO TUE MORNING AS A SECOND AND STRONGER COLD FRONT FOLLOWS IN BEHIND THIS INITIAL COLD FRONT. THESE SERIES OF FRONTS WILL MOVE RAPIDLY E WITH THEIR ASSOCIATED WIND FIELDS. HOWEVER...THE LARGER ISSUE WILL BE THE RELATED SURGES OF VERY LARGE AND LONG PERIOD NW SWELLS PROPAGATING SE ACROSS THE ENTIRE AREA THROUGH TUE...WITH SEAS POSSIBLY BUILDING TO AS HIGH AS 25 FT OVER THE FAR NW WATERS W OF THE SECOND COLD FRONT TONIGHT. YET A THIRD COLD FRONT IS FORECAST TO MOVE INTO THE FAR NW CORNER TUE EVENING PRECEDED BY SW WINDS TO 30 KT...AND MAY EASILY REACH GALE FORCE BEHIND THE FRONT AS HINTED AT BY SOME MODEL GUIDANCE. THE PRES DIFFERENCE BETWEEN WEAK HIGH PRES AND RELATIVELY LOWER PRES NEAR THE ITCZ SHOULD MAINTAIN AN AREA OF NE TO E 20 TO 25 KT TRADES FROM 7N TO 15N W OF 120W THROUGH TUE...WITH SEAS TO 11 FT IN NW SWELL AND NE WIND WAVES...INCREASING 12 TO 14 FT BY TUE AFTERNOON IN BUILDING NW SWELL. TO THE S AND SE OF THE ABOVE DESCRIBED TROUGHS...DEEP TROPICAL MOSITURE REMAINS LIMITED TO A NARROW BAND ALONG THE ITCZ. SEVERAL WEAK PERTURBATIONS/SURFACE TROUGHS WERE MOVING W 10-15 KT ALONG THE AXIS. GAP WINDS... NLY WINDS SPILLING OUT THROUGH THE GULF OF TEHUANTEPEC ARE ASSUMED TO STILL BE NEAR 20 KT PER RECENT MODEL GUIDANCE AS SCATTEROMETER PASSES MISSED THIS AREA THIS MORNING. THESE WINDS ARE FORECAST TO GRADUALLY DIMINISH TO 20 KT WITHIN 24 HRS...AND TO LESS THAN 20 KT AT OR NEAR 36 HRS AS HIGH PRES OVER THE WESTERN GULF OF MEXICO WEAKENS WHILE MOVING E...AND RELAXES THE GRADIENT ALONG THE SE MEXICAN COAST. GULF OF PAPAGAYO... AN ASCAT PASS FROM NEAR 0330 UTC SHOWED NELY WINDS 20 TO 25 KT WINDS OVER A SWATH E OF 88W. LATEST MODEL GUIDANCE SUGGEST THIS AREA OF WINDS MAY EXPAND WSW TODAY WITH WINDS INCREASING UP TO 30 KT...THEN DIMINISHING A BIT ON TUE. SEAS SHOULD BUILD UP TO 10 FT TONIGHT BEFORE SUBSIDING SLIGHTLY THROUGH TUE. GULF OF PANAMA... N WINDS TO 20 KT THROUGH THE GULF HAVE REACHED AS FAR S AS 6N BETWEEN 79W AND 81W. THESE WINDS ARE FORECAST TO CHANGE VERY LITTLE THROUGH TUE. LATEST MODEL GUIDANCE SUGGEST THAT THIS FLOW WILL WEAKEN BELOW 20 KT WED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ STRIPLING