000 AXPZ20 KNHC 191007 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC TUE JAN 19 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 ANALYZED FROM 03N77W TO 06N82W TO 05N92W TO 09N120W TO 06N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 60 NM N OF AXIS BETWEEN 85W AND 91W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS WITHIN 210 NM N AND 60 NM S OF AXIS W OF 117W. ...DISCUSSION... THE OVERALL BROAD SCALE PATTERN HAS CHANGED VERY LITTLE DURING THE PAST 24 HRS AS VERY STRONG UPPER WESTERLY FLOW CONTINUES ACROSS THE NORTHERN PORTION OF THE AREA N OF ABOUT 25N. A SERIES OF EMBEDDED SHORTWAVE TROUGHS CONTINUE TO MOVE EASTWARD WITHIN THIS UPPER FLOW PATTERN. THE FIST OF THE TROUGHS HAS PUSHED WELL EASTWARD TO THE N CENTRAL GULF OF MEXICO WITH A LINGERING AXIS THAT STRETCHED BACK SW ACROSS SRN MEXICO AND INTO THE FAR EASTERN PACIFIC TO NEAR 9N110W WHERE IT TRANSITIONED TO A TUTT LIKE SHEAR AXIS EXTENDING WSW TO 2N150W. THE NEXT TROUGH UPSTREAM...A VIGOROUS SHORTWAVE TROUGH...WITH MID TO UPPER LEVEL CYCLONE LIFTING NNW AND JUST OFFSHORE OF THE PACIFIC NW COAST...WITH TROUGH MOVING E ACROSS SRN CALIFORNIA AND NRN BAJA EXTENDING SW TO 27N122W. A WEAKENING SURFACE COLD FRONT ASSOCIATED WITH THIS UPPER TROUGH EXTENDED INTO THE AREA FROM 32N115W TRAILING SW TO 23N140W. WINDS HAS DIMINISHED TO 20 KT OR LESS ALONG AND JUST BEHIND THIS FRONT DURING THE PAST 12 HOURS...WITH SEAS IN THE RANGE OF 12 TO 18 FT IN NW SWELL BEHIND THE FRONT AND SEAS 8 TO 12 FT E OF THE FRONT. YET ANOTHER SHORTWAVE TROUGH MOVING RAPIDLY EASTWARD WAS INDICATED IN WATER VAPOR IMAGERY JUST CROSSING 130W NEAR 30N. A SURFACE COLD FRONT ASSOCIATED WITH THIS TROUGH WAS DRAPED ACROSS A CENTRAL PACIFIC RIDGE ACROSS THE HAWAIIAN ISLANDS...AND WAS SWEEPING ACROSS THE FAR NW CORNER OF THE AREA...WITH A LARGE AREA OF GALE FORCE WINDS DAMMING UP BEHIND THE FRONT AND INTO NW PORTIONS OF THE FORECAST AREA. A THIRD COLD FRONT ASSOCIATED WITH ANOTHER SHORTWAVE TROUGH WELL NW OF THE AREA IS FORECAST TO MOVE INTO THE AREA ALONG A LINE FROM 30N120W TO 21N140W IN ABOUT 48 HRS. GALE FORCE WINDS ARE EXPECTED WITHIN 240 NM AHEAD OF THE FRONT E OF 125W...WITH STRONG GALES OF 30-40 KT BEHIND THE FRONT N OF 27N. A VERY LONE FETCH OF NWLY GALES SET UP BEHIND THIS FRONT WILL GENERATE VERY HIGH SEAS ACROSS THE AREA FRI INTO THE WEEKEND..WITH SEAS IN EXCESS OF 30 FT ENTERING N PORTIONS. THIS TRAIN OF FRONTAL BOUNDARIES WILL CONTINUE TO GENERATE LARGE AND LONG PERIOD NW SWELLS PROPAGATING SE INTO THE DISCUSSION AREA OVER THE SEVERAL FEW DAYS. A REINFORCING SURGE OF COLD AIR BEHIND THIS THIRD FRONT WILL PUSH SE AND THROUGH THE SRN BAJA PENINSULA AND INTO OLD MEXICO...WITH THE FRONT WASHING OUT ACROSS THE TROPICAL PACIFIC ALONG ABOUT 12N. THE DEMARCATION LINE BETWEEN THE PERSISTENT STRONG WESTERLY FLOW AND LIGHTER FLOW TO THE S WAS OBSERVED TO BE A STRONG JETSTREAM BRANCH THAT ENTERED THE AREA AT 32N140W THEN DOVE SE TO 26N127W TO 23N115W WITH MAXIMUM WINDS OF 150-180 KT IN THE JET CORE REGION. TO THE SW OF THIS JET BROAD AND DOMINANT HIGH PRES PREVAILED WITH ITS CENTER LOCATED WELL W OF THE AREA JUST SE OF THE HAWAIIAN ISLANDS. ITS ASSOCIATED RIDGE EXTENDED EASTWARD INTO THE AREA THROUGH 16N140W SE TO 14N131W. WATER VAPOR IMAGERY SHOWED STRONG SUBSIDENCE WITH ASSOCIATED DRY STABLE AIR MASS COVERING THE AREA TO THE N OF THE ITCZ AND W OF 105W ALLOWING FOR ONLY PATCHES OF MOSTLY BROKEN STRATOCUMULUS CLOUDS TO BE PRESENT FROM 14N TO 25N W OF 116W. COLD AIR STRATOCUMULUS CLOUDS RACING SE WERE NOTED N OF 29N W OF THE WEAKENING COLD FRONT. STRONG SUBSIDENCE ALSO WAS PRESENT TO THE SE OF THE FIRST SHORTWAVE TROUGH MENTIONED AND HAD SUPPRESSED ANY DEEP CONVECTION IN THIS AREA. DIFFLUENT UPPER LEVEL FLOW NEAR TUTT/UPPER SHEAR AXIS WAS ENHANCING CONVECTIVE ACTIVITY ALONG THE ITCZ W OF 117W. THE PRES GRADIENT BETWEEN HIGH PRES TO THE NW AND THE ITCZ WAS ALLOWING FOR AN AREA OF TRADES IN THE RANGE OF 20 TO 25 KT TO PERSIST FROM 5N TO 15N W OF 125W WITH SOME DECREASE IN AREAL COVERAGE THROUGH THE NEXT 48 HRS. A STATIONARY 1016 MB SURFACE HIGH WAS CENTERED NEAR 22.5N115W WITH A WEAK RIDGE SE TO NEAR 17N106W. BROKEN/OVERCAST STRATOCUMULUS CLOUDS ARE N OF 14N W OF 120W TO THE COLD FRONT. NE TO E WINDS OF 20 TO 25 KT THROUGH THE GULF OF PAPAGAYO MAY BRIEFLY INCREASE TO 30 KT TUE THEN LESSEN TO 20 KT WED. NLY WINDS AROUND 20 KT ACROSS THE GULF OF PANAMA ARE FORECAST TO PERSIST THROUGH 24 HOURS THEN DIMINISH TO 20 KT OR LESS BY THU MORNING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ STRIPLING