000 AXPZ20 KNHC 190343 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0315 UTC. ...ITCZ... AXIS WAS CENTERED ALONG 3N78W 6N87W 5N97W 6N110W TO 6N125W 6N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION WAS WITHIN 90 NM S OF THE AXIS BETWEEN 120W-124W...AND WITHIN 60 NM S OF THE AXIS BETWEEN 124W-130W. SCATTERED MODERATE CONVECTION WAS WITHIN 120 NM S OF THE AXIS W OF 138W...AND WITHIN 30 NM S OF THE AXIS BETWEEN 133W-135W. ...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 RIDE EASTWARD WITHIN THIS UPPER FLOW PATTERN. THE FIST OF THE TROUGHS HAS PUSHED WELL EASTWARD TO THE WESTERN GULF OF MEXICO WITH A LINGERING AXIS THAT STRETCHED BACK SW ACROSS CENTRAL MEXICO TO INTO THE FAR EASTERN PACIFIC NEAR 16N103W SW TO 8N117W WHERE IT TRANSITIONED TO A SHEAR AXIS SW TO 7N124W TO 5N132W TO W OF THE AREA AT 4N140W. A VIGOROUS SHORTWAVE TROUGH EXTENDED FROM JUST OFFSHORE THE CENTRAL CALIFORNIA COAST SE TO 32N120W THEN SW TO 28N124W. A WEAKENING SURFACE COLD FRONT ASSOCIATED WITH THIS TROUGH EXTENDED INTO THE AREA FROM 32N118W SW TO 25N135W MOVING E 20 KT. STRONG PRES GRADIENT HAS PRODUCED W TO NW WINDS OF 25 TO 30 KT WITHIN 240 NM W OF THE FRONT N OF 28N...AND SW WINDS OF 20 TO 25 KT WITHIN 300 NM E OF FRONT WITH SEAS IN THE RANGE OF 15 TO 21 FT IN NW SWELL BEHIND THE FRONT AND SEAS TO 14 FT E OF THE FRONT. YET ANOTHER SHORTWAVE TROUGH MOVING RAPIDLY EASTWARD WAS NOTED ON WATER VAPOR IMAGERY JUST CROSSING 140W NEAR 32N. A SURFACE COLD FRONT ASSOCIATED WITH THIS TROUGH WAS JUST APPROACHING THE FAR NW CORNER OF THE AREA WITH A LARGE AREA OF GALE FORCE WINDS PASSING N OF THE 30N AND W OF 137W. 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 30N123W TO 23N140W IN ABOUT 48 HRS. GALE FORCE WINDS ARE EXPECTED WITHIN 180 NM AHEAD OF THE FRONT N OF 29N...WITH STRONGER GALE WINDS OF 30-40 KT BEHIND IT N OF 27N. BESIDES WINDS REACHING GALE FORCE...THE MAIN ISSUE WITH EACH PASSING FRONT WILL BE LONG PERIOD NW SWELLS PROPAGATING SE INTO THE DISCUSSION AREA OVER THE NEXT FEW DAYS. LATEST WAVEWATCH MODEL GUIDANCE SHOWED SEAS BUILDING UP TO 24 TO 30 FT IN NW SWELLS BEHIND THE THIRD FRONT WED NIGHT INTO THU. NWP MODELS HINT THAT GALE WINDS BEHIND THE FRONT SHOULD LAST THROUGH THE END OF THE WEEK AS THEY GRADUALLY SPREAD E ACROSS THE NORTHERN WATERS WHILE SLOWLY LETTING UP. ANOTHER IMPRESSIVE NW SWELL TRAIN IS FORECAST TO SWEEP INTO THE AREA REINFORCING THE PREVIOUS ONES WELL INTO THE END OF THE WEEK. 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...WITH ONLY ISOLATED SHOWERS ALONG THE ITCZ. HOWEVER...DIFFLUENT UPPER LEVEL FLOW NEAR THE SHEAR AXIS WAS ENHANCING CONVECTIVE ACTIVITY ALONG THE ITCZ W OF 118W. A SURFACE TROUGH WAS ANALYZED IN THE DEEP TROPICS WITH ITS AXIS FROM 4N118W TO 9N117W TO 14N113W...AND WAS NOTED ON SATELLITE IMAGERY. THE PRES GRADIENT BETWEEN THE TROUGH AND HIGH PRES TO THE N WAS ALLOWING FOR AN AREA OF TRADES IN THE RANGE OF 20 TO 25 KT TO PERSIST FROM 5N TO 15N W OF 120W 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 TO 20 KT ACROSS THE GULF OF PANAMA ARE FORECAST TO DIMINISH TO LESS THAN 20 KT BY WED MORNING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ AGUIRRE