000 AXPZ20 KNHC 232202 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED DEC 23 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2130 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N79W 7N91W 4N104W 6N115W 8N124W 8N140W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 119W-122W. ...DISCUSSION... A DEEP LAYER TROUGH CROSSING 140W N OF 5N HAS AMPLIFIED QUITE NOTICEABLY DURING THE PAST 24 HRS. AT THE SURFACE...THE TROUGH IS MARKED BY A COLD FRONT THAT IS JUST ENTERING THE NW PART OF THE AREA FROM NEAR 30N140W TO 21N142W. WIDELY SCATTERED SHOWERS AND ISOLATED WEAK TSTMS ARE ALONG AND WITHIN 90 NM E OF THE FRONT. SURFACE WINDS AHEAD OF THE FRONT N OF 25N E TO 135W HAVE INCREASED TO SE TO S 20 TO 25 KT WITH SEAS 9 TO 13 FT IN A NW SWELL. THE REMAINDER OF THE DISCUSSION AREA E OF THE TROUGH IS UNDER THE DOMINANCE OF RATHER BROAD MID/UPPER LEVEL RIDGING WITH A FAINT RIDGE AXIS EXTENDING FROM 30N126W TO 17N121W TO NEAR 9N121W. THE SURFACE RIDGE AXIS EXTENDS 30N128W SE TO NEAR 21N117W. A JET STREAM BRANCH ROUNDS THE BASE OF THE TROUGH...AND EXTENDS NE TO 25N132W TO 28N125W THEN MAKES A EASTWARD TRAJECTORY TOWARDS CENTRAL BAJA CALIFORNIA NEAR 26N113W. MAXIMUM JET CORE SPEEDS AS NOTED BY SATELLITE DERIVED WINDS ARE IN THE RANGE OF 60-100 KT. OVER THE FAR NE PORTION...A STRONG SHORTWAVE TROUGH HAS MOVED INLAND THE SW U.S. FOLLOWED BY STRONG CONFLUENT FLOW DUE TO STRONG N FLOW SPILLING SWD OVER THE WESTERN U.S. AROUND THE EASTERN PERIPHERY OF THE MID/UPPER LEVEL RIDGE...AND MERGING WITH THE FAST ZONAL FLOW RIDGING UP AND ACROSS THE MID/UPPER LEVEL RIDGE. THIS CONFLUENT IS ALLOWING FOR A SLOT OF MODERATE SUBSIDENCE AND DRY AIR TO PUSH SOUTHWARD INTO THE FAR NE CORNER OF THE AND ARE AS WELL AS INTO FAR NW MEXICO. THE SURFACE COLD FRONT HAS MOVED WELL INLAND NORTHERN MEXICO. THE UPPER FLOW AHEAD OF THE TROUGH CONTINUES TO PULL A PLUME OF MOSTLY MID AND UPPER LEVEL MOISTURE CONSISTING OF MOSTLY BROKEN HIGH CLOUDS NE AND E OVER THE AREA N OF 15N W OF 121W...AND FROM 15N TO 28N E OF 121W TO ACROSS SOUTHERN BAJA CALIFORNIA AND WELL ACROSS CENTRAL MEXICO TO THE GULF OF MEXICO. SCATTERED TO BROKEN PATCHES OF LOW CLOUDS WITH ISOLATED SHOWERS ARE NOTED FROM 19N ELSEWHERE AT THE SURFACE...A WEAK AND PERSISTENT WEAK 1011 MB LOW DRIFTING W IS NEAR 8N124W WITH A TROUGH ALONG 124W FROM 6N-12N. AN AREA OF NE TO E 20 KT TRADE WINDS INDUCED BY A TIGHTENING OF THE PRES GRADIENT BETWEEN SURFACE HIGH PRES TO THE N AND NW OF THE LOW IS LOCATED FROM 13N TO 23N BETWEEN 118W AND 132W. WITH THE LOW WEAKENING FURTHER AND HIGH PRES TO THE N ALSO WEAKENING WHILE MOVING S IN ADVANCE OF A STRONGER COLD FRONT APPROACHING THE FAR NW PORTION OF THE AREA...THIS AREA OF WINDS WILL DIMINISH CONSIDERABLY THROUGH THE NEXT 48 HRS...BUT SEAS UP 11 FT IN LARGE NW SWELLS WILL BE POSSIBLE OVER THE FAR W AND NW SECTIONS THU AND FRI. THE SOUTHERN PORTION OF A RATHER SHARP MID/UPPER LEVEL TROUGH EXTENDS FROM THE FAR WESTERN CARIBBEAN SEA SSW TO ACROSS CENTRAL AMERICA...AND REACHES TO NEAR 2N89W. THE UPPER FLOW PATTERN BETWEEN THE TROUGH AND THE WESTERN EXTENSION OF MID/UPPER LEVEL RIDGING THAT EXTENDS OVER S AMERICA ALONG 8N IS ADVECTING UPPER LEVEL ITCZ MOISTURE NORTHWARD ACROSS PANAMA FROM N OF 5N. SATELLITE WATER VAPOR IMAGERY SHOWED ABUNDANT MODERATE SUBSIDENCE INDICATIVE OF DRY SINKING AIR AND VERY STABLE CONDITIONS COVERING JUST ABOUT THE ENTIRE AREA S AND SE OF THE ABOVE MENTIONED PLUME OF CLOUDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ AGUIRRE