000 AXPZ20 KNHC 260339 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SAT DEC 26 2009 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... ITCZ AXIS IS CENTERED ALONG 5N77W 5N90W 4N105W 6N118W 6N127W 5N140W. SCATTERED MODERATE CONVECTION IS WITHIN 45 NM S OF THE AXIS BETWEEN 90W-92W. ...DISCUSSION... A DEEP LAYER TROUGH EXTENDS FROM A LARGE CYCLONIC VORTEX CENTERED OVER THE NORTHERN MID-WEST SW TO ACROSS THE SW U.S AND OVER NORTHERN BAJA CALIFORNIA CONTINUING SW TO 20N121W TO 12N126W THEN TURNS MORE WESTERLY TO W OF THE AREA AT 4N140W. SATELLITE WATER VAPOR IMAGERY SHOWED AN AREA OF MODERATE SUBSIDENCE WITH ASSOCIATED DRY AIR WITHIN ABOUT 600 NM NW OF THE TROUGH. NW OF THIS DRY AND STABLE ENVIRONMENT...THE ATMOSPHERE IS BECOMES RATHER MOIST IN VERY PRONOUNCED WESTERLY FLOW. SCATTERED TO BROKEN HIGH CLOUDS STREAMING EASTWARD ARE N OF 24N W OF 127W. E OF THE DEEP LAYER TROUGH BROAD MID/UPPER LEVEL RIDGING IS NOTED WITH A RIDGE AXIS EXTENDING FROM 24N110W SE TO A MID/UPPER LEVEL ANTICYCLONE MOVING E NEAR 11N93W. A JET STREAM BRANCH EXTENDS NE FROM 07N130W TO 20N119W TO ACROSS SOUTHERN BAJA CALIFORNIA AND NORTHERN NORTHERN MEXICO AND WELL E OF THE AREA ACROSS THE NORTHERN GULF OF MEXICO. MAXIMUM JET CORE WIND SPEEDS AS NOTED BY SATELLITE DERIVED WIND DATA ARE IN THE RANGE OF 70-110 KT WITHIN 300 NM SE OF THE JET STREAM BETWEEN 110W AND 117W. WITH THE JET STREAM BEING SO PERSISTENTLY STRONG...OVERCAST TO BROKEN MULTILAYERED...MOSTLY OF THE MID AND HIGH CLOUD TYPES...ARE STREAMING NE TO ACROSS NORTHERN AND CENTRAL MEXICO SE OF THE JET STREAM TO A LINE FROM NEAR ACAPULCO TO 11N113W TO THE BASE OF TROUGH. POSSIBLE WIDELY SCATTERED SHOWERS ALONG WITH SOME AREAS OF RAIN MAY BE OCCURRING UNDER THESE CLOUDS. SCATTERED TO BROKEN LOW CLOUDS MOVING W TO SW WITH POSSIBLE ISOLATED SHOWERS ARE NOTED FROM 17N TO 26N W OF 120W. SIMILAR CLOUDS MOVING N ALSO WITH POSSIBLE ISOLATED SHOWERS ARE AHEAD OF THE BELOW MENTIONED COLD FRONT N OF 26N W OF 131W. AT THE SURFACE...A 1018 MB HIGH IS NEAR 28N126W WITH A WEAK RIDGE SE TO NEAR 17N115W. A COLD FRONT ASSOCIATED WITH ANOTHER DEEP LAYER TROUGH JUST SKIRTING THE FAR NW PORTION OF THE AREA EXTENDS FROM 30N134W TO 24N140W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 30-60 NM OF THE FRONT. A POST FRONTAL TROUGH MOVING QUICKLY SE IS JUST NW OF THE AREA WITH SCATTERED SHOWERS AND ISOLATED WEAK TSTMS JUST APPROACHING 30N140W. WINDS NW OF THE FRONT ARE W-NW 20-25 KT WITH SEAS 13-20 FT IN A NW SWELL. WINDS WITHIN ABOUT 240 NM E OF THE FRONT N OF 28N ARE SW 20 KT WITH SEAS 10-12 FT IN NW SWELL. THE FRONT IS FORECAST TO REACH FROM NEAR 30N126W TO 24N129W...THEN BECOME ILL DEFINED TO 14N140W IN 24 HRS...AND AS A DISSIPATING FRONTAL TROUGH FROM 30N124W TO 23N128W IN 48 HRS. A RATHER VIGOROUS GALE CENTER N OF THE AREA IS FORECAST DROP SE TO NEAR 31N128W WITH A PRES OF 1008 MB IN 48 HRS WITH AN ASSOCIATED COLD FRONT EXTENDING FROM IT SW TO 30N129W TO 24N131W. LATEST 10M AND 30M MODEL GUIDANCE INDICATES THAT A SWATH OF GALE FORCE WILL MOVE INTO THE AREA WITHIN ABOUT 180 NM OF THE LOW IN THE SW QUADRANT IN 48 HRS WITH LARGE SEAS UP TO 21 FT IN AN NW SWELL. ELSEWHERE AT THE SURFACE...A WEAK TROUGH BISECTS THE ITCZ ALONG 132W FROM 3N-10N. THE PRES GRADIENT THROUGHOUT THE TROPICAL REGION OF THE AREA REMAINS WEAK WITH RELATIVELY LIGHT WINDS...EXCEPT FOR A SMALL SWATH OF NE-E WINDS TO 20 KT FOUND JUST TO THE N OF THE LOW UNDER SLIGHTLY TIGHTER PRES GRADIENT. NE-E TRADES TO 20 KT ARE FORECAST TO MATERIALIZE FROM 12N-19N BETWEEN 122W-134W IN ABOUT 12 HRS AS THE 1021 MB HIGH TO THE N DRIFTS SE. THESE WINDS ARE FORECAST TO FURTHER INCREASE IN AREAL COVERAGE OVER THE NEXT 24-48 HRS AS A NEW AND STRONGER HIGH PRES BUILDS EASTWARD INTO WESTERN PORTION OF THE AREA BEHIND THE ABOVE MENTIONED GALE CENTER AND ASSOCIATED COLD FRONT. HOWEVER ...THE MAIN STORY OUTSIDE THE FORECAST GALE ABOVE WILL BE RELATED TO THE MARINE ISSUE OF SEA STATE. SEAS WILL BUILD UP TO 13 FT PRIMARILY IN A LARGE NW SWELL IN 24 HRS...POSSIBLY MAXING OUT UP TO 19 FT IN 48 HRS OVER THE FAR WESTERN PORTION OF THE AREA AS ADVERTISED BY WAVEWATCH MODEL GUIDANCE. OVER THE SE PORTION OF THE AREA TO THE SE OF THE LARGE AREA OF CLOUDS ASSOCIATED WITH THE JET STREAM...THE ATMOSPHERE CONTINUES TO BE UNDER MODERATE SUBSIDENCE AS SEEN ON SATELLITE WATER VAPOR IMAGERY ALLOWING FOR MOSTLY STABLE CONDITIONS TO PREVAIL THERE WITH CONVECTION SUPPRESSED ALONG THE ITCZ. THE ONLY EXCEPTION IS A SMALL AREA OF ISOLATED MODERATE CONVECTION NOTED ALONG THE ITCZ BETWEEN 85W-92W. SCATTERED MODERATE CONVECTION IS SEEN FROM 3N-5N E OF 80W. THIS IS DUE TO THE TAIL END OF A NARROW UPPER TROUGH THAT EXTENDS FROM THE CENTRAL CARIBBEAN SEA SW TO ACROSS PANAMA TO NEAR 4N85W. THE UPPER FLOW PATTERN BETWEEN THE TROUGH AND THE WESTERN EXTENSION OF MID/UPPER LEVEL RIDGING THAT EXTENDS OVER S AMERICA ALONG 5N IS ADVECTING UPPER LEVEL MOISTURE ALONG THE COAST OF COLOMBIA NE ACROSS SRN PANAMA...BEFORE IT QUICKLY EVAPORATES IN THE DRY AIR UNDER THE MODERATE SUBSIDENCE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ AGUIRRE