000 AXPZ20 KNHC 190959 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT DEC 19 2009 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 0930 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 5N77W TO 7N95W TO 5N105W TO 7N115W TO 7N121W TO 7N140W. SCATTERED STRONG CONVECTION IS WITHIN 120 NM OF THE AXIS BETWEEN 82W-85W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 90 NM N OF THE AXIS BETWEEN 124W-128W AND BETWEEN 131W-134W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM S OF THE AXIS BETWEEN 116W-118W AND BETWEEN 121W-124W. ...DISCUSSION... A HIGHLY AMPLIFIED UPPER PATTERN CONSISTS OF A MID/UPPER LEVEL TROUGH EXTENDING FROM THE CENTRAL PORTION OF THE U.S. SW TO ACROSS NORTHERN MEXICO AND TO 13N113W. TO THE W OF THE TROUGH...RIDGING DOMINATES THE AREA WITH A MEAN RIDGE AXIS EXTENDING FROM A SMALL MID/UPPER LEVEL ANTICYCLONE NEAR 9N133W NNE TO 25N130W TO WELL N OF THE AREA AT 30N128W. WITH THE TROUGH EXITING THE EASTERN PORTION OF THE AREA IN THE NEXT 24 HRS...THE RIDGE WILL FOLLOW THROUGH AFTERWORDS AS A LARGE DEEP LAYER TROUGH W OF THE REGION PUSHES E THROUGH MON. AN EMBEDDED MID/UPPER LEVEL CYCLONIC CIRCULATION NEARS 17N140W BY LATE MON NIGHT. A SURFACE COLD FRONT ASSOCIATED WITH THE TROUGH W OF THE AREA IS JUST ENTERING THE FAR NW CORNER OF THE AREA...AND WILL REACH FROM 30N136W TO 26N140W BY LATE SAT NIGHT...THEN BECOME DIFFUSE FROM 30N127W TO 25N134W BY LATE SUN NIGHT AS UPPER SUPPORT LIFTS WELL TO THE N OF THE AREA. SW WINDS TO 20 KT ARE EXPECTED WITHIN 180 NM E OF THE FRONT N OF 28N WITH LARGE NW SWELLS UP TO 16 FT. WINDS W OF THE FRONT WILL BE LESS THAN 20 KT...BUT LARGE NW SWELLS POSSIBLY UP TO 14 FT ARE FORECAST THERE BY THE LATEST WAVEWATCH GUIDANCE. AS THE TROUGH ADVANCES E...THE DEEP LAYER RIDGE WILL BREAK DOWN CAUSING SURFACE RIDGING TO WEAKEN. NE TO E TRADE WINDS OF 20 TO 25 KT FROM 8N TO 15N W OF 122W WILL CONFINED FROM 10N TO 19N W OF 131W BY LATE SUN NIGHT WITH SEAS 8 TO 10 FT IN NW SWELL. A SURFACE TROUGH EXTENDS FROM 5N121W TO A 1008 MB LOW NEAR 7N120W AND NE TO NEAR 11N119W. THIS SYSTEM WILL MOVE SLOWLY W THROUGH THE NEXT 24-36 HRS THEN REMAIN JUST AS A TROUGH. WINDS TO 20 KT ARE PRESENTLY NOTED WITHIN 120 NM IN THE N SEMICIRCLE OF THE LOW WITH SEAS 8 TO 10 FT IN NW SWELL...BUT DIMINISH TO LESS THAN 20 KT IN 48 HRS WITH SEAS LESS THAN 8 FT. A PERSISTENT SOUTHERN JET STREAM BRANCH CONTINUES TO EXTEND FROM JUST N OF THE LOW NORTHEASTWARD ALONG THE BASE OF THE FAR EASTERN PACIFIC TROUGH AND INTO CENTRAL MEXICO NEAR 19N104W. BROKEN TO OVERCAST CIRRUS CLOUDS ASSOCIATED WITH UPPER LEVEL MOISTURE TRANSPORTED BY THE JET ARE NOTED N OF THE ITCZ AND TO THE E OF 120W...TURNING NE WITHIN 250 NM EITHER SIDE OF THE LINE FROM 7N114W TO 11N106W TO 16N98W. OVER THE FAR EASTERN SECTION CLOSER TO LAND...NW WINDS TO 20 KT ARE EXPECTED TO BEGIN AGAIN ACROSS THE GULF OF CALIFORNIA N OF 28N...AND TO N OF 26N IN 24 HRS DUE TO THE PRES GRADIENT CREATED BETWEEN THE INTERACTION OF CLIMATOLOGICAL TROUGHING ALONG THE EASTERN GULF OF CALIFORNIA AND PERSISTENT HIGH PRES OVER THE GREAT BASIN. WINDS THEN DIMINISH BY 48 HRS AS THE GRADIENT WEAKENS. GAP WINDS...N TO NE WINDS OF 20 TO 25 KT THROUGH THE GULF OF TEHUANTEPEC ARE EXPECTED TO CHANGE LITTLE THROUGH LATE SUN NIGHT. THE COMBINATION OF STRONG TRADE WINDS IN THE CARIBBEAN AND LOCAL DRAINAGE EFFECTS WILL ALLOW FOR NE 20 KT WINDS THROUGH THE GULF OF PAPAGAYO TO PULSATE ON AND OFF WITH MAXIMUM PEAK OCCURRENCES IN THE MORNINGS INTO EARLY NEXT WEEK. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ AGUIRRE