000 AXPZ20 KNHC 170327 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC WED DEC 16 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 0300 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE LIES ALONG 05N77W TO 07N82W TO 07N111W TO 08N133W TO 06N140W. ISOLATED MODERATE CONVECTION CAN BE FOUND WITHIN 120 NM S OF THE ITCZ AXIS BETWEEN 80W AND 86W AS WELL AS WITHIN 75 NM EITHER SIDE OF AXIS BETWEEN 102W AND 117W. WIDELY SCATTERED MODERATE CONVECTION CAN BE FOUND WITHIN 200 NM N AND 150 NM S OF THE ITCZ AXIS BETWEEN 121W AND 131W. ...DISCUSSION... AN AMPLIFIED NORTHERN STREAM PATTERN IS IN PLACE WITH A SHARP UPPER LEVEL TROUGH FOUND FROM THE TEXAS BIG BEND TO THE MEXICAN COAST NEAR 19N105W AND 12N113W. AN UPPER JET LIES ON THE LEADING EDGE OF THIS TROUGH AND IS TRANSPORTING MID TO UPPER LEVEL TROPICAL MOISTURE NORTHEASTWARD ACROSS THE CENTRAL MEXICAN COAST TO THE EASTERN RIO GRANDE VALLEY. NEAR THE TAIL OF THE JET...A 1007 MB LOW IS ANALYZED NEAR 07N111W ALONG A SURFACE TROUGH FROM 12N110W TO 03N112W. SCATTERED MODERATE CONVECTION CAN BE FOUND FOCUSED ALONG THE ITCZ WITHIN 500 NM E QUADRANT AND 200 NM W QUADRANT OF THE LOW. TOTAL PRECIPITABLE WATER SATELLITE IMAGERY SHOWS THE LOW TO MID LEVEL MOISTURE POOLED NEAR THIS LOW AS WELL E OF A SECOND SURFACE TROUGH EMBEDDED IN THE ITCZ 11N132W TO 03N133W. AS MENTIONED IN THE ITCZ SECTION...WIDELY SCATTERED MODERATE CONVECTION CAN BE FOUND MAINLY N OF THE AXIS WITHIN 700 NM E OF THE SURFACE TROUGH. THIS TROUGH LIES UNDER AN UPPER LEVEL DIFFLUENT AREA ASSOCIATED WITH AN UPPER ANTICYCLONIC CIRCULATION NEAR 08N130W. HOWEVER...THE SOUTHERN STREAM JET LIES JUST TO THE NORTH OF THIS ANTICYCLONE...WITH STRONG WESTERLY FLOW FOUND NORTH OF 12N. WIND SHEAR DUE TO THIS JET IS RESULTING IN A LACK OF ANY SIGNIFICANT DEEP CONVECTION...BUT UPPER LEVEL MOISTURE AND CONVECTIVE DEBRIS CLOUDINESS IS CONTINUING TO BE TRANSPORTED BY THE JET WITH CIRRUS FOUND PRIMARILY BETWEEN 10N AND 15N W OF 117W. THE AMPLIFIED LONGWAVE PATTERN ALOFT SHOULD BE SLOW TO CHANGE. THE MEAN UPPER TROUGH OVER MEXICO WILL RELOAD THU AS IT PHASES WITH A NORTHERN STREAM SYSTEM CURRENTLY OVER THE NW U.S. AS WELL AS SOUTHERN STREAM ENERGY WHICH HAD SUPPORTED A COLD FRONT THAT DISSIPATED OVER THE NW WATERS LAST NIGHT BUT GENERATED THE NW SWELL CURRENTLY OVER MUCH OF THE AREA. THE DEEP LAYER RIDGE AXIS WILL SHIFT SLIGHTLY TO THE W AS THE TROUGHS TO ITS E AND W RELOAD WITH ENERGY MOVING INTO THEIR WESTERN EDGES. THE PRES GRADIENT BETWEEN THE SURFACE RIDGE STEMMING FROM A 1025 MB HIGH PRES NEAR 30N125W EXTENDING SW TO 23N140W AND THE WESTERN SURFACE TROUGH HAS INDUCED 20 TO 25 KT TRADE WINDS IN MUCH OF THE REGION BETWEEN 10N AND 20N W OF 115W AS DEPICTED IN A COUPLE EARLIER ASCAT PASSES FROM 16/1730 UTC AND 16/1900 UTC. THE SLIGHT WESTWARD MIGRATION OF THE DEEP LAYER RIDGE WILL SHIFT THE TRADES SLIGHTLY WESTWARD...PREVENTING THE NEXT FRONTAL SYSTEM ASSOCIATED WITH THE LONGWAVE TROUGH IN THE CENTRAL PACIFIC FROM PUSHING INTO THE FAR NW WATERS BEFORE SATURDAY. S-SW WINDS UP TO 25 KT ARE FORECAST TO BEGIN IMPACTING THE FAR NW CORNER OF THE HIGH SEAS AREA BY FRI MORNING WITH ANOTHER ROUND OF HIGHER SEAS AND NW SWELL FOLLOWING IN ITS WAKE THROUGH THE REMAINDER OF THE WEEKEND. CLOSER TO LAND...AN EARLIER 16/1728 UTC ASCAT PASS SHOWS WINDS IN THE 20 TO 25 KT RANGE OVER SOUTHERN PORTIONS OF THE GULF OF CALIFORNIA. AS HIGH PRES MOVES EASTWARD BEHIND THE COLD FRONT CURRENTLY OVER THE NORTHWESTERN GULF OF MEXICO...EXPECT THE PRES GRADIENT TO DECREASE ACROSS THE GULF OF CALIFORNIA AND WINDS TO GRADUALLY DIMINISH BELOW 20 KT BY SATURDAY. GAP WINDS...GAP WINDS PERSIST THROUGH THE GULFS OF PAPAGAYO AND TEHUANTEPEC. THE COMBINATION OF STRONG TRADE WINDS IN THE CARIBBEAN AND LOCAL DRAINAGE EFFECTS WILL ALLOW FOR WINDS TO 25 KT IN PAPAGAYO THROUGH TONIGHT AND DIMINISH THROUGH LATE THU INTO FRI MORNING. GALE FORCE WINDS WILL CONTINUE IN THE GULF OF TEHUANTEPEC THROUGH FRIDAY AFTERNOON AS THE COLD FRONT PUSHES INTO THE SW GULF OF MEXICO. WINDS ARE EXPECTED TO DIMINISH BELOW GALE FORCE BY FRI EVENING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN