000 AXPZ20 KNHC 100343 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN JAN 10 2010 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 4N78W 4N90W 5N100W 6N110W 8N120W 8N130W 7N140W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM S OF THE AXIS BETWEEN 81W-84W...AND 60 NM N OF THE AXIS BETWEEN 133W-136W AND W OF 137W. ...DISCUSSION... THE UPPER PATTERN OVER THE FORECAST AREA IS BECOMING LESS AMPLIFIED AS THE SOUTHERN STREAM TROUGH THAT HAD SLOWLY MADE ITS WAY THROUGH EASTERN WATERS IS PHASING WITH THE MEAN LONGWAVE TROUGH OVER THE EASTERN U.S. THE UPPER JET ON THE LEADING EDGE OF THIS PHASED TROUGH IS PULLING NE AWAY FROM THE AREA...WITH THE JET CORE ALREADY WELL INTO THE GULF OF MEXICO AND THE SOUTHEASTERN U.S. CONVECTIVE ACTIVITY IN EASTERN WATERS HAS DECREASED AS A RESULT. A SURFACE TROUGH EMBEDDED IN THE ITCZ FROM 4N107W TO 11N104W RESIDES NEAR A REGION OF DECREASING SPEED DIFFLUENCE ALOFT AND MOIST LOW TO MID LEVEL CONDITIONS. ONLY ISOLATED WEAK CONVECTION IS SEEN NEAR THE TROUGH. UPPER LEVEL MOISTURE E OF THE TROUGH IS STREAMING NE TO ACROSS SOUTHERN MEXICO...TRANSPORTED BY THE MID TO UPPER LEVEL JET. SCATTERED TO BROKEN LOW CLOUDS WITH ISOLATED SHOWERS ARE NOTED E OF THE SURFACE TROUGH TO NEAR 99W. OVER THE WESTERN SECTION OF THE AREA...A DEEP LAYER TROUGH EXTENDS FROM 30N124W TO 19N133W TO W OF THE AREA AT 14N140W. SE OF THIS TROUGH AND BETWEEN THE EASTERN TROUGH BROAD MID/UPPER LEVEL RIDGING COVERS THE AREA WITH A MEAN RIDGE AXIS FROM 2N115W TO 15N118W TO 24N121W TO WELL N OF THE AREA AT 30N119W. A JET STREAM BRANCH WITH MAXIMUM CORE WIND SPEEDS OF 70-100 KT LIES IN BETWEEN THE TROUGH AND THE AREA OF BROAD MID/UPPER LEVEL RIDGING. THIS JET STREAM BRANCH IS EXPECTED TO MOVE EASTWARD OVER THE NEXT TWO DAYS TO ACROSS MEXICO AND EVENTUALLY JOIN THE AFOREMENTIONED JET ON THE LEADING EDGE OF THE PHASED TROUGH OVER THE EASTERN U.S. CURRENTLY...DIFFLUENCE INDUCED BY THE REAR RIGHT QUADRANT OF THIS JET IN THE VICINITY OF THE ITCZ W OF 130W IS ALLOWING FOR WEAKENING SCATTERED SHOWERS AND ISOLATED TSTMS ALONG WITHIN 120 NM N OF THE ITCZ. EXPECT THIS CONVECTIVE ACTIVITY TO SHIFT E WITH THE JET ALONG THE ITCZ OVER THE NEXT TWO DAYS. ELSEWHERE ACROSS THE AREA...SATELLITE WATER VAPOR IMAGERY SHOWS ABUNDANT MODERATE SUBSIDENCE WITH ASSOCIATED RATHER STABLE ATMOSPHERIC CONDITIONS NOTED. ONLY ISOLATED WEAK CONVECTION IS SEEN N OF THE ITCZ WITHIN 30 NM OF 6N87W AND S OF THE GULF OF PANAMA AIDED BY THE SOUTHERN STREAM TROUGH MENTIONED ABOVE IN COMBINATION WITH LOW LEVEL MOSITURE CONVERGENCE. ACTIVITY IS NOT EXPECTED TO LAST VERY LONG AS STABLE AIR ACTS TO EVAPORATE THE MOISTURE. AT THE SURFACE...A 1023 MB HIGH PRES IS CENTERED N OF THE AREA NEAR 33N125W WITH A RIDGE AXIS SW TO 23N140W. THE HIGH IS FORECAST TO REMAIN STATIONARY OVER THE NEXT TWO DAYS. LATEST MODEL GUIDANCE INDICATES THAT THE HIGH WILL BEGIN TO MOVE SE AND WEAKEN OVER THE NEXT COUPLE OF DAYS TO FINALLY ALLOW A COLD FRONT TO MOVE INTO THE FAR NW WATERS. S TO SW WINDS OF 20 KT HAVE ALREADY BEGUN TO THE N OF 28N AND W OF 137W DUE TO A TIGHTENING OF THE PRES GRADIENT BETWEEN A COLD FRONT ABOUT 450 NM NW OF THE REGION AND THE 1023 MB HIGH. BY MON EVENING...THE GLOBAL MODELS HINT THAT THE FRONT SHOULD BE WEAKENING FROM 30N137W TO NEAR 27N140W WITH SW WINDS OF 20 TO 25 KT N OF 28N AND WITHIN 360 NM E OF FRONT. LONG PERIOD NW SWELLS SHOULD ALLOW FOR MAXIMUM SEAS OF UP TO 17 FT WITHIN THIS AREA OF WINDS WITH EVEN MUCH LARGER SEAS W OF THE FRONT AS MUCH OF THE WAVE MODEL GUIDANCE SUGGESTS A MAXIMUM IN THE LOW 20S. GAP WINDS... GULF OF TEHUANTEPEC...N TO NE WINDS OF 40 TO 50 KT ARE FORECAST TO INCREASE POSSIBLY UP TO 55 KT OVERNIGHT AND INTO SUN EVENING WITH MODELS WIND FIELDS SUGGESTING THAT THESE WINDS SHOULD DECREASE TO 35 TO 45 KT BY LATE MON AFTERNOON INTO MON EVENING. MAX SEAS ARE EXPECTED TO BE UP TO 19 FT...WITH ONLY A SLOW DECREASING TREND INTO THE NEXT 48 HRS. GULFS OF PAPAGAYO AND FONSECA...THE STRONG COLD FRONT THAT HELPED TO INDUCE STORM FORCE CONDITIONS TO THE GULF OF TEHUANTEPEC IS EXPECTED TO BRING GALES TO PAPAGAYO BY SUN MORNING AND REMAIN THROUGH THE NEXT 48 HRS AND BEYOND AS STRONG SW CARIBBEAN TRADES FILTER THROUGH CENTRAL AMERICA AND INTO THE PACIFIC. NE TO E WINDS OF 20 TO 30 KT CAN BE FOUND DOWNWIND OF PAPAGAYO AS THE LEADING EDGE OF THE COLD AIR MAKES ITS WAY THROUGH HONDURAS AND NICARAGUA SAT. SIMILAR WINDS ARE FORECAST THROUGH THE GULF OF FONSECA INTO THE NEXT 48 HRS. GULF OF PANAMA...N TO NE WINDS TO 20 KT ARE S OF THE GULF TO ABOUT 6N AND BETWEEN 79W-81W. THESE WINDS ARE EXPECTED TO INCREASE TO 20-25 KT IN 24 HRS AND THROUGH 48 HRS AS HIGH PRES BUILDS SOUTHWARD INTO CENTRAL AMERICA AND THE SW CARIBBEAN SEA INCREASING THE PRES GRADIENT THROUGH THIS AREA AS IT INTERACTS WITH LOW PRES OVER NORTHERN COLOMBIA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ AGUIRRE