000 AXPZ20 KNHC 070320 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE DEC 07 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 0300 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM 06N79W TO 10N113W THEN RESUMES NEAR 08N119W TO 09N130W THEN RESUMES NEAR 09N135W TO 08N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 127W AND 130W. ...DISCUSSION... A NEW COLD FRONT IS BARELY IN THE EXTREME NW PORTION OF THE DISCUSSION AREA EXTENDING FROM 32N138W TO 31N140W. SW WINDS OF 20 TO 30 KT EXIST OUT AHEAD OF THE FRONT WITH A RECENT REPORT OF 30 KT WINDS FROM SHIP WITH CALL-SIGN WFLG NEAR 29N140W. THIS SHIP ALSO REPORTED SEAS TO 17 FT IN NW SWELL. THE SOUTHERN PORTION OF THIS FRONT WILL DISSIPATE AS IT ATTEMPTS TO ENTER THE AREA WHILE ENCOUNTERING HIGH PRES WHICH IS PRESENTLY 1023 MB AND LOCATED NEAR 32N122W. THIS HIGH WILL REMAIN NEARLY STATIONARY DURING THE NEXT FEW DAYS. EXPECT SW WINDS TO 20 KT TO PERSIST OVER THE FAR NW CORNER AS YET ANOTHER COLD FRONT APPROACHES FROM THE NW BY 48 HOURS. MEANWHILE THE LARGE NW SWELL WILL BUILD TO UP TO 20 FT NEAR 30N140W BY 48 HOURS. AN EARLIER ASCAT PASS INDICATED FRESH TRADES BETWEEN THE HIGH CENTER AND A SURFACE TROUGH EXTENDING FROM NEAR 19N128W TO 07N133W. THE TROUGH WILL DISSIPATE WITHIN 24 HOURS ALLOWING FOR WINDS TO DIMINISH TO LESS THAN 20 KT. MEANWHILE 1010 MB LOW PRES IS CENTERED NEAR 09N116W. AN EARLIER ASCAT PASS CAPTURED 20 TO 25 KT WITHIN 180 NM OF THE LOW CENTER. AN EARLIER JASON ALTIMETER PASS SHOWED SEAS TO 10 FT NEAR THIS SAME AREA OF STRONGEST WINDS. ASSOCIATED CONVECTION HAS COMPLETED DISSIPATED DURING THE PAST SEVERAL HOURS WITH ONLY SCATTERED SHOWERS NOW OCCURRING NEAR THIS FEATURE. THE LOW IS FORECAST TO OPEN UP INTO A TROUGH BY 48 HOURS WITH WINDS DIMINISHING TO 20 KT BY THEN. MODEL GUIDANCE INDICATES THAT 20 KT NORTHERLY FLOW HAS COMMENCED IN THE NORTHERN PORTION OF THE GULF OF CALIFORNIA AS OF 00 UTC THIS EVENING WITH HIGH PRES BUILDING OVER THE GREAT BASIN AND TROUGHING ALONG THE E COAST OF THE GULF OF CALIFORNIA. THESE WINDS WILL INCREASE TO 20 TO 25 KT AND EXPAND FROM 25N TO 30N BY 24 HOURS THEN WILL DIMINISH BACK TO 20 KT AND RETRACT FROM 26N TO 28N BY 48 HOURS. GAP WINDS... AN EARLIER WINDSAT PASS INDICATED 35 KT WINDS THROUGH THE GULF OF TEHUANTEPEC WITH A MORE RECENT ASCAT PASS INDICATING ASSOCIATED 20 KT WINDS ALL THE WAY DOWNWIND TO 10N102W. A RECENT OBSERVATION FROM SHIP WITH CALL-SIGN DMRG LOCATED NEAR 11N97W REPORTED 24 KT NE WINDS AND 12 FT SEAS. MEANWHILE OBSERVATIONS AT LAND BASED STATION IXTEPEC OAXACA MEXICO HAVE INCREASED TO 40 KT WITH GUSTS TO 50 KT DURING THE PAST FEW HOURS. EXPECT WINDS TO DIMINISH TO BELOW GALE FORCE BY 18 UTC TUE ALTHOUGH NE SWELL GENERATED BY THIS EVENT WILL CONTINUE TO PROPAGATE SW REACHING ROUGHLY FROM 06N TO 10N BETWEEN 100W AND 108W BY 00 UTC THU. AN EARLIER ASCAT PASS CAPTURED 20 KT WINDS IN AND DOWNWIND OF THE GULF OF FONSECA. EXPECT THESE WINDS TO HAVE SINCE DIMINISHED AS LAND BASED OBSERVATIONS RIGHT ON THE COAST AT AMAPALA HONDURAS HAVE DIMINISHED TO 04 KT. WINDS ARE EXPECTED TO PULSE BACK TO 20 KT BEGINNING AROUND 06 UTC AND PERSISTING THROUGH 18 UTC WITH ENHANCED DRAINAGE FLOW OCCURRING DURING THE LATE NIGHT AND EARLY MORNING HOURS. THE SAME ASCAT PASS ALSO SHOWED 20 KT WINDS IN THE GULF OF PAPAGAYO DOWNWIND TO NEAR 09N88W. EXPECT THESE WINDS TO PERSIST THROUGH AT LEAST THE NEXT 48 HOURS WITH THE STRONGEST WINDS OCCURRING DURING THE MORNING HOURS DUE TO THE ENHANCED DRAINAGE FLOW. THE LATEST GFS GUIDANCE INDICATES WINDS REACHING 30 KT AROUND 12 UTC TUE WHEN THE DRAINAGE FLOW WILL BE THE GREATEST. 1009 MB LOW PRES IS LOCATED JUST N OF THE ISTHMUS OF PANAMA IN THE FAR SW CARIBBEAN SEA. NORTHERLY WINDS TO 20 KT ARE FLOWING AROUND THE WESTERN SIDE OF THIS LOW AND INTO THE GULF OF PANAMA. EXPECT THESE WINDS TO PERSIST THROUGH AT LEAST 00 UTC THU AS THE LOW REMAINS NEARLY STATIONARY. $$ LEWITSKY