000 AXPZ20 KNHC 012158 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SUN JAN 1 2012 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM A LOW PRES CENTER THAT INTERMITTENTLY FORMS ALONG THE MONSOON TROUGH NEAR 05N78W AND CONTINUES W TO 08N85W TO 05N96W WHERE LOW LEVEL WINDS INDICATE A TRANSITION TO THE AN ITCZ WHICH THEN CONTINUES W TO BEYOND 08N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 180 NM EITHER SIDE OF A LINE FROM 05N112W TO 11.5N119W. ...DISCUSSION... A LONG WAVE TROUGH DOMINATES THE PACIFIC FROM ALASKA TO NEAR THE EQUATOR AT 140W. AN EMBEDDED SHORTWAVE TROUGH IS MOVING INTO THE NW CORNER OF THE DISCUSSION AREA ACCOMPANIED BY DRY UPPER AIR AND A SURFACE COLD FRONT EXTENDING FROM 30N137W TO 27N140W. ALTHOUGH THE FRONT WILL WEAKEN TO A TROUGH ALONG 30N130W TO 21N140W ON MON...A BATCH OF LONG PERIOD NW SWELLS WILL PROPAGATE INTO THE AREA BEHIND THE FRONT MIXING WITH NE SWELL...AND DRIVING COMBINED SEA HEIGHTS UP TO 20 FT. THESE LARGE SEAS WILL SUBSIDE TO ABOUT 12 FT BY THEY TIME THEY REACH THE NORTHERN BAJA CALIFORNIA PENINSULA TUE NIGHT. AN UPPER ANTICYCLONE IS NEAR 11S126W WITH AN UPPER RIDGE EXTENDING N THROUGH 32N122W TO OVER THE WESTERN SEABOARD OF N AMERICA. UPPER DIFFLUENCE IS ENHANCING THE ITCZ RELATED CONVECTION PREVIOUSLY DESCRIBED NEAR 08N116W. THE DEBRIS MOISTURE IS ADVECTED N FANNING OUT IN THE ANTICYCLONIC FLOW... MERGING WITH MOISTURE PRECEDING THE PREVIOUSLY MENTIONED UPPER TROUGH...WITH SOME OF THE MOISTURE CONTINUING E ACROSS CENTRAL OLD MEXICO S OF 24N EVENTUALLY CONCENTRATING INTO A PLUME ACROSS THE CENTRAL GULF OF MEXICO AND N FLORIDA. A SECOND LONGWAVE TROUGH DOMINATES CENTRAL N AMERICA AND CONTINUES S ACROSS THE WESTERN GULF OF MEXICO TO A BASE OVER THE TROPICAL PACIFIC AT 02N79W. THE UPPER LEVELS APPEAR VERY DRY S OF 12N E OF 100W...BUT THE LARGE AREA OF UPPER MOISTURE JUST DESCRIBED IS SPREADING E TOWARDS THE DEEP TROPICS S OF CENTRAL AMERICA. GULF OF TEHUANTEPEC... NORTHERLY WINDS AT 20-30 KT ARE FUNNELING THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC AND EXPECTED TO SOON INCREASE TO MINIMAL GALE FORCE. THE NORTHERLY FLOW WILL INCREASE TO STORM STRENGTH OF 50-55 KT MON NIGHT WITH LATEST GUIDANCE SUGGESTING THESE STORM CONDITIONS WILL PERSIST THROUGH LATE TUE NIGHT. THE ASSOCIATED SEAS ARE FORECAST TO 23 FT WITH N AND NE SWELL PROPAGATING S ACROSS THE WATERS N OF 06N BETWEEN 93W AND 109W LATE TUE. GULF OF PAPAGAYO... FRESH TO STRONG TRADE WINDS OVER THE WESTERN CARIBBEAN CONTINUE TO FUNNEL THROUGH NICARAGUA INTO THE GULF OF PAPAGAYO. PEAK WINDS WILL BE 20-25 KT DURING THE LATE NIGHT AND EARLY MORNING HOURS BUT INCREASE TO 20-30 KT TUE AS A COLD FRONT MOVES INTO THE FAR S CARIBBEAN. DOWNSTREAM SEAS ARE AT 6-9 FT BUT WILL INCREASE TO 11 FT LATE TUE IN WATERS FROM 08N-12N BETWEEN 85W AND 93W. SEEMS AS IF NE WINDS AT 15 TO 20 KT WILL WORK THEIR WAY INTO THE GULF OF FONSECA. GULF OF PANAMA... N-NE WINDS AT 20-25 KT FUNNELING S ACROSS PANAMA WILL DIMINISH BELOW 20 KT TONIGHT THEN RESUME MON NIGHT THROUGH AT LEAST WED NIGHT. $$ NELSON