000 AXPZ20 KNHC 300951 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC FRI DEC 30 2011 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH AXIS FROM 09N84W TO 05N94W TO 06N97W THEN ITCZ TO 07N102W TO 07N120W TO 09N130W AND BEYOND 06N140W. NO SIGNIFICANT CONVECTION NOTED NEAR AXIS. ...DISCUSSION... UPPER LEVELS CYCLONE AT 15N142W ADVECTING ABUNDANT MOISTURE INTO BASIN W OF 130 WITH MODERATE DIVERGENCE ALOFT JUST N OF WEAK SURFACE TROUGH ALONG 132W. SCATTERED MODERATE CONVECTION DIMINISHING QUICKLY INDICATES UPPER LEVEL RIDGE IS FORCING CYCLONE W. MODEL GUIDANCE WEAKENS CYCLONE AND BECOMES OPEN TROUGH BY LATE SAT. AT THE LOWER LEVELS... WEAK SURFACE TROUGH ALONG 132W/134W FROM 06N TO 12N DRIFTING W EXPECTED TO BE W OF 140W SAT. TROUGH ACTING AS UPLIFT MECHANISM FOR MOISTURE UNDER MODERATE UPPER LEVEL DIVERGENCE PROMPTING SCATTERED CONVECTION JUST N OF TROUGH. FRESH TO STRONG NE BREEZE W OF TROUGH AXIS EXPECTED TO DIMINISH AS AXIS MOVES W OF 140W SAT. GULF OF PAPAGAYO... GAP WINDS CONTINUE TO FUNNEL ACROSS NICARAGUA AS FRESH TRADE WINDS PERSIST ACROSS MUCH OF CARIBBEAN. LOCAL ENHANCEMENT BY WESTWARD MOUNTAIN DRAINAGE IN LATE EVENINGS ARE COUNTERED BY SEA BREEZE UNDER DAYTIME HEATING HRS. SIMILAR CONDITIONS EXPECTED TO CONTINUE THROUGH SUN. GULF OF TEHUANTEPEC... VIGOROUS GULF OF MEXICO COLD FRONT LIKELY FUNNEL COLD AIR MASS ACROSS CHIVELAS PASS CAUSING ANOTHER EPISODE OF GALE FORCE WINDS INTO GULF OF TEHUANTEPEC SUN NIGHT. STRONG COLD FRONT APPROACHES NW CORNER OF BASIN LATE SUN NIGHT INCREASING S-SW FLOW TO POSSIBLY FRESH TO STRONG BREEZE AND LARGE LONG PERIOD NW SWELL. TIMING DIFFERENCES IN GUIDANCE PREVENT RELIABLE PREDICTION ON THE ONSET OF WIND INCREASE. $$ WALLY BARNES