000 AXPZ20 KNHC 312127 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC TUE DEC 31 2013 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 2100 UTC. ...SPECIAL FEATURE... TIGHT PRES GRADIENT ACROSS THE ISTHMUS OF TEHUANTEPEC SUPPORTING MINIMAL GALE FORCE WINDS IN THE GULF OF TEHUANTEPEC...MAINLY AT NIGHT DURING PERIOD OF MAXIMUM DIURNAL DRAINAGE FLOW. THE STRONG GRADIENT WILL WEAKEN TONIGHT AND WED AS LOW PRES IN THE SW GULF OF MEXICO LIFTS NORTHWARD. WINDS WILL DIMINISH 25 KT WITH SEAS SUBSIDING BELOW 8 FT BY WED AFTERNOON AS A RESULT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 06N77W TO 07N84W TO 05N98W. THE ITCZ AXIS EXTENDS FROM 05N98W TO 08N116W TO 05N131W TO 08N140W. SCATTERED MODERATE CONVECTION WITHIN 30 NM S OF TROUGH W OF 81W. ...DISCUSSION... UPPER LEVEL TROUGH ROUGHLY ALONG 110W EXTENDS DEEP INTO THE TROPICS TO NEAR 03N. PLUME OF MID LEVEL MOISTURE IS STREAMING NORTHEASTWARD AHEAD OF TROUGH AXIS INTO CENTRAL MEXICO. WEAK SURFACE RIDGE PREVAILS OVER NORTHERN PART OF THE AREA N OF 15N BETWEEN 110W AND 140W. SURFACE TROUGH ALONG THE COAST OF WESTERN MEXICO FROM 25N108W TO 32N113W IS SUPPORTING FRESH NW WINDS IN THE CENTRAL PART OF GULF OF CALIFORNIA. STRONG TRADE WINDS IN SW CARIBBEAN ARE BEING FORCED ACROSS MOUNTAIN GAPS IN NICARAGUA INTO THE GULF OF PAPAGAYO. WINDS THERE WILL PULSE TO 20-25 KT LATER WED MORNING AND AGAIN THU MORNING...ENHANCED BY MOUNTAIN DRAINAGE. LOOKING AHEAD...A STRONG COLD FRONT WILL SWEEP SOUTHWARD INTO THE WESTERN GULF OF MEXICO THU AND INDUCE ANOTHER ROUND OF GALE FORCE WINDS AND SEAS TO 18-19 FT IN THE GULF OF TEHUANTEPEC THU NIGHT THROUGH SAT. $$ MUNDELL