000 AXPZ20 KNHC 141539 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SAT DEC 14 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1400 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC...THE 0636 UTC OSCAT PASS SHOWED 20-25 KT N WINDS IN THE GULF OF TEHUANTEPEC THIS MORNING. THIS STRONG BREEZE SHOULD HAVE QUICKLY DIMINISHED AFTER SUNRISE THIS MORNING AND WILL BECOME VARIABLE WINDS AT 5-10 KT BY THIS EVENING...WITH LITTLE CHANGE THEN EXPECTED THROUGH MIDNIGHT. NORTHERLY WINDS WILL SURGE THROUGH THE CHIVELA PASS LATE TONIGHT AND QUICKLY REACH GALE FORCE BY SUNRISE ON SUN. THE NORTHERLY WINDS WILL CONTINUE TO INCREASE ON SUN TO A MAXIMUM OF 50 KT WITH SEAS BUILDING TO OVER 20 FT SUN EVENING INTO MON MORNING. STORM FORCE CONDITIONS ARE EXPECTED TO PERSIST FROM AROUND SUNSET SUN THROUGH THE END OF THE FORECAST PERIOD AROUND SUNRISE MON BEFORE DIMINISHING BACK TO GALE FORCE. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS W FROM THE SW CARIBBEAN ACROSS PANAMA NEAR 08N78W TO 07N80W TO 09N85W TO 05N95W TO LOW PRES 08N114W 1009 MB TO 08N129W. THE ITCZ AXIS EXTENDS FROM 08N129W TO 07N140W. SCATTERED MODERATE CONVECTION LIES N OF 04N E OF 81W TO THE COAST OF PANAMA AND COLOMBIA AS WELL AS WITHIN 120 NM NM OF THE AXIS BETWEEN 85W AND 87W...INCLUDING THE GULF OF PAPAGAYO. ELSEWHERE...SCATTERED MODERATE CONVECTION LIES E OF LOW PRESSURE EMBEDDED IN THE MONSOON TROUGH WITHIN 120 NM N OF THE AXIS BETWEEN 106W AND 114W AND WITHIN 120 NM S OF THE AXIS BETWEEN 110W AND 114W. ...DISCUSSION... AN UPPER LOW NEAR 27N132W HAS DIRECTED THE UPPER JET FROM S TO N ON ITS SE SIDE. THE REAR RIGHT QUADRANT OF THE JET IS GENERATING DIFFLUENT FLOW ALOFT WHICH IS LIFTING THE MOIST AIRMASS POOLED NEAR THE MONSOON TROUGH AROUND 122N AND ENHANCING CONVECTION. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION CAN BE FOUND FROM 13N TO 18N BETWEEN 120W AND 123W. THE UPPER JET IS FORECAST TO WEAKEN AS THE UPPER LOW SLOWLY JOGS NORTHWARD. EXPECT THE CHANCE FOR ORGANIZED DEEP CONVECTION HERE TO DIMINISH OVER THE NEXT TWO DAYS AS A RESULT. AT THE SURFACE...HIGH PRESSURE DOMINATES THE OPEN PACIFIC WATERS OVER THE DISCUSSION AREA N OF 15N. THE MOST RECENT ASCAT AND OSCAT PASSES SHOW TRADE WINDS AROUND 20 KT SPANNING THE REGION FROM 13N TO 28N W OF 120W. LONG PERIOD NW SWELL IS MIXING WITH THE ASSOCIATED NE TRADE WIND SWELL...AND WITH LONG PERIOD CROSS- EQUATORIAL SOUTHERLY SWELL...RESULTING IN COMBINED SEAS OF 6-9 FT WITHIN THIS AREA OF ENHANCED TRADES. THE NW SWELLS ARE EXPECTED TO INCREASE AS THEY PROPAGATE SE ACROSS THE DISCUSSION WATERS TO THE N OF 18N W OF 134W TONIGHT...WITH THE COMBINED SEAS BUILDING TO 7-11 FT WITHIN THIS AREA. THE GRADIENT WILL RELAX SOME ON MON WHEN THE AREA OF FRESH TRADES SHRINKS AS THE DRIVING HIGH PRESSURE CENTER SHIFTS NORTHWARD...WEAKENING THE PRESSURE GRADIENT BETWEEN IT AND THE ITCZ/MONSOON TROUGH AXIS. GULF OF PAPAGAYO...ASCAT PASSES FROM 0244 UTC AND 0328 UTC BOTH SHOWED NE WINDS TO 25 KT DOWNWIND OF THE GULF OF PAPAGAYO...WELL BEFORE THE PERIOD OF MAXIMUM NOCTURNAL DRAINAGE. THESE WINDS ARE SUSPECTED TO HAVE DIMINISHED THIS MORNING AND SHOULD REMAIN BELOW A STRONG BREEZE THE REST OF TODAY THROUGH SUNDAY AHEAD OF THE NEXT STRONG COLD FRONT IN THE GULF OF MEXICO AND WESTERN CARIBBEAN THAT WILL INITIATE THE STORM FORCE EVENT IN THE GULF OF TEHUANTEPEC. THAT FRONT SHOULD IMPACT THE GULF OF PAPAGAYO BY EARLY MON MORNING...BRINING THE RETURN OF A STRONG NE BREEZE WITH SEAS BUILDING TO 8 FT BY SUNRISE. GULF OF CALIFORNIA...THE 0640 UTC OSCAT PASS SHOWED A STRONG NW BREEZE ESTABLISHED IN THE GULF OF CALIFORNIA FROM 23N TO 28N. BY THIS EVENING...WINDS ARE EXPECTED TO INCREASE TO 30 KT WITH SEAS 6-9 FT AS STRONG HIGH PRESSURE OVER THE U.S. INTERMOUNTAIN WEST ABUTS WITH ENHANCED TROUGHING ASSOCIATED WITH THE COLD FRONT BRINGING THE STORM EVENT TO THE GULF OF TEHUANTEPEC. AS THE FRONT PROCEEDS SOUTH...THE PRESSURE GRADIENT OVER THE GULF OF CALIFORNIA WILL WEAKEN. WINDS WILL DIMINISH BELOW A STRONG NW BREEZE BY MON MORNING. $$ SCHAUER