000 AXPZ20 KNHC 180326 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SAT JAN 18 2014 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0100 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...INCREASED SURFACE PRESSURE OVER THE WESTERN GULF OF MEXICO HAS TIGHTENED THE PRESSURE GRADIENT THROUGH CHIVELA PASS AND BROUGHT GALE FORCE WINDS TO THE GULF OF TEHUANTEPEC. THE 1850 UTC OSCAT PASS CONFIRMED THE GALE CONDITONS. WINDS ARE EXPECTED TO REACH 40 KT DURING THE PEAK DIURNAL DRAINAGE FLOW EARLY SAT MORNING. MINIMAL GALE CONDITIONS ARE THEN FORECAST TO PERSIST THROUGH AT LEAST 0000 UTC MON. RESULTANT SEAS WILL BUILD UP TO 16 FT SAT MORNING. AN IMPRESSIVE PLUME OF NE SWELL WILL CONTINUE TO PROPAGATE TO THE SW AWAY FROM THE IMMEDIATE GULF OF TEHUANTEPEC AREA...MIXING WITH LONGER PERIOD NW AND SW SWELL. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 02N79W TO 05N88W. THE ITCZ AXIS WAS ANALYZED FROM 05N88W TO 03N95W TO 08N120W THEN CONTINUES FROM 08N126W TO 07N140W. NO SIGNIFICANT CONVECTION WAS NOTED ALONG THE CONVERGENCE ZONE. A TROUGH FROM 13N120W TO 06N127W LIES WITHIN THE BREAK IN THE ITCZ. SCATTERED MODERATE CONVECTION WAS NOTED E OF THE TROUGH FROM 06N TO 10N BETWEEN 115W AND 121W. ...DISCUSSION... AN UPPER TROUGH ALONG 130W N OF 05N IS WEAKENING THE SUBTROPICAL RIDGE OVER THE FORECAST AREA. TRADE WINDS HAVE DIMINISHED TO A MODERATE BREEZE OR LESS. A SURFACE TROUGH ASSOCIATED WITH THE TROUGHING ALOFT IS FOUND FROM 13N121W TO 06N123W. CONVECTION JUST E OF THE TROUGH IS NOTED IN THE SECTION ABOVE. THE UPPER TROUGH AND THE REAR RIGHT QUADRANT OF THE SOUTHERLY UPPER JET ON ITS EASTERN SIDE ARE NOT EXPECTED TO MOVE MUCH THROUGH SUN MORNING WHICH WILL CONTINUE TO ENHANCE CONVECTION HERE. THE UPPER TROUGH IS EXPECTED TO TURN NEGATIVE TILT AS IT PHASES WITH A LONG-WAVE TROUGH APPROACHING FROM THE NW LATE SUN. THIS IS EXPECTED TO ENHANCE THE MID-LEVEL ENERGY ON THE LEADING EDGE OF THE TROUGH AND ITS SURFACE REFLECTION. AN AREA OF FRESH EASTERLY WINDS IS EXPECTED TO BECOME ESTABLISHED NEAR THE SURFACE TROUGH...WITH SEAS BUILDING TO 8 FT IN THIS AREA BY SUN EVENING. A NEW BATCH OF LONG-PERIOD NW SWELL HAS ENTERED THE NW PORTION OF THE AREA. SEAS AS HIGH AS 14 FT ARE EXPECTED BY EARLY SAT...WITH 20 SECOND WAVE PERIODS ON THE LEADING EDGE OF THE SWELL PROPAGATING SOUTHEASTWARD TO THE NORTHERN BAJA CALIFORNIA PENINSULA BY SAT AFTERNOON...PASSING SOUTH OF CABO SAN LUCAS BY SUNRISE SUN...AND REACHING CABO CORRIENTES BY SUN EVENING. A SECOND BATCH OF NW SWELL WILL ENTER THE FAR NW CORNER OF THE AREA NEAR 30N140W SUN EVENING...WITH SEAS EXPECTED TO REACH 15 FT AND WAVE PERIODS IN THE 18-20 SECOND RANGE. GAP WINDS... GULF OF PAPAGAYO...THE GRADIENT BETWEEN HIGH PRESSURE FROM THE YUCATAN PENINSULA TO EASTERN NICARAGUA AND LOWER PRESSURE ASSOCIATED WITH THE MONSOON TROUGH TO THE S WILL CONTINUE TO ENHANCE WINDS IN THE GULF OF PAPAGAYO THROUGH THE WEEKEND. MAXIMUM WINDS TO NEAR 30 KT ARE EXPECTED IN THE PERIOD OF PEAK DRAINAGE FLOW BETWEEN 06Z-12Z EACH MORNING WITH SEAS TO AROUND 10 FT. GULF OF PANAMA...FRESH TO STRONG N WINDS WILL CONTINUE TO PULSE IN THE GULF OF PANAMA SOUTHWARD TO 05N IN THE MORNING HOURS OVER THE WEEKEND AS RIDGING EXTENDS FROM THE YUCATAN PENINSULA INTO EASTERN NICARAGUA. ASSOCIATED SEAS WILL BUILD UP TO 8 FT JUST DOWNWIND OF THE GULF OF PANAMA ON SAT. $$ SCHAUER