000 AXPZ20 KNHC 180335 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE MAR 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 0300 UTC. ...SPECIAL FEATURES... HIGH PRESSURE IN THE WAKE OF A LATE SEASON COLD FRONT THAT SWEPT EASTWARD ACROSS THE EASTERN GULF OF MEXICO THIS EVENING IS FORCING COLD AIR THROUGH THE CHIVELAS PASS AND INTO THE GULF OF TEHUANTEPEC. MUCH EARLIER 1538 UTC AND 1632 UTC ASCAT PASSES CONFIRMED GALE FORCE WINDS...35 KT...HAVE ENTERED THE GULF OF TEHUANTEPEC. NWP GUIDANCE SUGGESTS THE WINDS ARE NEAR THEIR PEAK OF 40 KT AT THIS TIME. SEAS SHOULD REACH THEIR MAXIMUM VALUES OF 13 FT IN THE NEXT FEW HOURS. THIS GALE EVENT WILL BE VERY SHORT-LIVED AS IT IS EXPECTED TO END BY SUNRISE. WINDS WILL QUICKLY DIMINISH TO 15-20 KT AND SEAS WILL SUBSIDE TO LESS THAN 8 FT BY TUE AFTERNOON. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... EVIDENCE OF A WEAK MONSOON TROUGH EXTENDS FROM 11N86W TO 04N100W TO 03N113W. SOME LOW LEVEL WINDS ARE FLOWING INTO THE SEASONAL SOUTHERN HEMISPHERIC "SECOND" ITCZ ALONG 04-05S. THE MONSOON TROUGH TRANSITIONS TO THE ITCZ NEAR 03N113W THROUGH 06N127W TO 03N140W. THERE IS NO SIGNIFICANT CONVECTION NOTED. ...DISCUSSION... A SHARP UPPER TROUGH EXTENDS FROM THE DEEP SOUTH WSW ACROSS NE MEXICO TO A SHEARED MID LEVEL CYCLONE NEAR 21N107W...THEN WNW THROUGH THE MID LEVELS TO A WEAKENING MID LEVEL CYCLONE NEAR 23N130W. STRONG SUBSIDENCE IS NOTED WITHIN 120-180 NM TO THE S OF THE TROUGH...EXTENDING WELL SW OF THE S END OF THE BAJA CALIFORNIA PENINSULA. UPPER LEVEL RIDGING RESIDES TO THE E AND NW OF THE MAIN MID TO UPPER TROUGH. JUST S OF THE AREA OF STRONG SUBSIDENCE LIES A PERSISTENT CUT OFF LOW NEAR 14N118W. THIS LOW HAS ACTED IN PHASE WITH ANOTHER UPPER CYCLONE IN THE SOUTHERN NEAR 08S127W...TO PRODUCE DEEP LAYERED WLY FLOW ALOFT STRADDLING BOTH SIDES OF THE EQUATOR...AND CREATING A ZONE OF STRONG VERTICAL WIND SHEAR AND UPPER CONVERGENCE. THE CUT OFF LOW IS WEAKENING AND HAS BEGUN TO BE SHUNTED E-SE BY THE UPPER TROUGH ACROSS MEXICO...WITH ASSOCIATED UPPER FLOW ALONG THE EQUATOR BECOMING MORE NW. A LARGE AREA OF UPPER DIVERGENCE PERSISTING WELL TO THE SE OF THE CUT OFF LOW HAS BEEN VENTING DEEP CONVECTION N OF THE ITCZ. HOWEVER THIS UPPER DIVERGENCE APPEARS TO BE SHIFTING NE AND AWAY FROM THE ITCZ...AND THUS CONVECTION HAS WEAKENED THIS AFTERNOON AND EVENING. ACTIVE CONVECTION ALONG THE ITCZ EARLIER E OF 95W HAS DIMINISHED OVER THE PAST SEVERAL HOURS. AT THE SURFACE...BROAD RIDGING EXTENDS INTO THE AREA FROM THE NE PACIFIC...AND HAS WEAKENED SLIGHTLY DURING THE PAST 24 HOURS AS A COLD FRONT HAS MOVED TO ALONG 32N. DIRECTLY S OF THE RIDGE A ZONE OF 15-20 KT NE TO ENE TRADEWINDS PREVAILS FROM THE ITCZ TO NEAR 20N AND W OF 120W...WHERE SEAS ARE CURRENTLY 8 TO 10 FT IN MIXED NW SWELL AND ENE TRADEWIND SWELL. LARGE PULSES OF NW SWELL CONTINUE TO MOVE THROUGH THE REGIONAL WATERS TODAY AND ARE MAINTAINING SEAS ELSEWHERE TO THE N AND NW AT 8 TO 11 FT...WITH A RECENT NEW PULSE OF NW SWELL CREATING SEAS OF 9 TO 11 FT ACROSS THE NEAR AND OFFSHORE WATERS OF NORTHER BAJA CALIFORNIA... WHICH WILL INCREASE 2-3 FT OVER THE NEXT 24 HOURS BEFORE DIMINISHING. GAP WINDS... GULF OF PAPAGAYO...HIGH PRES WILL BUILD SE AND S ACROSS THE GULF OF MEXICO AND NW CARIBBEAN WITH THE PRES DIFFERENCE BETWEEN IT AND LOWER PRES OVER FAR NW COLOMBIA AND THE SW CARIBBEAN SEA FORECAST TO INDUCE AN INITIAL SURGE OF NE-E 20-25 KT WINDS THROUGH THE GULF BEGINNING WED MORNING. $$ COBB