000 AXPZ20 KNHC 131546 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Mar 13 2017 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 1545 UTC. ...SPECIAL FEATURE... GULF OF TEHUANTEPEC GALE WARNING... Strong n winds and 5 to 8 ft seas in and just downstream of the Gulf of Tehuantepec at sunrise this morning will diminish to a fresh breeze this afternoon, then quickly increase to a strong breeze this evening. This northerly drainage flow will then gradually increase tonight to minimal gale force by sunrise Tue with seas building to 11 ft near 15N95W. The gale conditions will likely persist throughout the day on Tue, and further increase to 30 to 40 kt on Tue evening with maximum seas of about 16 ft forecast downstream near 14.5N95.5W on Tue night. The n to ne flow may briefly diminish below gale force on Wed afternoon, but increase again to 30 to 35 kt on Wed evening through Thu morning, and increase again on Thu evening. The southern extent of strong ne flow will reach along 11N between 96W and 99W on Wed. The ne swell will propagate sw mixing with long-period cross-equatorial sw swell resulting in the southern extent of combined seas of 8 ft or greater reaching 09N between 95W and 103W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough meanders along the pacific coast of Colombia and the extreme nw coast of Equador with isolated moderate to convection flaring intermittently over and just offshore the coast of Colombia. A surface trough extends wnw from 04S81W through a 1010 mb surface low at 03S103W to 03.4S109W. Scattered moderate isolated strong convection is observed to the s of 02S and e of 110W. Scatterometer winds indicate that the ITCZ forms near 05N116W and extends wsw to beyond 00N140W with scattered moderate isolated strong convection within 90 nm either side of a line from 04N117W to 04N135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends se from 22N116W to 14N106W. Gentle w to nw flow expected through Wed morning to the w of 95W including across the Gulf of california, except becoming light and variable n of 22N w of 114W on Tue and a narrow swath of moderate nw winds forecast to pulse near 20N106W. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh drainage winds expected tonight with a narrow swath of strong ne winds forecast on Tue and Wed nights, with more significant events on Thu and Fri nights. The resultant ne swell will propagate w and merge with swell near 09N85W originating from the Gulf of Tehuantpec event. Gulf of Panama: Moderate to fresh nocturnal flow expected during the overnight hours this week. Light to gentle winds, and combined seas of 3 to 6 ft, are occurring elsewhere outside of the swells originating near the gap events. REMAINDER OF THE AREA... A nearly stationary surface high is centered near 32N132W and is maintaining broad ridging over the forecast area with fresh ne trades across the tropics from 05N to 13N w of 120W today, with mixed swell resulting in combined seas of 6 to 8 ft. Fresh northerly winds expected from 30N to 32N between 120W and 126W today. Fresh sw winds, and 6 to 9 ft seas, will develop across the waters n of 30N w of 136W tonight and Tue ahead of a cold front reaching a position from 32N137W to 30N141W Tue night. The front will stall from 32N131W to 28N140W on Wed night, and drift back n of 32N on Thu as the ridge restrengthens. This pattern repeats again beginning Thu night with strong southerly flow developing n of 28N w of 135W in advance of a strong cold front reaching 30N140W on Fri afternoon. $$ Nelson