000 AXPZ20 KNHC 092215 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sun Apr 09 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 1800 UTC surface analysis and satellite imagery through 2145 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 08N85W TO 03N106W where scatterometer winds indicate that the ITCZ forms, and continues w to 03N106W to 05N120W to 01N130W. Scattered moderate isolated strong convection is observed within 180 nm either side of a line from 08N83W to 05N97W. A surface trough is analyzed n of the ITCZ from 05N117W to 13N114W. Scattered moderate isolated strong convection is observed to the s of 09N within 270 nm either side of the trough. A surface trough extend w from 02S94W through a 1010 mb embedded surface low pres at 02S102W to 03S112W. Scattered moderate isolated strong convection is observed within 60 nm either side of a line from 02S107W to 03S112W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A post-frontal ridge extends across the offshore waters to the w of 108W. Fresh to locally strong anticyclonic winds are observed along the Pacific coast of Baja, with long period nw swell contributing to combined seas of 7 to 10 ft. The pressure gradient will begin to relax tonight, with moderate to locally fresh nw flow, and 5 to 8 ft seas, expected through Tue night when the gradient will begin to tighten again. Fresh to locally strong nw flow forecast to the n of 27N e of 117W on Wed. Gulf of California: Moderate to locally fresh nw flow across the northern gulf waters this evening should diminish late tonight, with a moderate nw breeze forecast throughout the gulf waters on Mon, and a light to gentle nw to n breeze forecast on Tue and Wed. Gulf of Tehuantepec...Light and variable flow expected through early Tue night, with a strong northerly surge forecast to begin late Tue night, and continue through sunrise Thu, with near gale force conditions possible on Wed night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to locally strong nocturnal drainage winds expected this week. Gulf of Panama: Moderate to fresh nocturnal northerly 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... Northwesterly swell resulting in combined seas of 7 to 10 ft across the area n of 05N w of 115W are expected to subside early this week. A surface high near 31N130W will shift slowly southward this week allowing a cold front to reach a position from 32N138W to 29N140W on Mon night accompanied by a strong sw- w-nw wind shift through Tue morning across the discussion waters from 29.5N to 32N. Large nw swell, in the form of 7 to 10 ft seas, will propagate into the far nw portion tonight ahead of the cold front, with seas building 8 to 12 ft w of the front with the highest seas along 32N. The front will weaken from 32N127W to 26N140W on Wed with seas of 8 to 10 ft shifting to n of 31N. Another batch of large nw swell will arrive at 30N140W late Wed behind a re-enforcing cold front. $$ Nelson