000 AXPZ20 KNHC 200331 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sun Nov 20 2016 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 0330 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec gale warning: Strong gale force winds of 30 to 40 kt early tonight will increase to 30 to 45 kt late tonight with seas building to about 23 ft downstream of the Gulf of Tehuantepec near 14N96W by sunrise Sun. Minimal storm force conditions winds are still a possibility, although the array of model guidance still indicates a 45 kt maximum near the surface. High profile vessels should expect storm force winds at 30 meters tonight. Gale conditions will end on Mon morning with near gale force continuing through sunrise on Tue before diminishing. The next gale event will occur late Wed night. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends w off the Pacific coast of northern Panama at 08N83W and wiggles westward to 09N114W where scatterometer winds indicate an ITCZ forms, and continues w through an embedded 1010 mb surface low at 09N124W. The ITCZ extends sw from the low to 08N130W, then turns nw to beyond 10N140W. Scattered moderate isolated strong convection is observed within 120 nm either side of a line from 09N84W to 08N98W, within 60 nm of 07N113W, within 60 nm either side of a line from 10N122W to 08N127W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features section for a strong gale warning in the Gulf of Tehuantepec. Light to gentle n winds with combined seas of 6 to 9 ft are observed w of the Baja Peninsula. Large nw swell in the form of 7 to 9 ft seas will reach 30N120W on Sun morning, reach the n coast of the Baja Peninsula on Sun evening, then spread se across all the offshore waters w of the Baja Peninsula on Mon night, then subside from the n to less than 8 ft on Wed morning. Light to moderate n winds will continue across the entire Gulf of California through this evening, gradually clock to the s across the northern gulf waters on Sun morning, then gradually increase to a fresh to strong s to sw flow just ahead of a cold front on Sun evening with seas building to 6 ft in the areas of longest fetch. The strong winds will clock to the nw behind the front on Mon morning, but quickly diminish to moderate to a locally fresh breeze with these conditions spreading se across the entire Gulf of California on Tue and Wed, before diminishing on Wed night into Thu. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: fresh to locally strong n to ne winds will develop across and just w of the Gulf of Papagayo tonight in association with a tropical low pressure in the SW Caribbean. A swath of strong nne winds are expected again on Sun and Mon nights. A narrow and brief pulse of strong nne winds will also surge through the Gulf of Fonseca on Sun night. Gentle to locally moderate n winds and combined seas of 3 to 6 ft are occurring elsewhere n of the monsoon trough which continues to meander e to w between 08N and 10N, while moderate to fresh sw flow is observed s of the monsoon trough with combined seas of 4 to 7 ft in long-period sw swell. Little change forecast through early next week. Mariners planning to transit through the Panama Canal are urged to monitor the broad area of low pressure in the Sw Caribbean that has the potential to become a tropical cyclone. REMAINDER OF THE AREA... A cold front along 32N124W to 23N140W will reach from 32N120W to 23N140W on Sun, and weaken as it crosses the northern Baja Peninsula on Sun night into Mon. Large nw swell will follow the front with seas of 8 of 16 ft initially with the highest seas between 30N and 32N, but subsiding to 7 to 11 ft by the time they reach the northern Baja Peninsula on Sun night. The post frontal high pressure will result in strong ne trades across the tropics n of the ITCZ and w of 125W through the middle of next week. $$ Nelson