000 AXPZ20 KNHC 172148 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Nov 17 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 1800 UTC surface analysis and satellite imagery through 2145 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec gale warning: a narrow swath of strong n to ne winds will continue to pulse through late Fri morning, then diminish briefly to a fresh breeze on Fri afternoon. Afternoon Peak heating will help produce another 20 to 25 kt surge around sunset Fri, with the winds quickly increasing throughout Fri night in building high pressure behind a strong Gulf of Mexico cold front, with the flow reaching minimal gale force again late Fri night. Strong gale conditions of 40 to 45 kt are expected across a large swath late Sat night, with minimal storm force conditions winds a possibility although current guidance indicates a 45 kt maximum. High profile vessels should expect storm force winds at 30 meters. Gale conditions will end late Mon night. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends wsw off the Pacific coast of northern Costa Rica at 10N85W TO 09N110W where scatterometer winds indicate an ITCZ forms and continues w to 07N125W, then turns nw to beyond 09N140W. Scattered moderate isolated strong convection is observed well s of the monsoon trough across the waters n of 06N e of 83W. Similar convection is noted within 60 nm of 10N104W and within 120 nm either side of a line from 14N101W to 07N115W and within 60 nm either side of a line from 14N115W to 11N120W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features section for a gale warning in the Gulf of Tehuantepec. The remnant circulation of former tropical cyclone Tina is still winding down near 19N113W and is estimated at 1011 mb. Moderate to fresh nw to n winds with combined seas of 7 to 13 ft are observed n of 22N w of the northern Baja Peninsula and southern California. These winds will diminish to a moderate n breeze on Fri, and light ne winds on Sat with the seas subsiding to 4 to 6 ft forecast w of Baja by late Sat. 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 late Sun, extend s across all the offshore waters w of Baja on Mon night, then subside to less than 8 ft on Tue. Moderate to locally fresh nw winds will spread s across the entire Gulf of California tonight and continue through Fri before diminishing some on Sat. Expect light and variable winds on Sun. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: moderate to locally fresh ne winds are expected across and just downstream of the Gulf of Papagayo late each night through sunrise each morning for the next several days. The cyclonic circulation associated with a broad area of low pressure developing in the sw Caribbean is expected to produce a strong nocturnal n to ne flow across the Gulf of Papagayo late Sun night. Light to gentle 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 along about 09N, while moderate to locally fresh sw flow is observed s of the monsoon trough, with combined seas of 4 to 7 ft primarily in long-period sw swell. Little change forecast through the upcoming weekend. The conditions early next week are dependent on the strength and position of the the broad low pressure in the SW Caribbean that has the potential to become a tropical cyclone. REMAINDER OF THE AREA... A surface high is centered n of the area near 35N128W. Large nw swell resulting in combined seas of 7-11 ft are observed w of 115W and n of the monsoon trough and ITCZ. These seas will gradually subside to less than 8 ft on Sat. A cold front will move into the far nw waters tonight accompanied by a fresh to strong sw to w to nw wind shift to the n of 31N, and a 15 to 20 kt wind shift along the front elsewhere n of 28N. The front is forecast to reach a position from 32N130W to 21N140W on Fri night with the associated wind shift diminishing to 15 to 20 kt. The front should reach a position from 32N122W to 23N123W on Sun night, and weaken as it moves across the northern Baja Peninsula on Mon night. Another round of large nw swell will follow the front with seas of 8 of 16 ft initially, but subsiding to 7 to 10 ft by the time they reach the northern Baja Peninsula on Sun. $$ Nelson