000 AXPZ20 KNHC 031502 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1502 UTC Wed May 3 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 1500 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning...A strong cold front is forecast to move through the Gulf of Mexico late tonight through the end of the week. High pressure is forecast to surge down eastern Mexico in the wake of the front and winds in the Gulf of Tehuantepec will quickly increase to fresh to strong out of the north late tonight, then reaching minimal gale force around sunrise. Gale force winds will then persist until around sunrise Saturday before diminishing to fresh to strong through Saturday evening. Seas will build to at least 14 ft after the commencement of gale force winds. Seas will gradually subside to less than 8 ft by Sunday afternoon. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough axis extends from 08N78W to 09N90W to 07N98W to 08N110W. The intertropical convergence zone axis extends from 08N110W to 07N123W to 03N140W. Scattered moderate and isolated strong convection is from 02N to 06N between 89W and 95W, within 300 nm southwest of a line from 06N98W to 08N102W to 10N108W to 10N111W to 08N116W, and also within 180 nm southwest of a line from 07N124W to 08N136W. In addition, scattered moderate convection is from 08N to 14N west of 136W under an area of upper level diffluence. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the special features section for information on the Gulf of Tehuantepec Gale warning. Mainly light to moderate winds will prevail through Friday. A cold front will approach the southwest United States and northwest Mexico by the end of the week. The front will move across northwest Mexico Friday night through Sunday. Winds will increase in the northern Gulf of California to fresh to near gale ahead of the front. Fresh to strong winds will arrive behind the front offshore of Baja California Norte and in the northern Gulf of California. Current combined seas of 5-7 ft in the open waters of the Pacific will build in northwest swell behind the front, with combined seas reaching 8-12 ft north of 22N through early next week. Seas of 2 ft or less in the Gulf of California, except 3-4 ft near the entrance, will build to 5-8 ft in the northern Gulf this weekend with the increasing winds. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle onshore winds during the day and gentle to moderate offshore winds during the night will prevail through the next several days. Offshore winds in the Gulf of Papagayo will increase to moderate to fresh late Saturday night into early Sunday. Seas will be mainly 4-6 ft. Looking ahead, global model guidance indicates the chance of developing low pressure south-southwest of Central America late in the weekend into early next week. REMAINDER OF THE AREA... High pressure of 1023 mb centered north of the area near 37N131W extends a ridge southwest to the northeast of the Hawaiian Islands near 25N150W. Another ridge axis extends from near 19N136W southeast to near 16N106W. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ is supporting gentle to moderate trades with seas in the 5-7 ft range north of the ITCZ. A cold front will approach the northwest waters Thursday which will freshen winds across this area Thursday night through the upcoming weekend with stronger high pressure building across the area in the wake of the front. The front will also usher in a fresh set of northwesterly swell with seas greater than 8 ft moving into the northwest waters late Thursday afternoon and evening, covering much of the area north of 20N west of 120W Saturday through Sunday. $$ LEWITSKY