000 AXPZ20 KNHC 090344 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 344 UTC Fri Feb 9 2018 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 0300 UTC. ...SPECIAL FEATURE... Gulf of Tehuantepec Gale Warning: A tight pressure gradient is setup across the Isthmus of Tehuantepec with strong high pressure in position to the N over the Sierra Madre Oriental range. The gale force winds which have been blowing offshore of the Gulf of Tehuantepec will diminish shortly after sunrise Fri as the high to the N weakens. Seas will peak to 14 ft overnight tonight. Winds will diminish below fresh to strong levels by Sat evening with light and variable winds thereafter through Mon. Please refer to the East Pacific High Seas Forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. Looking ahead, another gale force gap wind event may be possible early next week. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 10N84W to 06N89W. The ITCZ axis extends from 06N89W to 04N100W to 06N120W to 09N140W. No significant convection is noted. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak high pressure ridge prevails across the area anchored by a surface high located N of the area. The pressure gradient along and offshore of the Baja California peninsula is producing gentle to moderate NW winds, with seas generally 4-6 ft. A fairly quiet pattern should persist through early next week. The only exception will be NW swell of 7-8 ft that will reach the offshore waters off Baja California Norte Sun through Mon. Gulf of California: Gentle to moderate winds and 2-4 ft seas are expected through early Fri. A low pressure trough will develop over the Baja Peninsula on Fri and Sat, and S to SW winds E of the trough and N of 29N will strengthen to fresh to strong by Sat evening in advance of an approaching cold front. Winds will shift to NW behind the front Sun and will then decrease to below 20 kt Sun evening. Elsewhere, a pair of weakening upper level lows over the Baja California peninsula with an upper trough extending SE are supporting scattered showers and isolated thunderstorms over the offshore waters from Cabo Corrientes to La Paz. This activity will likely continue over the next 12-24 hours. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Nocturnal winds will pulse to fresh to strong each night through early next week. Areal coverage of gap winds near the Gulf of Papagayo will increase tonight and Fri morning and allow the wind-generated seas to propagate further downwind from its source region, merging with the seas downwind from the Gulf of Tehuantepec Fri and Sat. After a brief decrease in coverage of fresh to strong winds Sun, the winds will increase in coverage over the Gulf of Papagayo once again for Mon and Tue. Elsewhere, gentle to moderate offshore flow will prevail N of 09N, and light to gentle S to SW winds will generally prevail S of 09N through Fri night. REMAINDER OF THE AREA... The pressure gradient between high pressure N of 30N and lower pressure associated with the convergence zone will support moderate trade winds during the next several days. The one exception will be fresh to locally strong southerly winds expected to develop N of 16N and W of 136W through Sat, associated with an area of low pressure developing W of 140W. Seas will be 7-9 ft in the western waters through the weekend associated with this low. On Sun, a batch of NW swell of 8-9 ft accompanied by a weakening cold front will cross SE of 30N, and will reach as far S as 27N and as far W as 130W by Mon morning. $$ Lewitsky