000 AXPZ20 KNHC 081002 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Feb 8 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 0600 UTC surface analysis and satellite imagery through 0945 UTC. ...SPECIAL FEATURES... Strong broad high pressure will build and move across the Mississippi Valley Thursday night extending south across the Gulf of Mexico and southwest along Mexico. This will create a tight pressure gradient along southern Mexico that will lead to the development of gale force winds starting late Thursday night through Friday night. Please see the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFEP2/FZPN03 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ extends from 04N87W to 01N105W to 01N130W. No significant convection observed. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Moderate to fresh northwest winds are across the central and southern Gulf of California and off the Baja California peninsula between 1024 mb high pressure centered near 28N122W and a trough of low pressure extending along western Mexico and the Gulf of California. Seas are reach 5 ft over the Gulf of California and 5 to 7 ft off Baja California. The pressure gradient will further increase along the Gulf of California today as broad pressure over central United States builds south across northern Mexico. This will result in fresh to strong northwest winds over the central Gulf of California from 1500 UTC this morning through Thursday morning with seas building to 7 ft. The high pressure then shifts east, allowing winds and seas to diminish through Friday night across the region. Northwest swell will propagate into the waters off Baja California Norte early Saturday with seas to 8 ft spreading farther south into the waters off Baja California Sur through Sunday. A strong pressure gradient will develop across California extending south to the northern Gulf of California early Sunday morning, which will result in west to northwest fresh to near gale force winds N of 29N. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Strong gap winds will be the primarily forecast issue through Saturday. The pressure gradient between high pressure centered over the central Atlantic and lower pressures over the southwestern Caribbean Sea and Central America in combination with overnight drainage flow will support pulses of fresh to strong northeast winds through the Gulf of Papagayo tonight continuing into the weekend and Monday. New broad and strong high pressure north of the area Thursday will allow a much stronger pulse and longer lasting of gap winds through the Gulf of Papagayo Thursday night into early Friday, with a plume of seas to 8 ft reaching 420 nm to the west-southwest of the area. This will be joined by another plume of gap winds off Puerto Sandino on the coast of Nicaragua Friday, generating a plume of 8 to 10 ft confused seas well to the west of the area, aided in part by components of longer period northwest and southwest swell. Similarly a plume of fresh to strong north to northeast gap winds will reach from the Gulf of Panama to south of the Azuero peninsula of western Panama by late Friday, with a plume of seas to 9 ft in mixed swell reaching as far as 420 nm to the southwest. The ITCZ is setting up farther south closer to equator currently. Aside from occasional overnight convection off the coast of Colombia, no widespread showers or thunderstorms are noted. REMAINDER OF THE AREA... Strong southwest winds and seas of 8 to 15 ft in northwest swell are ongoing over the far northwest portion of the discussion area ahead of a cold front approaching from the west. 1024 high pressure centered near 28N122W will weaken over the next couple of days as the weakening front moves eastward to the north of 15N. Strong to near gale force wind will spread east, along and behind the front, eventually covering much of the discussion area from 24N to 30N west of the front later this morning. Jet dynamics aloft are supporting scattered showers and a few thunderstorms west of 130W as well. The winds will diminish tonight as the main support aloft for the front lifts out. Lingering northwest swell of 8 to 14 ft will propagate through the area north of 06N and west of 125W through Thursday night. Farther south, altimeter data and observations confirm the continuation of 8 ft seas south of 14N, likely due to a mix of local trade winds and longer period northwest swell. $$ NR