000 AXPZ20 KNHC 191442 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Wed Oct 19 2022 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 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 1430 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A strong cold front is moving across the Gulf of Mexico. Strong high pressure building across the slopes of eastern Mexico in the wake of the front is creating a tight pressure gradient across the Tehuantepec region. Strong to near gale force winds have started to funnel through the Chivela pass into the Gulf of Tehuantepec. These winds will rapidly increase to gale force this afternoon. The area of high pressure will shift eastward and weaken the second half of the week, loosening the pressure gradient. Winds will diminish below gale force late Thu night, then further diminish, to 20 kt or less, this weekend. Seas will peak near 14 ft during period of gale force winds. Please refer to the latest NWS High Seas Forecast at https://www.hurricanes.gov/marine for more details. Offshore of Southern Mexico: Shower and thunderstorm activity associated with a trough of low pressure located a couple hundred miles south of the southern coast of Mexico is becoming better organized. Environmental conditions appear conducive for additional development and a tropical depression is expected to form in the next day or two as the system moves generally west- northwestward, parallel to the southwestern coast of Mexico. Current winds are 20-25 kt with seas of 8-10 ft. Interests along the southwestern coast of Mexico should monitor the progress of this system. This system has a high chance of tropical cyclone formation through 48 hours. Regardless of development, increasing winds and building seas will be possible offshore southwestern Mexico, and a gale warning has been issued beginning Thu afternoon, with storm conditions possible as the system possibly rounds near Cabo Corrientes this weekend. Please refer to the latest NHC Tropical Weather Outlook at https://www.hurricanes.gov and the latest NWS High Seas Forecast at https://www.hurricanes.gov/marine for more details. ...TROPICAL WAVES... The axis of a tropical wave is near 82W/83W north of 04N, moving west at around 5 to 10 kt. Nearby convection is discussed below. The axis of a tropical wave is near 100W/101W north of 07N, and is described in the Special Features section above. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 16N100W to 09N130W to 11N140W. Scattered moderate isolated strong convection is noted north of 03N east of 80W, from 12N to 17N between 95W and 102W, from 10N to 15N between 105W and 114W, and from 07N to 10N between 129W and 138W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section above for details on a gale force gap wind event in the Gulf of Tehuantepec as well as possible tropical cyclone development offshore southwestern Mexico later this week where there is an associated gale warning. Aside from the Gulf of Tehuantepec and the developing area of low pressure, light to gentle winds prevail over the discussion waters. Seas are 4-5 ft in S-SW well west of 101W across the open waters, mixed with NW swell west of Baja California. Seas are 1-3 ft in the Gulf of California, and 3-4 ft from the entrance of the Gulf to Cabo Corrientes. For the forecast, other than the Gulf of Tehuantepec gale force gap wind event and possibly developing tropical cyclone off southwestern Mexico and associated gale warning, gentle to moderate winds and moderate seas will prevail through next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate S-SW winds prevail across the offshore waters south of 10N, and light to gentle westerly north of 10N. Seas are in the 4-6 ft range in S-SW swell, except to 7 ft well offshore Guatemala. For the forecast, moderate to occasionally fresh S-SW winds will prevail south of the monsoon trough. Light to gentle winds will prevail north of the monsoon trough, pulsing to moderate offshore southern Nicaragua and in the Gulf of Papagayo. Moderate seas in S-SW swell will dominate the waters, building offshore Guatemala by early Thu due to a Gulf of Tehuantepec gap wind event. REMAINDER OF THE AREA... A 1015 mb low pressure is centered near 29N130W with associated trough extending SW to near 22N136W. This area of low pressure has disrupted the high pressure that has prevailed over the northern waters, weakening the pressure gradient across the area. Gentle to moderate winds are found north of the monsoon trough to near 15N and west of 135W, with light to gentle winds prevailing elsewhere north of the monsoon trough. Moderate to locally fresh winds are south of the monsoon tough and east of 115W, with gentle to moderate winds west of 115W. Seas of 8 ft continue over the NW waters in a subsiding NW swell. Seas to 8 ft are also north of the monsoon trough in the region of strongest winds. Seas of 6-8 ft are noted south of the monsoon trough and east of 115W. Elsewhere, seas of 5-7 ft prevail. For the forecast, the low/trough will drift east across the north- central waters, eventually dissipating over the next day or so. Fresh sets of NW swell will propagate across the NW and north- central waters over the next several days, occasionally building seas to around 8-9 ft with each passing set. A set of SW swell with seas of at least 8 ft will breach 03.4S and the Equator by this evening, reaching to 10N by the end of the week. $$ AL