000 AXPZ20 KNHC 090657 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 800 UTC Mon Mar 9 2020 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 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Strong high pressure over the western Atlantic off the Carolinas, along with localized drainage flow are supporting persistent winds to gale force into the Gulf of Tehuantepec. Recent observations from Salina Cruz along the southern coast of the isthmus show winds to 30 kt. This is an indication gales continue in the offshore waters. Seas are estimated to be near 14 ft within 240 nm downstream. The pressure gradient will relax slightly through today as the high pressure shifts farther east, allowing wind to diminish just below gale force by late afternoon. The local drainage effects will again allow the winds to increase tonight to minimal gale force, and again on Tue night, with seas remaining 10 to 12 ft. Conditions improve enough by mid week as the pressure gradient relaxes further, with light to moderate winds and slight seas through late in the week. Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from 09N85W to 02N95W. The intertropical convergence zone continues from 02N95W to 08N128W, and again from 09N132W to beyond 07N140W. Scattered moderate convection is noted from 03N to 05N between 90W and 95W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details on an ongoing gale gap wind event in the Tehuantepec region. A weak 1019 mb high pressure center analyzed near over Guadalupe Island near 29N118W is maintaining generally light to moderate winds off Baja California and the Gulf of California, with a similar pattern noted farther south over Mexican offshore waters outside of the Gulf of Tehuantepec. Seas are 4 to 6 ft. A persistent subtropical jet continues to pump mid and high level moisture across central Baja California and the Gulf of California, possibly supporting a few embedded showers. The high pressure will weaken and shift east today ahead of cold front approaching the area from the west. Southerly winds will increase off Baja California Norte today, with seas building to 8 ft accordingly, between the high pressure and the front. The winds and seas will diminish into mid week as the front and an associated low pressure approach the region. However, NW winds will funnel over the southern Gulf of California into the waters between Los Cabos and Cabo Corrientes late Tue through Wed ahead of the front. Looking ahead, the surface low will drift across Baja California Norte and the northern Gulf of California through late week, with the weakening cold front following over the remainder of the region. Pulses of fresh westerly gap winds are possible over the northern Gulf of California late Thu into Fri as the low moves eastward. Meanwhile, farther south, long period southerly swell will dominate the Mexican offshore waters south of 20N through late week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: A tight pressure gradient between high pressure north of the area and lower pressure to the south continues to support northeast 20-30 kt winds across the Papagayo region. This flow tends to be the strongest during the early morning hours enhanced by drainage flow across the area. These winds will continue across the region through the middle of the week, with winds pulsing to near gale force each night and into the early morning hours. Wave heights will peak to near 10 ft downstream of the Gulf each morning during the next few days. Gulf of Panama: High pressure north of the area will maintain fresh to strong north to northeast winds over and downstream of the Gulf of Panama for the next few days. Wave heights with these winds are expected to reach up to 10 ft well downstream of the Gulf, mixing with a component of longer period southerly swell. Elsewhere, mixed northeast and southwest well is resulting in a large area of high seas, up to 11 ft, across much of the waters off the coast of Central America. These wave heights are expected to change little during the next couple of days as long period southerly swell moves into the area. REMAINDER OF THE AREA... A front is analyzed from 1006 mb low pressure near 32N133W through 30N127W to 22N140W. Recent ship observations indicate strong NW winds following the front. Concurrent altimeter satellite passes show the seas of 9 to 15 ft behind the front, likely with a component of NW swell. A few showers and thunderstorms are active near the front, north of 29N. Fresh to strong SE winds and seas to 9 ft are likely between high pressure off Baja California Norte and a trough in the deep tropics from 08N to 15N along 130W. These winds and seas will diminish today as the high weakens and shifts east. Elsewhere, the low to the north is weakening the usual subtropical ridge over the region, resulting in light to moderate trades across the deep tropics. The surface low and the front will weaken as they continue eastward through mid week, reaching 120W by late Wed. This will allow winds to diminish over waters north of 25N. NW swell in excess of 8 ft will cover most of the area north of 10N and west of 120W by week, before subsiding. By late week, high pressure will build north of the area in the wake of the front and low pressure, supporting fresh trade winds and seas to 8 ft in mixed swell over the deep tropics west of 120W. Farther east, seas from 8 to 11 ft cover a large area generally south of 12N between 90W and 115W. This is in an area of confused seas related to a mix of longer period southerly swell and components of shorter period NE and E swell related to the persist gap wind events in Tehuantepec and Papagayo. These seas will gradually subside through mid week as the gap winds diminish. $$ Christensen