000 AXPZ20 KNHC 100909 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 909 UTC Tue Mar 10 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: Gap winds to gale force continue this morning through the Gulf of Tehuantepec due to a combination of local drainage flow and a fairly tight pressure gradient between high pressure north of the area and lower pressure over the eastern Pacific. The areal extent of the gales has been decreasing as the pressure gradient relaxes, but sustained gales are still possible through tonight. Seas will reach up to 12 ft. Conditions improve substantially Wed as high pressure north of the area shifts east and warming temperature weaken drainage impacts. For more information 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 08N85W to 03N100W. The intertropical convergence zone continues from 03N100W to 09N127W, and again from 08N135W to beyond 07N140W. No significant convection is observed. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details on a gap wind event in the Tehuantepec region. A recent scatterometer satellite pass showed fresh to strong southerly winds in the offshore waters of Baja California Norte. These winds are active between a 1004 mb low near 32N128W and 1020 mb high pressure over Baja California Sur. The winds are also active ahead of a cold front approaching the region. Seas are likely 6 to 8 ft off Baja California Norte and 4 to 6 ft elsewhere. A few showers are probably occurring off Baja California Sur due to lift and deep layer moisture associated with an active subtropical jet moving across the area. For the short term, the upper dynamics supporting the low and front will lift to the northeast. As a result the winds and seas will diminish off Baja California Norte as the low and front weaken while they shift eastward. Northerly winds may increase through mid week over the southern Gulf of California toward Cabo Corrientes as the dissipating front moves into the region. This will diminish through late in the week, just as SW gap winds appear over the northern Gulf of California ahead of another front expected to move into Baja California Norte Fri into Sat. 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 around 10 ft downstream of the Gulf each morning during the next few days. As the high pressure slides eastward and weakens over the western Atlantic, these winds should subside late in the week. 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 tonight, with moderate to fresh pulses thereafter. 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 swell 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 only slowly subside during the next couple of days. REMAINDER OF THE AREA... Strong northerly winds and 8 to 12 ft NW swell follow a cold front form 30N121W to 18N135W. Scattered moderate to strong thunderstorms are active ahead of the front near 19N121W. The winds will diminish through mid weak as the front and its associated low pressure north of the area shift east and weaken. This will leave residual swell of 8 to 9 ft into Thu, before it subsides as well. Looking ahead, high pressure building north of the area in the wake of the front will support fresh trade winds and seas to 8 to 9 ft over the deep tropics from 08N to 15N west of 130W Fri into Sat. Farther east, a large area of 8 to 10 ft seas persists from roughly 04N to 11N between 93W and 115W in a mix of southerly swell and shorter period NE to E swell originating from gap wind events in the Gulfs of Tehuantepec and Papagayo. This will diminish below 8 ft for the most part through mid week. $$ Christensen