Tropical Weather Discussion
StatusIssued Active alert
Start TimeSun 01/19/2020 10:10 PM EST
End TimeSun 02/02/2020 10:10 PM EST
Full Alert Message
Tropical Weather Discussion NWS National Hurricane Center Miami FL 310 UTC Mon Jan 20 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A stronger and much border gale force gap wind event is expected across the Tehuantepec region later tonight through Tue night. This will be associated with a cold front moving quickly SE across the Gulf of Mexico. High pressure building across the eastern slopes of the Sierra Madre Mountains in Mexico, behind the cold front, will provide a very tight pressure gradient over the area, an bring an increase in winds funneling into the Gulf of Tehuantepec. Winds are forecast to rapidly increase to 40 kt tonight, and to 45 kt Mon night. Seas will peak 18 or 19 ft Mon night during the period of the strongest winds. Swell generated from this event will produce a plume of 8 ft or greater seas that will extend beyond 10N110W. Marine interest transiting across or in the vicinity of the of the Gulf of Tehuantepec tonight through Tue night should be aware of this upcoming wind event, and take necessary action to avoid hazardous marine conditions over the affected waters. Gale center near 25N132W: An earlier scatterometer satellite pass indicated a large area of gale force winds within 120 nm in the northwest quadrant of a 1010 mb low pressure area centered at that time near 26N135W. The low will weaken gradually as it continues to the east-northeast at 15 kt, and the winds may diminish slightly to near gale force overnight. Seas in the area of gale force winds are estimated to be near 14 ft. The low pressure will reach 28N130W Mon, before dissipating through Tue near Guadalupe Island. Please see 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 on this Gale Warning. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from near 09N84W to 07N97W. The ITCZ continues from 07N97W to 08N140W. Scattered moderate convection is noted from 04N to 06N between 80W and 88W. Scattered moderate to isolated strong convection is noted from 05N to 10N between 110W and 117W. Scattered moderate convection is noted from 07N to 09N between 130W and 138W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see above for more information on the upcoming gale force gap wind event in the Gulf of Tehuantepec, forecast to be near storm force. A surface ridge extends from 29N120W to near the Revillagigedo Islands. The pressure gradient between the ridge and a surface trough along western Mexico will continue to support moderate to locally fresh NW to N winds off the coast of Baja California with seas in the 5 to 7 ft range. These marine conditions will likely persist through early Tue. By late Tue, a new set of long period NW swell will reach the waters N of Punta Eugenia, building seas to 10 or 11 ft. This swell event, with seas of 8 ft or greater will propagate across the entire offshore waters W of Baja California by late Wed, reaching the Revillagigedo Islands by Wed night. High pressure over the Great Basin region is producing fresh to locally strong NW across the Gulf of California, mainly from 25N to 29N, with seas less than 8 ft. These winds will diminish to 20 kt or less by early evening. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Strong trade winds across the southwest Caribbean will continue to support strong to near gale force NE to E winds across and downstream of the Papagayo region through Tue. Winds will be greatest during the overnight and early morning hours with the assistance of the nocturnal drainage flow. Seas will build to 10 ft during the period of peak winds. Fresh to strong NE to E winds will prevail across the region most of the forecast period. Meanwhile diffluent flow aloft is supporting a few showers and thunderstorms are active near the trough along 05N/06N, mainly in the vicinity of Coco Island well off the coast of Costa Rica. The strong trades across the southwest Caribbean are also supporting fresh northerly winds in the Gulf of Panama mainly at night through Mon night with downstream seas building to 6-7 ft. REMAINDER OF THE AREA... The mid/upper disturbance supporting the gale center near 25N132W is also reaching into the deep tropics and supporting clusters of showers and thunderstorms along the ITCZ west of 130W. Another, broader mid to upper trough continues to move eastward between 105W and 110W, supporting the area of showers and thunderstorms along the ITCZ between 115W and 120W. The presence of the gale center over the subtropical region has disrupted to the typical subtropical ridge over the area, resulting in only moderate trade winds over the deep tropics. This is well evident in latest scatterometer data and buoy observations. Recent altimeter satellite data shows seas of 8 to 9 ft in the area of moderate trades currently. A new set of long period NW swell will follow the gale center. Seas are expected to build to 12 to 15 ft W of a line from 30N132W by Mon afternoon. High pressure in the wake of the low center will bring an increase in the trade winds by Tue morning, particularly from 10N to 14N W of 130W. In this area, expect fresh to strong NE trade winds and seas building to 12 or 13 ft.