000 AXPZ20 KNHC 080249 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 249 UTC Fri Mar 8 2019 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 FEATURE... Gulf of Papagayo Gale Warning: Earlier observations from Liberia, Costa Rica showed sustained winds to 30 kt with gusts to 50 kt. This was consistent with model initializations showing winds to near gale force over the Gulf of Papagayo. A gale warning has been issued to account for ongoing trends and the added impact of drainage flow overnight. 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 surface trough extends from Costa Rica at 10N86W to 06N90W. The intertropical convergence zone axis begins there and extends to 04N95W to 02N120W beyond 02N140W. Scattered moderate showers and thunderstorms are within 120 nm north of the ITCZ between 122W and 128W, and within 120 nm north of the ITCZ west of 133W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A nearly stationary frontal boundary west of the Baja California is drifting eastward into Baja California Norte and the northern Gulf of California. Deep layer moisture is evident across the central portions of Baja California into the Sonora Desert, and a few embedded showers are possible through the overnight hours. Moderate winds and 3 to 5 ft seas were noted in earlier scatterometer and altimeter satellite data off the coast of Baja California. Farther south, the pressure gradient over southern Mexico is relaxing with weak troughing over the Western Gulf of Mexico. Strong gap winds will linger through the Gulf of Tehuantepec tonight into Fri morning in the aftermath of a prolonged gale event. Earlier altimeter data indicated seas still to 9 ft well downstream of Tehuantepec, but seas will be subsiding as winds diminish. For the forecast, SW gap winds will increase tonight over the northern Gulf of California ahead of the weakening front drifting through the region. The front will dissipate through early Fri, allowing the winds to diminish. High pressure building in the wake of the front west of the region will support fresh to strong NW winds off the coast of Baja California Sur Fri into Sat. Looking ahead, another cold front will move into the region Sun night. Long period NW swell will follow the front into the waters off Baja California, reaching as far south as the Revillagigedo Islands early next week. Strong SW gap winds will develop ahead of the front over the northern Gulf of California into Mon. Reinforcing swell up to 12 ft will move into the waters off northern Baja California Norte by Tue. Hazardous surf conditions are possible early next week along the coast of Baja California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Please read the Special Features section for more details about the gale warning. A strong north-south pressure gradient across Central America is helping to funnel strong to near gale NE winds off the coast of Nicaragua. Earlier scatterometer and concurrent altimeter data showed near gale force winds with seas to 10 ft as far as 240 nm downstream of the Gulf of Papagayo. In addition to the gale force winds over the Gulf of Papagayo, strong to near gale force gap winds will continue to pulse mainly at night into the early morning through early next week. Fresh to strong gap winds will also pulse through the Gulf of Panama through Sat night, then diminish into early next week. Related plumes of short period NE to E swell will continue to pulse well downstream of the coast of Costa Rica and Nicaragua into early next week, mixing with longer period SW swell. REMAINDER OF THE AREA... A nearly stationary frontal boundary extends from northern Baja California Norte to 23N126W. The front will dissipate through Fri morning as the upper support lifts out. Gentle to moderate winds follow the front north of 20N, with decaying NW swell of 5 to 7 ft. Another weak cold front moving into the waters north of 25N west of 130W will dissipate through Fri. Farther south, modest trade winds persist in the deep tropics, but are enough of a component along with NW swell to support combined seas to 9 ft west of 135W. Trade wind convergence is also supporting clusters of showers and thunderstorms along the ITCZ west of 120W. Farther east, fresh winds and short period easterly swell originating from persistent gap winds off Central America are reaching as far west as 110W. For the forecast, weak ridging will build in the wake of the fronts, allowing trade winds to increase farther south west of 130W. Another front will enter the waters north of 20N by Sat, the move E of the area into Baja California by late Sun. Large long period swell will follow the front, bringing seas of 8 to 12 ft over the entire area west of 110W through Tue. High pressure building in the wake of the front will allow fresh to strong trade winds south of 20N west of 120W early next week. $$ Christensen