000 AXPZ20 KNHC 280916 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Jun 28 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 0600 UTC surface analysis and satellite imagery through 0830 UTC. ...SPECIAL FEATURES... Tropical Storm Alvin centered near 18.0N 116.3W at 28/0900 UTC moving NW at 13 kt. Estimated minimum central pressure is 994 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. Scattered strong convection is within 60 nm of the center. Alvin is expected to move NW and weaken through Saturday. See the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. Gulf of Tehuantepec Gale Warning: High pressure over Mexico combined with a tropical wave passing south of Tehuantepec is causing a Gulf of Tehuantepec gap wind event. Minimal N to NE gale conditions are expected to continue through Sat night then slowly diminish Sun and Mon. Peak seas are expected to reach around 13 ft today. 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 details. ...TROPICAL WAVES... A tropical wave is analyzed north of 05N near 88W, moving W around 15 kt. Significant convection is located well to the east of the wave axis, south of Panama. A tropical wave is analyzed north of 03N near 96W-97W, moving W around 15 kt. Scattered moderate to strong convection is from 05N to 10N between 92W and 102W, and from 04N to 13N between 102W and 109W. Model guidance suggests this wave will become better organized this weekend, and has the potential to develop into a tropical cyclone west of 100W after 48 hours. A tropical wave is analyzed from 04N to 14N near 135W, moving W around 15 kt. Scattered moderate and isolated strong convection is from 06N to 10N from 126W to 137W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends across the basin from 09N78W to 09N130W. The ITCZ is west of 140W. Scattered moderate to strong convection is occurring from 05N to 08N east of 85W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more details about the Gulf of Tehuantepec Gale Warning. Quiescent conditions are expected for the next several days over the Gulf of California. Tropical Storm Alvin is expected to not significantly impact the Mexican offshore zones, with moderate to fresh NW to N winds west of Cabo Corrientes and Baja California through at least Mon night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A tight north to south pressure gradient across Central America is causing a significant Gulf of Papagayo gap wind event. Fresh to strong NE winds are expected to extend from the coast of Central America to 9%W through Sat, then diminish by Sat night as the pressure gradient relaxes. The extended length of this plume of offshore winds extending from the Papagayo area will generate a broad zone of seas 7-10 ft through Sat that will combine with N swell from Tehuantepec to produce a large area of high seas between 90W and 100W through Sun. Moderate offshore winds will prevail north of the monsoon trough, with moderate S- SW winds south of the trough axis the next few days. New S to SW long-period swell will reach the equator beginning on Sun and produce rough waves. REMAINDER OF THE AREA... Please see the Special Features section for more details about Tropical Storm Alvin. A broad weak ridge extends from high pressure NNW of the area. Gentle to moderate trades prevail south of the ridge. Seas are mainly 5-8 ft in mixed northerly and southerly swell. Overall high pressure will continue for several more days. Trades will strengthen slightly in the W central waters this weekend into early next week, with seas building to 8-10 ft, and SE swell along the equator will gradually decay. $$ Mundell