837 AXPZ20 KNHC 270842 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Jun 27 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 15.1N 111.9W at 27/0900 UTC moving WNW at 11 kt. Estimated minimum central pressure is 999 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Scattered moderate to strong convection is within 75 nm of the center. Some additional strengthening is possible during the next 24 hours. a weakening trend is expected to begin early Fri, with Alvin expected to become a remnant low by Sat night. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. Gulf of Tehuantepec Gale Warning: Fresh to strong gap winds are expected to develop offshore in the Gulf of Tehuantepec today, due to a locally tight pressure gradient combined with nocturnal offshore flow. Winds will increase to gale force this evening, and remain 30 to 35 kt through early Sat. Peak seas will build to 12-13 ft downstream of the Gulf by Fri morning. 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 along 82W, moving W around 15 kt. Scattered strong convection is evident east of the wave axis, N of 05N and E of 80W. A tropical wave is analyzed north of 03N along 92W, moving W around 10 kt. Scattered moderate to strong convection is from 05N to 07N within 120 nm on either side of the wave axis. A tropical wave is analyzed from 02N to 15N along 128W, moving W around 10 kt. Scattered moderate convection is from 09N to 11N along the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N78W to 09N106W. The ITCZ extends from 09N116W to 09N137W. Scattered moderate isolated strong convection is within 90 nm on either side of the ITCZ W of 120W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section for more details about the Gulf of Tehuantepec Gale Warning. A broad and weak ridge axis extends from NW to SE north of Cabo Corrientes. Gentle to moderate winds prevail over the offshore zones based on scatterometer data. Seas are generally 4-6 ft except SW of southern Baja California and in the Gulf of Tehuantepec. Winds will become NW and increase to moderate to fresh offshore of Baja California this weekend as the ridging strengthens and builds eastward. Offshore seas will approach 7 to 8 ft by Sunday, and continue into early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Easterly winds in the Gulf of Papagayo will increase to fresh to strong today as high pressure over Central America strengthens the trade winds in the western Caribbean. Fresh to strong winds will persist into early Sat, diminish slightly this weekend, then increase again Sun night and Mon. Highest seas will peak around 10-11 ft downstream of Papagayo. Otherwise, mainly moderate offshore winds will prevail N of the monsoon trough, with moderate S-SW winds S of the trough axis for the next several days. Seas are mainly 4-6 ft, expected to build to around 6-8 ft in SW swell this weekend, and continue into early next week. REMAINDER OF THE AREA... Please read 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, except 8-9 ft along the equator S of 110W in SE swell. A low pressure area may develop in association with a tropical wave moving across the waters south of Central America this weekend, with a corresponding increase in winds and seas. Otherwise, a ridge 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