000 AXNT20 KNHC 122350 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 750 PM EDT Sat Oct 12 2019 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2330 UTC. ...SPECIAL FEATURES... The now Tropical Storm Melissa is centered near 38.4N 65.6W at 12/2100 UTC, or 270 nm SE of Nantucket Massachusetts, moving ENE at 10 kt. Estimated minimum central pressure is 999 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Scattered showers are noted north of 36N between 62W-68W. On the forecast track, Melissa will continue to move away from the U.S. Mid- Atlantic and New England coasts. See the latest NHC forecast/advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC for more details. ...Gulf of Mexico Gale Warning... A cold front extends across the Gulf of Mexico from 30N87W to 25N93W to 19N95W. Latest scatterometer data depicted gale force northerly winds over the W Gulf waters within 90 nm of the coast of Mexico between 19N-25N. Seas will range between 10-16 ft. The gale-force winds are expected to continue through Sun morning from 19N-21N and within 60 nm off the coast of Mexico. Refer to the High Seas Forecast product under AWIPS/WMO headers HSFAT2/FZNT02 KNHC for more details. ...Heavy rainfall event for Central America... A 1008 mb surface low is centered over the SW Caribbean near 11N82W. The low is forecast to move WNW toward Central America early next week, and some development is possible if the low moves over the northwestern Caribbean Sea near the coasts of Honduras, Guatemala, and Belize. Regardless of development, this system could bring heavy rains to portions of Central America late this weekend through early next week. ...TROPICAL WAVES... An eastern Atlantic tropical wave extends its axis from 18N36W to an embedded 1010 mb low near 11N39W to 02N39W, moving W at 10 kt. This wave is well depicted in satellite imagery and model guidance. Scattered showers are noted in the vicinity of the low and over the southern portion of the wave mainly south of 08N. A central Atlantic tropical wave extends its axis along 55W, from 07N-20N, moving W at 10-15 kt. No significant convection is related to this wave at this time. ...MONSOON TROUGH/ITCZ... The monsoon trough extends SW from the coast of Guinea near 11N14W to 06N22W to 07N36W. The ITCZ extends from 07N39W to the coast of French Guiana near 05N53W. Besides the convection mentioned in the tropical wave section, isolated moderate to isolated strong convection is S of the monsoon trough from 02N-10N between 08W-16W. Scattered moderate convection is from 01N-06N between 18W-35W. GULF OF MEXICO... Refer to the section above for details on the forecast Gale Warning currently in effect. A cold front extends from the eastern Florida Panhandle near 30N87W to 25N93W to 19N95W. Scattered showers are noted along and west of the front. Surface ridging prevails across the remainder of the basin, with gentle to moderate easterly winds. The cold front will become stationary then dissipate by Mon. N gale winds will continue behind the front in the waters near Veracruz through Sun morning. Elsewhere, high pressure northeast of the Gulf will promote quiescent conditions through Tue. On Wed, a new cold front will push eastward across the northern Gulf of Mexico. No tropical cyclone activity is expected for the next several days over the basin. CARIBBEAN SEA... Refer to the sections above for the heavy rainfall event currently occurring over Central America and the SW Caribbean. TPW imagery depicts abundant moisture over the southern Caribbean and northern South America. The Pacific monsoon trough extends from Colombia westward across the SW Caribbean into northern Costa Rica and southern Nicaragua. Scattered moderate convection covers the southern Caribbean mainly south of 18N and west of 68W. Scatterometer data depicts moderate trades across most of the basin, except the south-central area where locally fresh winds are noted between 70W-82W. The SW Caribbean low will slowly move WNW through Central America during the next few days. Fresh to strong trade winds are likely over the western Caribbean and waters adjacent to Central America Mon and Tue. There is a low chance that this system could become a tropical cyclone before it exits the Caribbean. ATLANTIC OCEAN... Refer to the section above for details on the Tropical Storm Melissa and tropical waves moving across the basin. A western Atlantic cold front extends from 32N62W to 29N63W, then becomes stationary from that point to 23N70W to 25N79W. Scattered moderate convection is within 90 nm of the front mainly S of 25N. To the east, a pair of 1011 mb surface lows are analyzed near 21N64W and 25N57W. A surface trough is connecting these lows. Scattered moderate convection is noted within the low centers. Another cold front is over the E Atlantic from 31N26W to 29N33W to 31N43W with scattered showers. Surface ridging prevails across the remainder of the basin. The western Atlantic front will gradually dissipate by Mon. High pressure north of the front will promote quiescent conditions through Tue. On Wed, moderate to strong SW winds will develop east of Florida ahead of the next cold front. Large N swell generated by Subtropical Storm Melissa well north of the area are beginning to decay. This will allow seas E of the Bahamas to subside below 8 ft Sun. No new tropical cyclone activity is expected for the next several days. $$ ERA