000 AXNT20 KNHC 102315 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sat Oct 10 2020 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 2300 UTC. ...TROPICAL WAVES... A tropical wave has its axis along 40W from 02N-17N, moving westward at 15-20 kt. Scattered moderate to isolated strong convection is noted on either side of the wave axis from 08N-16N between 37W and 43W. Slow development of this system could be possible later this weekend or early next week while the wave continues moving westward. Upper-level winds are forecast to become unfavorable for further development by the middle of next week. This system has a low chance of tropical cyclone formation within 48 hours and through 5 days. Please read the latest NHC Tropical Weather Outlook at https://www.nhc.noaa.gov/text/MIATWOAT.shtml for more details. Visible satellite imagery suggests that the tropical wave now located along 70W is farther E along 66W, where a well defined inverted-V pattern is noted. This wave should be re- located on the next surface map. The wave combined with a diffluent pattern aloft is supporting shower and thunderstorm activity over Puerto Rico, the US/UK Virgin Islands and regional waters. Another tropical wave is over western Caribbean with axis along 82W south of 20N. It is moving westward at 15 kt. The wave is helping to induce scattered showers and thunderstorms over the Cayman Islands. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean just N of Dakar, Senegal and drops southwestward to near 08N24W. The ITCZ continues from 08N24W to 06N38W to 10N52W to 12N60W. Scattered moderate convection is within about 90 nm S of the ITCZ between 40W-51W, and from 10N-13N between 57W-60W. GULF OF MEXICO... Delta becomes a non-tropical low and the heavy rain threat continues. At 10/2100 UTC, Post-Tropical Cyclone Delta is centered near 33.7N 90.0W or 70 nm WSW of Tupelo Mississippi moving NE at 10 kt. Estimated minimum central pressure is 998 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. Flood and Flash Flood watches remain in effect for portions of the Mid-South of United States and areas in and near the southern Appalachians. Weakening is forecast during the next 36 hours, and Delta's surface low is expected to dissipate across West Virginia late Sunday night. Future information on this system can be found in Public Advisories issued by the Weather Prediction Center at http://www.wpc.ncep.noaa.gov. Now that Delta has moved inland and continues to pull farther away from the Gulf waters, relatively weak high pressure from the western Atlantic has settled in over the area. However, the most recent scatterometer data showed moderate to locally fresh winds across the NW and north-central Gulf. Similar wind speeds are also noted over the eastern Gulf between Delta and the Atlantic ridge. Lines of showers, with embedded thunderstorms in a SE wind flow are seen on Mosaic Doppler Radar across the eastern Gulf, Florida and the waters E of Florida. An upper-level low is helping to induce convection over the Yucatan Peninsula. Weak high pressure will continue to build across the area into early next week producing mainly light to gentle winds. A cold front will move into the northern Gulf of Mexico Mon night and quickly dissipate over the northern Gulf on Tue. High pressure will follow the front. CARIBBEAN SEA... A couple of tropical waves are moving across the Caribbean Sea. Please, see the Tropical Waves section for details. Low-topped trade wind showers are seen elsewhere across the basin. Fresh trade winds over the south-central Caribbean will pulse to strong speeds at night through Mon. Gentle to moderate trade winds elsewhere will change little through the period. Seas will be in the slight range, except for moderate seas in the south- central Caribbean into next week. A strong tropical wave may bring higher winds and building seas to the Atlantic waters east of the Leeward Islands Tue through Thu. ATLANTIC OCEAN... The southwest periphery of high pressure centered well north of the area near 38N57W extends south-southwestward toward the Bahamas and Florida. The pressure gradient between the high pressure and Delta is allowing for fresh southeast winds to occur N of 30N W of 78W. These winds will diminish to moderate speeds Sun as Delta pulls farther to the northeast. A stationary front extends from 31N50W to 26N60W. A trough ahead of it is along a position from 26N56W to 20N63W and to just northeast of Puerto Rico. A cluster of moderate to isolated strong convection is near the southern end of the trough axis covering the waters from 19N-21.5N between 62W-66.5W. Another trough is analyzed from 28N42W to 17N44W. Scattered showers are near the northern end of the trough axis. The remainder of the Atlantic is under the influence of a 1036 mb high pressure located NE of the Azores. The pressure gradient between the high and lower pressures over W Africa is resulting in moderate to fresh N-NE winds across the Canary Islands and over the waters N of the Cabo Verde Islands to about 22N. As for the forecast, high pressure over the northern and central waters will begin to shift east-northeast tonight through Mon ahead of a cold front that will move off the SE U.S. coast Tue. This front will weaken and stall from Bermuda into the Central Bahamas for mid week. $$ GR