000 AXNT20 KNHC 092315 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Oct 9 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. ...SPECIAL FEATURES... At 5 pm CDT, the eyewall of Delta moved onshore on the southwestern coast of Louisiana, about 25 miles SSE of Cameron, Louisiana with maximum sustained winds of 90 kt. An hour later, at 6 pm CDT, the hurricane made landfall near Creole, Louisiana. Delta is a category 2 hurricane on the Saffir-Simpson Hurricane Wind Scale. The minimum central pressure estimated from Air Force Reserve reconnaissance aircraft data was 970 mb. Hurricane conditions and life-threatening storm surge is expected in the landfall area. Heavy rainfall will lead to significant flash flooding and minor to major river flooding in parts of Louisiana today and Saturday. Additional flooding is expected across portions of the central Gulf Coast into the Lower Mississippi Valley. On the forecast track, the center of Delta will move across central and northeastern Louisiana tonight and Saturday morning. After that time, the system is forecast to moves across northern Mississippi into the Tennessee Valley. Some weakening is possible before landfall, with rapid weakening expected after landfall. Delta is forecast to weaken to a tropical storm tonight and to a tropical depression on Saturday. Please, read the latest NHC Public Advisory, at https://www.nhc.noaa.gov/text/MIATCPAT1.shtml, and the Forecast/ Advisory, at https://www.nhc.noaa.gov/text/MIATCMAT1.shtml, for more details. ...TROPICAL WAVES... A tropical wave is along 33W/34W from 02N-17N, moving W at 15-20 kt. Scattered moderate convection is noted from 07N-10N between 32W-36W. Environmental conditions could be conducive for some slow development of the system this weekend or early next week while it is located over the tropical Atlantic well east of the Lesser Antilles. 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 through 5 days. An eastern Caribbean tropical wave axis extends along 63W/64W from 05N-22N, moving W at 10 kt. Currently, convection is limited near the wave axis. Moisture associated with this wave will reach Puerto Rico tonight into Sat increasing the likelihood of showers and thunderstorms. Another tropical wave is moving across the Caribbean Sea with axis along 76W, from 20N southward, moving westward 10 to 15 knots. The wave is helping to induce some convective activity over Jamaica and southern regional waters, particularly from 15N-18N between 75W-78W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean just N of Dakar, Senegal, then continues SW to near 08N31W. The ITCZ extends from 07N40W to 10N52W. Scattered moderate convection is seen from 06N-10N between 40W-50W, and from from 09N-13N between 50W-58W. The 925 mb streamlines and winds suggest the presence of a trough in this area. GULF OF MEXICO... Please, see the Special Features section above for details on Hurricane Delta. The most recent scatterometer data indicated that the fresh to strong winds associated with the periphery of the hurricane extend outward, covering the waters N of 23N W of 88W. Delta will weaken to a tropical storm near 31.1N 92.5W Sat morning, then reach 33.1N 91.0W Sat afternoon. Delta will weaken to a tropical depression near 34.4N 89.2W Sun morning and be near 35.9N 87.1W Sun afternoon. It is expected to become a remnant low in Kentucky Mon morning and dissipate Mon afternoon. In its wake, weak high pressure will build across the Gulf waters into early next week. Swell from Delta will spread across the Gulf into the weekend. CARIBBEAN SEA... An upper-level low is centered over the NW Caribbean. This system, along with abundant moisture at low to middle levels is supporting scattered showers and thunderstorms over the NW Caribbean, Cuba, the Yucatan Peninsula and northern Central America. Plenty of moisture in a gentle to moderate SE wind flow will dominate the NW Caribbean and adjacent land areas on Sat. For the forecast, building high pressure over the northwest Atlantic will support fresh trade winds and moderate seas over the south-central Caribbean, and gentle to moderate trade winds and slight seas elsewhere into Sat. Winds and seas will diminish across the basin through early next week as the high pressure shifts east. A tropical wave may impact Atlantic waters east of the Leeward Islands Tue and Wed. ATLANTIC OCEAN... A weak cold front enters the forecast area near 31N58W, and extends SW to near 27N71W, then continues as a stationary front to NE Florida. Scattered showers are along the frontal boundary. A surface trough is ahead of the front and stretches from 31N52W to 25N58W to 20N62W. Scattered moderate convection is ahead of the trough axis. Another surface trough is near 40W from 20N-27N. Scattered showers are near the trough. The remainder of the Atlantic is under the influence of a 1027 high pressure located over the Azores. For the forecast west of 65W, the aforementioned front will dissipate into Sat. North of the boundary, moderate to fresh east winds will prevail for the first half of the weekend, before weak high pressure building over the area leads to lesser winds for the start of next week. $$ GR