000 AXNT20 KNHC 090553 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Mon Nov 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 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...SPECIAL FEATURES... Tropical Storm Eta made landfall in the Florida Keys, near 24.9N 80.7W as of 09/0400 UTC. Eta is moving to the WNW at 12 kt. Estimated minimum central pressure is 991 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Most of the convection in the SW quadrant has been eroded due to dry air in the upper levels mixing in and around the entire circulation. Scattered moderate to isolated strong convection is within 270 nm north of the center, including over southern and central Florida. Isolated moderate convection is within 90 nm SE quadrant. Sustained tropical storm force winds have been reported along portions of the southeast Florida coast and Upper Florida Keys during the past several hours. Seas of 12 ft or greater are within 60 nm of the center except 30 nm NW quadrant with peak seas to 25 ft. On the forecast track, the center of Eta will pass near or over the Florida Keys this morning, and be over the southeastern Gulf of Mexico late today and Tuesday. Some strengthening is forecast during the next day or so and Eta is forecast to become a hurricane when it moves over the southeastern Gulf of Mexico. Heavy rainfall today over South Florida and the Bahamas could lead to additional flooding. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT4.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT4.shtml for more details. West Atlantic Gale Warning: The pressure gradient between Eta and high pressure over the Mid-Atlantic states is resulting in a large area of strong to near gale force easterly winds across the western Atlantic, west of 67W. Within this area, gale force winds are currently occurring west of 76W and south of 30N, according to a recent ASCAT pass. The gale warning will remain in effect for this area through this evening, before winds diminish below gale force tonight. Seas to 20 ft are expected in the area this morning. Please read the latest NHC High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. North Central Atlantic Gale Warning: A 1010 mb low is currently near 28N46W and is producing winds of 20-25 kt from 26N-31N between 41W-48W. Shower and thunderstorm activity is beginning to show some signs of organization. Scattered moderate to isolated strong convection is from 25N-32N between 36W-47W. The low has a medium chance of developing into a tropical or subtropical cyclone during the next 48 hours while the system moves eastward. Regardless of whether it becomes tropical, the low is forecast to produce gale force winds Tuesday morning north of 26N and east of 42W. Winds will diminish to below gale force on Wed as the low moves east of 35W. Seas of 12-17 ft are expected Tue through Wed north of 26N between 32W-42W. See the latest NHC High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...TROPICAL WAVES... A tropical wave is entering the eastern Caribbean with axis along 61/62W from 05N-19N, moving W at 10 kt. A surface trough is associated with this tropical wave, as noted in a recent ASCAT pass. Fresh SE winds are east of the wave axis. Scattered moderate to isolated strong convection is along and within 360 nm east of the wave axis from 12N-18N. Expect enhanced rainfall this morning over portions of the Windward and Leeward Islands. This tropical wave is forecast to move over the central Caribbean Sea, where an area of low pressure could form in a couple of days. Environmental conditions are forecast to be conducive for development, and a tropical depression could form late this week or over the weekend while the system moves slowly westward. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of West Africa near 11N15W to 08N18W. The ITCZ continues from 08N18W to 05N23W to 04N38W to 05N50W. Scattered moderate convection is from 02N-12N between 23W-46W. GULF OF MEXICO... Tropical Storm Eta is centered over the Middle Florida Keys as of 09/0400 UTC. A large upper-level low centered over T.S. Eta is aiding in wrapping dry air into the circulation from the southwest quadrant. Scattered showers associated with Eta cover the SE Gulf, east of 84W from 22N-29N. Fresh to strong NE winds are over the eastern Gulf, east of 88W, with tropical storm force winds near the Florida Keys. Seas over 8 ft are occurring east of 88W from 22N-28N, with much higher seas near Eta. For more details on Eta, please see the Special Features section above. West of 90W, mainly gentle wind speeds prevail. The NW Gulf has seas of 4 to 6 ft, while the SW Gulf is experiencing 2 to 4 ft seas. No significant precipitation is seen west of 85W. Tropical Storm Eta will move to near 24N84W this evening, strengthen to a hurricane near 23.5N85W Tue morning, and weaken to a tropical storm near 26.5N84.5W Wed evening. Eta will gradually weaken as it moves to near 28N84W late Thu. A cold front will move into the NW Gulf Wed and become stationary over the northern Gulf through Fri. CARIBBEAN SEA... Tropical Storm Eta is centered over the Middle Florida Keys. A large upper-level low centered over T.S. Eta extends upper-level troughing over the NW Caribbean. An upper-level ridge covers the remainder of the Caribbean. Due to the positioning of these upper-level features, strong upper-level diffluence and divergence are occurring over the southeast Bahamas, Hispaniola and Puerto Rico. As a result, scattered moderate to isolated strong convection is seen from 15.5N-21N between the British Virgin Islands and the eastern Dominican Republic, including near and over Puerto Rico. Scattered moderate convection is also seen east and south of Jamaica from 14N-19N between 75W-78W. Scattered moderate convection is over northern Nicaragua and southern Honduras due to the east Pacific monsoon trough. A tropical wave along 61/62W is producing convection over the Lesser Antilles. See the Tropical Waves section above for details. A recent ASCAT pass shows fresh to locally strong S winds from Jamaica to the Windward Passage and in the Mona Passage. Fresh W winds are over portions of the NW Caribbean, north of 16N and west of 80W. Gentle to moderate winds are seen elsewhere. Tropical Storm Eta will strengthen to a hurricane near 23.5N85W Tue morning before turning N and weakening to a tropical storm near 26.5N84.5W Wed evening. Expect seas in excess of 12 ft to reach the Yucatan Channel tonight, with N swell spreading through the western Caribbean Tue. Seas in the NW Caribbean will then gradually subside Wed. A tropical wave, currently moving through the Windward Islands, will reach the central Caribbean in a few days, where an area of low pressure could form. There is a medium chance of tropical cyclone formation within the next 5 days while the system moves slowly westward. ATLANTIC OCEAN... Tropical Storm Eta is centered over the Middle Florida Keys as of 09/0400 UTC. Scattered moderate to isolated strong convection directly associated with Eta extends between the NW Bahamas and South Florida. Scattered moderate convection also extends offshore central and northern Florida. Although the tropical storm force winds associated with Eta extend to 27N west of 78W, gale force E winds of 35 kt due to a tight pressure gradient extend northward from 27N-30N between 76W-81W. Strong winds are elsewhere from 23N-32N between 67W-82W. Of note, an area of strong upper-level diffluence is enhancing scattered moderate to isolated strong convection between the British Virgin Islands and the southeast Bahamas, from 18N-24N between 62W-74W. Additional scattered moderate convection is seen from 24N-31N, between 69W-77W. Please see the Special Features section above for more details on Tropical Storm Eta and the Gale Warning to the east of central and northern Florida. Farther east, a 1010 mb low near 28N46W is the subject of a Gale Warning and is also being discussed in the NHC Tropical Weather Outlook, with a medium chance of tropical cyclone formation within 48 hours. See the Special Features section above for details. A 1026 mb high is centered near 33N24W. Tropical Storm Eta will move to near 23.5N85W by Tue morning, and 25.5N85W Wed morning. Tropical storm force winds will continue east of the Florida Keys and Miami this morning. Gales due to a tight pressure gradient will persist north of the NW Bahamas and east of Florida through this evening. Large seas are expected in the western Atlantic through Tue before gradually subsiding through late Thu night. $$ Hagen