000 AXNT20 KNHC 071112 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Wed Jul 7 2021 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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 1100 UTC. ...SPECIAL FEATURES... Recently downgraded Tropical Storm Elsa is centered near 28.5N 83.5W at 07/0900 UTC or about 45 nm south-southwest of Cedar Key, Florida and 60 nm west-northwest of Tampa, Florida moving N at 12 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed has diminished to 55 kt gusts to 65 kt. Peak wave heights are estimated to be around 12 ft in within 60 nm of the center in the NW and SE quadrants and within 30 nm of the center in the NE quadrant. Latest satellite imagery shows that scattered moderate to strong convection is rapidly increasing within 120 nm of the center in the N and NE quadrants. Scattered moderate convection is well removed from the center is inland northern Florida from 30N to 31N between 81W-85W. Wide and detached outer rain bands consisting of scattered moderate to strong convection are present across the Florida peninsula from northeast Florida south-southwest to the southwest Florida coast and out over the southeastern Gulf of Mexico to near 25N84W. Isolated showers and thunderstorms are to the southwest of Elsa from 27N to 28N between 86W-89W. Elsa is forecast to track toward the north-northeast this afternoon late this afternoon or tonight, followed by a faster northeastward motion by late Thu. On the forecast track, Elsa will move near or over portions of the west coast of Florida this morning, then make landfall along the north Florida Gulf coast by late this morning or this afternoon. Elsa should then move across the southeastern and mid-Atlantic U.S. through Thu. Storm surge of 1-2 ft is probable from the Indian Pass to the Ochlockonee River, 2-4 ft from the Ochlockonee River to the Aucilla river, 3-5 ft from the Aucilla River to Engelwood (including Tampa Bay), 2-4 ft from Englewood to Bonita Beach (including Charlotte Harbor), and 1-3 ft from Bonita Beach to Flamingo. Rainfall of 3 to 6 inches with localized maximum totals of 9 inches are expected over the western and northern portions of the Florida peninsula today. Rainfall may result in considerable flash and urban flooding, along with minor to isolated moderate river flooding. Stay informed with your local NWS Weather Forecast Office and listen to possible instructions from you local emergency management office. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT5.shtml, Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT5.shtml, and High Seas Forecast issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. For marine information within 60 nm of the coast, please see products from your local NWS Weather Forecast Office at www.weather.gov. ...TROPICAL WAVES... A far eastern Atlantic tropical wave has its axis along 30W/31W from 03N to 17N, moving westward at 10-15 kt. Scattered moderate isolated strong convection is within 180 nm either side of the wave from 03N to 09N. This convection is on an increasing trend. A central Atlantic tropical wave has its axis along 48W south of 12N, moving westward at 15-20 kt. Scattered moderate convection is west of the wave to near 55W and from 04N to 09N. A low-amplitude eastern Caribbean tropical wave has its axis along 65W south of 12N, moving westward at about 16 kt. Scattered showers and isolated small thunderstorms are noted south of 13N to the coast of Venezuela and between 62W-65W. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the coast of Africa near 12N17W to 09N26W and to near 05N43W. A very small segment of the ITCZ extends from 02N47W to the coast of Brazil near 01N50W. Aside from the convection described above in the tropical waves section above, increasing clusters of mainly scattered moderate convection are seen from 04N to 10N between 16W-23W. This activity appears to be in advance of the next tropical wave that will emerge of the coast of Africa. Other scattered moderate convection is within 60 nm south of the trough between 33W-37W. GULF OF MEXICO... Tropical Storm Elsa is impacting the far eastern Gulf and western Florida areas. Please see the Special Features section above for details. As of 07/0900 UTC, a surface trough is analyzed just inland the Texas coast, with a 1008 mb low near 28N98W. Increasing scattered moderate to isolated strong convection is occurring from 24N to 28N west of 92W. Overnight ASCAT data indicated gentle to moderate south-southeast winds near this trough and elsewhere over the western Gulf west of 90W. An upper-level trough shifting south- southeast with time over northeastern Mexico is supporting an area of scattered moderate to isolated strong convection from 22N to 24N west of 95W to within 80 nm inland the coast of Mexico. Gentle to moderate east-southeast winds continue over the central and western Gulf, with wave heights in the 3-5 ft range due to a southeast swell. For the forecast: Topical Storm Elsa near 28.5N 83.5W 1004 mb at 5 AM EDT moving N at 12 kt, with maximum sustained winds of 55 kt gusts 65 kt will track north-northeast to near 30.2N 83.3W this afternoon as it continues to weaken and move inland to near 32.6N 82.0W by late tonight. Hazardous marine conditions over the NE Gulf will gradually improve through this evening. In the wake of Elsa, Atlantic high pressure will build westward across the area through the next few days. Swells from Elsa are likely to spread throughout the basin through Sat. Showers and thunderstorms are expected to continue across the north-central Gulf through at least tonight. CARIBBEAN SEA... An overnight ASCAT pass depicted near-gale force E winds in the south-central Caribbean within 120 nm of the coast of Colombia between 72W and 75W. Strong east winds extend to 14N between 71W and 77W. Mainly fresh east winds are over the remainder of the central Caribbean, with seas of 6-9 ft. Elsewhere in the basin, gentle to moderate trades prevail with wave heights in the range of about 3-6 ft. Isolated showers are noted from 19N to 21N between 61W-65W. For the forecast: Widespread fresh to strong trades will begin to increase in the south-central Caribbean beginning tonight and continue through late Fri. These winds may reach near gale force Thu through Fri night. Fresh to strong winds will pulse at night in the Gulf of Honduras through the rest of the week. ATLANTIC OCEAN... A 1028 mb high center is located north of the area near 35N40W, with a ridge stretching southwest and then westward along 30N to near 77W. High pressure covers the Atlantic north of 15N east of 61W and north of 19N between 61W-77W. West of this ridge, broad cyclonic flow is indicated in the latest surface analysis to cover the far western waters, including the Florida peninsula, and is attributed to Tropical Storm Elsa over the eastern Gulf of Mexico near the Florida west-central coast. Scattered showers and embedded thunderstorms associated with outer rain bands of Tropical Storm Elsa are over most of the central and northern Florida peninsula and the immediate coastal waters of northern and central Florida. These rain bands are lifting to the north. Very strong and gusty winds are possible with showers and thunderstorms in these bands. Strong to near-gale force winds are near the Canary Islands. The gradient induced by the high pressure and the lower pressure of the tropics is allowing for a broad area of fresh easterly trade winds to exist south of 23N west of 50W and for generally gentle to moderate trades elsewhere south of 28N. Wave heights are in the range of 4-6 ft per latest altimeter data passes, except for higher heights of 6-8 ft from 16N to 22N between 26W-44W. For the forecast: Fresh southeast winds will develop off the northern and central Florida coasts today and tonight as Tropical Storm Elsa, currently in the eastern Gulf of Mexico near the Florida west coast, moves inland across northern Florida. Elsa is forecast to track northeastward across the southeastern U.S.through Thu allowing for these winds to diminish. High pressure will then build westward across the area through the Sun night. East winds will pulse to fresh to strong speeds at night between the southeastern Bahamas and the Dominican Republic through the period. $$ Aguirre