008 AXNT20 KNHC 282356 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 756 PM EDT Fri Sep 28 2018 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 2315 UTC. ...SPECIAL FEATURES... Tropical Storm Kirk is centered near 14.7N 64.7W at 28/2100 UTC or 210 nm W of Martinique moving WNW at 12 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Kirk is forecast to weaken to a tropical depression tonight, and then degenerate into a trough of low pressure on Saturday. On the forecast track, the center of Kirk or its remnants will move across the eastern and central Caribbean Sea over the next day or two. Kirk is expected to produce total rainfall of 4 to 6 inches across the northern Windward and southern Leeward Islands with isolated maximum totals up to 10 inches across Martinique and Dominica. These rains may produce life-threatening flash floods and mudslides. Across Saint Croix and eastern Puerto Rico, Kirk is expected to bring 2 to 4 inches with isolated maximum totals of 6 inches tonight and Saturday. Scattered moderate and isolated strong convection is observed within 180 nm in the eastern semicircle. Please read the latest NHC Forecast/Advisory under AWIPS/WMO Headers MIATCMAT2/WTNT22 KNHC for more details. Subtropical Storm Leslie centered near 36.1N 48.1W at 28/2100 UTC or 1020 nm W of the Azores moving W at 9 kt. Estimated minimum central pressure is 986 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Earlier satellite data indicated that the powerful low is producing storm-force winds that extend several hundred miles from the center, and Leslie will likely continue producing strong winds and high seas over a large portion of the central Atlantic for the next few days. Scattered moderate convection is observed within 180 nm of the center. See latest NHC forecast/advisoryunder AWIPS/WMO headers MIATCPAT3/WTNT33 KNHC for more details. ...TROPICAL WAVES... A tropical wave is near 21W from 03N-19N. Scattered moderate convection is within 180 nm east of the wave axis south of 07N. This system shows up well in the Total Precipitable Water animation, and also has a sharp trough at the surface as seen by the ASCAT scatterometer pass. A second tropical wave near 45W extends from 02N-17N moving W at 10-15 kt. The TPW imagery shows a maximum E of the wave axis and there is a trough in the GFS 700 mb analyses, but little signature is seen at the surface. No significant convection is currently associated with the wave. A tropical wave is moving across the Caribbean Sea, near 82W from 21N southward. A pronounced 700 mb trough in the GFS analysis is noted with the wave, but little signature of the wave is seen at the surface. The wave, along with the monsoon trough, is helping to induce scattered moderate and isolated strong convection within 180 nm of the wave axis south of 14N. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean near 16N17W and continues SW to near 08N21W to 05N30W. The ITCZ extends from 05N30W to 08N44W. The ITCZ resumes W of a tropical wave near 08N46W to 08N55W. Widely scattered moderate convection is from 03N to 08N between 20W and 32W. ...DISCUSSION... GULF OF MEXICO... A stationary front is located in the N Gulf waters from the Florida Panhandle near 31N86W to Texas near 28N86W. Scattered moderate convection is within 120 nm of the front. Currents winds across the Gulf are moderate breeze or weaker out of the east, as a weak ridge is in place over the SE United States. The frontal boundary should dissipate by Saturday with little change to the winds during the next couple of days. Seas will remain below 8 ft through Sunday. CARIBBEAN SEA... Tropical Storm Kirk will bring strong winds and heavy rain over portions of the Lesser Antilles tonight. Please, see Special Features section for details. A tropical wave is moving across the western Caribbean Sea. See Tropical Wave section for details. Recent scatterometer data indicate generally easterly moderate breeze or weaker winds ahead of Kirk, except for an outflow boundary enhancement of winds to 25 kt in the southwestern Caribbean Sea. As tropical cyclone Kirk weakens over the Caribbean Sea, expect mainly moderate to fresh winds through early next week. Large northerly swell associated with Leslie will affect the tropical Atlantic waters tonight through Sunday, building seas to 10 or 11 ft. ATLANTIC OCEAN... Two tropical waves are currently between the coast of Africa and the Lesser Antilles. A stationary front enters the forecast region near 31N40W then continues SW to 21N58W. From there the feature is a dissipating stationary front to 25N72W. The front is associated with Leslie, which is centered N of area near 36N48W with a central pressure of 986 mb. This system is moving W at 9 kt. Please, see Special Features Section for more details. Large swell generated by Leslie is expected to propagate across the waters east of 75W by tonight, reaching the Bahamas, the waters N of Hispaniola and the Atlantic Passages E of la Mona Passage by early Saturday, and the north and central coast of Florida later on Saturday. A ridge extends from a 1022 mb high pressure located near 32N65W across the western Atlantic reaching Florida. Another ridge dominates the remainder of the Atlantic E of the aforementioned cold front. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa