907 AXNT20 KNHC 271751 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 151 PM EDT Thu Sep 27 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 1200 UTC surface analysis and satellite imagery through 1730 UTC. ...SPECIAL FEATURES... The center of Tropical Storm Kirk at 27/1800 UTC is near 14.0N 59.9W, or about 100 km NNW of Barbados or about 140 km ESE of Martinique. KIRK is moving WNW or 290 degrees 12 knots. The estimated minimum central pressure has risen to 1000 mb. The maximum sustained wind speeds are 45 knots with gusts to 55 knots. Scattered to numerous strong rainshowers are from 12N to 16N between 55W and 59W. Scattered moderate to isolated strong rainshowers are elsewhere from 11N to 19N between 50W and 60W. Kirk is expected to produce very heavy rain across the northern Windward and southern Leeward Islands from Thursday through much of Friday. It is possible that these rains may produce life- threatening flash floods and mudslides. The PUBLIC ADVISORIES for KIRK are transmitted via the WMO header WTNT32 KNHC, and via the AWIPS header MIATCPAT2. The FORECAST/ADVISORIES for KIRK are transmitted via the WMO header WTNT22 KNHC, and via the AWIPS header MIATCMAT2. Post-Tropical Cyclone Leslie is in the central Atlantic Ocean, several hundred miles to the west of the Azores. It remains a powerful non-tropical low pressure center, with storm-force winds. The associated rainshower activity gradually is becoming better organized. Leslie is expected to become a subtropical storm again, or possibly a tropical storm, tonight or on Friday, while it moves west-southwestward 10 mph in the north central Atlantic Ocean. The chance of formation into a tropical cyclone during the next 48 hours is high. Please read the HIGH SEAS FORECAST, AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and on the Web at https://ocean.weather.gov/shtml/NFDHSFAT1.shtml., for more details. ...TROPICAL WAVES... An Atlantic tropical wave is along 28W/29W from 19N southward. Isolated moderate rainshowers are from 06N to 22N between 24W and 32W. An Atlantic tropical wave is along 38W/40W from 19N southward. Any nearby precipitation is related to the ITCZ. A Caribbean Sea tropical wave is along 77W from 20N southward. The wave is moving across Jamaica, and it is moving through an area of upper level cyclonic wind flow. Isolated moderate rainshowers already are present in the area of upper level cyclonic wind flow. Strong rainshowers are off the coast of Colombia and Panama, near the monsoon trough. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Guinea Bissau near 12N16W to 10N19W. The ITCZ continues from 10N19W to 08N23W and 08N27W, from 07N30W to 06N39W, and from 05N41W to 02N50W. Widely scattered moderate to isolated strong rainshowers are from 03N to 08N between 10W and 22W. Isolated moderate rainshowers are from 04N to 12N between 35W and 47W. Upper level cyclonic wind flow covers the SE corner of the Caribbean Sea, and parts of NE South America near Venezuela and Trinidad and Tobago. Isolated moderate to locally strong rainshowers are in the Caribbean Sea from 15N southward from 64W eastward, and in the Atlantic Ocean from 10N southward from 57W westward. ...DISCUSSION... GULF OF MEXICO... An upper level NE-to-SW oriented trough cuts across Texas, from the north central part beyond the Far West corner of the state. A cold front passes through SE Louisiana, into the NW corner of the Gulf of Mexico, into the Deep South of Texas, and inland across northern parts of Mexico. Widely scattered moderate to isolated strong rainshowers are within 150 nm to the W/NW of the line that passes through 31N85W to 27N91W to 23N95W, and from 23N southward from 93W westward. A second upper level trough passes through the Florida Panhandle, into the central Gulf of Mexico, into the SW corner of the Gulf of Mexico. The current cold front will stall in the NW Gulf today, and enhance shower and thunderstorm activity through Friday, before the front weakens and drifts north of the area. Surface high pressure in the NE part of the region will support gentle to moderate E to SE winds and seas less than 4 ft across most of the region through Sunday. CARIBBEAN SEA... An upper level trough extends from 24N65W in the Atlantic Ocean, across Hispaniola, into the Caribbean Sea about 120 nm to the west of Jamaica. Upper level cyclonic wind flow covers the Caribbean Sea from 80W eastward. Isolated moderate rainshowers are from 72W eastward. A middle level inverted trough extends from SW Haiti, into the west central Caribbean Sea, toward the Costa Rica/Panama border. Isolated moderate rainshowers are elsewhere from the Windward Passage westward. The monsoon trough is along 10N from 74W in Colombia beyond Costa Rica. Upper level cyclonic wind flow covers a part of the SW corner of the Caribbean Sea, from 12N southward between Colombia and 79W. Scattered to numerous strong rainshowers are from the Gulf of Uraba to 12N between 75W and 79W. Tropical Storm Kirk near 13.8N 59.3W 999 mb at 11 AM EDT moving WNW at 13 kt. Maximum sustained winds 45 kt gusts 55 kt. Kirk will move to 14.3N 61.0W this evening, 14.9N 63.2W Fri morning, weaken to a tropical depression near 15.5N 65.4W Fri evening, 15.9N 67.7W Sat morning, and become a remnant low and move to 16.0N 72.0W Sun morning. Kirk will dissipate early on Monday. ATLANTIC OCEAN... A cold front passes through 32N32W to 24N40W, to 23N50W and 26N66W. The front is associated with Post-Tropical Cyclone Leslie, which is centered a 975 mb low pressure center that is near 37N42W. Widely scattered moderate to isolated strong rainshowers are from 29N northward between 30W and 35W, and within 30 nm to 45 nm on either side of the line that runs from 23N54W to 23N60W to 24N63W to 26N66W to 26N69W. Rainshowers are possible elsewhere within 60 nm on either side of the line that runs from 29N34W to 25N40W to 23N48W to 23N54W. More information is in the SPECIAL FEATURES SECTION, with respect to Post-Tropical Cyclone LESLIE. Surface high pressure will build southward across the west- central Atlantic Ocean today. Large swell, that is being generated by an intense north central Atlantic Ocean low pressure system, is expected to spread east of 75W by Friday night, and then to north Florida and E of the Bahamas early next week. For additional information please visit http://www.hurricanes.gov/marine $$ MT