000 AXNT20 KNHC 121053 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 653 AM EDT Thu Sep 12 2019 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 0600 UTC surface analysis and satellite imagery through 1030 UTC. ...SPECIAL FEATURES... A surface trough extends from the Atlantic Ocean, about 200 nm to the N of the SE Bahamas, to SE Cuba. Scattered moderate to strong rainshowers are from 23N to 26N between 66W and 69W, from 20N to 23N between 69W and 72W, and from 22N to 24N between 72W and 74W. The second and third areas of rainshowers are on top of and/or just to the east of the southern half of the Bahamas. Atmospheric conditions are forecast to become a little more conducive for a tropical cyclone to form during the weekend. It is likely that a tropical depression may form, as the system moves NW 5 to 10 mph, across the Florida Straits and southern Florida, and into the eastern Gulf of Mexico. It is likely that this disturbance may produce periods of locally heavy rainfall and gusty winds across the Bahamas through Friday, and across Florida during the weekend. An Air Force Reserve reconnaissance aircraft is scheduled to investigate the system this afternoon, if necessary. The chance of tropical cyclone formation during the next 48 hours is medium. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 28W/29W, from 20N southward. The wave is moving W 10 to 15 knots. Widely scattered moderate to isolated strong rainshowers are near the monsoon trough, from 04N to 16N from 35W eastward to Africa. Atmospheric conditions appear conducive for development of this system. It is possible that a tropical depression may form early next week, while the tropical wave moves westward in the tropical Atlantic Ocean toward the Lesser Antilles. An Atlantic Ocean tropical wave is along 40W/41W, from 19N southward, moving W 10 to 15 knots. Widely scattered moderate to isolated strong rainshowers are from 05N to 15N between 35W and 44W, and from 14N to 16N between 44W and 48W. An Atlantic Ocean tropical wave is along 53W/54W, from 20N southward, moving W 10 knots. Widely scattered moderate to isolated strong rainshowers are from 13N to 16N between 50W and 60W. This system is forecast to move westward, toward unfavorable upper level winds, and tropical cyclone formation is not anticipated. A Caribbean Sea tropical wave is along 74W/75W, from 20N southward, moving W 15 knots. Numerous strong rainshowers are in northern sections of Colombia, from 07N to 10N between the border of Colombia and Venezuela and the Caribbean Sea coast of Colombia near 76W. The monsoon trough is close also. A western Caribbean Sea tropical wave is along 86W/87W, from 18N southward, moving W 10 knots. The wave passes through Honduras and Nicaragua. Isolated moderate rainshowers are from 15N northward from 80W westward. Upper level cyclonic wind flow, from the Gulf of Mexico, is in the NW corner of the Caribbean Sea. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from Senegal near 14N17W, to 09N33W, to 14N47W, and 13N56W. Much of the precipitation that is in the area of the monsoon trough also is close to the tropical waves. GULF OF MEXICO... The upper level cyclonic circulation center, that was in SE Georgia/NE Florida nearly 24 hours ago, now is in the NE corner of the Gulf of Mexico. Upper level cyclonic wind flow and isolated moderate rainshowers cover the Gulf of Mexico to the north of the line that runs from the central coast of Louisiana through the Yucatan Channel. Upper level cyclonic wind flow continues from East Texas into southern interior sections of Mexico, including in the coastal waters from Texas into the SW corner of the Gulf of Mexico. Widely scattered moderate to isolated strong rainshowers are in the Gulf of Mexico from 26N southward from 90W westward. Isolated moderate rainshowers are elsewhere in Gulf of Mexico. Broad surface anticyclonic wind flow spans the Gulf of Mexico. A surface ridge extends from a SW Georgia 1021 mb high pressure center, into the SW corner of the Gulf of Mexico. High pressure N of the basin will support moderate to fresh NE to E winds into the weekend. A trough, possibly as a tropical cyclone, will move into the eastern Gulf of Mexico, from this weekend into early next week. This weather system will be accompanied by widespread rainshowers, thunderstorms, gusty winds and building seas. CARIBBEAN SEA... Isolated moderate rainshowers are in the area that is to the NW of the line that runs from the Windward Passage to eastern Honduras. This precipitation is in an overall area of more than one smaller areas of cyclonic wind flow. Part of the precipitation that is in the NW corner is related to the NE Gulf of Mexico upper level cyclonic circulation center. Another part of the precipitation is related to the surface trough that is reaching SE Cuba. The monsoon trough is along 09N/10N, between Lake Maracaibo in NW Venezuela, across northern Colombia, through Panama, and beyond southern Costa Rica, into the eastern Pacific Ocean. Scattered to numerous strong rainshowers are in northern Colombia, about 100 nm to the north of Panama between Colombia and 79W, and 180 nm to the south of Panama from 80W eastward, and within 60 nm of the Panama from 80W westward. High pressure N of the region will maintain moderate trade winds, that will pulse to fresh to strong, at times, in the S central Caribbean Sea. A tropical wave will cross from the central Caribbean Sea into the western Caribbean Sea on Friday. A strong tropical wave will approach the tropical N Atlantic Ocean and the eastern Caribbean Sea, during the time from the weekend into early next week. This feature also will bring widespread rainshowers and thunderstorms, gusty winds and building seas. ATLANTIC OCEAN... An upper level trough extends from a 34N46W cyclonic circulation center, to a 30N51W cyclonic circulation, to a 19N56W cyclonic circulation center, across the NE Caribbean Sea to a 16N74W central Caribbean Sea cyclonic circulation center, toward Costa Rica. A surface trough is along 30N51W 25N53W 21N55W. Widely scattered moderate to isolated strong rainshowers are within 180 nm on either side of the line that runs from 32N49W to 26N48W, and then within 90 nm on either side of the line that runs from 26N48W to 23N50W 21N54W 20N59W. A trough, from the Bahamas to eastern Cuba, will move WNW slowly, possibly as a tropical cyclone. This weather feature is forecast to reach the Florida Peninsula late on Friday. It will be accompanied by widespread rainshowers, thunderstorms, gusty winds and building seas. A strong tropical wave may approach the waters S of 22N, early next week. $$ MT