000 AXNT20 KNHC 170513 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 113 AM EDT Mon Aug 17 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. ...TROPICAL WAVES... An eastern Atlantic tropical wave extends its axis along 21W south of 19N, moving W at 15 kt. Numerous moderate isolated strong convection is noted from 07N-11N between 19W-23W. Environmental conditions are expected to become more conducive for the development of a tropical depression during the middle to latter part of this week while the system moves westward across the central tropical Atlantic. The chance of development during the next 48 hours is low. The axis of an eastern Atlantic tropical wave extends along 34W from 07N-22N, moving W at 10-15 kt. Scattered moderate isolated strong convection is within 150 nm either side of the wave axis from 10N-14N. A central Atlantic tropical wave extends its axis along 53W from 17N southward, moving W at 15 kt. Scattered moderate to strong convection is within 180 nm W and within 330 nm E of the wave axis from 09N-14N. The system will enhance rainfall over the Windward and southern Leeward Islands later today into Tuesday. After that time, upper-level winds could become a little more conducive for development while the system moves over the central and western Caribbean Sea. The chance of tropical cyclone formation during the next 48 hours is low. ...MONSOON TROUGH/ITCZ... The monsoon trough passes from the coast of Africa near 17N16W to 11N21W to 12N42W. The ITCZ continues from 12N42W to 11N51W, then resumes west of a tropical wave near 11N55W to 09N61W. Aside from the convection related to the tropical waves described above, scattered moderate to strong convection is from 08N-13N between 26W-30.5W and from 11N-13.5N between 57W-63W, including over the southern Windward Islands. GULF OF MEXICO... A 1015 mb surface high is situated over the NW Gulf of Mexico near 28N95W. Isolated showers are over the Bay of Campeche. Showers have decreased over the NE Gulf in association with a weakening surface trough. A 1011 mb low is near Tallahassee Florida with a weakening stationary front extending W from the low to 30N89W. A recent ASCAT pass shows light to gentle wind speeds across the Gulf of Mexico. Weak high pressure extending from the western Atlantic to across the central Gulf will support gentle winds and low seas across the Gulf into late week. A weak cold front will move off the northern Gulf coast today then stall into mid-week. CARIBBEAN SEA... An upper-level low has been nearly stationary over central Cuba for the last 24 hours. This low is enhancing scattered showers and isolated tstorms north of 19.5N between 75W-85W. Scattered showers and tstorms are also seen to the north of eastern Honduras and east of Nicaragua due to upper-level diffluence and enhanced moisture in the area. The SW end of a surface trough is bringing isolated showers to the Mona Passage. The trough should dissipate early this morning. Scattered moderate to isolated strong convection associated with the ITCZ is occurring over the southern Windward Islands and SE Caribbean. A recent ASCAT pass shows moderate trades across the central Caribbean and gentle in the western Caribbean. Expect showers and tstorms to increase over the Windward and southern Leeward Islands as a strong tropical wave moves through later today and tonight. This wave will then move through the eastern Caribbean Tue. The wave will be followed by fresh to strong east winds and accompanied by scattered showers and isolated tstorms, some possibly with strong gusty winds. This system has a low chance of becoming a tropical cyclone during the next 48 hours, but a moderate chance later in the week when it is located over the central and western Caribbean Sea. ATLANTIC OCEAN... A stationary front extending from Charleston South Carolina to Tallahassee Florida is generating scattered moderate showers and tstorms to the north of 30.5N between 72W and the coasts of Georgia and South Carolina. An upper-level low over Cuba is causing isolated showers over portions of the central Bahamas. Slightly farther east, an upper-level low is near 29N66W. A weakening surface trough axis is from 25N65W to the Mona Passage. Scattered moderate showers and tstorms are seen from 22N-31N between 61W-68W. A surface ridge extends over the subtropical Atlantic from a 1024 mb high near 33N25W to a 1021 mb high near 30N52W. Surface ridging also extends toward the NW Bahamas. The surface trough from 25N65W to the Mona Passage will dissipate early this morning. The stationary front from Charleston to Tallahassee will advance forward slowly as a weak cold front, then stall again into mid-week. Otherwise, weak high pressure will prevail. $$ Hagen