000 AXNT20 KNHC 171203 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 803 AM EDT Sun Jun 17 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 0600 UTC surface analysis and satellite imagery through 1100 UTC. ...TROPICAL WAVES... Three tropical waves are noted between the W coast of Africa and the Lesser Antilles. A tropical wave axis extends from 04N21W to 13N20W. This system is moving W around 10 kt well defined in the TPW product and in model diagnostics guidance. Scattered moderate convection is present within 120 nm of the wave axis between 04N and 09N. A tropical wave over the E Atlantic has an axis extending from 03N41W to 13N39W, moving W around 10 kt. A modest surge of moistened air is noted in association with the wave in TPW imagery. Only limited cloudiness and isolated showers are associated with this wave. A tropical wave over the central Atlantic has an axis extending from 05N54W to 14N52W, moving W around 20 kt. The wave coincides with a high amplitude bulge of moisture as depicted in the TPW product. Currently, scattered moderate and isolated strong convection is seen from 08N to 11N between 52W and 54W. A tropical wave moving westward over the eastern Caribbean has an axis extending from 12N70W to 19N68W, moving W around 15 kt. African dust surrounds the wave. As a result, only shallow moisture and virtually no convection is associated with this wave. A tropical wave moving across the border of Guatemala and Mexico has an axis extending from 12N92W to 19N92W and is moving W around 10 kt. TPW satellite imagery indicates this wave is embedded in deep layer moisture. Scattered to numerous moderate and isolated strong convection is occurring from 11N to 20N between 90W and 95W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from Senegal on the coast of Africa near 14N17W to 09N21W to 08N27W to 09N35W. The ITCZ is analyzed from 03N43W to 04N51W. Besides the convection mentioned in the Tropical Waves section, Scattered moderate and isolated strong convection is found from 05N to 10N between 10W and 16W. ...DISCUSSION... GULF OF MEXICO... A surface trough extends across the western Gulf from 20N96W to 27N94W. Fresh to locally strong winds are near the trough axis prevailing mostly across the central Gulf waters from 22N to 27N between 89W and 92W. Scattered moderate and isolated strong convection covers almost all of the central Gulf within 150 nm either side of a line from 21N87W to 19N96W. This activity is supported by an upper-level low currently centered over the SW Gulf near 22N94W. Heavy rains and gusty winds will continue to head NW across the Gulf waters this morning and reach portions of the Texas and southwestern Louisiana coasts. Weak 1019 mb high pressure resides over the eastern Gulf near Ft Myers Florida. The surface trough will move WNW through Sun night accompanied by numerous showers and thunderstorms that could produce rough seas. A tightening of the pressure gradient between the trough and high pressure that extends westward from the Atlantic will continue to support fresh to strong SE winds over the west-central Gulf waters. These winds will spread westward through Tue while gradually diminishing with the trough shifting inland over Texas. CARIBBEAN SEA... Strong trades across the south central Caribbean between 69W and 76W will gradually decrease in areal coverage through mid week. The strongest winds will become confined to the S central waters, with similar pulsing winds continuing in the vicinity of the Gulf of Honduras. A tropical wave will reach the waters E of the Lesser Antilles tonight, then enter the eastern Caribbean Tue through Wed night. This system is expected to be accompanied by scattered showers and thunderstorms. As the wave passes across the Lesser Antilles into the eastern Caribbean, it will bring gusty winds and a increase in showers and thunderstorms to the Leeward Islands, the UK/US Virgin Islands and Puerto Rico by mid week. ATLANTIC OCEAN... A cold front extends SW from 32N59W to 27N71W to 29N78W. Cloudiness, scattered showers and isolated thunderstorms are present along and up to 150 nm SE of the front to the E of 70W. A weak surface trough possessing no significant convection lies along the W shore of Andros Island in the Bahamas from 23N79W to 25N78W with no convection. High pressure measuring 1031 mb centered over the Azores near 39N27W ridges SW to N of Puerto Rico near 23N66W. The weak trough over the northern Bahamas will lose identity this morning. The cold front will stall over and east of the northern Bahamas during the next couple of days. The high pressure ridge over the Azores will continue to ridge SW across the western Atlantic. For additional information please visit http://www.hurricanes.gov/marine $$ McElroy