000 AXNT20 KNHC 181206 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 806 AM EDT Mon Jun 18 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 1145 UTC. ...TROPICAL WAVES... A tropical wave is in the E Atlc with axis extending from 02N28W to 12N27W, moving W at 15 kt. The wave is in a low or favorable deep layer wind shear envioronment. However, the GOES-16 Dust RGB and Split window imagery show the wave is being affected by dry air and dust, especially in the northern half of the wave environment. No deep convection is associated with the wave. A tropical wave is over the central Atlc with axis extending from 04N47W to 13N44W, moving W at 10 kt. Similar to the wave in the E Atlc, this wave is being affected by the presence of dry air and dust in its environment along with strong deep layer wind shear. Therefore, no deep convection is associated with this wave at this time. A tropical wave is within 225 nm SE of the Windward Islands with axis extending from 06N58W to 14N56W, moving W at 10 kt. This wave is within a very moist environment and under middle to upper level diffluent flow, which is supporting scattered moderate convection from 10N to 14N between 55W and 60W. A tropical wave moving westward over the central Caribbean has an axis extending from the Guajira Peninsula in NE Colombia near 12N73W to the S coast of the Dominican Republic near 18N71W, 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. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 12.5N17W to 08N24W. The ITCZ continues from 08N24W to 04N34W. In addition to the convection mentioned in the Tropical Waves section, Numerous moderate and scattered strong convection is evident from 05N to 11N between 16W and 22W. ...DISCUSSION... GULF OF MEXICO... An upper-level trough extends across the western Gulf from 28N89W to a low centered near 21N96W. Fresh to locally near gale force winds are occurring to the NE of the low primarily over the Gulf waters N of 22N between 88W and 94W due to a tight pressure gradient. Numerous moderate and scattered strong convection covers the NW half of the Gulf where heavy rains and gusty winds will persist and extend to the Texas coastal plain and SW Louisiana coast. Very heavy rainfall continues over the Yucatan Peninsula with localized flooding possible. Weak 1021 mb high pressure resides over the far NE Gulf near 30N84W. The upper-level trough will gradually move WNW through Mon, accompanied by numerous showers and thunderstorms that could produce rough seas. The upper-level trough is inducing surface troughing along the Texas coastal plain. The tight pressure gradient 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 as the trough shifts farther inland over Texas. CARIBBEAN SEA... Strong trades across the S central Caribbean from 11N to 14N between 73W and 79W will gradually decrease in areal coverage through mid week. Similar pulsing winds will continue in the vicinity of the Gulf of Honduras. A tropical wave will reach the waters E of the Lesser Antilles later 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 modest 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 32N56W to 26N70W to 21N80W with the western portion in the process of dissipating. Cloudiness, scattered showers and isolated thunderstorms are present along and up to 180 nm SE of the front to the E of 70W. High pressure measuring 1032 mb centered over the Azores near 39N26W ridges SW to the N of Puerto Rico near 22N68W. The cold front will stall over and E of the northern Bahamas during the next couple of days while weakening. 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 $$ Rivera/Ramos