000 AXNT20 KNHC 061020 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 620 AM EDT Sun Aug 6 2017 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 1015 UTC. ...SPECIAL FEATURES... A tropical wave is in the central Caribbean with axis extending from central Cuba near 22N78W to an embedded 1009 mb low near 14N79W to Panama near 09N79W, moving W at 15 kt. The wave is in a region of mostly low to moderate vertical wind shear, and is underneath upper level divergent flow. Fresh to near gale force winds was noted in satellite wind data. Clusters of scattered moderate to isolated strong convection are within 180 nm either side of the axis. The wave has a medium chance of becoming a tropical cyclone during the next 48 hours. Please read the latest NHC Tropical Weather Outlook under AWIPS/WMO headers MIATWOAT/ABNT20 KNHC for more information. ...TROPICAL WAVES... A tropical wave is over the central Atlantic with axis extending from 18N36W to 09N39W moving W at 10-15 kt. A 1010 mb low is W of the wave near 11N40W. Moderate to strong vertical wind shear is to the north of the low center. The wave and low are in a moist environment. Dry Saharan air is noted N of 18N. The wave axis is well depicted at 700 mb. Widely scattered moderate convection is from 10N-16N between 34W-41W. A tropical wave extends is E of the Lesser Antilles with axis extending from 19N54W to 10N58W, moving W at 15 kt. The wave is in a region of mainly moderate to strong vertical wind shear. The wave is in a moist environment as seen on SSMI TPW imagery. The wave has a 700 mb trough W of the current position. Widely scattered moderate convection is within 120 nm of the wave axis. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 10N14W to 08N20W to 13N32W to 11N40W to 07N46W. The ITCZ extends from 07N46W to 12N56W. Aside from convection associated with the tropical waves, scattered moderate to isolated strong convection is along the coast of W Africa from 06N-11N between 10W-17W. Similar convection is from 06N-10N between 24W-28W. ...DISCUSSION... GULF OF MEXICO... Weak surface ridging is over the N Gulf of Mexico with axis along 29N. 10-15 kt SE surface winds are over most of the Gulf. Further S, a surface trough is over the Yucatan Peninsula from 21N89W to Guatemala near 15N92W. Scattered showers are within 60 nm of the trough. In the upper levels, a broad upper level trough is over the N Gulf N of 27N with upper level moisture and cloudiness. Expect over the next 24 hours for airmass showers and thunderstorms to reform over the N Gulf during the afternoon and evening hours Sun. CARIBBEAN SEA... A special feature tropical wave with embedded low is moving across the central Caribbean. This is the main weather producer in the basin and has the potential for further development, as it moves WNW. See above. Elsewhere, numerous strong convection is inland over W Honduras and El Salvador. In addition, the extension of the Pacific monsoon trough is producing scattered moderate convection over Costa Rica. Of note in the upper levels, a small upper level low is centered over the SW Caribbean near 14N77W. A tropical depression or tropical storm could form over the northwestern Caribbean Sea before it reaches the Yucatan peninsula late Monday or Tuesday. ...HISPANIOLA... The tropical wave is W of the island, however residual scattered showers remain. More scattered showers are expected Sun afternoon and evening during maximum heating. ATLANTIC OCEAN... A tropical low and two tropical waves are over the tropical Atlantic. See above. Scattered showers linger along the N Florida coast N of 29N W of 79W. Otherwise, the remainder of the Atlantic is under the influence of surface highs anchored near 29N69W, and 29N48W. Of note in the upper levels, an upper level low is centered near 23N61W with upper level diffluence S and W of the center producing scattered showers. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa