000 AXNT20 KNHC 160540 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 140 AM EDT Sat Jun 16 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 0000 UTC surface analysis and satellite imagery through 0515 UTC. ...TROPICAL WAVES... A tropical wave is in the E Atlantic, with axis extending from 13N30W to 04N32W, moving W at 10 kt. The wave shows up well as a moisture surge in TPW imagery. The GOES-16 Geocolor RGB imagery shows the presence of the Saharan dust and dry air north of the wave. Scattered moderate convection is noted where the wave meets the ITCZ along 06N. A tropical wave is in the central Atlantic, with axis extending from 14N46W to 04N47W, moving W at 10 kt. The wave is well depicted in the TPW product. Shallow moisture and isolated showers are observed near the wave's axis. A tropical wave is moving westward across the eastern Caribbean. Its axis extends along 65W. African dust also surrounds the wave. As a result, shallow moisture with embedded showers is associated with the wave. Moisture related to this system will reach Puerto Rico tonight, and Hispaniola by early on Sun. A tropical wave is over the W Caribbean, with axis along 84W from 11N-18N, moving W at 10 kt. Scattered showers and tstms prevail over the SW Caribbean including Central America mainly south of 18N and west of 81W. The wave will continue moving westward through Central America through Saturday. The GFS model indicates plenty of moisture over Central America this upcoming weekend. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 11N16W to 07N22W. The ITCZ continues from 07N22W to 06N29W, then resumes west of a tropical wave from 07N34W to 05N45W. Besides the convection mentioned in the Tropical Waves section, scattered moderate convection is noted within about 75 nm on either side of the monsoon trough east of 22W. ...DISCUSSION... GULF OF MEXICO... A surface trough is analyzed over the SW Gulf from 23N95W to 20N94W with scattered showers. Another trough extends over the Yucatan Peninsula from 20N89W to 19N92W. Scattered moderate convection prevails with this trough. An upper-level low centered over the western Gulf is helping to induce this convective activity affecting the eastern Gulf, and parts of the Yucatan Peninsula and the Yucatan Channel. Environmental conditions are not expected to be favorable for significant development. However, heavy rains and gusty winds are likely to continue across the Yucatan Peninsula and the central Gulf of Mexico through Saturday. This activity is also likely to reach portions of the Texas and southwestern Louisiana coasts by Sunday. A ridge dominates the remainder of the basin. The surface trough across the Bay of Campeche will shift WNW moving over inland Mexico tonight. The second trough will continue to enhance convection across the southwest Gulf. A tightening pressure gradient east of this second trough will induce fresh SE winds in west-central Gulf waters tonight, becoming strong to near gale in the central Gulf this weekend, then spreading W through early next week. CARIBBEAN SEA... A large area of disorganized showers and thunderstorms over the northwestern Caribbean Sea and the Yucatan Peninsula supported at upper-levels by a diffluent flow. Scattered showers and tstms are also seen over the west Caribbean south of 18N and west of 81W. Two tropical waves are moving westward across the basin. Please, see the Tropical Wave section above for details. Recent scatterometer data provided observations of fresh winds across the central Caribbean, with seas of 10-11 ft. The aerial extent of these winds, roughly between 73W and 81W, will slightly diminish this weekend. However, fresh to strong winds will prevail across the Gulf of Honduras and the NW Caribbean over the next couple of days. ATLANTIC OCEAN... A stationary front prevails north of the area enhancing scattered moderate convection north of 30N and west of 70W. Two tropical waves are moving westward across the basin. Please, see the Tropical Wave section above for details. The remainder of the basin is under the influence of a surface ridge, anchored by a 1031 mb high pressure located SW of the Azores near 37N30W. A cold front will enter the northern portion of the basin this weekend enhancing convection through early next week. The surface ridge located S of this boundary will sink southward through this period. A new high pressure is forecast to build from N of the area by Tue. For additional information please visit http://www.hurricanes.gov/marine $$ ERA