000 AXNT20 KNHC 140003 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 803 PM EDT Wed Jun 13 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...TROPICAL WAVES... A tropical wave is in the E Atlc with axis extending from 11N24W to 02N25W, moving W at 10-15 kt. The wave is in a favorable wind shear environment, and the CIRA LPW show moderate moisture associated with it. However, the GOES-16 Geocolor RGB imagery show the presence of the Saharan Air Layer in that region N of 15N. Scattered showers are within 120 nm of the wave axis. A tropical wave is in the central Atlc with axis extending from 11N40W to 01N41W, moving W at 15 kt. GOES SAL and Dust RGBs show the wave has dry air and dust N of 12N. Upper level diffluent flow and shallow moisture in the vicinity of the ITCZ support isolated moderate convection from 03N to 08N between 36W and 44W. A tropical wave is about 300 nm E of the Windward Islands with axis extending from 13N55W to 03N56W, moving W at 5-10 kt. The Saharan Air Layer is N of 11N thus CIRA LPW imagery shows some dry air intrision over the northern portion of the wave. This factor along with strong wind sheer in the region is hindering the development of deep convection at the time. Isolated showers are from 06N-10N between 53W and 58W. A tropical wave is in the central Caribbean with axis extending from 19N76W to 10N78W, moving west at 20 kt. Meteosat Split Window imagery show SAL dry air moving across the central and E Caribbean, which along with strong wind sheer hinder the development of deep convection at the time. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 11N15W to 07N18W. The ITCZ extends from 07N26W to 05N39W, then resumes west of a tropical wave near 05N42W and continues to 06N55W. Besides the convection mentioned in the tropical waves section, scattered showers are within 120 nm of the remainder of the ITCZ. ...DISCUSSION... GULF OF MEXICO... The Atlc subtropical ridge continues to the NW Gulf of Mexico along 29N. Low level moisture is advecting from the Caribbean to the SW Gulfand the Bay of Campeche. Farther east, a surface trough along the E Yucatan Peninsula and Belize is generating disorganized showers and thunderstorms over the northwestern Caribbean Sea, extending into the Yucatan Channel. This area of disturbed weather is forecast to move west-northwestward to the southwestern Gulf by Thursday afternoon. No development is expected for the next day or so due to land interaction with the Yucatan Peninsula and strong upper-level winds. However, environmental conditions could become slightly more conducive for some development while it moves across the southwestern Gulf of Mexico on Friday and Saturday. CARIBBEAN SEA... Disorganized showers and thunderstorms over the northwestern Caribbean Sea are associated with a surface trough. This area of disturbed weather, accompanied by strong gusty winds, is forecast to move west-northwestward over Belize and the Yucatan Peninsula tonight, and move into the southwestern Gulf of Mexico by Thursday afternoon. Farther east, a tropical wave moves across the central Caribbean waters. See above. In addition, scattered moderate to isolated strong convection is over the W Caribbean and Central America W of 82W. ATLANTIC OCEAN... Southeasterly surface flow continues to advect moisture to the SW N Atlc. Additional diffluent upper level flow over this area supports widely scattered moderate convection W of 74W, to include the Bahamas. Farther east, an upper level trough in the NW Atlc continue to support a frontal system that extends as a cold front from 32N54W to 27N63W. A prefrontal trough is 120 nm E of the front. Scattered showers are within 240 nm E of the front. Otherwise, the Atlc subtropical ridge dominates the remainder basin. The ridge is forecast to shift east Fri and Sat allowing a weak cold front to move east through the waters north of 26N over the weekend. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa