000 AXNT20 KNHC 141159 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 759 AM EDT Thu Jun 14 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 1130 UTC. ...TROPICAL WAVES... A tropical wave is in the E Atlc with axis extending from 11N26W to 03N27W, 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. The GOES-16 Geocolor RGB imagery shows the presence of the Saharan Air Layer dust and dry air N of the wave at 15N. Scattered moderate convection is from 06N to 08N between 24W and 27W. A tropical wave is in the central Atlc with axis extending from 11N42W to 03N43W, 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 supports scattered moderate convection from 06N to 11N between 37W and 44W. A tropical wave is E of the Windward Islands with axis extending from 14N57W to 03N59W, moving W at 5-10 kt. The Saharan Air Layer dust and dry air is N of 11N. This factor along with strong wind sheer in the region is hindering the development of deep convection. A tropical wave is in the central Caribbean with axis extending S from the southern coast of Cuba near 20N76W to near the NW coast of Colombia near 10N76W, moving west at 15-20 kt. Meteosat Split Window imagery show SAL dry air moving across the central and E Caribbean, which along with strong wind sheer hinders the development of deep convection at the time. A tropical wave is over the SW Gulf of Mexico just W of the Yucatan Peninsula with axis extending from 23N91W to across SE Mexico, moving west at 10-15 kt. Scattered moderate to strong convection is S of 23N W of the wave axis to the coast of Mexico. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 12N16W to 08N18W. The ITCZ extends from 08N18W to 06N25W, then resumes west of a tropical wave near 06N28W continuing to 05N42W, then resumes again W of another tropical wave near 05N44W and continues to the coast of South America near 05N53W. Besides the convection mentioned in the tropical waves section, scattered moderate to strong convection is within 300 nm SW of the coast of Africa from 05N to 11N. Scattered moderate convection from 04N to 07N between 21W and 25W, and from 03N to 06N between 36W and 39W. ...DISCUSSION... GULF OF MEXICO... The Atlantic subtropical ridge extends W to the NW Gulf of Mexico along 29N. Scattered showers and thunderstorms extend from the Yucatan Channel northward to 27N to the E of 87W. In the upper levels, a large upper level trough is over the Gulf with axis along 90W with upper level moisture. The tropical wave in the SW Gulf will gradually weaken into a broad and elongated area of low pressure through Fri into early Sat, with the pressure gradient supporting fresh to strong SE flow across the western Gulf of Mexico on Sun. CARIBBEAN SEA... The tropical wave in the central Caribbean will continue westward across the remainder of the basin through the early part of the weekend, while another tropical wave currently in the Tropical N Atlantic will move into the eastern Caribbean on Fri and Sat. Scattered showers and thunderstorms are S of 11N in the SW Caribbean, and in the NW Caribbean W of 85W. Otherwise, mostly fair weather is over the E Caribbean. In the upper levels, an upper level trough is over the W Caribbean W of 80W. A large upper level ridge is over the remainder of the Caribbean with axis along 72W. Strong trades currently across the central Caribbean will shift slightly W across the waters between 70W and 85W through the end of the week, then begin to diminish into the early part of the weekend. ATLANTIC OCEAN... Southerly surface flow continues to advect moisture to the W Atlantic. Diffluent upper level flow is also over the W Atlantic. Widely scattered showers and thunderstorms is N of 22N and W of 74W including across the Bahamas. Farther E, an upper level trough in the central Atlantic supports a cold front from 32N51W to 25N62W. A pre-frontal trough is 60 nm SE of the front. Scattered showers and isolated thunderstorms are within 240 nm E of the front. Otherwise, a 1029 mb high is centered over the E Atlantic near 35N31W producing surface ridging over the E Atlantic E of 50W and N of 20N. This ridge is forecast to shift E Fri and Sat allowing the cold front to progress eastward through the waters north of 26N over the weekend. For additional information please visit http://www.hurricanes.gov/marine $$ Lewitsky