000 AXNT20 KNHC 240004 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 804 PM EDT THU JUN 23 2016 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 2345 UTC. ...TROPICAL WAVES... A tropical wave is in the west Tropical Atlantic with axis near 55W from 03N-12N, moving west at 20 kt over the past 24 hours. The wave coincides with a broad inverted trough at 500 mb and is embedded mainly in a dry environment as indicated by the surface to 850 mb CIRA LPW imagery. Enhanced Meteosat imagery show Saharan dry air and dust in the northern region of the wave, which is limiting the convection to isolated showers S of 12N between 50W- 60W. A tropical wave is in the southern Caribbean waters and across Venezuela with axis near 66W, moving west at 20 kt over the past 24 hours. The wave is embedded in an abundant moderate moist environment as indicated by the surface to 850 mb CIRA LPW imagery, however strong deep layer wind shear across the eastern Caribbean limits the convection to isolated showers S of 13N between 60W-66W. A tropical wave is in the Yucatan Peninsula with axis near 89W and associated with a 1014 mb low near 19N89W. The wave has been moving nearly at 10 kt within the last 24 hours. Abundant moderate moisture around the Yucatan Peninsula and divergent flow aloft support scattered heavy showers and isolated tstms that extends within 90 nm off the peninsula to Gulf of Mexico and NW Caribbean waters. ...ITCZ/MONSOON TROUGH... The monsoon trough extends across Africa into the east Tropical Atlantic near 11N15W and continues along 07N24W to 07N32W. The ITCZ begins then and extends to 05N44W to 05N53W. Scattered showers are from 04N-10N E of 34W. ...DISCUSSION... GULF OF MEXICO... The dominant feature at the surface continues to be a surface ridge that is anchored by a 1020 mb high pres center near 29N84W. This area of high pres provides gentle east to southeasterly flow N of 22N. Gentle to moderate north to northeasterly flow is in the Bay of Campeche associated with a tropical wave moving across the Yucatan Peninsula. See the tropical waves section for details. The wave is forecast to move to the Bay of Campeche early Fri morning and then weaken into a trough late Fri night into early Sat morning as it enters the region of Vera Cruz, Mexico. Otherwise, surface ridging will prevail elsewhere. CARIBBEAN SEA... A tropical wave moving across the Yucatan Peninsula and a favorable divergent environment aloft support scattered heavy showers and isolated tstms within 90 nm off the eastern Yucatan Peninsula and northern Belize. In the SE Caribbean, isolated showers are being supported by a second tropical wave that is moving mainly across inland Venezuela. See the tropical waves section above for details. Aloft, northerly flow dominates across the western half of the basin while the base of an upper trough over the central Atlc extends across the NE Caribbean. This is generating a diffluent environment across the Greater Antilles, which promotes lifting of warm moist air to support scattered heavy showers and isolated tstms. This shower activity is being noted across southern Cuba, Hispaniola and Puerto Rico as well as west and southern adjacent waters. Fresh to strong trades continue in the central basin generated by a strong gradient between low pres in the S-SW Caribbean and high pres to the N-NE. These winds will continue the next two days. A new tropical wave will enter the E basin near Fri sunrise and will move to central waters on Sun morning. ...HISPANIOLA... Northerly flow dominating across the western half of the Caribbean in the upper levels and troughing over the central Atlc extending across the NE Caribbean generate a diffluent environment across the Greater Antilles. This environment aloft is promoting lifting of warm moist air to support scattered heavy showers and isolated tstms across southern Hispaniola as well as west and southern adjacent waters. Similar shower activity is across La Mona passage. Global models guidance indicate that shower activity will continue through Fri, being enhanced in the afternoon by daytime heating. ATLANTIC OCEAN... A broad high pressure prevails across the basin N of 13N being anchored by a 1035 mb high NW of the Azores near 41N38W. A weakness in the ridge is analyzed as a surface trough from 30N50W to 23N43W to 21N33W with possible isolated showers within 60 nm either side of its axis. For tropical waves information, see section above. Little change is expected across the basin within the next 24 hours. For additional information please visit http://www.hurricanes.gov/marine $$ RAMOS