000 AXNT20 KNHC 181020 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 620 AM EDT SAT JUN 18 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 0600 UTC surface analysis and satellite imagery through 1015 UTC. ...TROPICAL WAVES... A tropical wave is in the East tropical Atlc with axis near 18W from 03N-13N, moving W at 15 kt during the last 24 hours. The wave coincides with broad 700 mb troughing between 07W and 30W according to the GFS model and low values of deep layer wind shear. CIRA LPW imagery indicate the wave is within a moderate moist environment from surface to 850 mb that along with a middle to upper level diffluent environment support scattered to isolated showers from 03N-14N E of 22W. A tropical wave is in the West tropical Atlc with axis near 47W from 04N-13N, moving W at 20 kt during the last 24 hours. The wave coincides with broad 700 mb troughing between 40W and 52W according to the GFS model and low values of deep layer wind shear S of 12N. CIRA LPW imagery indicate the wave is within a moderate moist environment from surface to 850 mb that along with an upper level diffluent environment support scattered to isolated showers from 04N-12N between 40W-52W. A tropical wave is in the West tropical Atlc with axis near 58W S of 15N, moving W at 20 kt during the last 24 hours. The wave coincides with 700 mb troughing between 54W and 62W according to the GFS model. CIRA LPW imagery indicate the wave is within a moderate moist environment from surface to 850 mb, however it is in a region of strong deep layer wind shear that in part inhibits convection at the time. A tropical wave is off the western Yucatan Peninsula with axis near 91W, moving W at 10-15 kt during the last 24 hours. The wave coincides with a very sharp 700 mb trough and a middle level low. The former described environment along with moderate moisture in the region support scattered to isolated showers S of 23N between 85W-96W, except for heavy showers and isolated tstms from 15N-21N between 84W-89W, including the Yucatan Peninsula and Belize. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 09N13W to 07N20W to 06N28W where the ITCZ axis begins and then continues to 06N38W to 0N47W. Aside from the convection associated with the tropical waves, a cluster of moderate convection is from 03N-07N between 24W-28W. ...DISCUSSION... GULF OF MEXICO... The main feature across the basin continue to be a tropical wave that is producing disorganized thunderstorms and cloudiness over the Yucatan peninsula of Mexico, Belize, northern Guatemala, and adjacent waters of the northwestern Caribbean Sea. A weak surface low pressure system could form over the southern Yucatan peninsula during the next day or so. The system is forecast to move westward to west-northwestward at about 10 mph during the next few days, emerging over the Bay of Campeche and the southwestern Gulf of Mexico by Sunday. Refer to the tropical waves section for more details. The remainder basin is dominated by weak surface ridging extending across the basin from the SW N Atlc waters. Scattered showers and tstms are in the E Gulf from 25N-27N E of 90W. Otherwise, gentle variable wind is E of 90W while SE gentle to moderate flow is to the W of 90W. CARIBBEAN SEA... A tropical wave over the Yucatan Peninsula continue to support scattered showers and isolated tstms across the NW Caribbean W of 84W and isolated showers in the Yucatan Channel. A middle level low over the Yucatan Peninsula and a ridge centered over Cuba generates diffluence in the region to support isolated showers along Cuba and adjacent waters. An upper level low and associated trough cover the central and eastern basin, however water vapor SSMI TPW and CIRA LPW imagery show mainly dry air in this region, which is favoring fair weather. Otherwise, a tight gradient between low pres in the SW basin and high pres in the N-NE Caribbean prevails, thus supporting NE to E strong to near gale- force winds from 11N- 13N between 74W-77W. Fresh to strong winds are S of 18N W of 85W, including the Gulf of Honduras. A new tropical wave will move into the eastern region by late today with possible showers. ...HISPANIOLA... Middle level troughing and an upper level low are over the the Island, however Water Vapor and CIRA LPW imagery show mainly dry air in this region, which is favoring fair weather. Similar conditions are expected during the remainder weekend. ATLANTIC OCEAN... Middle to upper level troughing continues along the far W Atlc waters with base reaching near the central Bahamas. Moderate moisture in this region along with lifting provided by the upper trough support scattered showers and isolated tstms between 62W- 72W N of 25N. Otherwise, besides the tropical waves discussed above, broad surface high pressure anchored NE of the Azores dominates elsewhere. For additional information please visit http://www.hurricanes.gov/marine $$ RAMOS