000 AXNT20 KNHC 212358 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 758 PM EDT TUE JUN 21 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 2315 UTC. ...TROPICAL WAVES... Tropical wave extends from 04N39W to 10N38W moving W at 15 kt. The wave position is based on long-term IR satellite imagery and extrapolation during the past few days. No significant deep convection is associated with the wave at this time. Tropical wave extends from 04N50W to 10N49W moving W at 15 kt. The wave remains embedded within the ITCZ and coincides with subtle 700 mb troughing between 45W-52W. Isolated moderate convection is within 90 nm either side of the axis. Tropical wave extends from 11N78W to 19N77W moving W at 20 kt. The wave coincides with 700 mb troughing noted between 72W-80W on the southwestern periphery of a mid-level ridge anchored over the SW North Atlc near 27N66W. Scattered moderate and isolated strong convection is from 09N-20N between 74W-87W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 15N17W to 07N26W. The Intertropical Convergence Zone axis extends from 07N26W to 05N31W to 07N46W to 06N57W. Scattered moderate isolated strong convection is within 120 nm of 07N19W. Isolated moderate convection is from 04N-10N between 42W-59W. ...DISCUSSION... GULF OF MEXICO... Water vapor imagery indicates an upper level low is centered over the northern Yucatan peninsula near 21N89W and a middle to upper anticyclone centered over North Texas and Oklahoma near 35N98W. Between these two features...NE flow aloft prevails over much of the basin this evening remaining relatively dry and stable. Further supporting stable conditions...at the surface a 1022 mb high is centered across central Alabama with ridge axis extending along 30N. Mostly moderate E-SE winds are noted on earlier scatterometer data and these winds are expected to persist through Saturday as the ridge remains stationary. Elsewhere...in closer proximity to the upper level low...widely scattered showers and isolated tstms are occurring across the SE Gulf S of 25N E of 89W...including portions of the Florida Straits and northern Yucatan peninsula. CARIBBEAN SEA... The main feature across the basin is a tropical wave along 78W bringing scattered showers and tstms to a large portion of the western Caribbean and portions of Central America S of 18N W of 74W. Most of this convection comes under the influence of not only the low-level moisture convergence associated with the tropical wave but middle to upper level lifting dynamics on the eastern periphery of an upper level low centered near 21N89W. In addition to the convection associated with the tropical wave... scattered showers and tstms are occurring Cuba and Hispaniola this evening...including the adjacent coastal waters. Across the SW Caribbean...the Monsoon Trough axis extends across Panama and is providing focus for scattered showers and tstms generally S of 12N W of 78W. ...HISPANIOLA... As a tropical wave along 78W continues to move westward away from the island...lingering widely scattered showers and isolated tstms are occurring this evening. While this area of moisture shifts west...overall surface troughing will remain across the western Caribbean along with low-level moisture convergence. This along with peak daytime heating and instability will likely generate afternoon showers and tstms on Wednesday. ATLANTIC OCEAN... A middle to upper level shortwave trough is noted on water vapor imagery over the western North Atlc near 43N60W that supports a stationary front extending from 32N63W SW to the NW Bahamas near 26N77W and into the Straits of Florida. Widely scattered showers and isolated tstms are occurring within 90 nm either side of the front...and mostly south of the boundary between 67W-79W. A surface trough extends from the front near 26N73W to across eastern Cuba near 20N76W. This troughing is likely energy fractured northward away from a tropical wave moving across the western Caribbean Sea this evening. In addition...this entire area falls beneath the influence of the eastern periphery of an upper level low centered near 21N88W. The front is expected to become diffuse through early Wednesday as ridging builds westward from the central Atlc. Farther east...the remainder of the central and eastern Atlc is under the influence of a surface ridge anchored by a 1031 mb high centered near 34N48W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN