000 AXNT20 KNHC 210521 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 121 AM EDT WED SEP 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 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...SPECIAL FEATURES... Tropical Storm Karl is centered near 19.9N 56.7W at 21/0300 UTC or about 335 nm ENE of the Leeward Islands and about 860 nm SSE of Bermuda moving W at 12 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Scattered moderate convection is from 19N-23N between 52W- 56W. See latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. Tropical Storm Lisa is centered near 17.1N 31.7W at 21/0300 UTC or about 445 nm W of the Cape Verde Islands moving NW at 9 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Scattered moderate and isolated strong convection is from 13N-20N between 25W-33W. See latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT3/ WTNT23 KNHC for more details. ...TROPICAL WAVES... Tropical wave extends from 11N74W to 19N74W moving W at 15 kt. The wave remains within broad 700 mb troughing over the western Caribbean Sea and is embedded within an area of maximum low-level moisture as noted in Total Precipitable Water imagery. The wave is expected to remain beneath the influence of an upper level low noted on water vapor imagery centered near 16N76W. No significant deep convection is noted with the wave at this time. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 14N17W to 12N21W then from 12N34W to 07N45W. Aside from convection associated with Tropical Storm Lisa...scattered moderate convection is from 06N-10N between 24W-29W. Isolated moderate convection is from 05N-09N between 32W-47W. ...DISCUSSION... GULF OF MEXICO... A weakening upper level low is centered over the NW Gulf near 27N94W and an upper level anticyclonic circulation is centered over the eastern Gulf near 26N85W providing much of the basin with relatively tranquil weather this evening. Given the southwesterly flow aloft between the two upper level features...moisture and cloudiness prevail across much of the southern portion of the basin with isolated showers and tstms occurring generally S of 25N. Some of this convective activity is focused on broad surface trough analyzed from 21N94W to 27N90W. The surface trough is expected to drift westward through early Thursday with primarily gentle to moderate cyclonic winds in close proximity to the boundary. Thursday and beyond...surface ridging is expected to build in across the SE CONUS and northern Gulf with gentle to moderate anticyclonic winds prevailing through the upcoming weekend. CARIBBEAN SEA... A very broad upper level low is centered over the central Caribbean near 16N76W and stretches NNW to over central Cuba and eastward to 16N65W. Water vapor imagery indicates much of the moisture embedded within this upper level low is focused over Cuba and portions of the NW Caribbean. Widely scattered showers and isolated tstms are occurring N of 15N between 75W-85W. In addition...the presence of a tropical wave along 75W is continuing to provide ample low-level moisture. Across the SW Caribbean... scattered showers and strong tstms are occurring S of 14N between 76W-84W as the Monsoon Trough axis extends along 10N/11N between northern Colombia and Costa Rica. Finally...moderate to occasional fresh trades persist with the strongest of these trades generally remaining across south-central portions of the basin. ...HISPANIOLA... Isolated showers continue to diminish across the island this evening as a tropical wave along 75W moves westward. E-SE flow aloft persists within the northern periphery of an upper level low centered over the central Caribbean near 16N76W. ATLANTIC OCEAN... The remnant low of Julia centered across far eastern North Carolinas is analyzed as a 1012 mb low with a cold front extending to near 31N78W. A surface trough boundary continue S-SW to the Florida peninsula near Cape Canaveral then to Tampa Bay. Isolated showers are possible within 90 nm E of the cold front and from 26N-30N W of 77W. Otherwise...the remainder of the SW North Atlc is under weak surface ridging with moisture and cloudiness most prevalent across the SE Bahamas and adjacent coastal waters between the SE Bahamas and eastern Cuba. Widely scattered showers and isolated tstms are occurring from 21N-24N between 74W-78W. This activity is likely enhanced due to an upper level low centered over central Cuba near 22N80W. Farther east...Tropical Storm Karl lies to the SE of an upper level low centered near 23N62W. Moisture and cloudiness associated with the upper level low is generating isolated showers and tstms well away from the center of Karl from 22N-26N between 60W-66W. Finally...the remainder of the central and eastern Atlc is under the influence of a surface ridge anchored by a 1026 mb high centered near 34N45W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN