000 AXNT20 KNHC 191041 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 641 AM EDT MON SEP 19 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 1000 UTC. ...SPECIAL FEATURES... Tropical Storm Karl is centered near 18.2N 47.7W at 19/0900 UTC or about 810 nm E of the Leeward Islands moving W at 13 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 18N-22N between 43W-48W. See latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. Tropical wave extends from 13N25W to 22N25W moving W at 5-10 kt. A 1007 mb low is analyzed at the southern extent of the wave axis and remains embedded within the Monsoon Trough as a broad low- level monsoonal gyre covering the area from 08N-20N between 17W- 35W. Widely scattered moderate convection is from 12N-18N between 21W-29W. Isolated moderate convection is elsewhere from 05N-12N between 18W-33W. See latest NHC Tropical Weather Outlook under AWIPS/WMO Headers MIATWOAT/ABNT20 KNHC for more details. ...TROPICAL WAVES... Tropical wave extends from 11N65W to 21N64W moving W at 15 kt. The wave remains within broad 700 mb troughing over the Caribbean Sea between 65W-76W and is embedded within an area of maximum low-level moisture as noted in Total Precipitable Water imagery. The wave is expected to remain on the eastern periphery of an upper level low noted on water vapor imagery centered near 14N68W. Isolated moderate convection is from 10N-16N between 63W-69W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 15N17W to 13N25W to 09N37W. Aside from convection associated with the tropical wave along 25W...widely scattered moderate convection is from 04N-11N between 12W-16W. ...DISCUSSION... GULF OF MEXICO... An upper level ridge anchored over western Mexico extends a ridge axis eastward over the Gulf basin through 25N97W to over the northern Florida peninsula near 29N82W. The ridging aloft supports a pair of high pressure centers...one a 1016 mb high centered near 26N86W and the other a 1015 mb high centered near 27N94W. Water vapor imagery also indicates a middle to upper level shortwave trough moving over the lower Mississippi River valley this morning that is supportive of a weak surface trough boundary analyzed from 31N87W to 28N90W generally in the area between the two surface highs. Isolated showers and tstms are occurring across a portion of the north-central Gulf waters N of 25N between 87W- 92W. Given the overall tranquil conditions with high pressure in place...gentle to moderate anticyclonic winds are expected through Tuesday. CARIBBEAN SEA... An upper level low is centered over the eastern Caribbean near 15N68W. Within the eastern periphery of the upper level low...a tropical wave is noted along 66W that supports isolated showers and tstms across the eastern Caribbean S of 17N between 63W-69W. Otherwise...farther west...an upper level ridge is anchored over Central American near 14N84W. Ample diffluence aloft continues to generate scattered showers and tstms across portions of Central America and the adjacent coastal waters from 13N-18N between 81W- 89W. 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 are noted across portions of the island and adjacent coastal waters as an upper level low is centered across the Caribbean Sea near 15N68W. A tropical wave noted within the eastern periphery of the upper level low along 66W will continue to provide increased cloudiness and higher probability of precipitation through the first half of the week. ATLANTIC OCEAN... The remnant low of Julia in the SW North Atlc is analyzed as a 1011 mb low centered off the South Carolina coast near 33N78W. A surface trough extends from 31N77W to 28N78W providing focus for scattered showers and isolated tstms occurring within 75 nm either side of the boundary. Isolated showers are elsewhere from 26N-32N between 72W-79W. Farther east...a broad area of weaker surface pressures is noted focused on a surface trough analyzed from 32N63W SW to 29N67W to 24N74W. Scattered showers and tstms are occurring from 27N-31N between 60W-66W with isolated showers and tstms occurring elsewhere N of 25N between 60W-70W. Otherwise...aside from Tropical Storm Karl and the special features tropical wave along 26W...the remainder of the central and eastern Atlc is under the influence of a surface ridge anchored by a 1033 mb high centered well north of the discussion area near 44N29W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN