000 AXNT20 KNHC 211758 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1258 PM EST MON NOV 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 1200 UTC surface analysis and satellite imagery through 1715 UTC. ...SPECIAL FEATURES... Tropical Storm Otto is centered near 11.5N 79.3W at 21/1800 UTC or about 150 nm ESE of San Andres Island or about 265 nm E of Bluefields Nicaragua remaining nearly stationary. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Scattered moderate convection is from 08N-15N between 77W-83W. See latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 12N16W to 12N19W. The Intertropical Convergence Zone axis extends from 13N38W to 10N50W to 07N58W. Widely scattered moderate convection is from 04N-08N between 02W-17W. Scattered moderate convection is from 09N-22N between 23W-38W. Much of this area of convection is enhanced by a middle to upper level low centered near 23N37W and focused on a 1014 mb surface low centered near 20N33W and the associated surface trough extending SW from the low center to 14N38W. ...DISCUSSION... GULF OF MEXICO... The Gulf is under the influence of dry and stable westerly flow aloft with a subtle upper level trough axis along 96W and mid- level ridging over the basin and central CONUS. At the surface... broad ridging is providing overall fair skies and conditions with gentle to moderate anticyclonic winds. One exception is a surface trough extending across the SW Gulf from 19N93W to 23N98W with possible isolated showers occurring S of 23N W of 92W. Looking ahead...the ridge is expected to gradually shift eastward across the SE CONUS and into the SW North Atlc through Wednesday with S-SE return flow re-establishing itself across portions of the western Gulf waters. An area of low pressure will eject out of the Rockies into the central Plains during this time with the associated weak cold front to emerge off the Texas and Louisiana coasts by Wednesday afternoon. The weak front will quickly become stationary and diffuse across the NW Gulf and north-central Gulf coast Thursday night. CARIBBEAN SEA... The main feature in the Caribbean Sea is Tropical Storm Otto. Otto is located at the western extent of a stationary front extending across Puerto Rico to 15N70W to 13N76W. While convection remains centralized in the vicinity of Otto...widely scattered showers and tstms are occurring generally within 180 nm either side of the stationary front. In addition...to the W of the front strong N to NE winds are occurring between 70W-84W across portions of the western Caribbean. The front is supported aloft by a broad middle to upper level trough over the western North Atlc and a global model indicated ribbon of mid-level energy extending from 27N61W SW to 19N79W. Otto is expected to drift slowly westward with fresh to strong NE winds expected W of 70W to continue between the area of lower pressure and a ridge anchored across the SE CONUS through much of the week. ...HISPANIOLA... A stationary front extends across Puerto Rico to 15N70W to 13N76W providing focus for scattered showers and isolated tstms within 180 nm either side of the boundary. Increased cloudiness and possible isolated showers are noted across southeastern portions of Hispaniola this afternoon. With the front expected to remain in place to the SE of the island...precipitation and possible convection is likely through Wednesday. ATLANTIC OCEAN... Broad middle to upper troughing is noted on water vapor imagery over the SW North Atlc region this afternoon supporting a cold front analyzed from 32N61W SW to 26N70W to the central Cuba coast near 22N79W. Isolated showers are possible within 75 nm either side of the front. Otherwise...the remainder of the area to the W of the front is influenced by surface ridging anchored across the lower Mississippi River valley. To the E of the cold front across the central Atlc...embedded within the broad troughing... mid-level energy supports a stationary front analyzed from 32N53W to 20N64W and across Puerto Rico into the central Caribbean Sea. Low-level moisture convergence in the vicinity of the front along with middle to upper level diffluence is generating scattered showers and isolated tstms within 180 nm either side of the front. Finally...across the eastern Atlc...a 1014 mb low is centered near 20N33W. This area of low pressure is supported aloft by a middle to upper low centered near 23N37W. A surface trough extends NW from the low center to 26N38W and SW from the low center to 14N38W. Widely scattered showers and isolated tstms are occurring from 22N-28N between 23W-40W. Scattered showers and widely scattered tstms are occurring from 09N-23N between 23W-38W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN