000 AXNT20 KNHC 220001 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 705 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...SPECIAL FEATURES... Tropical Storm Otto is centered near 11.3N 79.2W at 21/2100 UTC or about 165 nm east-southeast of San Andres Island or about 275 nm east 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 to isolated strong convection is from 10N-13N between 78W-80W. Scattered showers and possible isolated thunderstorms are from 14N to over Panama and Costa Rica between 78W-83W. Please see latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough extends across Africa into the east Tropical Atlantic near 13N17W to 13N18W. The ITCZ begins near 13N39W along 11N46W to near 11N55W. Clusters of scattered moderate to isolated strong convection are from 9N-15N between 25W-40W and from 8N-10N between 53W-55W. ...DISCUSSION... ...GULF OF MEXICO... A dry and stable airmass remains over the Gulf of Mexico this evening with a surface ridge extending over the Gulf from the east CONUS anchored by a 1027 mb high over Indiana and a 1025 mb high over southeast Louisiana. This is giving the Gulf clear skies and tranquil conditions except in the southwest Gulf where a weak surface trough extends just off the coast of Mexico from 23N97W to 19N93W. Isolated showers are possible within 60 nm of the surface trough. The surface ridge will shift eastward tonight, diminishing winds and seas. A cold front will move into the north Gulf Wednesday night, then stall and weaken on Thursday. ...CARIBBEAN SEA... The primary concern this evening is newly formed Tropical Storm Otto. Please see Special Features above. A leading stationary front extends from the central Atlantic across central Puerto Rico along 14N72W to northeast of T.S. Otto near 13N77W. Scattered showers and possible isolated thunderstorms are within 120 nm east and 150 nm west of this front. A second remnant stationary front extends from the west Atlantic across Cuba near 22N78W then west of the Cayman Islands to 19N84W. This front is embedded within dry, stable air aloft limiting shower activity. T.S. Otto is expected drift west through Wednesday and could become a hurricane later in the week. The remnant front over the northwest Caribbean is beginning to wash out. The leading stationary front will persist through Wednesday. ...HISPANIOLA... The stationary front that extends from the central Atlantic across Puerto Rico into the Caribbean is generating scattered showers and possible isolated thunderstorms over the the Dominican Republic this evening. In addition, daytime heating is producing some isolated showers dotting the remainder of the island. Lingering moisture coupled with the close proximity of the front could continue to give the island showers and possible thunderstorms through Thursday, with the highest concentration over the Dominican Republic. ...ATLANTIC OCEAN... A broad upper trough covers the west into the central Atlantic supporting a leading stationary front that extends through 32N53W along 24N61W into the Caribbean across Puerto Rico. Scattered showers and possible isolated thunderstorms are within 60 nm east of the front. A reinforcing cold front extends through 32N60W along 26N67W to the Bahama Islands near 23N75W where it pulls up stationary across Cuba and into the northwest Caribbean near 22N78W. This reinforcing cold front is embedded within dry, stable air aloft, limiting shower activity. A surface ridge anchored over the eastern CONUS extends over the far west Atlantic west of the reinforcing cold front. An upper ridge anchored along the coast of Venezuela and extends a ridge axis across the northern Leeward Islands into the central Atlantic and is providing difflunce aloft to generate dense overcast clouds with possible scattered showers within 200 nm of the leading stationary front south of 27N. An upper low in the east Atlantic is centered near 23N37W supporting a surface trough that extends from 26N39W through a 1011 mb low near 20N34W continuing to 15N37W. The upper low is generating scattered showers and possible isolated thunderstorms from 23N-26N between 35W-39W. An upper ridge to the east of the upper low is providing difflunce aloft to generate scattered showers from 15N- 22N between 24W-34W. A surface ridge dominates the east Atlantic north of 26N east of 50W anchored by a 1031 mb high about north of the Azores. The west Atlantic reinforcing cold front will continue to move east merging with the leading stationary front Tuesday. The stationary portion of the reinforcing front will dissipate by Tuesday. For additional information please visit http://www.hurricanes.gov/marine $$ PAW