000 AXNT20 KNHC 312350 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 750 PM EDT MON OCT 31 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 2345 UTC. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 11N16W to 05N23W to 06N31W where the ITCZ begins and continues to 07N43W. Scattered moderate convection is within 250 nm either side of the Monsoon Trough between 20W-30W. ...DISCUSSION... ...GULF OF MEXICO... An elongated surface ridge covers the southeastern CONUS and extends south reaching the northern Gulf waters. To the southwest, a surface trough extends across the Bay of Campeche from 25N92W to 19N93W. Scattered moderate convection prevails along the northern portion of the trough from 23N-25N and west of 93W. A shearline was analyzed from 22N91W to 23N85W to 25N80W. Scatterometer data depicts fresh to strong northeasterly winds from 23N-28N and east of 90W while gentle to moderate easterly winds prevail elsewhere. The surface ridge will be reinforced by a stronger high pressure system on Tuesday, maintaining fresh to locally strong winds over the southeast Gulf and the Straits of Florida through this period. ...CARIBBEAN SEA... A shearline across the Florida Straits supports isolated showers over western Cuba. In the western portion of the basin, scatterometer and surface data depict a surface trough that extend from 21N86W to 17N85W to 15N82W to 11N83W. This feature combined with a diffluent flow aloft is supporting scattered moderate convection in the vicinity of the trough from 15N-20N and west of 84W affecting portions of Honduras, Belize and the Yucatan Peninsula. To the south, the Monsoon trough extends across Costa Rica and Panama enhancing scattered moderate convection south of 12N between 78W-83W. Another surface trough extends over Hispaniola with scattered showers and thunderstorms north of 17N between 68W-72W. This trough and the proximity of a 1009 mb surface low just north of Puerto Rico are supporting scattered showers across the northeastern Caribbean waters north of 17N and east of 67W. Scatterometer data depict gentle trades across the basin. Strong northeast winds will develop late tonight as the surface high over the northeast CONUS moves east-southeast. These winds will spread across the Yucatan, Cuba's adjacent waters and Windward Passage on Tuesday and prevail through early Thursday. ...HISPANIOLA... A 1009 mb surface low just north of Puerto Rico extends its trough across the southern portion of the island enhancing scattered moderate convection south of 19N between 69W-72W. The low is forecast to move south-southwest closer to Puerto Rico through early Tuesday. This will result in an increase in shower activity across the entire island through the next 24 hours. ...ATLANTIC OCEAN... A 1009 mb surface low is located just north of Puerto Rico near 20N67W with surface trough extending from Hispaniola near 18N72W to the low to 24N57W to a 1014 mb low located near 29N48W. An area of scattered showers is observed within 460 nm east of these features between 40W-65W. A pair of surface troughs extend from 20N46W to 16N49W and from 19N36W to 13N37W. Isolated showers are observed along the troughs. Surface ridging prevails elsewhere. The surface low in the southwest Atlantic will drift southwest through tonight to near the Mona Passage then move northeast into the central Atlantic through Wednesday. A strong high pressure will build over the northwest Atlantic pushing weak frontal boundaries south to along 27N enhancing winds/seas. For additional information please visit http://www.hurricanes.gov/marine $$ ERA