000 AXNT20 KNHC 141202 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 702 AM EST Tue Nov 14 2017 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 1115 UTC. ...SPECIAL FEATURES... A 1008 mb low pressure center is near 34N31W, about 300 nm to the SSW of the Azores. A surface trough extends from the low center to 30N30W 27N33W 26N40W. Rainshowers are possible from 25N northward between 28W and 40W. The low center is supported aloft by a middle level to upper level cyclonic circulation center, that is near 34N29W. Precipitation: widely scattered to scattered moderate and isolated strong rainshowers from 30N to 37N between 25W and 30W. This low pressure center has a medium chance of becoming a subtropical cyclone during the next couple of days as it moves to the NE, before upper-level winds become unfavorable. Expect near gale-force winds during the next day or two. ...ITCZ/MONSOON TROUGH... The monsoon trough passes through coastal sections of Sierra Leone near 08N13W to 08N17W. The ITCZ continues from 08N17W to 08N22W, 04N30W, 05N41W, and 03N46W. Precipitation: scattered strong from 03N to 05N between 10W and 13W. scattered moderate to isolated strong from 04N to 09N between 14W and 20W. widely scattered moderate to isolated strong from 03N to 08N between 17W and 25W. isolated moderate to locally strong from 08N to 13N between 20W and 53W. rainshowers are possible elsewhere from 15N southward from 60W eastward. Upper level SW wind flow covers the Atlantic Ocean to the S and SE of the line from 26N15W to 25N22W to 14N50W to 08N52W. Broken to overcast multilayered clouds and possible rainshowers are in this same area. ...DISCUSSION... THE GULF OF MEXICO... An upper level trough passes through coastal South Carolina, to east-central Florida into the SE corner of the area. The trough supports a cold front, that passes through 32N73W to the Florida coast near 29N81W. A surface trough is from 120 nm to 180 nm to the east of the cold front from 26N to 32N. Upper level NW wind flow is moving across the entire Gulf of Mexico. Upper level SW wind flow is moving from the NW corner of the Caribbean Sea, across Cuba, and beyond the Bahamas. The upper level SW wind flow is part of a larger-scale area of anticyclonic wind flow that is extending from the Caribbean Sea, across the Greater Antilles, into the Atlantic Ocean. Precipitation: rainshowers are possible from 25N southward from 90W eastward. Mist and fog are being reported from Alice Texas to interior sections of the deep South of Texas. A surface ridge passes through SW Louisiana, through the deep south of Texas, to Mexico near 20N98W, into the Isthmus of Tehuantepec of southern Mexico. The current pressure gradient is expected to relax somewhat by Wednesday. The wind speeds will be decreasing, into gentle-to- moderate breezes, and gentle southerly return flow re- establishing itself across the NW waters. THE CARIBBEAN SEA... Large-scale upper level anticyclonic wind flow spans the area. A ridge extends from the SW corner of the area, beyond 30N65W in the Atlantic Ocean. A surface trough extends from a 1005 mb low pressure center that is near 11N78W, to 15N81W. Precipitation: scattered strong from the Colombia/Venezuela border near 09N73W to the Caribbean Sea from 13N southward between 73W and 80W. A second surface trough extends from 23N75W in the Atlantic Ocean, across Cuba to 18N81W. Precipitation: widely scattered moderate to isolated strong from 20N northward from 63W westward. Upper level anticyclonic wind flow is moving on top of this area, with the upper level ridge that runs from the SW corner of the Caribbean Sea to 30N65W in the Atlantic Ocean. A third surface trough is along 17N83W, into the Gulf of Honduras. Widely scattered moderate to isolated strong from 14N northward from 73W westward, in the NW corner of the Caribbean Sea. Moderate to fresh tradewinds prevail, and they are expected to persist through Tuesday. Global models indicate a broad and stretched out area of surface low pressure developing from the waters NE of Cuba to Jamaica and into the SW Caribbean Tuesday night into Wednesday quickly moving E-NE and merging with a frontal boundary in the SW North Atlc Wednesday night into Thursday. ...HISPANIOLA... Widely scattered moderate to isolated strong rainshowers are in the Windward Passage. Some showers are reaching parts of SW Haiti. Surface observations are not reporting rainshowers. Cumulonimbus clouds are being reported in Santo Domingo in the Dominican Republic. Upper-level W-to-NW wind flow is moving across the area. Low-level moisture convergence continues to be maximized across the region within E-SE tradewinds. This overall pattern will persist through Thursday with precipitation expected to increase during the next 24 to 48 hours. THE ATLANTIC OCEAN... A surface trough is along 24N27W 21N28W 17N29W. Upper level SW wind flow covers the Atlantic Ocean to the S and SE of the line from 26N15W to 25N22W to 14N50W to 08N52W. Broken to overcast multilayered clouds and possible rainshowers are in this same area. For additional information please visit http://www.hurricanes.gov/marine $$ MT