000 AXNT20 KNHC 180438 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1238 AM EDT Thu Oct 18 2018 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 0000 UTC surface analysis and satellite imagery through 0415 UTC. ...SPECIAL FEATURES... The Central American Gyre has moved into the Eastern Pacific Ocean, to the south of Guatemala. Any continued development into a tropical cyclone will occur in the Eastern Pacific Ocean. Widely scattered to scattered moderate and isolated strong rainshowers are inland and in the Caribbean Sea from 10N to 17N between 78W and 90W. Isolated moderate rainshowers are elsewhere from the Windward Passage westward. Local flooding still remains a threat in inland areas. A slowly-moving cold front/quasi-stationary front passes through the Florida Big Bend, into the Gulf of Mexico to 29N90W just off the coast of SE Louisiana, curving to 27N93W. The front becomes stationary, and it continues to the coast of Mexico near 18N94W, in the SW Gulf of Mexico. The front is not continuous between 94W and 97W. The stationary front is dissipating, inland, from 18N97W to 25N101W. Numerous strong rainshowers are from 16N to 20N between 93W and 97W in the SW corner of the Gulf of Mexico and in parts of the Isthmus of Tehuantepec. Isolated moderate to locally strong rainshowers are elsewhere in the Gulf of Mexico from 90W westward. The forecast for the next 18 hours for the Gulf of Mexico consists of: NW-to-N GALE-force winds, and sea heights ranging from 8 feet to 14 feet, S of 25N W of 95W. Expect NW-to-N GALE-force winds for another six hours, and sea heights ranging from 8 feet to 14 feet, S of 21N W of 95W. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 15N30W 10N33W 05N35W. 28W/29W. Widely scattered moderate to isolated strong rainshowers are from 10N to 15N between 25W and 33W. A Caribbean Sea tropical wave is along 66W/67W from 20N southward. An upper level trough is along 20N60W in the Atlantic Ocean, to Hispaniola, into the NW corner of the Caribbean Sea. Isolated moderate to locally strong rainshowers are within 120 nm on either side of the line that runs from 13N65W to 16N70W to central Hispaniola. A Caribbean Sea tropical wave is along 83W/84W from 20N southward. The tropical wave is moving through an area of upper level cyclonic wind flow, and into the area of precipitation in the SW corner of the Caribbean Sea. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Sierra Leone near 08N13W, curving to 06N18W. The ITCZ continues from 06N18W to 05N23W, and 05N28W. Widely scattered moderate to isolated strong rainshowers are from 03N to 10N between 33W and 46W. Isolated moderate rainshowers are from 10N southward from 30W eastward. Rainshowers are possible elsewhere from 10N southward from 60W eastward. GULF OF MEXICO... A stationary front extends from the Florida Panhandle to the NW Gulf near 26N94W to 22N94W to the Bay of Campeche near 18N94W. Gale force northerly winds behind the front offshore of Mexico will persist through Thursday, with fresh to strong winds N of there and behind the front. The wind speeds will diminish to less than gale-force on Thursday night and Friday, as the front weakens and becomes diffuse. A second cold front will enter the Gulf waters on Saturday. The second front will stall from central Florida to southern Texas on Sunday night, and then it will lift N through early next week. CARIBBEAN SEA... An upper level trough is along 20N60W in the Atlantic Ocean, to Hispaniola, into the NW corner of the Caribbean Sea. Isolated moderate to locally strong rainshowers cover the Atlantic Ocean and the Caribbean Sea from 10N to 14N between 54W and 68W. Moderate to fresh trades will prevail the next several days, except locally strong near the Gulf of Honduras, approach to Windward Passage, S of Hispaniola, and in the Lee of eastern Cuba through the end of the week, and then returning near the approach to Windward Passage and S of Hispaniola next week. ATLANTIC OCEAN... An upper level trough passes through 32N43W, to a 29N50W cyclonic circulation center, to 22N58W, to 18N63W in the Caribbean Sea, and eventually to Hispaniola. A surface trough is along 45W/47W from 17N to 31N. Isolated moderate rainshowers cover the area from 20N to 31N between 34W and 66W. An upper level cyclonic circulation center is near 23N21W. Cyclonic wind flow covers the Atlantic Ocean from 15N northward between Africa and 30W. Gentle to moderate return flow N of 27N and moderate to fresh, locally strong, trade winds S of 27N, will prevail through tonight with high pres NE of the area. A backdoor cold front will drop S of 31N on Thursday, with freshening winds and building seas through Friday, before decreasing on Saturday. Another cold front may enter the NW part of the area on Saturday night, once again with increasing winds and building seas behind the front through Monday, with the front weakening by Monday night. For additional information please visit http://www.hurricanes.gov/marine $$ mt