National Hurricane Center's Tropical Weather Discussion

North America - Central America - Gulf of Mexico - Caribbean - Atlantic Ocean

382 AXNT20 KNHC 180005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT Wed Oct 17 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 1800 UTC surface analysis and satellite imagery through 2330 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 74W westward, mainly from 15N southward from 77W 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, toward SE Louisiana, curving to 28N93W. The front is stationary, and it continues to the coast of Mexico near 18N along 93W/94W, in the SW Gulf of Mexico. The front continues toward the west, and then the northwest, inland in Mexico, to 20N99W, 25N101W. Widely scattered moderate to isolated strong rainshowers are in the Gulf of Mexico from 90W westward, and inland in southern Mexico including in the Isthmus of Tehuantepec, between 90W and 100W. The forecast for the next 24 hours for the Gulf of Mexico consists of: NW GALE-force winds to the S of 20N to the W of the front, and sea heights ranging from 10 feet to 14 feet. Expect NW-to-N GALE-force winds for another six hours, from 21N southward to the west of the front. The sea heights will range from 8 feet to 12 feet. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 28W/29W from 03N-17N, moving W at 10 kt. SSMI TPW imagery shows a distinct maximum in moisture around the wave axis. Scattered showers are within 120 nm of the wave axis. A Caribbean Sea tropical wave is along 64W from 05N-21N, moving west at 10-15 kt. A 700 mb trough is associated with the wave, and there is a local maximum in SSMI TPW. Scattered moderate to isolated strong convection is from 08N-20N between 61W-64W. A Caribbean Sea tropical wave is along 80W from 07N-20N, moving W at 15 kt. SSMI TPW imagery shows a distinct maximum in moisture around the wave axis. Scattered moderate convection is from 08N- 18N between 79W-84W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Sierra Leone near 09N13W, curving to 06N18W. The ITCZ continues from 06N18W to 08N30W, and from 07N35W to the coast of French Guiana near 05N52W. Isolated moderate to locally strong rainshowers cover the Atlantic Ocean from 03N to 15N from 46W eastward. GULF OF MEXICO... A slowly-moving cold front/quasi-stationary front passes through the Florida Big Bend, into the Gulf of Mexico, toward SE Louisiana, curving to 28N93W. The front is stationary, and it continues to the coast of Mexico near 18N along 93W/94W, in the SW Gulf of Mexico. The front continues toward the west, and then the northwest, inland in Mexico, to 20N99W, 25N101W. Gale-force northerly winds behind the front offshore of Mexico will persist through Thu, with fresh to strong winds N of there and behind the front. Winds will diminish below gale force Thu night and Fri as the front weakens and becomes diffuse. A second cold front will enter the gulf waters Sat. The front will stall from central Florida to southern Texas Sun night. CARIBBEAN SEA... An upper level low is centered S of Hispaniola near 17N73W enhancing scattered showers from the Leeward Islands to E Cuba. 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. ATLANTIC OCEAN... A 1033 mb high pressure center is near 42N26W. A surface ridge extends to the central Atlantic. A surface trough is in the central Atlantic from 28N43W to 19N45W enhancing trade wind showers north of 19N between 30W- 50W. This area of showers is moving west at 15 kt. Gentle to moderate return flow N of 27N and moderate to fresh, locally strong, trades S of 27N will prevail through Wed night with high pres NE of the area. A backdoor cold front will drop S of 31N Thu with freshening winds and building seas through Fri before decreasing Sat. Another cold front may enter the NW portion Sat night, once again with increasing winds and building seas behind the front. For additional information please visit http://www.hurricanes.gov/marine $$ mrf/al/mt