000 AXNT20 KNHC 052330 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 630 PM EST Fri Jan 5 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 2315 UTC. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 05N08W to 04N20W. The Intertropical Convergence Zone axis extends from 04N20W to 03N30W to the Equator near 43W into NE Brazil. Convection is limited. ...DISCUSSION... GULF OF MEXICO... A ridge dominates the entire Gulf region anchored by a 1031 mb high pressure located across Mississippi near 32N89W. Cold air stratocumulus clouds are noted across much of the region. Thick low clouds are banked up along the E slopes of the Sierra Madre mountains. Gentle to moderate E-NE winds prevail, and are expected to continue through early Saturday morning. Thereafter, the ridge will move eastward as a trough develops within the easterly winds across the central Gulf along 90W Saturday afternoon and evening. The pressure gradient between the trough and strong high pressure of 1040 mb over the Mid Atlantic States will bring an increase in winds across the east and central Gulf by Sat night. These winds are expected to persist through Mon morning, ahead of the next cold front forecast to emerge off the Texas and Louisiana coasts on Monday. CARIBBEAN SEA... A stationary front extends from central Hispaniola to 15N77W to the coast of Panama near 09N78W. Clusters of moderate to isolated strong convection are noted along the the frontal boundary, particularly from 12N to 17N between 75W and 78W. Patches of low level moisture is noted elsewhere across the basin. The most recent scatterometer pass showed fresh to strong northerly winds on the west side of the front to the coast of Nicaragua, and between Jamaica and about 82W. E of the front, mainly moderate easterly winds prevail. The front will remain nearly stationary N of 15N and drift W to the S of 15N through Sun. Fresh to strong northerly winds off Central America from Honduras to Panama are expected to continue through Sun morning, while fresh to strong NE winds in the Windward Passage and lee of Cuba will briefly reach gale force early Sun through Sun evening due to the presence of a strong high pressure N of the region. As this high pressure moves eastward into the Atlantic ocean, winds will gradually veer to NE to E across the entire basin. Large NW swell will reach the regional Atlantic waters this evening and persist through Sun. ...HISPANIOLA... Cloudiness with embedded showers and isolated tstms will persist across the island tonight and Saturday as a frontal boundary remains stationary across Hispaniola. There is a risk of heavy rain leading to flash floods and mudslides. Fresh to strong NE winds are expected through the Windward Passage and northern coast exposures through Sunday night. These winds will briefly reach gale force on Sunday. ATLANTIC OCEAN... A mid-to-upper level trough is noted on water vapor imagery over the eastern CONUS supporting a cold front that enters the forecast area near 31N58W, and extends SW to near 22N67W where it becomes stationary to across Hispaniola and into the Caribbean Sea. A wide band of cloudiness with embedded showers and isolated tstms is associated with the front over the Atlantic. A secondary cold front is clipping the area near 30N70W. West of the main front, a ridge extends across the SW N Atlantic, including Florida and the Bahamas. The remainder of the central and eastern Atlantic is under the influence of a surface ridge anchored by a 1034 mb high centered W of the Azores near 37N37W. Mainly fresh to locally strong trades are seen along the southern periphery of the ridge between the coast of Africa and the Lesser Antilles based on scatterometer data. A cold front is pushing southward between the Madeira and the Canary Islands. For additional information please visit http://www.hurricanes.gov/marine $$ GR