000 AXNT20 KNHC 310601 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 101 AM EST Wed Jan 31 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 0545 UTC. ...SPECIAL FEATURES... Caribbean Sea Gale Warning: A slightly tighter pressure gradient between a strong surface ridge building over the SE CONUS in the wake of a low pressure system centered in the NW Atlc, and low surface pressure in northern South America will support minimal gale-force winds pulsing at night near the coast of Colombia through Thu night. Sea heights to range from 10 feet to 14 feet during that period. Please read the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Liberia near 06N10W to 05N14W. The ITCZ continues from 05N14W to 01N30W to 0N50W. Scattered moderate to locally strong convection is within 165 nm either side of the ITCZ between 13W and 35W. ...DISCUSSION... ...GULF OF MEXICO... A strong surface ridge extends southward from Ohio SW to Mississippi, across the Gulf of Mexico and into the far NW Caribbean. As a cold front in the SW Atlc continue to move SE, NE winds in the eastern Gulf continue to diminish with the latest scatterometer pass showing fresh to strong winds mainly S of 28N E of 87W. Similar winds prevail in the Bay of Campeche. The ridge will shift E on Wednesday and Thursday, thus allowing SE return flow to set up across the entire basin by Wed night. The next cold front is forecast to enter the northern Gulf waters on Friday morning. The front is forecast to extend from central Florida to the western-central Gulf waters on Saturday morning when the portion of the front over the Gulf will stall before transitioning to a warm front. No significant showers are expected over the basin with this front. ...CARIBBEAN SEA... A cold front passes through eastern Cuba near 21N77W where it stalls and continues SW to the western Gulf of Honduras near 15N88W. Scattered rainshowers are within 75 nm west of the front S of 20N. Isolated showers are within 90 nm either side of the remaining front. Strong to minimal gale force winds are expected near the coast of Colombia primarily late at night and into the early morning hours through Thursday night as strong high pressure moves from the SE CONUS to the SW N Atlc and then into the central Atlc waters. Please read the SPECIAL FEATURES section for details. The stationary front will continue to weaken today and its remnants will transition to a shear line at night, which will dissipate on Thursday. Fresh to strong N-NE winds and building seas are NW of the front and in the SW basin as noted in latest scatterometer data. Moderate trades dominate the easter Caribbean with some localized fresh winds noted near the coast of Venezuela. GOES-16 water vapor imagery show very stable conditions from the lower to the upper levels, except for the NW Caribbean where convection is associated with the front. ...ATLANTIC OCEAN... A system of low pressure with storm force winds in the NW Atlc waters supports a cold front that enters the SW N Atlc waters from 30N64W to the southern Bahamas to the eastern coast of northern Cuba where it transitions to a stationary front to the Gulf of Honduras in the Caribbean. With only shallow moisture in the vicinity of the front, scattered showers are limited to N of 26N between 60W and 65W. In the central Atlc, a middle to upper level low continue to support scattered heavy showers from 20N to 31N between 38W and 48W. SW of this convection, the reflection of the low aloft is seen as a 1012 mb low centered near 23N51W with an associated trough extending from the low SW to 22N56W. There is no convection associated with these joint features. The remainder eastern Atlc continues under the influence of the Azores ridge that anchors by a 1037 mb high just N of the islands. The cold front will reach from 30N55W to 25N61W tonight and from the last point it will stall to the approaches of the Windward Passage. Fresh to strong NW-N winds will dominate the entire area that is to the west of the front, including the Old Bahama Channel. High pressure in the wake of the front will dominate the region through Thursday. Another cold front is forecast to arrive in the northern waters on Friday evening. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos