000 AXNT20 KNHC 132339 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 705 PM EST Fri Jan 13 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...SPECIAL FEATURES... A strong pressure gradient between lower pressure across South America and a ridge anchored across the SW North Atlantic is generating gale force winds in the SW Caribbean Sea from 9.5N- 12.5N between 74W-79W with NE winds 30-35 kt and seas 11-13 ft. This gale will last 24 hours. See latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 07N13W to 03N22W. The intertropical convergence zone axis extends from 03N22W to 01N30W to 01N40W to the coast of South America near 01S45W. Scattered moderate to strong convection is from 01N-06N between 12W-20W. Isolated moderate convection is from 01S-04N between 38W-44W. ...DISCUSSION... GULF OF MEXICO... 10-20 kt E to SE surface return flow is over the Gulf of Mexico maintaining warm temperatures. The Gulf has patches of scattered showers moving W to NW. Showers are over central Florida, over the SE Gulf, over N Yucatan Peninsula, NW of the Yucatan Peninsula, and along the coast of SE Louisiana. An upper level ridge is over the Gulf with axis along 95W. Very strong subsidence covers the entire Gulf. This overall synoptic pattern is expected to persist through the remainder of the weekend. The next front is not expected until Tuesday evening along the coast of Texas. CARIBBEAN SEA... Gale conditions are along the coast of N Colombia. See above. A shear line extends from Trinidad near 11N60W to N Colombia near 11N74W. Scattered showers are within 60 nm of the shear line, especially along the coast of Venezuela. Elsewhere, radar imagery shows scattered showers over Puerto Rico advecting in from the Atlantic. Hispaniola and E Cuba has similar conditions especially over the upper elevations. More scattered showers are over the Gulf of Honduras and along the coast of Costa Rica. In the upper levels, a broad upper level ridge is over the Caribbean Sea with axis along 60W. Strong subsidence covers the entire Caribbean. Expect showers along the shear line to become diffuse over the next 24 hours, however, a new line of showers will advect to the coast of Venezuela with the NE surface flow. ...HISPANIOLA... Fresh to strong NE winds prevail across the island and adjacent coastal waters. This wind field is due to a relatively strong pressure gradient between the NW Caribbean and the Atlantic low near 21N53W. Scattered showers are over the northern portions of the island especially over higher elevations. Expect showers to continue as the NE flow persists through the remainder of the weekend. ATLANTIC OCEAN... A 1031 mb high is centered over the W Atlantic near 33N72W. A ridge axis extends WSW to N Florida. A 1011 mb low is centered E of the Lesser Antilles near 21N53W. A surface trough extends SW from the low to 16N57W. Scattered showers are within 60 nm of the low and trough. An upper level low is centered near 25N47W. Upper level diffluence E of this center is producing isolated moderate convection from 21N-28N between 33W-48W. Expect in 24 hours for the surface low to drift to 19N52W with a trough remaining to the SW. Also expect another surface trough to be over the central Atlantic from 31N38W to 24N41W with showers. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa