000 AXNT20 KNHC 131652 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1151 AM 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 1200 UTC surface analysis and satellite imagery through 1615 UTC. ...SPECIAL FEATURES... A strong pressure gradient between lower pressure across South America and a ridge anchored across the SW North Atlc and Florida peninsula is generating near gale to gale force winds in the SW Caribbean Sea. These conditions are expected to pulse during the late night and early morning hours through Sunday. 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 05N10W to 05N15W to 03N21W. The Intertropical Convergence Zone axis extends from 03N21W to the Equator near 41W. Scattered moderate convection is S of 09N between 09W-17W. Isolated moderate convection is from 02N-06N between 37W-52W. ...DISCUSSION... GULF OF MEXICO... Middle level ridging remains anchored across the eastern Gulf waters and portions of the SW North Atlc that supports surface ridging with axis extending from central Georgia SW to southern Mexico near 21N98W. Moderate to occasional fresh E-SE winds are occurring across the basin this afternoon with mostly fair skies noted on visible satellite imagery. This overall synoptic pattern is expected to persist through the weekend. The next front is not expected to emerge off the Texas and Louisiana coasts and into the NW Gulf until Tuesday night into Wednesday. CARIBBEAN SEA... West-southwesterly flow aloft prevails over the basin between broad upper level troughing over southern Mexico and Central America...including a portion of the adjacent east Pacific waters and an upper level ridge anchored over the northeastern South American continent. Another middle to upper level low is also noted on water vapor imagery centered over the central Atlc near 23N52W supporting a shear line analyzed from 12N60W W across Tobago to NW Venezuela near 11N69W to northern Colombia near 12N73W. Scattered to occasional numerous showers are occurring within 90 nm either side of the shear line boundary. In addition...strong to near gale force NE winds are occurring in close proximity to the coast of Colombia due to a strengthened pressure gradient across the region. Otherwise...fresh to strong trades persist elsewhere. The shear line boundary is expected to remain nearly stationary and gradually become diffuse through Sunday. ...HISPANIOLA... Fresh to strong NE winds prevail across the island and adjacent coastal waters this afternoon. This wind field is due to a relatively strong pressure gradient across the region and SW North Atlc waters. Isolated showers are expected to continue as the NE flow persists through the weekend. ATLANTIC OCEAN... A middle to upper level low is centered near 23N52W that supports a nearly collocated 1013 mb surface low centered near 21N53W. The associated cold front extends from a triple point near 23N50W S-SW to 15N54W and becomes a shear line into the far SE Caribbean Sea near Tobago. A partial occlusion extends from NW of low to the triple point with the warm front analyzed from 23N50W to 23N44W. Widely scattered showers and isolated tstms are occurring from 21N-28N between 43W-55W. The remainder of the SW North Atlc is under the influence of a surface ridge anchored by a 1032 mb high centered near 33N70W and a 1031 mb high centered near 35N61W. Mostly moderate to fresh NE to E winds prevail on the southern periphery of the ridge which are forecast through Sunday. The low pressure area along the front is expected to drift southward through Saturday and weaken well E of the Lesser Antilles by Saturday night into Sunday. Farther east...a surface trough extends from 21N42W to 26N38W providing focus for scattered showers and isolated tstms from 19N-31N between 32W-42W. This area of activity continues to be enhanced by marginal middle to upper level diffluence to the east of the upper level low. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN