000 AXNT20 KNHC 272319 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 719 PM EDT THU OCT 27 2016 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 2300 UTC. ...TROPICAL WAVES... Tropical wave extends from 09N43W to 14N42W moving W at 10-15 kt. The wave remains low-amplitude and relatively difficult to track as a result. Subtle 700 mb trough is noted in global model fields between 41W-47W. Isolated moderate convection remains within close proximity to the ITCZ axis from 07N-12N between 41W-45W. Tropical wave extends from 11N69W to 22N67W moving W at 10-15 kt. The wave coincides with 700 mb troughing between 67W-72W. The northern portion of the wave is soon to merge with a stationary frontal boundary to the north and west and a shear line analyzed to the west. Widely scattered moderate convection is from 18N-25N between 62W-68W...and from 14N-17N between 67W-70W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from near 15N27W to 11N36W to 09N42W. The Intertropical Convergence Zone axis extends from 09N42W to 08N52W. Scattered moderate and isolated strong convection is from 10N-14N between 24W-29W...with scattered moderate convection elsewhere from 08N-17N between 28W-40W...and from 07N-10N between 44W-54W. ...DISCUSSION... GULF OF MEXICO... A middle to upper level trough is noted on water vapor imagery with axis extending from over the lower Mississippi River valley S-SW to a broad base over the SW Gulf and southern Mexico near 19N94W. This troughing aloft is inducing a weak surface trough analyzed across the SW Gulf from 24N92W to 19N92W providing focus for widely scattered showers and isolated tstms generally S of 25N W of 90W. Elsewhere to the east of the upper level troughing... southerly flow aloft prevails with plenty of moisture advection and cloudiness covering much of the eastern Gulf waters...Florida peninsula and Florida Straits. Scattered showers and isolated tstms are occurring generally S of 27N E of 90W. Aside from convection...a strengthened pressure gradient exists between higher pressure across the SE CONUS and an area of developing low pressure across the western Caribbean Sea. Fresh to strong easterly winds are expected across eastern portions of the basin through Thursday night into early Friday with slightly weaker winds...moderate to fresh E-NE winds occurring across western portions of the basin through Friday night. CARIBBEAN SEA... Southerly flow aloft prevails between an upper level trough over the western Gulf of Mexico and an upper level anticyclonic circulation centered over the central Caribbean near 16N70W. Tropical moisture continues to advect northward and interact with a shear line analyzed from the Windward Passage near 20N73W to the northern coast of Jamaica into a 1009 mb low centered near 17N84W. A surface trough extends S-SE from the low to 15N83W to 10N81W. Scattered showers and widely scattered tstms are occurring N of 16N W of 79W...with widely scattered showers and isolated tstms occurring elsewhere N of 14N W of 75W and S of 14N W of 79W. Convection ongoing across Costa Rica and Panama continues to be enhanced due to the close proximity to the Monsoon Trough analyzed along 09N. Farther east...beneath the diffluence generated by the upper level ridging...a tropical wave along 69W continues to provide focus for scattered showers and tstms occurring north of Puerto Rico...but also across the central Caribbean from NW Venezuela to across Hispaniola from 10N-23N between 70W-75W. Energy associated with the tropical wave is expected to continue moving westward however northern portions will continue to merge with the previously mentioned shear line that lies across the Windward Passage region. ...HISPANIOLA... Upper-level anticyclonic wind flow prevails across the island. Scattered showers and isolated tstms are occurring across western and central portions of the island this evening along with the adjacent coastal waters. Little change in the synoptic pattern is expected through the next 24-36 hours as energy from the tropical wave along 69W merges with the shear line analyzed across the Windward Passage region. ATLANTIC OCEAN... A surface ridge prevails across the SW North Atlc anchored by a 1027 mb high centered near 35N73W. With generally lower pressures to the south across the Caribbean Sea due to a developing area of low pressure across the NW Caribbean and a tropical wave along 69W...a strengthened pressure gradient persists generally W of 65W. Strong to near gale force E-NE winds persist with plenty of cloudiness and precipitation W of a line from coastal South Carolina SE to 20N68W. To the east...a stationary front extends from 32N50W SW to 23N70W then becomes a shear line to the Windward Passage. Isolated showers and possible tstms are occurring N of 27N within 90 nm either side of the stationary front. As mentioned above with the tropical wave...front...and shear line all coming together across an area N of Hispaniola and Puerto Rico... scattered showers and tstms are occurring from 18N-25N between 62W-69W. A surface trough extends from 16N57W to 22N57W with isolated showers and tstms occurring from 17N-21N between 54W- 57W. Finally across the NE Atlc discussion waters...a 1003 mb surface low centered near 33N24W extends a surface trough from the low to 31N23W to 26N29W. Isolated showers and tstms are from 29N- 35N between 19W-24W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN