000 AXNT20 KNHC 091803 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 203 PM EDT FRI SEP 9 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 1200 UTC surface analysis and satellite imagery through 1715 UTC. ...SPECIAL FEATURES... Tropical wave extends from 12N41W to 20N41W moving W at 20 kt. A 1010 mb low is centered at the southern extent of the wave axis that remains embedded within the Monsoon Trough as a broad monsoonal gyre. Scattered moderate convection is from 05N-10N between 37W-44W...and from 12N-17N between 37W-44W. As of 09/1500 UTC...a 1014 mb low was centered in the Florida Straits near 24N80W. An elongated surface trough extends from near Grand Bahama Island into the low then SW across western Cuba. Scattered moderate convection is from 21N-24N between 77W-80W. Regardless of development through the overnight hours into Friday...gusty winds and the potential for heavy rainfall across Cuba and the Florida Keys is expected with strong winds and building seas across the adjacent marine areas through Saturday. ...TROPICAL WAVES... Tropical wave extends from 11N73W to 19N72W moving W at 15 kt. The wave coincides with broad 700 mb troughing between 68W-77W and a maximum in 850 mb relative vorticity in the vicinity of the wave axis near 15N. No significant deep convection is noted on satellite imagery at this time. Tropical wave extends from 13N87W to 23N86W moving W at 15 kt. Abundant low-level moisture is noted in Total Precipitable Water imagery across the western Caribbean Sea and eastern Gulf of Mexico in association with the wave. Isolated moderate convection is from 22N-26N between 85W-88W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the west African coast near 10N14W to 10N17W to 14N33W to 12N41W to 10N42W to 08N45W. The Intertropical Convergence Zone axis extends from 08N45W to 05N52W. Aside from the convection associated with the tropical wave along 42W...scattered moderate convection is 05N-12N between 11W-23W... and from 05N-07N between 51W-55W. ...DISCUSSION... GULF OF MEXICO... An upper level low is noted on water vapor imagery centered over the NW Gulf near 27N95W while an upper level anticyclonic circulation is centered over the SE Gulf near 24N84W. Only a few isolated showers are occurring across the NW Gulf waters this morning as mostly dry air is noted W of 90W. A tropical wave extends across the Yucatan Channel and along with a favorable upper level diffluent environment aloft in association with the ridging...scattered showers and tstms are occurring S of 25N between 82W-88W. The wave is expected to move W to WNW during the next 24 hours while weakening across the SW Gulf during the weekend. Otherwise...gentle to moderate E-SE winds are expected to persist through Saturday as surface ridging anchored by a 1018 mb high centered across Alabama remains nearly stationary through Saturday. The ridge will gradually erode as broad troughing moves westward across the Florida peninsula and Florida Straits late Sunday into Monday. CARIBBEAN SEA... The primary feature across the Caribbean this afternoon is a tropical wave along 87W. Most of the convective activity associated with the wave is noted across the SE Gulf of Mexico...however isolated showers and tstms extends southward W of 80W...including portions of Central America. To the NE of the exiting tropical wave...weak surface troughing extends to near Bermuda...likely a fractured portion of energy from the tropical wave is generating scattered showers and tstms N of 20N between 76W-81W...including portions of central Cuba. This troughing is expected to gradually move westward into the Gulf of Mexico during the next 24 to 36 hours. Otherwise...a broad upper level low is noted on water vapor imagery over the eastern Caribbean centered near 17N66W. While dry air embedded within the upper level low is providing for mostly clear skies across the eastern Caribbean...a surface trough extends from Saint Kitts and Nevis to 21N61W providing focus for scattered showers and tstms across the SW North Atlc waters from 18N-22N between 59W-66W. Finally...moderate to fresh trades prevail across much of the basin with occasional strong trades within 120 nm of the coast of Venezuela. ...HISPANIOLA... Fair weather conditions prevail across the island this afternoon supported by both unfavorable deep layer wind shear and strong subsidence aloft within NE flow. A surface trough analyzed across the NE Caribbean Sea will move across Hispaniola during the weekend with increased probability of showers and tstms expected. ATLANTIC OCEAN... Diffluent flow between an elongated upper level low centered near 31N74W and a broad upper level anticyclone centered over the SE Gulf of Mexico supports scattered showers and tstms across central Cuba and the SW North Atlc waters from 21N-26N between 73W-81W. This activity is focused on a surface trough extending from Grand Bahama island to western Cuba. To the NE...the upper level low supports another surface trough analyzed from 30N64W to 27N66W to 24N72W. Another area of scattered showers and tstms is occurring within the vicinity of the surface trough and the area of maximum middle to upper level diffluence east of the upper level low from 25N-32N between 65W-73W. As mentioned above...an upper level low is centered over the eastern Caribbean Sea near 17N66W supporting a surface trough extending from Saint Kitts and Nevis to 21N61W. Scattered showers and tstms are noted from 17N-22N between 53W- 66W. Otherwise...the remainder of the central and eastern Atlc remains under the influence of a surface ridge anchored by a 1029 mb high centered near 35N42W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN