000 AXNT20 KNHC 030537 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 137 AM EDT SAT SEP 3 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 0000 UTC surface analysis and satellite imagery through 0530 UTC. ...SPECIAL FEATURES... Tropical Storm Hermine is centered near 34.1N 78.4W at 03/0300 UTC or about 26 nm west-southwest of Wilmington, North Carolina and about 156 nm west-southwest of Cape Hatteras, North Carolina moving northeast at 19 kt. Estimated minimum central pressure is 997 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Scattered moderate convection is from 32N-39W between 71W-79W. Locally heavy rainfall and flooding is possible in the path of Hermine. Please see the latest NHC Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC and the full Forecast/Advisory under the AWIPS/WMO headers MIATCMAT4/ WTNT24KNHC for more details. Tropical Storm Gaston is centered near 40.1N 28.7W at 03/0300 UTC or about 91 nm northwest of Faial Island in the central Azores and about 109 nm west-northwest of Lajes Air Base in the Azores moving east-northeast at 14 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. No deep convection is noted with this system. Please see the latest NHC Forecast/Advisory under the AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. ...TROPICAL WAVES... A tropical wave is over the eastern Atlantic with an axis extending from 21N26W to a 1011 mb low near 17N27W to 09N27W, moving west at 10-15 kt. The northern portion of this wave is interacting with African dust which is inhibiting convection. Scattered moderate convection prevails where the wave interacts with the Monsoon Trough mainly south of 12N between 24W-29W. A tropical wave is moving across the central Atlantic with axis extending from 20N47W to a 1009 mb low near 13N47W to 07N47W, moving west at 15-20 kt. This wave is embedded in a moderately moist environment with upper-level diffluence supporting scattered moderate convection from 14N-17N between 46W-53W. This wave is also generating a broad area of fresh to strong easterly winds across the northern portion of it. A tropical wave was introduced in this analysis, extending across the central Caribbean from 16N73W into northern Colombia near 08N74W. This feature is well depicted in model guidance and it is embedded in an area of abundant moisture, as noted in TPW imagery. Scattered moderate convection is observed along the southern portion of the wave mainly south of 12N between 72W-77W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 16N17W to the 10111 mb low and wave near 17N27W. The boundary resumes near 11N28W to the 1009 mb low and wave near 13N47W. Aside from the convection associated with the tropical waves, scattered moderate convection is from 04N-12N between 30W-40W. ...DISCUSSION... GULF OF MEXICO... A surface trough extends across the Bay of Campeche from 25N93W to 19N96W. Isolated convection prevails near the trough. A thermal surface trough extends across the Yucatan Peninsula enhancing convection over the southern portion of the Peninsula. To the east; a trailing surface trough related to T.S. Hermine extends from 26N90W to 28N83W. Scattered moderate convection prevails south of this trough mainly between 85W-90W. Scatterometer data depicts gentle easterly winds over the western half of the basin while gentle to moderate southerly winds prevail east of 90W. During the next 24 hours: the trough over the eastern Gulf will remain nearly stationary. The trough over the southwestern Gulf will drift toward the Mexico coast with ongoing showers and thunderstorms. CARIBBEAN SEA... A tropical wave is moving across the central Caribbean. Please refer to the section above for details. An upper-level low prevails over the western Caribbean centered near 20N83W supporting isolated convection west of 81W. Scatterometer data depicts moderate to locally fresh trade winds across the basin. Expect during the next 24 hours the tropical wave to continue moving west over the central/west Caribbean helping to bring an increase in the trades over the south central Caribbean. Another tropical wave will reach the eastern Caribbean by Saturday night to Sunday with showers and thunderstorms. Fresh to strong easterly winds will accompany the northern portion of this wave. ...HISPANIOLA... The southern portion of a surface trough extending into the Atlantic supports isolated showers and thunderstorms across the island. This activity will dissipate within the next few hours and dry conditions will prevail overnight. A tropical wave will help increasing easterly winds across the island along with showers and thunderstorms by Sunday. ATLANTIC OCEAN... Tropical Storm Gaston is rapidly weakening as it nears the Azores while Tropical Storm Hermine is just inland over the Carolinas. Please refer to the section above for details. Two tropical waves are moving across the basin. Please refer to the tropical waves section above for details. Strong to near gale southwesterly winds are north of 28N west of 75W as well as seas to 13 feet. To the east; a surface trough extends from north-central Hispaniola to 23N70W. Isolated showers and thunderstorms are observed along this boundary. A surface ridge prevails across the remainder of the basin anchored by a 1023 mb high near 29N49N and a 1023 mb high near 33N28W. During the next 24 hours: Tropical Storm Hermine will track northeastward north of our area. However, fresh to strong winds and large seas will continue along the extreme northwestern portion of our discussion waters over the weekend. The tropical waves will continue to produce showers and thunderstorms as they move westward across the remainder of the central tropical Atlantic through late Saturday. For additional information please visit http://www.hurricanes.gov/marine $$ ERA