000 AXNT20 KNHC 160602 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 202 AM EDT Wed Aug 16 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 0000 UTC surface analysis and satellite imagery through 0545 UTC. ...SPECIAL FEATURES... Hurricane Gert is centered near 34.8N 70.3W at 16/0300 UTC or about 310 nm WNW of Bermuda moving NE at 13 kt. Estimated minimum central pressure is 979 mb. Maximum sustained wind speed is 75 kt with gusts to 90 kt. Numerous moderate to isolated strong convection is from 33N-37N between 67W-71W. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC for more details. ...TROPICAL WAVES... A tropical wave is in the central Atlc associated with a 1011 mb low pressure located near 14N32W. The wave axis extends from 22N33W to the low and has been moving W at 15-20 kt. The wave is in a region of low to moderate vertical wind shear, however intrusion of Saharan dry air and dust to the wave environment limit convection to scattered moderate within 220 nm NW quadrant of low pressure center. Slow development of this system is anticipated during the next day or two, but conditions are forecast to become more conducive for tropical cyclone formation by later in the week while the system moves WNW over the tropical Atlantic. A tropical wave is E of the Lesser Antilles with axis extending from 21N55W to 10N59W, moving W at 25 kt. The wave is in a region of moderate to strong vertical wind shear and continue to be affected by Saharan dry air and dust, which is limiting convection to isolated showers within 200 nm of its axis. A tropical wave is in the central Caribbean with axis extending from 17N78W to 09N78W, moving W at 20-25 kt. The wave is in a region of moderate to strong vertical wind shear and dry air subsidence, which is hindering deep convection at the time. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 08N13W to 14N28W to 14N43W to 10N47W. The Intertropical Convergence Zone axis extends from 10N48W to 10N57W. Outside of convection associated with the tropical waves, numerous heavy showers and isolated tstms are off the W African coast from 08N to 15N E of 21W associated with the next tropical wave that will emerge to E Atlc waters later today. Otherwise, a 1011 mb low embedded in the monsoon trough near 14N44W support isolated showers from 11N to 16N between 42W and 48W. ...DISCUSSION... GULF OF MEXICO... Upper level divergent flow persists over the northern Gulf coast and interior portions of the SE CONUS between a broad upper level low centered NW of the Yucatan Peninsula near 22N91W and an upper level anticyclone centered near 30N80W. Isolated showers are occurring over Louisiana adjacent waters N of 26N between 89W- 93W. Similar shower activity is over the E Bay of Campeche associated with a surface trough that is moving off the W Yucatan Peninsula. Otherwise, the E Gulf is under the influence of a surface ridge anchored by a 1018 mb high centered near 26N84W. Gentle to moderate SE flow is W of 90W while variable light to gentle flow is over the eastern half of the basin. The high is expected to persist across the NE Gulf waters through Friday. A surface trough will develop each evening across the Yucatan peninsula shifting W into the Bay of Campeche during the overnight hours. Locally higher winds can be expected in the vicinity of the trough axis. CARIBBEAN SEA... A tropical wave is moving into the W Caribbean, however it lacks deep convection. This tropical wave will continue to propagate westward across the remainder of the basin through Wednesday night. Another tropical wave is E of the Lesser Antilles where it is supporting isolated showers. This second wave will move into E Caribbean waters later this morning and is forecast to support showers across Puerto Rico and adjacent waters. The wave will move to the central basin Thu supporting showers across Hispaniola. Diffluent flow between an upper ridge located NE of Jacksonville, Florida and an upper low centered N of Hispaniola continue to support isolated showers over Haiti and the Windward Passage. Similar activity is occurring over E Cuba adjacent waters. Otherwise, fresh to strong winds in the south-central waters are expected through Thursday with moderate to fresh trades elsewhere. ...HISPANIOLA... Diffluent flow between an upper ridge located NE of Jacksonville, Florida and an upper low centered N of Hispaniola continue to support isolated showers over Haiti and the Windward Passage. This shower activity is forecast to continue today, increasing overnight due to an approaching tropical wave. The tropical wave will move over the central Caribbean Thu supporting showers across the Island. ATLANTIC OCEAN... Isolated showers are N of 26N between 68W and 76W associated with the convective rainbands of Hurricane Gert centered north of the discussion area. Otherwise...the remainder of the basin generally N of 20N is under the influence of the Azores subtropical high which supports fair weather. For information about tropical waves, see section above. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos