000 AXNT20 KNHC 271158 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 758 AM EDT Sun Aug 27 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 0515 UTC. ...SPECIAL FEATURES... Tropical Storm Harvey is centered near 29.0N 97.6W at 27/1200 UTC or about 39 nm WNW of Victoria Texas and about 56 nm ESE of San Antonio Texas, moving SSE at 1 kt. Estimated minimum central pressure is 998 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Scattered to numerous moderate and isolated strong convection is from 28N-32N between 92W-97W. Scattered moderate convection is elsewhere from 25N-33N between 90W-99W. See latest Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC and the full Forecast/Advisory under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details. A 1011 mb low is centered across the northern Florida peninsula near 29N81W. Surface troughing extends N-NE to 31N80W and SW across Tampa Bay to 27N86W in the eastern Gulf of Mexico. Scattered to numerous moderate convection is from 25N-28N between 81W-85W and from 27N-31N between 76W-81W with widely scattered moderate convection elsewhere from 23N-32N between 75W-87W. The surface low remains under the influence of relative divergent flow aloft on the eastern periphery of an upper level ridge anchored over the central Gulf of Mexico near 25N91W. The low is forecast to track NE through Sunday into the SW North Atlc waters and move along the coast to the Mid-Atlc region by Tuesday night. ...TROPICAL WAVES... A tropical wave extends from 14N28W to 24N26W moving W at 5-10 kt. The wave coincides with amplified 700 mb troughing between 24W-33W. Infrared satellite imagery shows the presence of Saharan dust surrounding the wave environment N of the monsoon trough axis. No significant deep convection is associated with the wave at this time. A tropical wave extends from 11N53W to 22N53W moving W at 15-20 kt. The wave coincides with broad troughing at 700 mb between 50W- 56W and continues to generate scattered moderate convection from 15N-21N between 51W-57W. A tropical wave extends from 11N67W to 21N66W moving W at 15-20 kt. This wave has moved across the central Atlc waters and Lesser Antilles the past few days as a surface trough and continues to provide isolated moderate convection across the eastern Caribbean Sea and adjacent Atlc coastal waters N of Puerto Rico and the US/UK Virgin Islands this morning. A tropical wave extends from 13N97W to 20N96W moving W at 10-15 kt. Global model guidance suggests subtle 700 mb troughing and a maximum in 850 mb relative vorticity S of 20N between 95W-100W moving over portions of southern Mexico and the adjacent East Pacific waters. Scattered moderate and isolated strong convection is from 14N-20N between 92W-98W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from 14N28W to 11N44W to 11N48W. Scattered moderate convection is from 03N-17N between 12W- 22W...and from 06N-14N between 39W-48W. ...DISCUSSION... GULF OF MEXICO... With the surface circulation of Harvey inland across southern Texas...scattered showers and tstms continue across the NW Gulf waters generally N of 25N W of 91W. Harvey remains on the northwestern periphery of an upper level ridge anchored over the central Gulf near 25N91W that extends influence over the entire Gulf basin and the Florida peninsula. To the east of Harvey... upper level divergence associated with the ridging supports the Special Features low centered across the Florida peninsula near 29N81W. The remainder of the Gulf is under mostly moderate southerly winds with the exception of gentle to moderate cyclonic winds across the eastern Gulf in closer proximity to the low across Florida. Harvey is expected to remain in the vicinity of the Texas coast through mid-week with a ridge axis extending from the Florida peninsula to the SW Gulf as the Florida low moves NE into the SW North Atlc waters. CARIBBEAN SEA... Much of the NW Caribbean and portions of Central America are under the influence of NE flow aloft with upper level convective debris cloudiness moving over the NW Caribbean this morning. To the east...an upper level low is centered over the Windward Passage region generating widely scattered showers and tstms from 17N-21N between 73W-79W...including portions of western Hispaniola and Jamaica. As the upper level low continues to retrograde...upper level ridging will build in over the eastern portion of the basin through Monday. A tropical wave currently across the eastern Caribbean along 67W will likely benefit with a favorable divergent environment aloft supporting scattered showers and isolated tstms occurring within 240 nm either side of the wave axis. Lastly...moderate to fresh trades prevail and this overall synoptic pattern is expected to persist through Tuesday. ...HISPANIOLA... An upper level low is centered over the Windward Passage region this morning supporting widely scattered showers and tstms across western portions of the island. As the low moves westward through Sunday night...a tropical wave is expected to move across the island and adjacent coastal waters bringing scattered showers and isolated tstms through early Monday. ATLANTIC OCEAN... Upper level ridging and an overall divergent upper level pattern prevails over the SW North Atlc this morning generating scattered showers and tstms remaining N of 30N W of 61W...and N of 25N W of 75W. Water vapor imagery also indicates long wave upper level troughing offshore of the eastern CONUS with the base of this trough remaining generally N of 32N. The trough supports a stationary front extending from 36N60W to coastal Georgia near 31N81W to the Florida panhandle. An upper level low is centered near 30N49W and supports a surface trough analyzed from 29N55W to 33N51W. Isolated showers and tstms are occurring from 30N-33N between 45W-53W. The remainder of the central and eastern Atlc is under the influence of a surface ridge anchored by a 1027 mb high centered W of the Azores near 39N35W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN