000 AXNT20 KNHC 260559 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 158 AM EDT Sat Aug 26 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... Hurricane Harvey is centered near 28.2N 97.0W at 26/0600 UTC or about 5 nm N of Rockport Texas and about 40 nm S of Victoria Texas moving NW at 5 kt. Estimated minimum central pressure is 942 mb. Maximum sustained wind speed is 110 kt with gusts to 135 kt. Numerous moderate and isolated strong convection is within 90 nm of center. Scattered moderate convection is elsewhere from 26N- 31N between 91W-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. ...TROPICAL WAVES... A tropical wave extends from 11N30W to 22N28W moving W at 10-15 kt. The wave coincides with amplified 700 mb troughing between 18W-32W. Infrared satellite imagery shows the presence of Saharan dust surrounding the wave environment N of the monsoon trough axis. Isolated moderate convection is from 15N-18N between 22W- 26W. A tropical wave extends from 09N44W to 19N44W moving W at 5-10 kt. A weak 1012 mb low is analyzed along the wave axis near 15N and is providing focus for isolated moderate convection from 14N- 18N between 44W-50W. A tropical wave extends from 10N92W to 19N88W moving W at 10-15 kt. Global model guidance suggests subtle 700 mb troughing and a maximum in 850 mb relative vorticity S of 18N between 88W-94W moving over portions of Central America and the East Pacific waters. Scattered moderate and isolated strong convection is from 11N-20N between 87W-97W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 18N16W to 13N33W to 15N45W. Widely scattered moderate convection is from 04N-08N between 02W-15W...and from 06N-10N between 37W-52W. ...DISCUSSION... GULF OF MEXICO... The primary concern for the Gulf of Mexico is Hurricane Harvey that has made landfall this evening. Harvey remains on the western periphery of an upper level ridge anchored near 28N89W that extends influence over the Lower Mississippi River valley southward over the central and eastern Gulf...including the Florida peninsula. The ridging also extends influence over the SW Gulf and central Mexico. To the east of Harvey...upper level divergence associated with the ridging supports a 1012 mb low centered N of Tampa Bay near 28N82W. A surface trough extends N from the low to near Jacksonville and SW from the low across Tampa Bay to 26N86W. The low along with the boundaries in place and upper level divergence are generating scattered showers and tstms generally E of 87W...including portions of the Florida peninsula. As Harvey impacts the NW Gulf waters and coastal Texas through the upcoming weekend...the troughing and weaker low pressure across the eastern Gulf waters and Florida peninsula are expected to maintain unsettled conditions across the region as the low moves NE into the SW North Atlc waters through Sunday night. CARIBBEAN SEA... Much of the NW Caribbean and portions of Central America are under the influence of NW flow aloft and an overall divergent pattern supporting widely scattered showers and isolated tstms occurring N of 17N between 77W-86W...and across interior portions of Central America S of 17N W of 85W. Otherwise...farther east...much of the central and eastern Caribbean are under dry air aloft and mostly fair conditions at the surface this evening. However...a weak surface trough currently along 59W is expected to move westward across the Lesser Antilles later tonight into Saturday bringing possible isolated showers to the eastern waters E of 66W. Finally...moderate to fresh trades prevail and this overall synoptic pattern is expected to persist through the weekend into Monday. ...HISPANIOLA... Mostly clear skies prevail this evening across the island with these overall conditions expected to persist through the weekend. Isolated afternoon showers and tstms are possible across western Hispaniola with maximum daytime heating and instability...along with local sea breeze effects. ATLANTIC OCEAN... Upper level ridging and an overall divergent upper level pattern prevails over the SW North Atlc this evening generating scattered showers and tstms remaining W of a line from 32N68W to the coast of central Cuba near 22N78W. Water vapor imagery also indicates longwave upper level troughing offshore of the eastern CONUS with the base of this trough remaining generally N of 34N. The trough supports a stationary front extending from 34N73W to coastal Georgia near 32N81W to the Florida panhandle. Farther east across the remainder of the central and eastern Atlc...ridging prevails anchored by a 1029 mb high centered W-NW of the Azores near 41N39W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN