000 AXNT20 KNHC 251811 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 211 PM EDT Fri Aug 25 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... Hurricane Harvey is centered near 27.1N 96.3W at 25/1800 UTC or about 75 nm ESE of Corpus Christi Texas and about 80 nm S of Port O'Connor Texas moving NW at 9 kt. Estimated minimum central pressure is 945 mb. Maximum sustained wind speed is 95 kt with gusts to 115 kt. Numerous moderate and scattered strong convection is present within 90 nm of the center. Scattered moderate convection is observed elsewhere from 25N to 31N between 90W and 98W. 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 12N27W to 22N24W moving W around 10 kt. A weak 1010 mb low is analyzed along the wave axis near 17N26W. The wave coincides with amplified 700 mb troughing. Infrared satellite imagery shows the presence of Saharan dust flanking the north side of the wave. Scattered moderate and isolated strong convection is found from 11N to 14N between 28W and 31W. A tropical wave extends from 11N40W to 19N44W moving W around 10 kt. A weak 1010 mb low is analyzed along the wave axis near 14N43W and is providing focus for scattered moderate and isolated strong convection within 30 nm of the low center. The wave coincides with amplified 700 mb troughing. A tropical wave extends from 08N89W to 18N88W moving W at 10-15 kt. Global model guidance suggests subtle 700 mb troughing between 85W-90W moving over portions of Central America and the East Pacific waters to the S. Scattered moderate and isolated strong convection is present from 10N to 13N between 87W and 97W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from 20N17W to 13N28W to 14N32W to 12N40W to 11N44W. The Intertropical Convergence Zone axis continues from 11N44W to 11N55W then resumes from 10N58W to 10N62W. No significant deep convection is associated with the monsoon trough or ITCZ at this time. ...DISCUSSION... GULF OF MEXICO... The primary weather threat for the Gulf of Mexico continues to be Hurricane Harvey which continues to track NW toward the southern Texas coast. Harvey continues to be steered by the western flank of deep layer ridging extending from over the Lower Mississippi River valley southward over the central Gulf to over the northern Yucatan peninsula. A weak 1011 mb surface low is centered on the Florida coast close to Sarasota near 27N82W. Troughs extend westward from the low to 26N86W and northward from the low to 30N84W. The low is interacting with a small upper- level trough extending W from the Atlc over central Florida to generate scattered moderate and isolated strong convection from 24N to 27N between 80W and 85W...including most of the southern Florida peninsula. As Harvey slows down and impacts the NW Gulf waters and coastal Texas through the upcoming weekend...the troughing and weaker low pressure across the eastern Gulf waters are expected to maintain unsettled conditions across the Florida peninsula before the low moves NE into the SW North Atlc waters on Sunday or Sunday night. CARIBBEAN SEA... Much of the NW Caribbean and portions of Central America remain under the influence of divergent NE upper-level winds. This is supporting scattered moderate and isolated strong convection from 20N to 23N between 81W and 85W. Otherwise...farther east...much of the central and eastern Caribbean are beneath a subsident air mass associated with an upper-level trough that crosses the Caribbean from the Mona Passage to western Venezuela. Accordingly, mostly fair conditions are currently seen at the surface. 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 morning 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 remains in place to the west of an upper-level trough extending from near Bermuda to the Mona Passage. This setup is generating scattered showers and tstms N of 27N and W of 77W and N of 26N between 66W and 70W. A stationary front extending from SE Georgia near 31N81W to SW Louisiana near 30N94W has little convection associated with it. Farther east across the remainder of the central and eastern Atlc...ridging prevails anchored by a 1027 mb high centered W-NW of the Azores near 40N42W. For additional information please visit http://www.hurricanes.gov/marine $$ McElroy