000 AXNT20 KNHC 032353 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 753 PM EDT Sun Sep 3 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...SPECIAL FEATURES... Hurricane Irma is centered near 17.4N 50.3W at 04/0000 UTC or about 660 nm E of the Leeward Islands moving W at 12 kt. Estimated minimum central pressure is 959 mb. Maximum sustained wind speed is 100 kt with gusts to 120 kt. Scattered to numerous moderate and isolated strong convection is within 90 nm of center. Scattered moderate convection is elsewhere from 14N-20N between 45W-53W. See the latest NHC Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT1/WTNT31 KNHC and the full Forecast/ Advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details. ...TROPICAL WAVES... A tropical wave extends from 05N32W to 16N32W moving W at 10 kt. The wave coincides with 700 mb troughing between 28W-37W and a maximum in 850 mb relative vorticity in the vicinity of a 1011 mb low centered along the monsoon trough near 10N32W. Widely scattered moderate convection is from 05N-13N between 30W-38W. A tropical wave extends from 10N74W to 22N72W moving W at 10-15 kt. The wave coincides with broad 700 mb troughing between 69W- 76W and continues to move W away from influence of an upper level inverted trough over the eastern Caribbean Seas along 69W. Widely scattered moderate convection is from 17N-20N between 67W-78W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 12N17W to 11N23W to 10N37W. Scattered moderate convection is from 05N-12N between 12W-17W. Widely scattered moderate convection is elsewhere from 05N-09N between 17W-42W. ...DISCUSSION... GULF OF MEXICO... Water vapor imagery indicates an upper level trough extending from over the SE CONUS to a broad base over much of the basin this evening. The troughing provides for a fairly weak pressure gradient across the entire Gulf with most ongoing convection occurring across the southern waters. Scattered showers and tstms are S of 25N between 83W-99W...including coastal area of eastern Mexico. A surface trough analyzed from 18N92W to 22N94W is providing the focus for broad gentle to moderate cyclonic flow across the SW Gulf. This feature is expected to dampen out by late Monday night into early Tuesday. Elsewhere...gentle to moderate easterly winds prevail with isolated showers and tstms occurring across the Florida peninsula and across the NW waters W of 95W. A surface ridge axis is expected to anchor along 30N Tuesday... gradually slide southward...and weaken by Wednesday as a weak frontal boundary moves off the Texas and Louisiana coasts. CARIBBEAN SEA... Water vapor imagery indicates most moisture remains W of 83W with scattered showers and isolated strong tstms occurring across interior portions of Central America and the Yucatan peninsula. Otherwise...a weak inverted upper level trough remains along 80W and is generating isolated showers and tstms N of 16N between 75W-83W...on the heels of an approaching tropical wave along 74W. Convection associated with the tropical wave continues this evening across Jamaica...eastern Cuba...and Hispaniola as it moves westward. Looking beyond this weekend...Hurricane Irma looms across the central tropical Atlc and is forecast to approach 60W Tuesday evening into the overnight hours. ...HISPANIOLA... Scattered showers and tstms are expected to continue through the overnight hours into Monday as a tropical wave currently along 74W continues moving westward. The wave is expected to pass west of the island by late Monday with conditions gradually improving on Tuesday. Looking ahead...Hurricane Irma is forecast to approach from the east and likely be centered N-NE of the island Thursday afternoon. ATLANTIC OCEAN... A middle to upper level trough is progressing over the NE CONUS this evening supporting a cold front extending from 32N77W to 30N82W. Isolated showers are occurring within 120 nm either side of the front...and N of 25N W of 77W as southwesterly flow aloft prevails over the SW North Atlc. Isolated showers and tstms are also occurring across the Bahamas from 24N-28N between 75W-78W. Farther east...an upper level low is centered near 27N62W and supports a dissipating stationary front extending from 32N56W SW to 27N67W. While isolated showers are occurring within 120 nm either side of the boundary...upper level divergence between the upper level low and an upper level anticyclone centered near 27N70W is generating an area of scattered showers and tstms from 21N-29N between 59W-67W. Lastly...Hurricane Irma remains on the southern periphery of a ridge anchored by a 1023 mb high centered near 33N42W. The eastern Atlc is under the influence of another ridge anchored by a 1022 mb high centered S-SE of the Azores near 34N25W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN