000 AXNT20 KNHC 050559 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 159 AM EDT Tue Sep 5 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... The center of Hurricane Irma at 05/0600 UTC is near 16.6N 56.4W, or about 310 nm to the E of the Leeward Islands. Irma is moving W, or about 270 degrees, 11 knots. The estimated minimum central pressure is 939 mb. The maximum sustained wind speeds are 120 kt with gusts to 145 kt. Convective precipitation: Numerous strong is within 120 nm of the center in the N semicircle, and within 65 nm of the center in the S semicircle. Isolated moderate to locally strong from 12N to 20N between 42W and 50W. Warnings and watches have been issued for the Leeward Islands, Virgin Islands and Puerto Rico. Some strengthening is forecast during the next 48 hours. Please read the latest NHC Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT1/WTNT31 KNHC and the Forecast/ Advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details. A tropical wave is about 1100 nm to the ESE of Hurricane Irma, along 37W/38W from 15N southward. The wave is moving W 10 to 15 knots. A 1011 mb low pressure center is along the wave near 10N. Convective precipitation: scattered moderate to strong from 08N to 12N between 36W and 42W. widely scattered moderate to isolated strong from 15N to 17N between 32W and 36W. The wave is within a distinct 700 mb trough. Environmental conditions are expected to be conducive for gradual development. The chance for tropical cyclone formation within the next 48 hours is medium. A surface trough is in the SW corner of the Gulf of Mexico, along 24N96W 21N96W 19N94W. Convective precipitation: scattered moderate to isolated strong from 20N to 24N between 94W and the coast of Mexico. Numerous strong is in Mexico from 17N to 19N between 95W and 97W in the western part of the Isthmus of Tehuantepec of southern Mexico. It is possible that a low pressure center may form along the trough, near Tampico Mexico, during the next 24 hours or so. The chance for tropical cyclone formation within the next 48 hours is medium. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 18W/19W from 17N southward, moving westward 10 knots. Convective precipitation: scattered to numerous strong is from 14N to 17N between 14W and 18W, still mostly in Africa. A Caribbean Sea tropical wave is along 80W/81W, from 21N southward to Panama, moving westward 10 knots. The wave covers the area from the waters that are to the south of Cuba, to the area that is to the east of Honduras, Nicaragua, and Costa Rica. Convective precipitation: isolated moderate to locally strong from Jamaica to the coastal waters that are on the southern side of Cuba, from 18N to Cuba between 77W and 83W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough passes through the coastal sections of SW Mauritania, to 12N20W, 10N23W, 09N30W, 09N40W, and 12N46W. Convective precipitation: isolated moderate to locally strong elsewhere from 03N to 14N between Africa and 58W. ...DISCUSSION... ...THE GULF OF MEXICO... Upper level anticyclonic wind flow spans the Gulf of Mexico. Multilayered clouds and possible rainshowers cover the rest of the area, away from the surface trough that is in the SW corner of the Gulf of Mexico. ...THE CARIBBEAN SEA... Hurricane Irma is a major hurricane that is approaching the Leeward Islands. Please read the Special Features section. Expect the Leeward Islands to be under the influence of Hurricane Irma during the next 36-60 hours. The monsoon trough is along 10N/11N between northern coastal Colombia and Costa Rica. No significant deep convective precipitation. Expect the Leeward Islands to be under the influence of Hurricane Irma over the next 36-60 hours. 24-hour rainfall totals in inches, for the period that ended at 05/0000 UTC, according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are: 0.01 in Guadeloupe, and a trace in Tegucigalpa in Honduras. ...HISPANIOLA... Hurricane Irma is forecast to approach the area of Hispaniola early on Thursday. An upper level inverted trough extends from Hispaniola toward Costa Rica. Convective precipitation: widely scattered moderate to isolated has been moving from the western parts of the island into the Windward Passage. The GFS MODEL forecast for 250 mb shows that day one will consist of SE wind flow across the area, with a cyclonic circulation center that will move toward Jamaica. Day two will consist of anticyclonic, and easterly, wind flow for much of the time. NE wind flow will move across the area, replacing the anticyclonic wind flow, around the middle of day two. The NE wind flow will be associated with a second cyclonic circulation center that will be approaching NE Hispaniola from the east, with Hurricane Irma. The GFS MODEL forecast for 500 mb shows that day one will consist of E wind flow, becoming NE by the end of the day. Day two will consist of more NE wind flow, that is associated with the Hurricane Irma cyclonic circulation center. The GFS MODEL forecast for 700 mb shows that day one will consist of anticyclonic wind flow. Day two will consist of NE and cyclonic wind flow, with the Hurricane Irma cyclonic circulation center, that is forecast to be on the Atlantic Ocean side of Hispaniola. ...THE ATLANTIC OCEAN... Major Hurricane Irma continues to represent a threat for the Leeward Islands. An upper level trough extends from a 27N33W cyclonic circulation center, to 15N40W. A surface trough is along 30N31W 26N33W 22N34W. Cyclonic wind flow covers the Atlantic Ocean from 15N northward between 20W and 43W. Convective precipitation: Rainshowers are possible in the area of the upper level cyclonic wind flow. An upper level cyclonic circulation center is about 750 nm to the NNW of Hurricane Irma, near 27N63W. A surface trough is within 360 nm to the west of the 27N63W cyclonic circulation center, along 29N68W 26N71W 23N73W. Convective precipitation: rainshowers are possible from 20N northward between 60W and the Bahamas. A separate area of precipitation: scattered moderate to isolated strong rainshowers is from 24N to 27N between 56W and 60W, on the eastern side of the cyclonic wind flow that is moving around the 27N63W cyclonic center. A surface ridge passes through 34N60W, across Bermuda, to Florida near the Tampa metropolitan area. For additional information please visit http://www.hurricanes.gov/marine $$ mt