000 AXNT20 KNHC 061808 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 208 PM EDT Wed Sep 6 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 1715 UTC. ...SPECIAL FEATURES... The center of Hurricane Irma, at 06/1800 UTC is near 18.5N 64.7W, or about 17 nm ENE of St. Thomas, and about 78 nm E of San Juan Puerto Rico. Irma is moving WNW, 285 degrees, at 14 knots. The estimated minimum central pressure is 920 mb. The maximum sustained wind speeds are 160 kt with gusts to 195 kt. Irma is the strongest hurricane to be in the Atlantic basin outside of the Caribbean Sea and the Gulf of Mexico. Irma has a well defined eye about 25 NM in diameter. Numerous strong convection is within 120 nm of the center. Scattered moderate convection is elsewhere from 14N-22N between 60W-68W. 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. The center of Tropical Storm Jose, at 06/1500 UTC is near 13.1N 44.5W, or about 1105 NM ESE of St. Martin. Jose is moving WNW, 285 degrees, at 15 knots. The estimated minimum central pressure is 998 mb. The maximum sustained wind speeds are now 60 kt with gusts to 75 kt. Numerous strong convection is within 90 nm of the center. Scattered moderate convection is elsewhere from 11N-17N between 41W-47W. Please read the latest Forecast/Advisory under AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. The center of Tropical Storm Katia, at 06/1500 UTC, is in the SW Gulf of Mexico near 21.7N 95.9W, or about 117 nm ESE of Tampico, Mexico, moving ESE, 120 degrees, at 4 knots. The estimated minimum central pressure is 1004 mb. The maximum sustained wind speeds are 40 kt with gusts to 50 kt. Scattered moderate to strong convection is from 18N-26N between 91W-98W. Please read the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC for more details. ...TROPICAL WAVES... A tropical wave is off the coast of W Africa. Its axis extends from 15N26W to 03N27W, moving W at 15 kt. SSMI TPW imagery shows the wave is in a very moist area. The wave is also within a distinct 700 mb trough. Scattered showers are within 180 nm W of the wave axis. A tropical wave is in the central Caribbean with axis extending from W Cuba at 23N82W to 07N81W, moving W at 10-15 kt. SSMI TPW imagery shows the wave is in a moderately moist area. The wave is also within a distinct surface and 700 mb trough. Scattered showers are over within 90 nm of the wave axis. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 18N16W to 06N27W to 06N32W. Aside from the convection associated with the Atlantic tropical wave, widely scattered moderate convection is from 03N-08N between 14W-22W. ...DISCUSSION... GULF OF MEXICO... T.S. Katia is over the SW Gulf of Mexico. See the special feature section above. Further N, the tail end of a cold front is over the N Florida and the NE Gulf of Mexico from 31N85W to 28N91W. Widely scattered moderate convection is within 120 nm of the front. In the upper levels, an upper level trough is over the N Gulf N of 26N. Upper level diffluence SE of the trough is enhancing the convection over N Florida and the NE Gulf. Expect T.S. Tatia to intensify and remain over the SW Gulf for the next two to three days. Also expect increased convection over S Florida and the Straits of Florida over the next 24 hours. CARIBBEAN SEA... Hurricane Irma is a major hurricane over the Leeward Islands near St Thomas. See Above. A tropical wave is also over the W Caribbean. See above. In addition, the eastern extent of the E Pacific monsoon trough traverses Costa Rica and Panama intersecting the tropical wave. Scattered moderate convection is over the SW Caribbean and Panama S of 11N. In the upper levels, an upper ridge is over the Caribbean Sea with axis along 80W. Expect Irma to be just NE of Hispaniola in 24 hours. ...HISPANIOLA... Presently, mostly fair weather is over the Island, however, cloudiness and convection is rapidly approaching due to Hurricane Irma. Upper level subsidence and dry air is still over the Island. Hurricane warnings are in effect for N Hispaniola. See Special Features for more details. ATLANTIC OCEAN... Major Hurricane Irma and T.S. Jose are over the Atlantic. A tropical wave is also off the coast of W Africa. See above. Scattered moderate convection is over the W Atlantic from 29N-32N between 77W-80W due to an approaching cold front. A 1030 mb high is centered over the central Atlantic near 39N47W. Another 1034 mb high is centered over the E Atlantic near 42N26W. Of note in the upper levels, an upper level low is centered over the E Atlantic near 32N35W. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa