000 AXNT20 KNHC 180557 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 157 AM EDT Wed Sep 18 2019 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 0520 UTC. ...SPECIAL FEATURES... Hurricane Humberto is centered near 31.5N 70.4W at 18/0600 UTC or 290 nm W of Bermuda moving ENE at 10 kt. Estimated minimum central pressure is 951 mb. Maximum sustained wind speed is 100 kt with gusts to 120 kt. Humberto is a category 3 hurricane. Numerous strong convection is within 100 nm in the NE semicircle and 90 nm in the SW and SE semicircle. Scattered moderate convection is elsewhere within 300 nm in the NE quadrant, 120 nm in the S semicircle, and 180 nm in the NW quadrant. Humberto will continue to move NE with a gradual increase in forward speed through early Thursday, followed by a northeastward to north- northeastward motion through Friday. On the forecast track, the core of Humberto is expected to pass just to the northwest and north of Bermuda Wednesday night. Some fluctuations in intensity are likely during the next day or so, but Humberto should remain a powerful hurricane through early Thursday. A steady weakening trend should begin later on Thursday. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC for more details. Tropical Depression Ten is centered near 13.7N 46.7W at 18/0300 UTC or 900 nm E of the Leeward Islands moving WNW at 9 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Numerous strong convection is within 150 nm in the W quadrant. Scattered moderate convection is within 90 nm in the E semicircle, and elsewhere within 200 nm in the W semicircle. A west-northwestward motion at a somewhat faster forward speed is expected over the next few days. On the forecast track, the system will be near the northern Leeward Islands Thursday night or Friday. Strengthening is forecast during the next couple of days, and the depression is expected to become a tropical storm by Wednesday morning. The system is forecast become a hurricane by the time it moves near the northern Leeward Islands. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPAT5/WTNT35 KNHC for more details. Tropical Depression Imelda is centered near 29.8N 95.5W at 18/0300 UTC, or 9 nm NW of Houston, Texas, moving N at 5 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate convection is within 80 nm in the NE and SW quadrants, within 210 nm in the SE quadrant, and within 50 nm in the NW quadrant. Imelda is expected to continue moving north over the next couple of days and will be over eastern Texas through Thursday. Gradual weakening is forecast during the next 48 hours, and the system should become a remnant low by late Thursday. Imelda is expected to produce total rainfall accumulations of 6 to 12 inches with isolated maximum amounts of 18 inches across the upper coastal region of Texas, including the Houston and Galveston areas. Rainfall amounts of 4 to 6 inches with isolated totals of 10 inches are possible across portions of southeast Texas and southwest Louisiana through Thursday. This rainfall may produce significant to life- threatening flash floods. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPAT1/WTNT31 KNHC for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave with an axis along 35W S of 17N is moving W at 10 kt. Scattered moderate convection is from 12N- 16N between 34W-38W. A central Caribbean tropical wave with an axis along 71W S of 19N, is moving W at 10-15 kt. Scattered moderate and isolated strong convection is from 15N-19N between 67W-72W. A western Caribbean tropical wave with an axis along 80W S of 18N, is moving W at 10-15 kt. Scattered convection is from 11N-17N between 77W-81W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Mauritania near 20N16W to 12N26W to 15N51W. Aside from the convection already discussed in the Tropical Waves section above, scattered showers are noted from 03N-09N between 12W-37W. GULF OF MEXICO... T.D Imelda is moving across the Houston, Texas area. Refer to the section above for details. Scattered moderate to strong convection is moving across the eastern Bay of Campeche from 18N-21N and E of 94W. The rest of the Gulf remains quiet under the strong upper level ridge. A 1015 mb high near 27N87W. The latest scatterometer data depicts calm to light anticyclonic winds in the eastern Gulf with gentle to moderate southerly winds in the NW Gulf. High pressure will build over the north central Gulf in the wake of Imelda tonight, supporting gentle to moderate winds through mid week, except for moderate to fresh winds off the west coast of Yucatan at night. The high pressure will dissipate later in the week in advance of a weak cold front that is forecast to move across the eastern Gulf of Mexico then stall and dissipate over the southeast Gulf Friday into Saturday. Fresh winds and building seas will follow the front over the eastern Gulf Friday into Saturday. CARIBBEAN SEA... Refer to the Tropical Waves section above for details on the two tropical waves currently over the Caribbean. Numerous moderate to strong convection is moving south of Cuba toward the Grand Cayman Islands, from 20N-22N between 79W-84W. Scattered moderate convection is also seen in the Windward Passage. Latest scatterometer data depicts light to gentle trades prevailing across most of the basin except east of 69W, where moderate to fresh winds are depicted. Moderate to fresh trade winds will dominate much of the basin. Tropical Depression Ten will change little in intensity as it moves to 21.5N 67.0W late Saturday, and continue to 24.5N 70.5W Sunday. ATLANTIC OCEAN... Refer to the sections above for details on Hurricane Humberto, T.D.Ten, and the tropical wave moving across the basin. A 1020 mb surface high is over the central Atlantic near 31N43W. To the east, a cold front enters the discussion area near 31N27W to 29N31W, then stalls from 29N31W to 21N51W. Showers are seen along the front. Hurricane Humberto will move to 32.0N 68.9W Wednesday morning, 33.4N 65.5W Wednesday evening. Humberto will pass north of Bermuda Wednesday night and farther into the central north Atlantic waters into Friday. Tropical Depression Ten will strengthen to a tropical storm near 14.4N 48.2W Wed morning, move to 15.3N 50.4W Wednesday evening, 16.2N 53.0W Thursday morning, 17.3N 56.0W Thursday evening, and strengthen to a hurricane near 19.5N 62.0W Fri evening. Ten will change little in intensity as it moves to 21.5N 67.0W late Sat, and continue to 24.5N 70.5W Sun. $$ AKR