000 AXNT20 KNHC 190000 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 800 PM 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Hurricane Humberto is centered near 33.4N 65.0W at 18/0000 UTC or 70 nm N of Bermuda moving ENE at 17 kt. Estimated minimum central pressure is 952 mb. Maximum sustained wind speed is 105 kt with gusts to 130 kt. Numerous moderate to strong convection is within 120 nm in the S semicircle, 180 nm in the NW quadrant, and 420 nm in the NE quadrant. A trough extends from just SW of Humberto through 32N62W to near the Turks and Caicos Islands with scattered moderate and isolated convection within 120 nm SE of the trough. On the forecast track, the core of Humberto is expected to pass just to the NW and N of Bermuda later tonight. Humberto should remain a powerful hurricane through early Thursday, then 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 Storm Jerry is centered near 15.2N 51.2W at 18/0000 UTC or 620 nm E of the Leeward Islands moving WNW at 13 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Numerous moderate to strong convection is within 75 nm in the E semicircle, 120 nm in the SW quadrant, and 60 nm in the NW quadrant. An additional band of scattered moderate to strong convection is between 60 and 180 nm in the NW quadrant of Jerry, as well as another far outer band between 270 and 420 nm in the SE quadrant, and between 300 nm and 480 nm in the SW quadrant. Jerry is forecast to become a hurricane on Thursday, with little change in strength anticipated on Friday or Saturday. On the forecast track, the center of Jerry will be near or N of the northern Leeward Islands Friday and pass N of Puerto Rico on Saturday. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPAT5/WTNT35 KNHC for more details. Tropical Depression Imelda is centered near 30.8N 95.0W at 18/2100 UTC or 70 nm NNE of Houston Texas moving N at 4 kt. Estimated minimum central pressure is 1010 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. Significant rainfall will continue to be possible with life threatening flash floods from the upper Texas coast into eastern Texas, as well as portions of SW Louisiana. Scattered moderate to strong convection also extends across the eastern Texas and SW Louisiana coastal waters into the offshore waters N of 27N between 91W and 95W. Imelda will gradually decrease in speed this evening and then make a gradual turn towards the NW. Little change in strength is forecast overnight before a gradual weakening trend begins. See latest WPC forecast/advisory under WMO headers WTNT31 KWNH for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave with an axis along 40W S of 19N is moving W at 10-15 kt. Scattered moderate to strong convection is from 13N-15N between 36W-39W, and from 03N-07N between 38W-41W. A central Caribbean tropical wave was relocated slightly to the E with an axis along 71W from the central Dominican Republic to NW Venezuela, moving W at 10 kt. Scattered moderate to strong convection is N of 13N between 65W-71W. A western Caribbean tropical wave with an axis along 81W S of 18N is moving W at around 5 kt. Limited convection is present with this tropical wave. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 13N17W to 08N27W to 16N40W. The ITCZ extends from SW of Tropical Storm Jerry near 11N53W to 10N62W. No significant convection is noted outside of the tropical wave and Tropical Storm Jerry mentioned above. GULF OF MEXICO... Please read the Special Features section for more details about Tropical Depression Imelda located inland over Texas. Otherwise, the basin is fairly quiet with 1017 mb high pressure located in the NE Gulf near 27N81W. Broad ridging extends WSW from the high to the NE coast of Mexico, and eastward toward Tampa Bay, Florida. A weak surface trough was analyzed over the S central Gulf near 23N91W to the western Yucatan Peninsula. High pressure will prevail over the Gulf waters through the remainder of the week into the weekend. Gentle to moderate winds will prevail much of the period, with winds becoming fresh to strong over the northeastern Gulf Thu night into early Sat. CARIBBEAN SEA... Please read the Special Features section for more details about Tropical Storm Jerry. A weak surface trough was noted in earlier scatterometer sampling and visible satellite imagery from near 17N75W to 13N73W with isolated showers and thunderstorms in the vicinity of the trough. Additional scattered moderate and isolated strong convection was SW of the trough from S of 13N to the Coast of Colombia and Panama between 78W-78W. Another surface trough was noted from central Cuba to just NW of the Cayman Islands near 19N84W. Drier and more stable air was noted behind the trough with thunderstorm development ahead of it over land areas. Gentle to moderate trade winds will persist elsewhere over the Caribbean through the next several days. ATLANTIC OCEAN... Please read the Special Features section for more details about Tropical Storm Jerry. Elsewhere, a cold front extends from N of the area through 32N22W to 29N31W, continuing as stationary to 28N45W to 23N52W. No significant convection is noted near the frontal boundary. Weak and broad 1018 mb high pressure is located N of the front near 30N37W. A surface trough is located NE of the Caribbean from 24N58W to 17N56W with limited convection in the vicinity. Little significant impact is noted with this trough. Another surface trough extends from SE of Hurricane Humberto to across the central and SE Bahamas to central Cuba and associated convection is discussed above. Moderate to fresh, locally strong, NE flow follows the trough in the offshore waters. Moderate to fresh trades will prevail in the wake of this trough, and ahead of any potential impacts from Jerry. $$ Lewitsky