000 AXNT20 KNHC 051805 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 204 PM EDT Thu Sep 5 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 1200 UTC surface analysis and satellite imagery through 1730 UTC. ...SPECIAL FEATURES... Hurricane Dorian is centered near 32.8N 78.9W at 05/1800 UTC or 50 nm S of Myrtle Beach South Carolina moving NNE at 7 kt. Minimum central pressure is 958 mb. Maximum sustained wind speed is 95 kt with gusts to 115 kt. The eye of Dorian passed directly over a NOAA buoy around 1500 UTC this morning. The buoy measured a minimum pressure of 959.6 mb. Numerous moderate with embedded scattered strong convection is seen within 150 nm N semicircle and 75 nm S semicircle. Scattered moderate to isolated strong convection is seen elsewhere within 300 nm NE quad, 120 nm SE quad, 150 nm SW quad, 180 nm NW quad. This includes the eastern half of South Carolina as well as eastern North Carolina. On radar, the eye is about 30 nm in diameter, and on satellite, the eye is about 35 nm in diameter. The South Carolina coast between McClellanville and North Myrtle Beach is currently experiencing the core of Dorian as of 1730 UTC. On the forecast track, the center of Dorian will continue to move close to the coast of South Carolina this afternoon, and then move near or over the coast of North Carolina tonight and Friday. The center should move to the southeast of extreme southeastern New England Friday night and Saturday morning, and approach Nova Scotia later on Saturday. Dorian is a category 2 hurricane on the Saffir-Simpson Hurricane Wind Scale. Slow weakening is expected during the next few days. However, Dorian is expected to remain a powerful hurricane as the center moves near the coasts of the the Carolinas. See the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMAT5/WTNT25 KNHC or the website hurricanes.gov for more details. Tropical Storm Gabrielle is centered near 22.8N 35.5W at 05/1500 UTC or 770 nm NW of the Cabo Verde Islands moving NW at 9 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Scattered moderate convection is seen on the north side only, extending from 90 to 360 nm N of the center. Gabrielle's NW motion is expected to continue for the next few days with an increase in forward speed. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC or the website hurricanes.gov for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave extends its axis along 20W, from 20N southward, moving W at 10-15 kt. Scattered moderate showers are seen from 03N-17N between 14W-25W. Environmental conditions appear to be conducive for gradual development. A tropical depression could form early next week while it moves westward across the tropical Atlantic Ocean. An Atlantic tropical wave extends its axis along 54/55W from 05N-22N, moving W at 10-15 kt. Scattered moderate to isolated strong convection is located about 435 nm east of the Leeward Islands from 15N-21N between 51W-57W. Scattered showers are elsewhere within 90 nm of the wave axis. Any development from the northern portion of this wave is expected to be slow to occur while it moves slowly northwestward. The chance of tropical cyclone formation during the next 48 hours is low. An eastern Caribbean tropical wave extends its axis along 67W, from 02N-17N, moving W at 10 kt. Scattered moderate to isolated strong convection is inland over W Venezuela and E Colombia from 01N-10N between 68W-72W. Scattered showers are also seen over eastern portions of the ABC Islands. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from 17N16W to 07N25W to 11N38W to 11N46W. The ITCZ is from 11N46W to 15N52W, then resumes W of a tropical wave from 14N58W to 12N64W. Aside from the convection mentioned in the section above, scattered moderate showers are seen from 02N-14N between 25W-33W, and from 10N-13N between 39W- 48W. GULF OF MEXICO... A tail of enhanced moisture about 60 nm wide extends from the east side of Dorian to the Florida Keys to 24N90W to the lower Texas coast to the remnants of Fernand, which are analyzed as a surface trough well inland over northern Mexico from 28N100W to 25N101W. Scattered showers and isolated tstorms are underneath this swath of enhanced moisture, except for scattered moderate to isolated strong convection seen in the west-central Gulf of Mexico from 25N-27N between 95W-97.5W. Drier air is over the northern Gulf of Mexico, with a 1018 mb surface high centered just W of Houston Texas. The latest ASCAT pass shows moderate W winds over the far NE Gulf of Mexico, with gentle winds elsewhere in the basin. Weak high pressure will prevail across the basin through the weekend, producing gentle to moderate winds, that will strengthen some early next week. CARIBBEAN SEA... Refer to the section above for details on the tropical waves moving across the basin. An upper-level trough is over the W Caribbean with upper-level ridging over the eastern Caribbean. Scattered moderate convection is seen from 13N-18N between 78W-81.5W, including over western Jamaica. To the south of 13N in the SW Caribbean, numerous moderate with embedded isolated strong convection is being enhanced by the upper-level trough and the East Pacific monsoon trough from 08.5N-13N between 76W-85W. Elsewhere, scattered showers and tstorms are see in the far NW Caribbean just south of the Yucatan Channel and just south of western Cuba. The latest ASCAT pass shows strong trades in the south-central Caribbean from 11N-15N between 73.5W-77W. A weak Atlantic ridge extends from the central Atlantic to the SE Bahamas. Fresh to strong tradewinds will pulse in the S central Caribbean tonight. Otherwise, mainly moderate to fresh tradewinds are expected. ATLANTIC OCEAN... Refer to the sections above for details on Dorian, Gabrielle and two tropical waves moving across the basin. Scattered showers and tstorms extend over the southern tip of Florida, the Florida Keys, Florida Straits and NW Bahamas. This activity is due to a tail of enhanced moisture that emanates from the eastern side of Hurricane Dorian. Farther east, a 1011 mb low pressure center is near 35N61W, a few hundred nm NE of Bermuda. A surface trough extends from the low to 31N61W to 29N63W. Scattered moderate convection is from 28N-33N between 57W-63W. Increasingly unfavorable upper-level winds, produced by Hurricane Dorian, are expected to inhibit further development during the next several days as the system moves northeastward into the central north Atlantic. The chance of a tropical cyclone developing during the next 48 hours is low. Elsewhere, an upper-level low near 26N45W is producing scattered showers and isolated tstorms from 25N-30N between 41W-49W. The center of Hurricane Dorian is forecast to be near or over the Outer Banks of North Carolina Friday morning at 1200 UTC. Winds of tropical storm force and seas over 18 ft associated with Hurricane Dorian's southern extent will move north of 31N latitude this afternoon. However, winds of 25-33 kt and seas of 12-17 ft will continue tonight north of 29N between 73W-80W. Winds of 25-30 kt and seas of 12-14 ft will continue Friday north of 30N between 72W-76W. The large northerly swell from Dorian will dominate the SW N Atlantic through the weekend. Much more tranquil marine conditions are forecast by early next week. $$ Hagen