000 AXNT20 KNHC 281801 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 200 PM EDT Mon Aug 28 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 1745 UTC. ...SPECIAL FEATURES... Tropical Storm Harvey is centered near 28.6N 95.8W at 28/1800 UTC or about 35 nm ENE of Port O'Connor Texas moving ESE at 3 kt. Estimated minimum central pressure is 998 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Scattered moderate convection and tstms are N of 23N between 88W and 95W. Isolated showers and tstms are elsewhere N 21N between 85W and 97W. The center of Harvey is expected to be just offshore of the middle and upper coasts of Texas through Tuesday night. See latest Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC and the full Forecast/Advisory under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details. Potential Tropical Cyclone Ten is centered near 31.8N 80.3W at 28/1800 UTC or about 60 nm SSW of Charleston South Carolina and about 190 nm SW of Wilmington North Carolina. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Numerous moderate convection and scattered tstms are N of 29N between 77W and 80W. The system will move over or near the coast of South Carolina today and move along the North Carolina Outer Banks on Tuesday. See latest Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT5/ WTNT35 KNHC and the full Forecast/Advisory under AWIPS/WMO headers MIATCMAT5/WTNT25 KNHC for more details. A tropical wave is in the E Atlc associated with a 1012 mb low that is located near 12N21W. The wave axis extends from 19N20W to the low to 06N20W and is forecast to move at 5 kt within the next 24 hours. The wave is in a region of low to moderate vertical wind shear and CIRA LPW imagery show dry air intrusion to the wave environment mainly NW of the low center. Moderate moisture at the lower levels and middle to upper level diffluent flow support scattered moderate convection from 07N to 14N between 21W and 29W. This system has become better organized since yesterday, and a tropical depression could form in a few days over the eastern Atlantic. Regardless of development, heavy rain is possible in portions of the Cabo Verde Islands through Wednesday. There is a medium chance for this system to become a tropical cyclone within the next 48 hours. ...TROPICAL WAVES... A tropical wave is in the central Atlc with axis extending from 24N33W to 13N35W, moving W at 10 kt within the last 24 hours. Enhanced infrared satellite imagery show extensive Saharan dry air and dust in the wave environment, which is hindering convection at this time. A tropical wave is in the E Caribbean with axis extending from 23N62W to 11N62W, moving W at 15 kt. The wave is in a region of strong vertical wind shear, and CIRA LPW imagery show patches of dry air in its environment. Shallow moisture is supporting scattered showers and tstms from 16N to 22N between 60W and 66W, including the Leeward Islands. A tropical wave is in the central Caribbean with axis extending from 20N74W to 09N75W, moving W at 15 kt. The wave is in a region of strong vertical wind shear, however shallow moisture and upper level diffluence support scattered showers and isolated tstms from 15N to 18N between 75W and 78W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from 12N16W to 10N30W to 11N38W to 10N53W. Besides from the convection associated with the tropical wave in the E Atlc, scattered moderate convection is from 08N to 12N between 30W and 44W. A surface trough extends from 16N48W to 07N49W with similar convection within 210 nm either side of its axis. ...DISCUSSION... GULF OF MEXICO... Tropical Storm Harvey is crossing the coastline of Texas and moving into the NW Gulf waters. The rainbands associated with this system continue to support scattered moderate convection and tstms N of 23N between 88W and 95W. To the east of Harvey, upper level divergence associated with a middle to upper level ridge centered near 25N90W support scattered showers and tstms in the NE Gulf N of 25N. A middle level short-wave trough is over the western Florida Peninsula extending to adjacent waters where it supports a 1009 mb low near 28N83W, which is forecast to move across Florida today and merge with Potential Tropical Cyclone Ten early Tue. The remainder of the Gulf is under mostly gentle to moderate southerly winds. Harvey is expected to remain in the vicinity of the Texas coast through mid-week. For further details see special features. CARIBBEAN SEA... Two tropical waves are moving across the Caribbean waters, one along 63W generating showers in the NE basin, and a second wave along 76W supporting showers SSE of Jamaica and in the Windward Passage. Between these two waves, middle level diffluence support scattered showers and tstms from 12N to 15N between 65W and 71W. In the SW Caribbean, a 1010 mb low sits in the eastern extension of the EPAC monsoon trough near 10N77W, which is supporting scattered moderate to isolated strong showers and tstms S of 13N between 75W and 82W. Strong vertical wind shear and dry air subsidence is elsewhere, thus supporting fair weather. Moderate to fresh trades prevail and are expected to persist through Tuesday night. Thereafter, trades across south-central portions of the basin will increase as a center of high pressure establishes in central Atlc waters. ...HISPANIOLA... A tropical wave is moving across central Caribbean waters with axis along 75W and supports isolated showers in the Windward Passage and the western half of the Island. This wave will continue to move W away from the Island today, however a second tropical wave, currently in the E Caribbean, will move over the Island Tue morning supporting scattered to isolated showers. ATLANTIC OCEAN... Potential Tropical Cyclone Ten centered N of the area continues to impact the northwestern portion of the discussion area with scattered showers and tstms, and wind gusts to 40 kt. Seas are up to 13 ft. Diffluent flow between an elongated upper low over the W Caribbean and a ridge over the central Caribbean support isolated showers and tstms across the southern Bahamas. Farther east, the northern portion of a tropical wave moving across E Caribbean waters support scattered showers and tstms S of 22N between 61W and 65W. In the northern-central Atlc waters, a middle to upper level low support similar convection from 29N to 32N between 47W and 51W. The remainder of the central and eastern Atlc is under the influence of a surface ridge anchored by a 1029 mb high centered near the Azores at 39N31W. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos