000 AXNT20 KNHC 132107 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Tue Sep 14 2021 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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2030 UTC. ...SPECIAL FEATURES... Tropical Storm Nicholas is centered near 27.4N 96.4W at 13/2100 UTC or 60 nm S of Port Oconnor Texas moving NNE at 10 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Peak seas are currently 21 ft. Numerous moderate and isolated strong convection is noted north of 25N and west of 92W, with scattered moderate convection elsewhere north of 22N and west of 90W. On the forecast track, the center of Nicholas is expected to make landfall along the central Texas coast later tonight. Some additional strengthening is forecast this evening, and Nicholas could be near hurricane strength when it reaches the central Texas coast. Weakening is anticipated on Tue and Wed while Nicholas moves over land, weakening to a tropical depression near Wed morning, becoming a remnant low Thu, and dissipating Fri afternoon. Dangerous storm surge, as well as flooding at urban and low-lying areas and near rivers and streams, is likely. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT4.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT4.shtml for more details. ...TROPICAL WAVES... A tropical wave is in the Atlantic Ocean near the coast of Africa along 18W from 04N to 17N, moving W at around 10 kt. Numerous moderate and scattered strong convection is noted from 09N to 15N between 11W and 18W, mainly over land. Scattered moderate convection is noted from 06N to 11N between 19W and 23W. The National Hurricane Center is monitoring this feature and there is a low chance of tropical cyclone formation through the next 48 hours, and a high chance through the next 5 days. Please read the latest Atlantic Tropical Weather Outlook at www.hurricanes.gov for more information. A tropical wave is in the Atlantic Ocean along 35W from 19N southward, moving W at around 15 kt. Associated convection is described in the section below. A tropical wave is in the Atlantic Ocean along 58W from 20N southward, moving W at 15 to 20 kt. Drier air at the mid-levels is hindering any significant convection near this wave. A tropical wave is in the Caribbean Sea along 75W near the approach to the Windward Passage from 20N southward to across north-central Colombia, moving W at around 10 kt. Scattered moderate and isolated strong convection is noted in the southwest Caribbean Sea from 09N to 13N between 73W and 85W, mainly associated with the eastern extent of the Pacific Ocean monsoon trough. A tropical wave is exiting the NW Caribbean Sea near eastern Belize along 88W from 18N southward into the Pacific Ocean, moving W at around 10 kt. No significant convection is noted. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from near The Gambia and Senegal border at 13N17W to 09N26W to 07N45W. Scattered moderate and isolated strong convection is noted from 05N to 10N between 33W and 44W. ...GULF OF MEXICO... Refer to the Special Features section above for details on Tropical Storm Nicholas moving northward across the NW Gulf. Convergent fresh to strong SE winds feeding toward Nicholas are triggering scattered showers and isolated thunderstorms over the Bay of Campeche. Convergent trade winds are producing scattered showers and isolated thunderstorms across the SE Gulf, including the Straits of Florida and the Florida Keys. Outside of Nicholas, fresh to strong SE to S winds with seas at 6 to 9 ft across the W central Gulf. Elsewhere, mainly gentle to moderate E-SE winds. Seas are 2 to 4 ft in the eastern Gulf, and 4 to 7 ft elsewhere outside of Nicolas. For the forecast, Nicholas will move to 28.7N 96.1W Tue morning, inland to 29.9N 95.3W Tue afternoon, move inland and weaken to a tropical depression near 30.4N 94.4W Wed morning, then to 30.9N 92.9W Wed afternoon, to 31.1N 91.4W Thu morning, and become a remnant low as it moves to 32.0N 90.6W Thu afternoon. Nicholas will dissipate Fri afternoon. ...CARIBBEAN SEA... Convergent trades are coupling with divergent winds aloft to produce scattered showers and thunderstorms over the NE portion of the basin north of 12N and east of 68W, including the Leeward Islands. Late afternoon/early evening showers and thunderstorms are over the Greater and Lesser Antilles. Refer to the Tropical Waves and Monsoon Trough/ITCZ sections for additional convection in the Caribbean Basin. Fairly tranquil marine conditions are noted across the basin with gentle with locally moderate trades. Seas at 3 to 5 ft across the majority of the waters, except 2 to 4 ft north of Venezuela. For the forecast, moderate to fresh trades will prevail across the basin through Wed. By mid-week, fresh E winds return in the Gulf of Honduras and south-central Caribbean, and will then continue through the forecast period. ...ATLANTIC OCEAN... An old frontal boundary that was reaching from southeast of Bermuda to near the Treasure Coast of Florida has dissipated. Even so, plentiful moisture remains with scattered showers and isolated thunderstorms across much of the basin west of 60W. Refer to the Tropical Waves and Monsoon Trough/ITCZ sections for additional convection. Outside of any convection, fairly tranquil marine conditions prevail across the basin with gentle to moderate trades. Seas of 3 to 6 ft dominate as well, except 5 to 8 ft north of 28N between the Canary Islands and 35W. For the forecast west of 65W, quiescent conditions will prevail through Wed. Meanwhile, an area of low pressure is forecast to form by midweek a couple of hundred miles north of the southeastern or central Bahamas as a tropical wave interacts with an upper-level trough. Some gradual development of this system is possible thereafter, and a tropical depression could form later this week while the system moves NW across the western Atlantic. This system has a low chance of formation in the next 48 hours, and a medium chance through the next 5 days. Please read the latest Atlantic Tropical Weather Outlook at www.hurricanes.gov for more information. $$ Lewitsky