000 AXNT20 KNHC 131803 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Mon Sep 13 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... Tropical Storm Nicholas is centered near 26.4N 96.8W at 13/1500 UTC or 40 nm NE of mouth of The Rio Grande and moving N at 10 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained winds are 50 kt with gusts to 60 kt. Numerous moderate to strong convection is noted within a 160 nm semicircle E of the center. Scattered moderate to isolated convection is seen up to 50 nm SW of the center. Similar conditions are also found farther N of the center, along the Texas coast and adjacent waters. Seas are peaking at 16 to 17 ft near and just NE of the center. Dangerous storm surge is expected from the Mouth of the Rio Grande northeastward to Intracoastal City. On the forecast track, the center of Nicholas will pass near or just offshore of the coast of south Texas this morning and move onshore along the coast of south or central Texas late this afternoon or this evening. Strengthening is forecast today, and Nicholas could reach the northwest Gulf coast as a hurricane. Weakening is anticipated on Tuesday and Wednesday while Nicholas moves over land. Nicholas is expected to produce 6 to 10 inches of rain with locally higher amounts from just NE of Corpus Christi northeastward across Houston to E of Lake Charles. Flooding at urban and low-lying areas, as well as near rivers and streams is likely. The potential for flash flooding will also increase. Please read the latest High Sea Forecast issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Nicholas NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave is along the African coast near Senegal, Gambia and Guinea. Scattered moderate convection is seen from 06N to 13N between the coast 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 Tropical Weather Outlook at www.hurricanes.gov for more information. An Atlantic tropical wave is along 33W from 19N southward and moving W at 10 to 15 kt. Scattered moderate convection is noted from 02N to 9N between 27W to 35W. Another Atlantic tropical wave is near 55W from 20N southward and moving W near 15 kt. Drier air at mid levels is hindering any significant convection near this wave. A Caribbean tropical wave is along 74W from W Hispaniola to N Colombia, and moving W at 10 to 15 kt. No significant convection is seen near this wave. Another Caribbean tropical wave is near 88W from the coast of Belize southward across Honduras and El Salvador to the E Pacific Ocean, and moving W near 10 kt. No significant convection is found. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic ocean near Guinea-Sierra Leone border at 09N13W to 08N34W. Numerous moderate to isolated strong convection is occurring over Guinea and SW Senegal. The ITCZ continues from 08N34W to 06N45W. Scattered moderate convection is present up to 70 nm on either side of the ITCZ between 35W and 41W. The eastern end of the E Pacific monsoon trough is triggering scattered showers and isolated thunderstorms over the SW Caribbean Basin, including the coast of Panama, Costa Rica and S Nicaragua. ...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 thunderstorms over the Bay of Campeche. Convergent trade winds are producing scattered showers and isolated thunderstorms across the SE Gulf, including the Florida Strait and Keys. Outside of Nicholas, the latest scatterometer pass provides observations of fresh to strong SE to S winds with seas at 6 to 9 ft across the central and W central Gulf. Elsewhere, mainly gentle to moderate E to ESE winds and seas of 2 to 5 ft are found. For the forecast, Tropical Storm Nicholas is near 26.4N 96.8W with a central pressure at 1002 mb at 1500 UTC. It is moving N at 10 kt with maximum sustained winds at 50 kt with gusts to 60 kt. Nicholas will move to 27.5N 96.7W this evening, inland to 29.1N 96.3W Tue morning, move inland and weaken to a tropical depression near 30.2N 95.4W Tue evening, inland to 31.0N 94.0W Wed morning, inland to 31.5N 92.5W Wed evening, and become a remnant low and move to 32.0N 91.1W Thu morning. Nicholas will dissipate by early Fri. ...CARIBBEAN SEA... Convergent trades are coupling with divergent winds aloft to produce scattered showers and thunderstorms over the NE corner of the basin, including the Leeward Islands. Refer to the Tropical Waves and Monsoon Trough/ITCZ sections for additional convection in the Caribbean Basin. Satellite derived wind data show mainly gentle with locally moderate trades across the basin. Seas at 3 to 5 ft across the majority of the waters, except 2 to 3 ft N of Venezuela. For the forecast, moderate to fresh trades will prevail across the basin through Wednesday. By the end of the week, fresh SE winds return in the Gulf of Honduras. ...ATLANTIC OCEAN... A stationary front reaches west-southwestward from E of Bermuda to N Florida. Scattered showers and isolated thunderstorms are evident near this feature N of 28N between 45W and 71W. An upper- level low near the N coast of Hispaniola at 20N71W is generating scattered showers and thunderstorms from 19N to 22N between 61W and 71W, and farther N from 24N to 26N between 62W and 67W. Moderate to fresh winds and seas at 5 to 7 ft are noted near these showers and thunderstorms. Convergent trades are causing scattered showers and isolated thunderstorms from SE Florida, northeastward across the NW Bahamas to near 28N71W. Another upper-level low near 28N50W is producing isolated thunderstorms over the central Atlantic. A weakening cold front is generating scattered showers near the Canary Islands. Refer to the Tropical Waves and Monsoon Trough/ITCZ sections for additional convection. Light to gentle E to ESE trades and seas of 2 to 4 ft prevail off the Florida- Georgia coast. Otherwise, gentle to moderate trades and seas at 4 to 6 ft dominate the rest of the Atlantic Basin. For the forecast west of 65W, a frontal boundary will linger across the area through today which will bring showers and thunderstorms across the area. Otherwise, quiescent conditions will prevail through Wednesday. 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 north-northwestward or northward 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. $$ Chan