CURRENT TROPICAL CYCLONES
Tropical Cyclone Nicholas…is located about 35 miles south-southwest of Matagorda, Texas
A tropical wave located over the far eastern tropical Atlantic is producing an area of disorganized cloudiness and thunderstorms. Environmental conditions are forecast to be conducive for gradual development of this disturbance over the next several days, and a tropical depression is likely to form by later this week while the system moves westward at about 15 mph across the eastern tropical Atlantic Ocean.
* Formation chance through 48 hours…medium…40 percent
* Formation chance through 5 days…high…80 percent
An area of low pressure is expected 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.
* Formation chance through 48 hours…low…10 percent
* Formation chance through 5 days…medium…50 percent
Gulf of Mexico
Tropical Cyclone Nicholas
NICHOLAS BRINGING HEAVY RAINS, STRONG WINDS, AND STORM SURGES TO PORTIONS OF THE CENTRAL AND UPPER TEXAS COASTS
According to the NHC Advisory 7A…Nicholas is moving toward the north-northeast near 12 mph (19 km/h) and this general motion is expected to continue through tonight, followed by a turn toward the northeast by late Tuesday. On the forecast track, the center of Nicholas is expected to make landfall along the central Texas coast later tonight. Maximum sustained winds have increased to near 70 mph (110 km/h) with higher gusts. Some additional strengthening is possible during the next few hours, and Nicholas could become a hurricane when it reaches the Texas coast. Weakening is anticipated on Tuesday and Wednesday while Nicholas moves over land. Tropical-storm-force winds extend outward up to 115 miles (185 km) from the center. A WeatherFlow station at Matagorda Bay recently reported a sustained wind of 55 mph (89 km/h) with a gust to 71 mph (115 km/h).
HAZARDS AFFECTING LAND
RAINFALL: Nicholas is expected to produce storm total rainfall of 6 to 12 inches, with isolated maximum amounts of 18 inches, across portions of the middle and upper Texas coastal areas through Wednesday. Life-threatening flash flooding impacts, especially in highly urbanized metropolitan areas, are possible across portions of the upper Texas Gulf Coast and far southwestern Louisiana. Across interior southeast Texas into southern-central Louisiana and southern Mississippi, rainfall totals of 4 to 8 inches with locally higher amounts near 10 inches are expected through Thursday. This rainfall may produce areas of considerable flash and urban flooding. The potential for minor to isolated moderate river flooding exists across the entire region, along with isolated major river flooding, especially in the smaller river basins and urban areas.
STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide…
Port O’Connor, TX to San Luis Pass including Matagorda Bay…3-5 ft
San Luis Pass to Rutherford Beach, LA including Galveston Bay…2-4 ft
Port Aransas, TX to Port O’Connor, TX…2-4 ft
Aransas Bay and San Antonio Bay…2-4 ft
Rutherford Beach, LA to Intracoastal City, LA…1-3 ft
Sabine Lake and Calcasieu Lake…1-3 ft
Baffin Bay to Port Aransas, TX…1-3 ft
Corpus Christi Bay…1-3 ft
Mouth of the Rio Grande to Baffin Bay…1-2 ft
The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by large and dangerous waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances.
WIND: Tropical storm conditions are expected within the warning area across the central and upper Texas coasts through tonight, making outside preparations difficult or dangerous. Hurricane conditions are possible in the Hurricane Watch area as early as this evening.
TORNADOES: A couple of tornadoes will be possible through tonight, mainly along the upper Texas coast.
SURF: Swells generated by Nicholas will continue affecting portions of the northwest Gulf coast through Tuesday. These swells are likely to cause life-threatening surf and rip current conditions.