Tropical Storm Nicholas formed over the southwestern Gulf of Mexico on Sunday morning. At 11:00 a.m. EDT on Sunday the center of Tropical Storm Nicholas was located at latitude 20.5°N and longitude 94.8°W which put it about 405 miles (645 km) south-southeast of the Mouth of the Rio Grande River. Nicholas was moving toward the north-northwest at 13 m.p.h. (20 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were’ wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1008 mb.
A Tropical Storm Warning was issued for the portion of the coast from Barra el Mezquital, Mexico to Port Aransas, Texas. A Tropical Storm Watch was issued for the portion of the coast from Port Aransas to High Island, Texas.
An Air Force Reserve Hurricane Hunter reconnaissance plane found sustained winds of tropical storm force in a low pressure system over the southwestern Gulf of Mexico on Sunday morning and the National Hurricane Center designated the system as Tropical Storm Nicholas. The circulation around Tropical Storm Nicholas was still organizing. Thunderstorms began to form near the center of Nicholas. Thunderstorms were also developing in bands revolving around the center of circulation. Winds to tropical storm force extended out 100 miles (160 km) in the northeastern quadrant of Tropical Storm Nicholas. The winds in the other parts of the circulation were blowing at less than tropical storm force.
Tropical Storm Nicholas will move through an environment favorable for intensification during the next 24 hours. Nicholas will move over water where the Sea Surface Temperatures are near 30˚C. It will move between and upper level low over northern Mexico and an upper level ridge over the northwestern Caribbean Sea. The upper low and ridge will produce south-southwesterly winds that will blow toward the top of Nicholas’ circulation. Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification. The upper level winds are forecast to weaken on Monday and Tropical Storm Nicholas could strengthen more quickly when that occurs. There is a chance that Nicholas could intensify to a hurricane on Monday.
Tropical Storm Nicholas will move around the western side of a high pressure system that extends over the Gulf of Mexico. The high will steer Nicholas toward the north-northwest during the next 24 hours. On its anticipated track Tropical Storm Nicholas will approach the coast near the Mouth of the Rio Grande River on Monday. Nicholas will bring gusty winds and locally heavy rain to coastal areas of northern Mexico and southern Texas on Monday. Tropical Storm Nicholas could also cause a storm surge of up to 7 feet (2 meters) along portions of the coast.