The depression formerly known as Tropical Depression Nine, which has been keeping the southern coast of Texas and northern Mexico on alert, has strengthened to become Tropical Storm Harold, as per the 2 a.m. Eastern Time update from the National Hurricane Center (NHC).
The storm has winds of 72 km/h (45 mph) with stronger gusts and is moving west-northwest at 29 km/h (18 mph).
Harold is expected to bring heavy rain and tropical storm-force winds to parts of southern Texas later in the morning. The system is predicted to make landfall by midday on Tuesday. A tropical storm warning is in effect from the mouth of the Rio Grande to Port O’Connor, Texas. A tropical storm watch is in effect from Port O’Connor to Sargent, Texas.
Tropical Storm Harold is forecasted to produce rainfall ranging from 76 to 127 millimeters (3 to 5 inches) with isolated totals up to 178 mm (7 inches) across southern Texas through the early hours of Wednesday. In Mexico, rainfall of 102 to 152 mm (4 to 6 inches) is expected, with isolated amounts up to 254 mm (10 inches) in northern Coahuila and northern Nuevo León on Tuesday and Wednesday.
A storm surge of up to 1 meter (3 feet) is expected from the mouth of the Rio Grande to Sargent, as well as in the Baffin Bay, Corpus Christi, and Matagorda Bay areas.
The potential for a couple of tornadoes exists in southern Texas today.
Life-threatening surf and currents are expected along the entire southern Texas coast until Tuesday.
Conditions in the Gulf of Mexico are conducive to the development of a tropical storm at this time. Sea surface temperatures in the Gulf of Mexico are warmer than ever, according to analysis from NOAA data by hurricane expert Michael Lowry.
Current water temperatures provide any potential tropical system with the ability to thrive. Moreover, there is currently very low wind shear in the Gulf. Wind shear is what tears apart tropical systems, so without it, the storm could develop and organize more efficiently.
With limited time for this storm to intensify, most forecast models depict the system as a weak tropical storm or tropical depression upon landfall. However, with favorable conditions in the Gulf, strengthening is possible.
“I would certainly say the system has the potential for significant intensification before landfall,” said Phil Klotzbach, a research scientist at the Department of Atmospheric Science at Colorado State University.