Brief report on Tropical Storm Hermine and Impacts on the Lower Rio Grande Valley

Storm Overview
A persistent are of showers and thunderstorms over the extreme southwestern Gulf of Mexico east of the City of Veracruz, Mexico, during the early morning hours of Sunday, September 5th, gradually organized into Tropical Depression Number 10 shortly after sunset. Convection increased overnight on the 5th and into the early morning hours of Monday, September 6th, as the system began moving northward, and Tropical Storm Hermine was born at 4 AM CDT on the 6th. Hermine tracked steadily north–northwestward while gradually intensifying on the 6th, reaching the coast of northeastern Tamaulipas State, Mexico, about 40 miles south of Brownsville at 830 PM CDT with peak sustained winds estimated at 65 mph.

Hermine would track to the north–northwest at a steady 14 mph, with the center of circulation crossing the Rio Grande near Los Indios (Cameron County) at around midnight on Tuesday, September 7th. The center reached Harlingen at around 1 AM, Raymondville at around 2 AM, and progressed through the west portion of the King Ranch before exiting Deep South Texas near Falfurrias at around 5 AM. During that time, peak 1 minute sustained winds around the east periphery of the cyclone lessened only slightly, falling from 60 to 50 mph.

A swath of damaging winds and flooding rains pounded Brownsville, Harlingen, and Raymondville as the eyewall of Hermine tracked along and east of Federal Highway 77 in Cameron and Willacy Counties. Peak wind gusts reached or exceeded 70 mph, causing widespread damage to trees and power lines. Rainfall of more than 3 inches in just a few hours flooded roads and farmland. More than 250,000 residents were impacted by the core of Hermine during the middle of the night, making for a memorable end to the Labor Day weekend.

A map of the track, courtesy of the National Hurricane Center, is shown at the bottom of the page.

Impacts
Hermine arrived in fits and starts, with frequent gusty feeder band showers followed by relatively calm conditions through the day and early evening of September 6th. Between 930 and 10 PM, the action got underway as the central core of Hermine brought a rapid increase in sustained winds and gusts, along with increasingly heavy rainfall. Between 11 PM and Midnight, the northern "doughnut" crossed the Rio Grande over lower populated southwest Cameron County. Meanwhile, intense feeder bands east of the center, where some of the strongest winds were sampled, pounded Brownsville, Port Isabel, and South Padre Island with sustained winds of 40 to 50 mph and gusts up to 60 mph. Between midnight and 1230 AM, a very intense band would reform around the center, curling from just south of Harlingen to north of Brownsville. This band would cross Harlingen just prior to 1 AM, and produce 70+ mph wind gusts which damaged a number of roofs, knocked down limbs and uprooted trees, and wiped out power to more than 14,000 residents.

Boaters, particularly Mexican shrimping vessels, did their best to seek refuge in the Port of Brownsville prior to the arrival of the storm. Sixty–four vessels reached the Port, but 5 others became stranded at the coast, including three running aground in Texas and two in Mexico.

Moving northward, the band waned for a few moments before reintensifying in southern Willacy County, ultimately slamming through Raymondville at around 1 AM with wind gusts estimated just below hurricane force (70 mph). Widespread damage included hundreds of snapped limbs, dozens of uprooted trees, power outages to 75 to 80 per cent of the county, and destruction of several poorly constructed roofs and lean–tos. At one home, a trampoline sailed into a window, causing a minor injury to a 5 year old girl. At a motor hotel along the expressway, roof decking was blown out, forcing 10 guests to escape the facility. Significant injuries were not reported, though at least one of the guests had minor scratches.

Additional information, including damage estimates, will be available in the coming weeks. Click here for a preliminary formatted text report.