Tropical Storm — Northern Hidalgo County, Texas

2020-07-25 to 2020-07-26 · Northern Hidalgo County, Texas

Event narrative

The slowly weakening inner eyewall of Hurricane Hanna eased into northern Hidalgo County during the early evening of July 25th and would exit a few hours after midnight on the 26th. The Automated Weather Observing System 11 miles north of Edinburg reported a peak sustained wind of 45 mph with a peak gust of 54 mph soon after 6 PM CST on the 25th before the sensor stopped reporting. Farther east, near the Willacy County line, a sensor reported a peak gust to 80 mph (Texas Agriscience Center, just a few miles from the Willacy County line) as the southern inner eyewall crossed at 1005 PM CST - just on the edge of the Northern Hidalgo zone area.

A NWS Storm Survey team investigated some of the area and found dozens of large tree limbs blown down along IH 69C/US 281. No significant structural damage was reported along the route, though not all areas were surveyed and it's likely that there may have been additional rural damage between San Manuel and Raymondville along and near SR 186. Based on NCEI's total dollar damage estimate (divided among the affected counties by local storm data experts) there was likely $33.25 million in damage for Northern Hidalgo.

Wider weather episode

Hurricane Hanna, the 2020 Atlantic season's first Hurricane, made landfall along the unpopulated Padre Island National Seashore on the mid-Kenedy County coastline as a Category 1 storm at around 5 PM Central Time Saturday, July 25th, carrying sustained 90 mph winds with gusts over 100 mph in a small portion of the inner eye wall. The hurricane spun slowly but steadily into southern Kenedy and northern Hidalgo County through just after midnight on the 26th, then through Starr County as a Tropical Storm before moving into Tamaulipas before daybreak and eventually near Monterrey, Nuevo Leon, by noon before dissipating during the evening of the 26th. Following the passage of the inner eye wall, broad feeder bands of torrential rains and gusty tropical storm force winds continued through the mid to late morning hours of July 26th, slowly migrating from east to west across the populated Rio Grande Valley.

Other than storm surge flooding, which peaked just north of Baffin Bay on the Kleberg and Nueces County coast near Corpus Christi, Hanna's memory for the Rio Grande Valley will be flooding rainfall, power outages, and an array of damage to poorly constructed buildings, from minor roof damage to complete demolition. Between 8 and 15 inches of rain fell from Port Mansfield to Harlingen, and along Interstate Highway 2 out through Mission and Sullivan City. The combination of high rainfall, locally high rainfall rates, and poor drainage left between 18 inches and four feet of water depth in many areas, most commonly from western Cameron through southeastern Hidalgo County, as well as a separate pocket in the Mission/La Joya/Sullivan City area. The rainfall wiped out 95% of the region's cotton crop; the combination of crop loss and production loss was more than one third of a billion dollars alone ($366 million)...most of which was in the Rio Grande Valley region.

At the peak of the storm, 250 thousand electric customers were without power, including all of Willacy County. Though storm surge was cut short by strong westerly flow across Cameron County, radiating swells did produce a notable surge of 3 feet or greater (estimated) from near Port Mansfield through Kenedy County. When the damage and economic loss is counted to infrastructure and agriculture combined, it is likely that Hanna cost at least one billion dollars across the Rio Grande Valley and the Deep S. Texas ranch country.

Source: NOAA Storm Events Database, event_id 914181. Narrative written by the NWS forecast office that issued the report.