Heat — Coastal Kenedy, Texas

2023-06-17 · Coastal Kenedy, Texas

Event narrative

The Cameron County Airport ASOS near Bayview reported around seven hours of heat index at or above 111 degrees during the afternoon of June 16th, peaking at 117 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period.

Interpolation between these sites and the slightly more inland site near Sarita (Kenedy - Texas Water Development Board Mesonet station 100), which had similar heat index values (generally, 111 to 115, briefly peaking at 118 degrees around 6 PM CDT) is a good proxy for Coastal Kenedy.

Wider weather episode

A dome of strong atmospheric high pressure - known locally as La Canicula, provided a prolonged period of hot to very hot temperatures combined with high humidity to lead to excessively heat index values in mid-June. High temperatures were in the upper 90s to middle 100s June 13th through June 17th. Heat indices ranged from 116 to 125-degrees every afternoon across much of the area, from Hidalgo and Brooks County eastward. Heat indices ranged from 111 to 115 in these counties and farther west (Jim Hogg, Starr, and Zapata) on occasion through the period; these are considered Heat Advisory days with a slightly lower threshold for life-threatening conditions, but still dangerous.

The heat dome would continue through the end of June, with advisory or warning level heat index for all or part of the Rio Grande Valley and Deep South Texas through the period, and into July.

Local hospitals noted an increase in heat-related emergency room visits during this period when compared with the same period a year earlier, which was also hot but not at the level of 2023. Percentage increases ranged from 11 to 18 percent more visits during the month of June. Detailed information on heat-related illnesses (actual numbers of injuries or fatalities) was not known as of the end of August.

Source: NOAA Storm Events Database, event_id 1117040. Narrative written by the NWS forecast office that issued the report.