Storm Surge/Tide — Coastal Kenedy County, Texas

2020-09-21 to 2020-09-23 · Coastal Kenedy County, Texas

Event narrative

A tide gage at Baffin Bay, just north of the Kenedy/Kleberg County line, peaked at 2.34 feet above Mean Sea Level (MSL) around 8 PM CST September 21, and continued above 2 feet above MSL through 5 PM CST on the 23rd. Though tide levels inside Laguna Madre remained high through the 23rd, the lack of landward push of water from Beta that day as the cyclone had already made landfall on the 22nd along the central Texas coast, well north of Port Mansfield, suggested that the push may have ended earlier. However, since northern Kenedy County was much closer to the outswell from slow-moving Beta for several days, it's possible that additional run-up to or just into the dunes occurred for two or more day period.

Wider weather episode

As Hurricane Beta traversed northward across the Gulf of Mexico in late September, outgoing swell propagated into the lower Texas coastal waters on September 20th through the 22nd. This swell was powerful enough to push water into the dunes across South Padre Island around high tide, which occurred at 7:30 PM CDT on the 20th and 9:37 PM CDT on the 21st. The highest level that was reported was 2.42 feet above Mean Higher-High Water (MHHW; or the level above normally dry ground at the shoreline) at 3:24 AM CDT on the 21st and 2.54 feet above MHHW at 11:24 PM CDT also on the 21st. Levels remained above 1.25 feet MHHW for several hours surrounding the occurrence of high tide on both evenings of September 20th through the 21st and again on the 21st through the 22nd. This activity was enough to cause some coastal erosion.

Farther up the coast, similar wave action and minor coastal flooding was likely - but there were no comparative measurements based on MHHW.

Source: NOAA Storm Events Database, event_id 922927. Narrative written by the NWS forecast office that issued the report.