Storm Surge/Tide — Upper St. Bernard, Louisiana

2020-09-21 · Upper St. Bernard, Louisiana

Event narrative

Minor to moderate storm surge inundation occurred across Upper St. Bernard Parish with many NOS and USACE observations reporting between 4.14 ft MHHW and 5.28 ft NAVD88 inundation levels across the area.

Wider weather episode

Tropical Storm Beta initially developed as a disturbance in the Bay of Campeche early on September 10th. The system drifted around the Bay of Campeche for several days as development was unlikely due to unfavorable upper-level winds produced by nearby Hurricane Sally. This system eventually began to organize and became Tropical Depression Twenty-Two on September 17th and became Tropical Storm Beta on September 18th. The storm continued to intensify reaching a peak of 60mph winds and a central pressure of 994mb (29.36 inHg) on September 19th as the storm became nearly stationary after turning westward over the Gulf of Mexico. Tropical Storm Beta approached the Texas coast and weakened before making landfall on the Matagorda Peninsula on September 22nd with maximum sustained winds of 45mph and a pressure of 999mb (29.50 inHg).

A tight pressure gradient between Beta and an area of high pressure to the northeast resulted in persistent moderate to strong onshore east and northeast winds across the area. This caused an extended duration of impacts to the area between the days of September 19th and September 23rd. The strongest winds and highest water levels occurred when Beta's center of circulation was well removed from the local area and thus much of the local impacts were mainly confined to marine and coastal areas where tropical storm watches and warnings were in effect.

Source: NOAA Storm Events Database, event_id 921977. Narrative written by the NWS forecast office that issued the report.