Storm Surge/Tide — Lower St. Bernard, Louisiana

2020-09-15 · Lower St. Bernard, Louisiana

Event narrative

Impacts to portions of the parish were the result of storm surge and affected areas outside the HSDRRS Levees. Storm surge flooding overtopped ring levees in the Delacroix and Woodlake areas, resulting in one to two feet of inundation inside those leveed areas. The lower portion of the parish below the Verret Flood gates was cut off due to flooding. Observations across the area ranged in the 5.35 MHHW to 5.92 NAVD88 range in Bayou Dupree (BDML1) and Shell Beach (SHBL1) on the 15th between 12:12CDT and 13:00 CDT.

Wider weather episode

Hurricane Sally initially formed as an area of disturbed weather over the Bahamas late on September 10th, 2020. Over the next few days, the system became better organized and became Tropical Depression Nineteen in the afternoon hours on September 11th. Later that night around midnight CDT on September 12th, TD Nineteen made landfall at Key Biscayne with peak winds of 35 mph and a central pressure of 1007mb (29.74 inHg). The system continued west emerging into the east-central Gulf of Mexico and quickly strengthened into a Tropical Storm later in the day on the 11th. This system continued to drift northwestward with time and strengthened into a hurricane in the morning hours on September 14th with maximum sustained winds of 85 mph and a central pressure of 985 mb (29.09 inHg) and continued to strengthen becoming a category 2 hurricane shortly after. Sally would then eventually weaken some, and slow down in forward speed before turning very slowly northwards making landfall near Gulf Shores, Alabama as a strong Category 2 hurricane with peak winds of 105 mph and a central pressure of 965mb (28.50 inHg) early in the morning hours on September 16th.

Impacts to southeastern Louisiana and southern Mississippi was mostly confined to coastal counties of southern Mississippi, southeastern Louisiana and adjacent marine areas. Main impacts included storm surge inundation for coastal areas, as well as some wind damage across portions of Jackson and Harrison County, MS while Hurricane Sally was making landfall east across Gulf Shores, AL. Rainfall was of little impact across coastal MS and westward with only small areas of rainfall totaling around 3 inches reported in eastern Jackson county.

Source: NOAA Storm Events Database, event_id 922167. Narrative written by the NWS forecast office that issued the report.