Tropical Storm — Upper St. Bernard, Louisiana

2017-10-07 to 2017-10-08 · Upper St. Bernard, Louisiana

Event narrative

A few tropical storm wind gusts occurred in upper St Bernard Parish. A 37 knot (43 mph) wind gust was reported at the Weatherflow site at Bayou Bienvenue. No significant impacts were noted.

Wider weather episode

Hurricane Nate began as a tropical depression over the northwest Caribbean Sea on the morning of October 4th and moved fairly rapidly northward, with forward speeds in excess of 20 mph, for the next several days while gaining strength. The storm moved north-northwestward through much of the day on the 7th, as it approached southeast Louisiana before turning northward.

Two landfalls occurred in the CWA. The first was near the mouth of the Mississippi River at 7 pm CDT as a Category 1 hurricane. The second landfall was near Biloxi, Mississippi at 1230 am CDT October 8th, also as a Category 1 hurricane. As the hurricane approached southeast Louisiana and coastal Mississippi, it became asymmetric with much of shower and thunderstorm activity along with the stronger winds primarily on the east side of the system. The storm continued moving rapidly to the north and north-northeast, and had weakened to a tropical depression near Birmingham, Alabama by 10 am CDT on the 8th.

Minor impacts due to storm surge flooding were noted over several parishes in southeast Louisiana, while moderate impacts due to strong winds and storm surge were noted over the Mississippi coastal counties. Storm tides of 4 to 8 feet were generally noted along the Mississippi Coast resulting in storm surge values (water levels above normal astronomical levels) ranging from 2 to 4 feet in western areas to 4 to 7 feet in eastern sections. Minor to moderate impacts were noted from storm surge.

In southeast Louisiana, storm tides of 2 to 4.5 ft were noted resulting in storm surge of surge (water levels above astronomical tides) of 1 to 3 feet. Only minor impacts from storm surge were reported.

The lowest measured barometric pressure was 984.4 mb at a Weatherflow station near Biloxi. Keesler Air Force Base in Biloxi recorded a maximum sustained wind of 46 kt (53 mph) and a 61 knot (70 mph) gust at 2253CST on Aug 7. A shipyard at Pascagoula Mississippi recorded a wind gust 71 kts (82 mph) on a anemometer with height of 19.8 Meters

In Louisiana, the lowest pressure was recorded at the Southwest Pass NOAA CMAN station (BURL1) with a reading of 989.5mb. Maximum winds were recorded at the Pilot Station automated weather station (PSTL1) with a maximum sustained wind of 46 kt (53 mph) gusting to 57 Kts (66 mph) at 1554CST on Aug 7. Anemometer height of 20.3 meters

Rain amounts of 3 to 6 inches were common over the Mississippi coastal counties. rainfall amounts in Louisiana were generally 2 inches or less.

Source: NOAA Storm Events Database, event_id 720053. Narrative written by the NWS forecast office that issued the report.