Hurricane Ida was a category 4 major hurricane that made landfall in Louisiana on the 29th of August 2021 with 1-minute sustained winds of 150 mph. The author rode out the storm in Morgan City at 29.700N 91.199W. The sea level of the location was approximately 5 feet. Ida’s center passed approximately 35 miles east of Morgan City around 4 PM CDT. The author collected meteorological data with the WeatherFlow Windmeter on a rotating mount and surveyed the damage of regions hit by the eyewall.
Ida had a distinct concentric eyewall feature shown on the radar. Concentric eyewalls are characterized as a double eyewall structure with a dry slot known as the “moat” separating the inner and outer eyewall. The inner eyewall is generally where the strongest winds occur because a narrower eyewall tends to have a steeper pressure gradient. Hurricane Ida maintained a concentric eyewall structure for approximately 6 hours after landfall before a widening of the inner eyewall was observed. Cities such as Houma and Raceland took a direct hit from the inner core.
Radar image of Hurricane IDA at 16:20 pm CDT 29 August— mesovortices likely explain the jagged edges of the eye. (Image: https://weather.us/radar-us/terrebonne/reflectivity/KLIX_20210829-212621z.html)
Morgan City was located on the dry westward side of the storm and did not receive any hurricane-force winds. Conditions started to deteriorate at approximately noon. Morgan City lost power around 2 PM and lost communication around 7 PM. Peak conditions at Morgan City occurred at approximately 3 PM. The author’s device recorded peak sustained winds of 12m/s gusting to 26m/s and minimum air pressure of 992 mbr. Hurricane chaser Josh Morgerman, who was in Houma, recorded pressure of 964 mbr with a Kestrel 4500.
Figure: Air pressure data from Josh Morgerman at Houma
There was no damage in Morgan City except for fallen tree branches. Storm surge did not reach the city despite the low elevation. Widespread catastrophic wind damage was observed between Houma and New Orleans. The author consistently observed torn roofs, shredded gas stations, downed powerlines, and tree trunks snapped in half in those heavily hit areas. The worst wind damage occurred in areas where the front right quadrant of the eyewall passed over. Raceland in particular had entire forests snapped in half and houses that were missing interior walls. New Orleans had wind damage comparable to Houma despite its much further proximity from the center. This is likely due to the movement of the storm contributing to the right front quadrant winds. Louis Armstrong International airport was closed for several days due to heavy damage. The author was able to fly out of Louisiana from cities west of Morgan City that weren’t heavily impacted by the Hurricane.
Source: Kevin Lu