Extreme Cold/Wind Chill — Coastal Jefferson Parish, Louisiana

2025-01-22 · Coastal Jefferson Parish, Louisiana

Event narrative

Temperatures were below freezing for approximately 60 hours from the evening of January 20th through the afternoon of January 23rd. The coldest period was the morning of January 22nd when air temperatures and wind chills dropped to around 10 to 15 degrees across the parish.

Wider weather episode

An Arctic airmass infiltrated the region on January 21st, resulting in widespread snowfall accumulations ranging from several inches to nearly one foot across Southeast Louisiana, southwestern Mississippi, and coastal Mississippi. The presence of this snowpack was a key contributor to significant nocturnal radiational cooling, which facilitated a dramatic drop in minimum temperatures by the morning of January 22nd, values not observed in the region for nearly four decades.

The last comparable cold-air outbreak with widespread single-digit minimum temperatures occurred on December 23'24, 1989. In this year's event, several sites recorded minimum temperatures second only to the infamous 1899 Arctic outbreak, with the entire region ranking within the top five coldest events on record. When considering the average of consecutive nightly minima, this event likely ranks within the top tier of historical cold spells for the area.

The persistence of anomalously low temperatures was underscored by an extended period of subfreezing conditions, with many locations remaining below freezing for approximately 60 consecutive hours. A majority of parishes and counties observed single-digit lows, with the lowest recorded temperature being 1F in Grosse Tete.

Of additional meteorological interest was the rapid temperature decline observed on the evening of January 21st. In several locations across coastal Mississippi and the New Orleans metropolitan area, the the coldest temperature occurred before midnight, slightly lower than the official morning low as readings actually rose a few degrees after midnight.

Unfortunately, there were 2 fatalities during this event. A 62 yr old Female perished in a fire caused by a space heater in Orleans Parish and an 85 year old male perished with hypothermia being a contributing factor in Pointe Coupee Parish.

Source: NOAA Storm Events Database, event_id 1244933. Narrative written by the NWS forecast office that issued the report.