Hurricane Francine, the fourth hurricane of the 2024 Atlantic season, struck the Louisiana coast on the evening of Sept. 11 as a Category 2 storm, causing flooding and knocking out electricity to thousands, according to a Triple-I summary of news reports.
Francine made landfall in Terrebonne Parish, about 30 miles southwest of Morgan City, with maximum sustained winds near 100 mph. The storm caused severe flooding and led to a flash flood emergency in the New Orleans metro area. Shortly after landfall, Francine was downgraded to a Category 1 hurricane with 90 mph winds. It was downgraded to a tropical depression with sustained winds of 35 mph by the morning of Sept. 12. More than 400,000 customers lost power in Louisiana, over 66,000 customers lost power Mississippi, and more than 12,000 in Alabama as of Sept. 12, Triple-I’s summary notes.
Despite an early and intense start to the 2024 Atlantic hurricane season, with Hurricane Beryl becoming the earliest Category 5 hurricane in the Atlantic on record, the storm activity had been muted until Francine formed. Hurricanes Debby and Ernesto were the last named storms in early- and mid-August.
Colorado State University recently put out an update discussing the lull, stating that potential reasons for the dearth in recent activity include:
- A northward-shifted monsoon trough resulting in African easterly waves emerging at too far north a latitude.
- Extremely warm upper-level temperatures resulting in stabilization of the atmosphere.
- Too much easterly shear in the Atlantic.
- Unfavorable sub-seasonal variability associated with the Madden-Julian oscillation.
“Only one other time in the satellite era has the Atlantic not produced any named storms between August 13 and Sept. 3,” states the report. “That other year was 1968. This pronounced [quiet] period is especially remarkable given that it coincides with the time of year where the Atlantic climatologically gets very busy.”
CSU did not issue a new seasonal forecast with the analysis and stands by its original prediction of an above-average hurricane season, “given that large-scale conditions appear to become more favorable around the middle of September.”
CLM’s coverage of CSU’s previous update noted that the 2024 Atlantic hurricane season was expected to have activity well above the 1991-2020 average. “We estimate that 2024 will have 23 named storms (average is 14.4), 115 named storm days (average is 69.4), 11 hurricanes (average is 7.2), 45 hurricane days (average is 27.0), five major (Category 3-4-5) hurricanes (average is 3.2) and 13 major hurricane days (average is 7.4). We predict Atlantic basin Accumulated Cyclone Energy (ACE) and Net Tropical Cyclone activity in 2024 to be ~170% of their 1991-2020 average. We have maintained the same forecast numbers that we issued with our initial early April prediction,” CSU said at the time.