Francine — 2024

A well-defined low formed over the Bay of Campeche in early September and organized into Tropical Storm Francine on September 9, 2024, about 215 nautical miles southeast of the mouth of the Rio Grande. The storm moved generally northwestward and then turned northeast ahead of a trough, strengthening to a hurricane around 0000 UTC September 11 while about 305 n mi southwest of Morgan City, Louisiana. Francine accelerated northeastward, made landfall on the southern Louisiana coast late on September 11, weakened inland to a tropical storm by the morning of September 12 near western Lake Pontchartrain, moved over central Mississippi by midday September 12, became a tropical depression later that day, and transitioned to an extratropical low on September 12–13 before dissipating over southeastern Arkansas on September 14. Francine made landfall in the remote coastal marshes of Terrebonne Parish, Louisiana, at about 2200 UTC on September 11. The National Hurricane Center’s best estimate of the storm’s intensity at that landfall was 90 kt (105 mph), Category 2 on the Saffir–Simpson scale, with a minimum central pressure of 972 mb. After landfall the center tracked northeast across southeastern Louisiana into central Mississippi where it rapidly weakened. The peak sustained wind used in the official record was 90 kt (105 mph) at landfall, based primarily on aircraft reconnaissance; the minimum central pressure at that time was 972 mb. Observed surface stations near the landfall area reported sustained winds in the 63–66 kt range at some marine and coastal sites, and hurricane-force gusts were measured in locations such as Louis Armstrong New Orleans International Airport. Francine produced dangerous storm surge and heavy rainfall along the central Gulf Coast. Peak storm surge inundation of about 5 to 8 feet above ground level occurred just east of the landfall point in Terrebonne Parish, affecting communities such as Cocodrie and Dulac; a USGS gauge at Caillou Lake Sister Lake recorded 5.5 ft above mean higher high water. Lake Pontchartrain and adjacent Mississippi coasts saw 3 to 5 ft inundation, with gauges showing 5.2 ft above MHHW at Bonnet Carré and 4.8 ft at Waveland, Mississippi. Rainfall maxima included 11.93 inches near Covington, Louisiana, and 14.61 inches at Navarre, Florida; Danville, Alabama, recorded 13.65 inches. The heavy rain caused flash flooding around Lake Pontchartrain and other areas. There were no reported deaths directly attributed to Francine in the NHC report. Four injuries were reported (two from falling trees, one during a rescue, one unspecified), and emergency responders conducted multiple water rescues in Lafourche Parish and New Orleans. The economic loss estimate reported by NOAA’s NCEI was about $1.3 billion (U.S.), with hundreds of structures damaged or destroyed in St. Charles and Jefferson Parishes, widespread downed trees and power outages (peaking near 500,000 customers), disruptions to offshore oil and gas operations, flooding in Matamoros, Mexico, and impacts to facilities such as SpaceX’s Starbase in southern Texas. Notable items in the post-storm analysis include difficulties forecasting Francine’s long-range genesis and initial location; the storm’s genesis area and timing were poorly anticipated in early Tropical Weather Outlooks. NHC track forecasts performed about as well or better than recent averages, while intensity forecasts tended to underpredict Francine’s peak intensity. Storm surge watches and warnings were issued well before landfall (watch about 51 hours and warning about 45 hours prior), and the observed surge and inland inundation in many areas fell within the NHC post-event surge analysis and forecast ranges.