Between December 28–29, 2024, a late season tornado outbreak affected the Deep South. Multiple tornadoes caused severe damage in the Greater Houston area and in Port Arthur, Texas while additional tornadoes caused damage in other states, including Louisiana, Mississippi, and Alabama. Overall, at least four people have been killed; one in the Houston area, two in Mississippi and one in North Carolina, and 17 more have been injured, two indirectly. In total, 106 tornado warnings were issued during the outbreak and 110 tornadoes were confirmed, making this the second largest December outbreak on record behind only the December 2021 Midwest derecho and tornado outbreak, which had 120 tornadoes.
Meteorological synopsis
Prior to December 28 On December 21, the Storm Prediction Center first noted in their day 4–8 outlook that "An additional focus for increasing deep convective potential will be into the Thursday/Day 6, Friday/Day 7, and Saturday/Day 8 time frame", making their first mention of a potential severe weather setup in the West South Central states, although confidence was limited mainly as a result of uncertainty regarding the evolution of the approaching upper-level trough and potential effects from a preceding trough and accompanying cold front ahead of it. This was further noted on the next day that highlighted a potential severe weather setup for severe weather across the Mississippi Valley, although the predictability remained too low for forecasters to outline a risk area.
The Storm Prediction Center did not include any definitive risk areas on December 23 in their day 4–8 outlook as a result of low predictabilities and confidence to include one; the agency however noted a "low-end" severe weather potential on December 26. The Day 3 convective outlook released on December 24, denoted a slight (level 2/5) risk that included population centers and areas including Shreveport, Louisiana, College Station, Texas, Tyler, Texas and The Woodlands, Texas. A separate day 4–8 outlook published by the SPC mentioned further severe weather potential around the December 27–28 timeframe, although confidence was limited for a specific risk area during this time due to the uncertain extent of favorable instability/buoyancy accompanying the trough. This and uncertainty regarding morning convection affecting the main risk later in the day led to lowered confidence in issuing a risk area but the SPC noted at least "some" severe weather potential ahead of the favorable upper to mid-level synoptic support model guidance had showed for this time period. The Day 2 outlook on December 25 maintained the "slight" risk area; it was expanded into far-southern Arkansas. A 5% tornado risk was outlined within the "slight" risk area, accompanied by a 15% chance for hail and a 15% chance for damaging wind. The Day 1 Convective Outlook featured the addition of an "enhanced", level 3-of-5 risk for East Texas, with a "slight" risk region pushing from southern Arkansas to far-western Mississippi. The Day 1 Convective Outlook the following day, on December 26, saw the "enhanced" risk be retracted but a "slight" risk be outlined for much of Louisiana, outlined by a 5% tornado risk.
December 28
A "moderate", level 4-of-5 risk was issued by the Storm Prediction Center for December 28, as a shortwave trough was expected to move through Texas and Louisiana, with the risk area also extending into Mississippi and extreme south bringing the expectation of large hail and multiple tornadoes, some being strong (EF2+). Several factors, led to developing convection, including rich Gulf moisture bringing dewpoints ranging from , and strengthening low-level jet (LLJ) with large-scale ascent ahead of the approaching surface low that was expected to provide the necessary lift for convection.
Additionally, destabilization caused by sufficient daytime heating led to lead to high levels of atmospheric instability with convective available potential energy (CAPE) expected to range around 1500–2000 j/kg. Both a bowing quasi-linear convective system and discrete supercells were expected to form in the risk area. A high risk had been considered for central Louisiana into central Mississippi, but local National Weather Service offices advised against it. As the evening progressed, it was expected to shift into a powerful squall line with the potential to cause intense downburst wind damage in addition to embedded tornadic mesocyclones.
Confirmed tornadoes
December 28 event