What caused the 2007 groundhog day tornado?

A deadly tornado event occurred across the NWS Melbourne County Warning Area within Lake and Volusia Counties during the early morning hours of February 2, 2007. A discontinuous swath of damage was observed from the town of Lady Lake (Lake County) to New Smyrna Beach (Volusia County) - a distance of over 70 miles. A total of 21 fatalities occurred within Lake County. Synoptic & Mesoscale Situation: East Central Florida was located in the warm sector ahead of an advancing cold front. Large scale lift was supported by a very strong jet aloft, with strong vertical shear evident from the surface to aloft, conducive for rotating thunderstorms and tornadoes. Instability increased overnight with temperatures and dew points increasing through the pre-dawn hours. A moderate threat of tornadoes was indicated within the Hazardous Weather Outlook. A long-tracked supercell thunderstorm traveled from Sumter County to the coastal waters of Volusia County during the early morning hours of February 2, 2007. Three tornadoes touched down along this track. Damage Surveys: The first tornado began near Wildwood in Sumter County at 308 am and crossed into Lake County, lifting east of Lady Lake at 325 am. NWS Melbourne issued a Tornado Warning for Lake County at 306 AM. Post-storm surveys indicated the tornado reached a peak intensity of EF-3 (155-160 mph) and had a track length of 16.5 miles. Eight fatalities were associated with the tornado. The second tornado touched down in rural Lake County at 337 am and impacted the Lake Mack area at 348 am before crossing into Volusia County and affecting Deland at 402 am, then lifted east of Interstate 4 at 410 am. NWS Melbourne issued a Tornado Warning for Volusia County at 352 AM. Post-storm surveys indicated the tornado reached a peak intensity of EF-3 (160-165 mph) and had a track length of 26 miles. Thirteen fatalities occurred in association with this tornado. The third tornado formed in eastern Volusia County to the east of Interstate 95 at 422 am and remained on the ground until 425 am when it reached the Intracoastal waterway in New Smyrna Beach. Post-storm surveys indicated the tornado reached a peak intensity of EF-1 (100-105 mph) and had a track length of 3 miles. Tornado scenarios such as this are classified as very dangerous, especially due to the threat of tornado occurrence during overnight hours when most individuals are asleep. A NOAA Weather Radio containing an alarm feature can be a life-saving device in these situations. Most tornado deaths in Florida occur in the early morning hours.