▁the ▁April ▁ 2 , ▁ 1 9 8 2 ▁torn ado ▁out break ▁across ▁the ▁southern ▁and ▁central ▁Great ▁Pla ins . ▁ ▁While ▁histor ically ▁applied ▁only ▁to ▁severe ▁th under st orm , ▁torn ado ▁and ▁flash ▁flo od ▁watch es ▁( i . e ., ▁Se vere ▁Local ▁Storm ▁" pol yg onal " ▁events ), ▁P DS ▁word ing ▁could ▁theoret ically ▁be ▁applied ▁to ▁other ▁types ▁of ▁weather ▁watch es ▁( such ▁as ▁winter ▁storm , ▁high ▁wind , ▁h urr icane , ▁or ▁fire ▁weather ▁watch es ) ▁when ▁an ▁en hanced ▁threat ▁for ▁such ▁conditions ▁exists . ▁These ▁watch es ▁have ▁generally ▁( but ▁not ▁always ) ▁been ▁issued ▁during ▁a ▁high ▁risk ▁or ▁an ▁upper - end ▁moder ate ▁risk ▁either ▁of ▁severe ▁storm s ▁from ▁the ▁S PC ' s ▁con ve ct ive ▁out look s ▁or ▁of ▁flash ▁flo oding ▁from ▁the ▁We ather ▁Pred iction ▁Center ▁( W PC )' s ▁Ex cess ive ▁Rain fall ▁Out look s . ▁ ▁On ▁April ▁ 2 4 , ▁ 2 0 1 1 , ▁the ▁National ▁We ather ▁Service ▁We ather ▁Fore cast ▁Office ▁in ▁M emph is , ▁Tennessee ▁issued ▁the ▁first ▁P DS ▁flash ▁flo od ▁watch ▁to ▁highlight ▁the ▁threat ▁for ▁w ides p read , ▁significant ▁and ▁potentially ▁life - th re aten ing ▁flash ▁flo oding ▁due ▁to ▁repeated ▁r ounds ▁of ▁severe ▁th under st orm s . ▁ ▁On ▁December ▁ 1 9 ,