DS ▁red ▁flag ▁warning ▁to ▁communicate ▁the ▁threat ▁of ▁life - th re aten ing ▁fire ▁danger ▁due ▁to ▁strong ▁g ust y ▁wind s ▁and ▁low ▁hum id ity . ▁ ▁P DS ▁Se vere ▁Th under st orm ▁Watch ▁ ▁P DS ▁severe ▁th under st orm ▁watch es ▁are ▁issued ▁when ▁there ▁is ▁a ▁higher ▁than ▁normal ▁risk ▁of ▁severe ▁th under st orm ▁wind s ▁capable ▁of ▁major ▁struct ural ▁damage ▁( in ▁addition ▁to ▁large ▁ha il ▁and ▁perhaps ▁a ▁few ▁isolated ▁torn ado es ), ▁usually ▁due ▁to ▁a ▁strong ▁and ▁persistent ▁dere cho . ▁These ▁watch es ▁are ▁very ▁rare ▁( account ing ▁an ▁average ▁of ▁only ▁two ▁each ▁year ), ▁as ▁the ▁risk ▁for ▁torn ado es ▁must ▁remain ▁low ▁enough ▁to ▁not ▁war rant ▁a ▁torn ado ▁watch ▁( a ▁normal ▁torn ado ▁watch ▁would ▁be ▁issued ▁if ▁the ▁torn ado ▁risk ▁is ▁significant ▁alongside ▁the ▁extreme ▁wind ▁threat ). ▁ ▁This ▁P DS ▁Se vere ▁Th under st orm ▁Watch ▁shown ▁below ▁was ▁issued ▁by ▁the ▁Storm ▁Pred iction ▁Center ▁in ▁Norman , ▁Oklahoma ▁on ▁July ▁ 1 9 , ▁ 2 0 1 9 ▁for ▁an ▁extreme ▁wind ▁threat ▁in ▁northern ▁Wisconsin . ▁ ▁P DS ▁Special ▁Marine ▁Warning ▁ ▁P DS ▁Special ▁Marine ▁W arn ings ▁are ▁issued ▁by ▁the ▁National ▁We ather ▁Service ▁to ▁inform ▁mar in ers ▁of ▁weather ▁conditions ▁that ▁present ▁a ▁considerable ▁threat ▁to ▁life ▁and ▁property . ▁ ▁On ▁April ▁ 1 9 , ▁ 2