iction ▁Center . ▁Rec ently , ▁they ▁have ▁been ▁issued ▁as ▁P DS ▁Flash ▁Flo od ▁Emer gen cies , ▁most ▁not ably ▁by ▁the ▁National ▁We ather ▁Service ▁offices ▁in ▁Houston , ▁T X ▁and ▁Cor pus ▁Christ i , ▁T X . ▁ ▁This ▁warning ▁was ▁issued ▁in ▁the ▁morning ▁of ▁May ▁ 3 0 , ▁ 2 0 1 8 ▁by ▁the ▁National ▁We ather ▁Service ▁Fore cast ▁Office ▁in ▁Green ville - S part an burg , ▁South ▁Carolina , ▁while ▁Sub t rop ical ▁Storm ▁Alberto ▁was ▁affect ing ▁the ▁area . ▁It ▁also ▁contains ▁the ▁Flash ▁Flo od ▁Emer gency ▁phrase , ▁which ▁further ▁unders c ores ▁the ▁risk ▁of ▁life - th re aten ing ▁flash ▁flo oding . ▁ ▁P DS ▁Red ▁Flag ▁Warning ▁ ▁P DS ▁red ▁flag ▁warnings ▁are ▁issued ▁by ▁the ▁National ▁We ather ▁Service ▁to ▁inform ▁the ▁public ▁that ▁there ▁is ▁an ▁unus ually ▁high ▁threat ▁of ▁wild land ▁fire ▁comb ust ion , ▁and ▁rapid ▁spread ▁of ▁wild f ires , ▁due ▁to ▁very ▁dry ▁fu els , ▁very ▁low ▁hum id ity ▁levels , ▁and ▁strong ▁wind s . ▁ ▁The ▁P DS ▁Red ▁Flag ▁Warning ▁below ▁was ▁issued ▁by ▁the ▁National ▁We ather ▁Service ▁in ▁Ren o , ▁Nev ada ▁on ▁December ▁ 1 9 , ▁ 2 0 1 7 . ▁ ▁On ▁August ▁ 3 , ▁ 2 0 1 8 , ▁the ▁National ▁We ather ▁Service ▁in ▁Ren o , ▁Nev ada ▁issued ▁another ▁P