▁the ▁formation ▁of ▁the ▁February   2 0 1 3 ▁nor ' e aster ▁were ▁rather ▁anom alous ▁and ▁were ▁condu ci ve ▁for ▁cy c log en esis . ▁Such ▁conditions ▁included ▁the ▁presence ▁of ▁a ▁r idge ▁over ▁the ▁North ▁Atlantic ▁and ▁the ▁strength ening ▁of ▁a ▁tr ough ▁in ▁California . ▁The ▁impact ful ▁nature ▁of ▁the ▁event ual ▁winter ▁storm ▁event ▁was ▁first ▁predicted ▁in ▁National ▁Cent ers ▁for ▁Environment al ▁Pred iction   ( N CE P ) ▁and ▁H yd rom eteor ological ▁Pred iction ▁Center   ( HP C ) ▁forec asts ▁at ▁ 1 2 0 0   UTC ▁on ▁February   6 , ▁when ▁the ▁accum ulation ▁of ▁at ▁least ▁ ▁of ▁snow ▁in ▁the ▁en su ing ▁hours ▁was ▁considered ▁a ▁moder ate ▁probability ▁in ▁parts ▁of ▁Wisconsin ▁and ▁Michigan . ▁Fue led ▁by ▁energy ▁origin ating ▁from ▁the ▁G ulf ▁of ▁Al aska ▁and ▁carried ▁by ▁the ▁polar ▁jet ▁stream , ▁a ▁low - press ure ▁area ▁formed ▁as ▁anticip ated ▁in ▁Mont ana ▁at ▁ 1 2 0 0   UTC ▁the ▁next ▁day . ▁The ▁cy clone ▁track ed ▁in ▁a ▁general ▁east - n ortheast ward ▁direction ▁throughout ▁the ▁day , ▁reaching ▁central ▁Indiana ▁by ▁early ▁on ▁February   8 . ▁ ▁As ▁the ▁low - press ure ▁system ▁over ▁the ▁United ▁States ▁Mid west ▁developed , ▁energy ▁associated ▁with ▁the ▁subt rop ical ▁jet ▁over ▁the ▁Mexican ▁plate au ▁track ed ▁into ▁the ▁G ulf ▁of ▁Mexico ,