The winter storm warningissued early this morning has been upgraded for some areas, meaning the likelihood of heavy snow is increasing.

Winter storm warning criteria at this time of mid-winter is six inches or more of snow is likely, or slightly lesser snow and some freezing rain ice accumulation. The winter storm warning area could have either of those weather situations. Right now one-tenth to two-tenths of an inch of ice accumulation from freezing rain is possible in the heavy snow area. If the ice accumulation does occur, it will be at the expense of a couple of inches of snow.

Either way the weather goes, there are going to bedangerous driving conditions eventually on Thursday.

As noted on the snow and freezing rain forecast, the main period of heavy winter precipitation is slower than yesterdays thought. The winter storm warning now goes into effect at 3 p.m. Thursday, showing the expected later timing of the most significant snow. The winter storm warning now also expires a little later at 3 a.m. Friday.

The winter storm warning is in effect from the southwest Michigan border counties to Battle Creek, Jackson, Hillsdale, Coldwater, Adrian, Ann Arbor, the entire Detroit area, Oakland County and St. Clair County.

The official snow forecast from the National Weather Service is four to eight inches of snow in the winter storm warning area. The warning area also can expect one-tenth to two-tenths of an inch of ice accumulation from freezing rain and sleet. A few of the best computer chartsshow six to seven inches of snow will be common. An isolated nine inch amount is also likely.

By F.Aslam