The National Weather Service in Salt Lake City has issued a winter storm warning for today and Monday.

All of Utah will be affected by a pair of storms blowing in — one from California and one from Alaska, according to the service.

Monday's morning commute is expected to be hit hard, and some mountain roads may be impassable, according to the service.

Warm temperatures that thrilled residents in northern Utah Saturday are expected to drop to around 15 degrees by Monday. Forecasters expect about half an inch of new snow in the valleys.

Wasatch and Kane counties are expected to see heavy rain; flash-flood warnings have been issued for the duration of the storm.

In addition, high wind warnings have been issued for most of western Utah.

Forecasters say Utah's weather pattern is likely to continue. A snowstorm is expected for Wednesday that will likely bring more cold air, according to the service's Web site.