Enjoy the relatively balmy conditions while they last. MesoWest observations today are simply fascinating and show cold air approaching northern Utah from both the north and the east.
In extreme northeast Idaho, northeasterly flow is pulling cold air across the continental divide and into the upper Snake River Plain. At Island Park, temperatures have fallen from a high of 43F yesterday afternoon to a minimum of -5F this morning (although they have since rebounded to 3F).
Meanwhile, cold air is moving westward across Wyoming toward Evanston through the low elevation basin between the Uinta and Wind River Mountains. Rock Springs has remained solidly at 10F all day today.
Thus, cold air will be approaching Utah from two directions. There is nowhere to hide!