An Arctic blast is expected to cause hazardous driving conditions across Texas this week. In the Houston area, the National Weather Service has issued a Winter Storm Watch that goes into effect Monday evening and lasts through Tuesday afternoon.

Another Arctic blast of freezing temperatures will test the ERCOT grid during this Martin Luther King Jr. holiday weekend and early next week.

As a slug of polar vortex-fueled arctic air overtakes the eastern two-thirds of the U.S. next week, a storm system could bring snow, sleet and freezing rain to places deep in the heart of Texas, but the forecast isn’t a lock just yet.