Along with the snowfall came a light glaze of ice and periods of freezing drizzle, making travel especially risky. At Atigun Pass, which rises to 4,739 feet, the northbound descent features grades of up to 12 percent, leaving little room for driver error. There is also no alternate route across the Brooks Range, meaning travelers either cross the pass or delay their journey.The unusual weather did not stop with snowfall.Updated observations showed temperatures dropping to around 26 degrees Fahrenheit near Atigun Pass,. Without tire chains, cold-weather clothing, shovels or emergency supplies, motorists can quickly find themselves in trouble if road conditions deteriorate unexpectedly. Snow showers may continue to develop despite the advisory ending, keeping roads slippery through changing temperatures.