Winter Storms, Beltway, Image: NOAA

Early snow storms are a boon to ski retailers, but they also cause massive headaches for travelers and powerful snow storms can knock out power to thousands. The National Weather Service is now putting out its Winter Weather Guide.

As far as traveling in cold weather states, when bad weather is coming, the NWS has the following advice:

• Keep the gas tank full to keep the fuel line from freezing.
• Let someone know your destination, route, and when you expect to arrive.
• Keep a cell phone or other emergency communication device with you.
• Pack your car with thermal blankets, extra winter clothes, basic tool kit, (including a good knife and jumper cables), an ice scraper and shovel, flashlights or battery-powered lanterns with extra batteries, and high calorie, nonperishable food, and water.
• Use sand or kitty litter under your tires for extra traction, especially if you find yourself stuck in a slippery spot.

When a winter storm hits, there are four types of possible precipitation. The following graphic from NOAA illustrates the four types.

Snow starts off as frozen precipitation high up in the atmosphere. If the temperature is below freezing as the snowflake falls, it never melts., and lands on the ground or in the palm of your hand as a snowflake. Sleet is a snowflake that melts as it falls into warmer air, but then refreezes when it hits a layer of subfreezing air close to the ground. Sleet looks like ice pellets. Freezing rain starts off as snow,  then melts in warmer air, and then refreezes after it hits the ground. Freezing rain is often referred to as “black ice” because when drivers hit a patch of ice on the highway, often they don’t see it because it is the same color as the asphalt. Finally, if the column of air is above freezing throughout most of the atmosphere, the frozen precipitation will melt and fall as rain. USA Today has a great graphic with more thorough information on the four different types of winter precipitation. For more information on winter weather advisories and warnings, see the NWS’s Winter Weather Guide.   -Dawn Brown