Winter Weather Awareness Week Virginia 12/2 - 12/6, 2024

Monday

Winter Season Outlook and winter weather terminology

This will provide you with some terms the National Weather Service uses to describe winter weather as well as the definitions of watches, warnings, and advisories issued for winter weather events.

Winter infographics

Tuesday

Winter Storms affecting Virginia

The most dangerous winter weather systems for Virginia, which can produce major amounts of snow and ice, are strong coastal low pressure systems known as nor'easters.  These types of storms can impact the region a couple times a season and when the temperatures are cold enough, these types of storms can produce big snowfall events.  For example, On January 22 - 23, 2016, the commonwealth was impacted by a nor'easter with heavy snow with some locations in Northern Virginia seeing up to 4 Feet of snow.  At the same time, strong winds along the coast produced near Blizzard Conditions.  The maps below show just how much snow fell with this storm.

Winter storms can make driving and walking extremely dangerous.  The aftermath of a major winter storm can have a devastating impact for days or even weeks. Winter storms can be deceptive killers because most deaths are indirectly related to the storm.  People die in traffic accidents on icy roads, have heart attacks while shoveling snow, or succumb to fires or carbon monoxide while trying to heat their home improperly.  With proper planning and preparation, you can limit or even mitigate the impacts from winter storms. 

Lastly for today, The National Weather Service needs accurate snowfall measurements during winter storms.  Those accurate snowfall measurements help us to adjust continually update the forecast and warnings during the event.  Are you willing to be a snow observer to help the NWS?  Below is graphic that shows you how to take an accurate snow measurement.  Once you have your report, you can send it to your local NWS office in Blacksburg, VA by:

• Phone -  540-553-8900
• Email - rnk.skywarn@noaa.gov
• Social Media -  X/Twitter or Facebook

Winter infographics

Wednesday

Excessive Cold and Preparing your home for winter

Cold weather is a fact of winter.  Up until this winter, the NWS only warned for low wind chill temperatures.  But for much of Virginia, our coldest times occur at night with light to calm winds.  However, starting this winter, the NWS will now issue warnings for when it is extremely cold air is in place, with or without wind.  So no longer will the NWS issue Wind Chill Warnings or Advisories, but instead will issue Extreme Cold Watches/Warnings and Cold Weather Advisories.  The chart below shows the names of the old products and what the NWS will be issuing now when the temperatures or wind chills drops to excessively low values.

The temperature guidance that will be the NWS used to issue these new products will vary across the state to line up with the climatology of the region.  The values that will be used are linked here for the Extreme Cold Warning and Cold Weather Advisory.

With the cold temperatures comes an increase in the number of house fires.  House fires resulting from heating material within the home ranks second for the most deaths and property loss.  Chimney fires are the number one cause of home heating fires and typically the result of a poorly maintained chimney where creosote is allowed to build up. Space heaters are typically involved in 25 percent of home heating fires and account for 74 percent of the deaths.  Be sure to test smoke and carbon monoxide detectors and replace any broken detectors and dead batteries. 

Severe winter storms can produce conditions which can isolate you in your home for several days.  Prolonged loss of power can severely limit your ability to heat your home.  Also obtaining supplies, food and other necessities can be hampered or prevented by poor road conditions.  Make sure to stock an emergency supply of food and water prior to the onset of a winter storm.  Include food items which require no cooking such as canned meats, peanut butter and other non-perishables.  Also do not forget to have necessary medicines and baby items on hand.  A three to five day supply of food and medicine is generally sufficient.  A lot of these items may already be in your home from your hurricane kit. 

Example home emergency supply kit

Winter infographics

Thursday

Dangers associated with freezing rain and sleet

Ice falling in the form of freezing rain is particularly dangerous and poses a variety of problems.  The ability of freezing rain to accumulate on nearly every surface, including trees, power lines, and bridges, makes it one of the most dangerous forms of winter weather.  As little as a quarter of an inch of freezing rain can create widespread power outages.  Four winters ago, central and southern portions of Virginia saw one of the worst ice storms in the last 20 years.  On February 12 - 13, 2021 a long period of light to moderate rain developed and fell into areas with surface temperatures around 30 degrees.  This lead to trees and powerlines being coated in ice and eventually lead to widespread power outages that took nearly two weeks to be fully repaired in some locations

         Power Outages at peak of storm                        Icing in Floyd, VA                               Ice Amounts
               (credit: PowerOutage.us)                     (credit: Jean Martin)                 

When driving, ice can be very difficult to recognize.  The roadway may appear to be wet when in reality when appears to be water may actually be ice.  If the temperature outside is below freezing, ice can form on the roads, especially on bridges and overpasses.  When encountering ice, do not panic and do not stomp on your brakes.  It is safer to slowly decelerate to a stop. 

Winter infographics

Friday

Driving in winter weather

Seventy-five percent of all winter weather related deaths occur on the road, either in accidents or by people becoming stranded. When the weather is bad and driving conditions are poor, the best bet is to stay at home

1. Make sure your car is in good running condition. Make sure that your battery, antifreeze, windshield wipers, ignition and thermostat are all in good working order. Be sure your tires have enough tread. Replace any of these items if necessary.
2. If you must go out when snow and ice are on the ground, let someone know your destination and when you plan to arrive. Also take a cell phone with you if possible. 
3. Clean snow and ice off all parts of your car before you drive away.
4. Keep your gas tank as full as possible when snow and ice are forecast. This will not only give you added peace of mind, it also increases the weight of your car and this will provide additional traction.
5. Keep the following basic items in your car - windshield scraper and brush, booster/jumper cables, a tow chain or rope, bag of sand or salt, blankets, flashlight, first aid kit and road map.
6. Overall drive slow. Driving at even posted speeds is extremely dangerous when snow and ice are on the road. Many vehicles will lose traction especially at higher speeds resulting in serious accident and vehicle rollovers. 
7. Steer your car into the skid. If your vehicle loses traction and begins to skid, steer the front tires into the direction of the skid. Never hit your brakes as this will result in a more serious skid and spinning of the vehicle. When your vehicle skids keep your cool and remain calm. Again driving at slower speeds will help you recover from a skid. 

Winter infographics

Winter Weather Video Series - Weather You Want to Know (or not)

1.  Snow Storm Patterns 
   
   


2.  Snow Types 
   
   


3.  How to Measure Snow 
   
   

Frequently Asked Questions

1.  Christmas Weather – Greatest 24 hour Snow Amounts on Christmas for each of our Virginia climate sites?
   
   
   
   Roanoke
   
   Lynchburg
   
   Danville
   
   Blacksburg
   
    
2.  Chances for a White Christmas? 
   
   National White Christmas Climatology information 
   
    
3. What are the biggest snows to impact...
   
   Roanoke
   
   Lynchburg
   
   Danville
   
   Blacksburg
    
4. What is the correct way to measure snow and ice?
   
   
   
   
    

   You can also send your snow or ice report to NWS Blacksburg using our Storm Report Form!
   
    

5. What items should be included in a vehicle Winter Storm Kit?
   
   
   
   Get more information at build your winter storm kit and prepare for cold weather.
    

6. What is the polar vortex?
   
   
   
   The polar vortex is a large area of low pressure and cold air surrounding both of the Earth’s poles. It ALWAYS exists near the poles, but weakens in summer and strengthens in winter. The term "vortex" refers to the counter-clockwise flow of air that helps keep the colder air near the Poles. Many times during winter in the northern hemisphere, the polar vortex will expand, sending cold air southward with the jet stream (see graphic above). This occurs fairly regularly during wintertime and is often associated with large outbreaks of Arctic air in the United States. 
   
   Get more information at: Polar Vortex FAQ.
    

7. What is Wind Chill, and how is it calculated?
   
   
   
   Wind Chill is how cold people or animals feel when outside. Wind chill is based on the rate of heat loss from exposed skin caused by wind and cold. As the wind increases, it draws heat from the body, driving down skin temperature and eventually the internal body temperature. Therefore, the wind makes it FEEL much colder. If the temperature is 0°F and the wind is blowing at 15 mph, the wind chill is -19°F. At this wind chill temperature, exposed skin can freeze in 30 minutes. The wind chill temperature is calculated using the following formula:
   
   Wind chill (ºF) = 35.74 + 0.6215T - 35.75(V^0.16) + 0.4275T(V^0.16)

   Where: T = Air Temperature (F)
   V = Wind Speed (mph)
   ^ = raised to a power (exponential)
   
   Wind chill Temperature is only defined for temperatures at or below 50°F and wind speeds above 3 mph. Bright sunshine may increase the wind chill temperature by 10°F to 18°F.
   
   More information on Wind Chill is included at Wind Chill FAQs.
   
    

8. What is the difference between frostbite and hypothermia?
   
   
    

9. What is meant by black ice?
   
   

10. Why do bridges and overpasses freeze before other surfaces? 
    
    
     

11. What is a snow squall, and what is the difference between a snow squall and a snow storm?
    
    
    
    The difference between a snow squall and a snowstorm really just comes down to the duration of the event. Snow squalls are usually very short-lived (on the order of 30-60 minutes) and extremely intense. A snow storm could last for several hours or even days. More information is available at Snow Squall FAQ.

12. What is the Winter Storm Severity Index (WSSI)? 

    The Winter Storm Severity Index (WSSI) is a spatial assessment of the societal impacts of winter storms. It highlights regions and localities with the forecasted potential of damaging and life-threatening effects brought on by winter weather. This includes, but is not limited to tree damage, school closures, transportation issues like flight cancellations, traffic accidents, and road closures. These winter storms can create a direct risk to life and property and cause millions of dollars in damages. For additional information on WSSI click here.