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Fire & Water - Cleanup & Restoration

When Are Local Winter Weather Warnings, Watches and Advisories Issued?

1/19/2021 (Permalink)

Winter weather weather icon with text "Winter Weather Alerts" SERVPRO of Upper Darby has experience restoring homes affected by storms.

When winter weather impacts our area, the National Weather Service issues several types of alerts. These include winter storm watches, warnings and advisories.

Advisories: Be Aware

Winter Weather Advisories are issued when a winter storm event (sleet, ice, snow, freezing rain, snow and blowing snow, or a combination of events) is expected to meet or exceed local winter weather advisory criteria in the next 12 to 36 hours but stay below warning criteria.

Criteria for Snow: 4 inches or more in 12 hours or less covering at least 50 percent of the zone or encompassing most of the population. Use "mid-point" of snowfall range to trigger advisory (i.e. 2 to 5 inches of snow = advisory).

Criteria for Ice: Any ice accumulation less than 1/2 inch over at least 50 percent of the zone or encompassing most of the population. Winter Weather Advisory can also be issued for black ice. This is optional.  Be prepared for winter driving conditions and possible travel difficulties.  Use caution when driving. 

Freezing Rain Advisories are issued when light ice accumulation (freezing rain and/or freezing drizzle) is expected in the next 12 to 36 hours, (but will remain below 1/2 inch) for at least 50 percent of the zone or encompassing most of the population and not reach warning criteria. 

Expect a glaze on roads resulting in hazardous travel.  Slow down and use caution while driving because even trace amounts of ice on the roads can be dangerous. 

Wind Chill Advisories are issued when low wind chill temperatures are expected to meet or exceed local wind chill advisory criteria in the next 12 to 36 hours, but will not reach local warning criteria. Wind chill temperatures may reach or exceed -15°F.  Extremely cold air and strong winds will combine to generate low wind chill readings. 

If you must venture outdoors, take precautions against frostbite and hypothermia. See the NWS Wind Chill Chart.

Watches: Be Prepared

Blizzard Watches are issued when conditions are favorable for a blizzard event in the next 24 to 72 hours. There is a potential for falling and/or blowing snow with strong winds or frequent gusts greater than or equal to 35 mph and extremely poor visibilities to less than a ¼ mile for 3 or more hours. 

This can lead to whiteout conditions and make travel very dangerous. 

Winter Storm Watches are issued when conditions are favorable for a significant winter storm event (heavy sleet, heavy snow, ice storm, heavy snow and blowing snow or a combination of events.)  There is a potential to meet or exceed local winter storm warning criteria in the next 24 to 72 hours.

Criteria for Snow: 7 inches or more in 12 hours or less; or 9 inches or more in 24 hours covering at least 50 percent of the zone or encompassing most of the population. Use "mid-point" of snowfall range to trigger a watch (i.e. 5 to 8 inches of snow = watch).

Criteria for Ice: 1/2 inch or more over at least 50 percent of the zone or encompassing most of the population.

Wind Chill Watches are issued when Conditions are favorable for wind chill temperatures to meet or exceed local wind chill warning criteria in the next 24 to 72 hours. There is the potential for a combination of extremely cold air and strong winds to create dangerously low wind chill values. 

See the NWS Wind Chill Chart.  Wind chill temperatures may reach or exceed -25°F.

Warnings: Take Action!

Blizzard Warnings are issued when a blizzard event is imminent or expected in the next 12 to 36 hours and means severe winter weather conditions are expected or occurring.  There is potential for frequent gusts greater than or equal to 35 mph accompanied by falling and/or blowing snow with strong winds, frequently reducing visibility to less than ¼ mile for three hours or more.  May lead to whiteout conditions making travel extremely difficult. 

Do not travel!  If you must travel, have a winter survival kit with you.  If you get stranded, stay with your vehicle and wait for help to arrive. 

Winter Storm Warnings are issued for a winter storm event (heavy sleet, heavy snow, ice storm, heavy snow and blowing snow or a combination of events) and is expected to meet or exceed local winter storm warning criteria in the next 12 to 36 hours.

Criteria for Snow: 7 inches or more in 12 hours or less; or 9 inches or more in 24 hours covering at least 50 percent of the zone or encompassing most of the population. Use "mid-point" of snowfall range to trigger warning (i.e. 5 to 8 inches of snow = warning).

Criteria for Ice: 1/2 inch or more over at least 50 percent of the zone or encompassing most of the population. Travel will become difficult or impossible in some situations.  Delay your travel plans until conditions improve.

Ice Storm Warnings are usually issued when there is an ice storm event is expected to meet or exceed local ice storm warning criteria in the next 12 to 36 hours.

Criteria for Ice: 1/2 inch or more over at least 50 percent of the zone or encompassing most of the population.

This amount of ice accumulation will make travel dangerous or impossible and likely lead to snapped power lines and falling tree branches.  Travel is strongly discouraged. 

Wind Chill Warnings are issued when wind chill temperatures are expected to meet or exceed local wind chill warning criteria in the next 12 to 36 hours and for a combination of very cold air and strong winds that will create dangerously low wind chill values. Wind chill temperatures may reach or exceed -25°F. This level of wind chill will result in frostbite and lead to hypothermia if precautions are not taken. 

Avoid going outdoors and wear warm, protective clothing if you must venture outside.  See the NWS Wind Chill Chart.

Have Winter Storm Damage?
Call SERVPRO of Upper Darby (610) 352-0700

Why Choose SERVPRO of Upper Darby?

SERVPRO of Upper Darby has experience restoring homes affected by storms. We can respond immediately with highly trained technicians who employ specialized equipment and techniques to restore your home or business back to pre-storm condition.

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