An ice storm is a winter weather event characterized by freezing rain that coats surfaces with a layer of ice. Ice storms have facts, formation processes, and forms of precipitation. The duration of ice storms varies, and they occur within a temperature range. Understand the definition, facts, formation, form, duration, and temperature conditions associated with ice storms to grasp their impact and significance.
Ice storms and snowstorms differ in their precipitation types and formation processes. Ice storms produce freezing rain that coats surfaces with a glaze, while snowstorms generate snowfall in colder temperatures. Freezing rain in ice storms forms when liquid droplets pass through warm then cold air layers, whereas snowflakes in snowstorms form and fall in below-freezing conditions throughout. Ice storms coat surfaces with a layer of ice exceeding 0.25 inches (0.635 cm), causing damage to trees and power lines. Ice storms maintain visibility and require winds below 16.093 km/h (10 mph) to sustain the air layer aloft. Snowstorms reduce visibility due to falling and blowing snow and are accompanied by winds exceeding 56.327 km/h (35 mph).
Ice storms occur in December and January, depositing up to 11 inches (27.94 cm) of ice on surfaces. Ice storms cause 15 deaths in the United States, with 70% of winter deaths related to snow and ice occurring in car accidents. Ice from storms increases the weight on tree branches and power lines by 30 times. Winter storms, including ice storms, cover more areas than hurricanes and affect millions of people. Ice storms are responsible for more lives lost and property damage than hurricanes, according to the National Weather Service. Ice storms last for days, causing disruptions and are called glaze events or silver storms due to the ice layer.
Ice storms form when subfreezing air traps warm air underneath, creating conditions for freezing rain. Rain falls through the air layer, melting ice crystals, and refreezes as it passes through the air near the ground. Icestorms occur at or below 0°C (32°F), with temperature differences between warm and cold air layers creating the conditions. Supercooled raindrops develop as they pass through subfreezing air, reaching temperatures around -4°C (25°F) while remaining liquid due to a lack of freezing nuclei. Freezing occurs when these supercooled raindrops strike the ground or objects at or below 0°C (32°F). Ice accumulations of 6 mm (0.236 inch) or more are considered an ice storm, with exposed surfaces freezing and becoming hazardous.
Ice storm preparation requires emergency kits containing flashlights, batteries, radio, first aid supplies, and non-perishable food. People stay informed about weather conditions, prepare heat sources, and pack a go-bag with medications and documents. Insulating pipes in areas like garages and basements protects homes. Trimming tree branches near power lines reduces damage. Obtaining a battery-powered or hand-crank radio ensures access to weather updates and emergency instructions. Keeping vehicles fueled and stocked with emergency supplies is essential. After the storm, people use salt or sand to melt ice on walkways and driveways, remove icicles, and monitor for damage by inspecting downed power lines, roofs, and gutters.
Canada experiences a high frequency of ice storms, with 12-15 ice storms annually. Quebec averages 5-7 ice storms per year, with the majority occurring between December and March. Japan ranks second in ice storm frequency, experiencing 10-12 ice storms. Sapporo averages 5-7 ice storms per year and receives snowfall of 191 cm (75.197 inches). The United States follows behind in ice storm frequency, experiencing an average of 10-12 ice storms per year, affecting northeastern states. Russia experiences 7-9 ice storms annually, occurring in western and eastern regions. China faces 6-8 ice storms per year, in provinces like Heilongjiang, Jilin, and Liaoning.
What is the definition of an ice storm?
Ice storm is a type of winter storm characterized by the formation of an ice layer on exposed surfaces. The National Weather Service defines an ice storm as resulting in at least 0.25 inches (6.4 mm) of ice accumulation. Ice storms occur when freezing rain or drizzle falls and freezes upon contact with the ground and surfaces. Freezing rain happens when a warm air layer is trapped under a cold air layer, causing precipitation to fall as rain and freeze on impact. Ice storms create hazardous conditions, covering everything in a glaze of ice and making roads and outdoor surfaces difficult to navigate.
Ice storm characteristics involve ice buildup on trees, power lines, roads, and structures. Ice storm temperature ranges from -2°C to 0°C (28-32°F) at the surface. Ice storm occurrence is common in mid-latitude regions, such as the northeastern United States and southeastern Canada. Ice storm warnings are issued by weather agencies when forecasts predict at least 0.25 inches (6.4 mm) ice accumulation.
Ice storms result in hazardous travel conditions, power outages, and property damage. Ice storm description includes a transparent ice layer coating all exposed surfaces. Ice storms are distinguished by freezing rain, ice buildup, temperatures, and winds. The ice storm meaning encompasses a winter weather event causing disruptions and hazards to daily activities.
What is the difference between an ice storm and a snowstorm?
Ice storms produce freezing rain that freezes onto objects, creating a hazardous glaze coating. Snowstorms generate snowfall in colder temperatures. Freezing rain forms when liquid droplets pass through warm then cold air layers. Snow accumulates on the ground. Ice accumulation causes disruptions. Both storms are characterized by precipitation forms.
The difference between an ice storm and a snowstorm is explained in the table below.
Aspect | Ice Storm | Snowstorm |
Temperature Conditions | Near or below freezing (32°F / 0°C), typically between 25°F (-4°C) and 32°F (0°C) | Below freezing throughout (below 28°F / -2°C), typically between 15°F (-9°C) and 25°F (-4°C) |
Precipitation Type and Formation | Freezing rain (raindrops freezing into transparent ice pellets) or sleet (snowflakes melting and refreezing into translucent ice pellets), with a melting layer of 1,000-2,000 ft (305-610 m) | Snowflakes forming and falling in below-freezing conditions, with a typical snowflake diameter of 0.05-5 mm (0.002-0.2 in) |
Accumulation and Hazards | Coats surfaces with ice (>0.25 inches / 6.4 mm), damaging trees and power lines, with a weight of 0.5-1.5 pounds per square inch (psi) (3.4-10.3 kPa) | Blankets with snow, affects transportation, requires plowing, with a typical snow depth of 2-6 inches (5-15 cm) and a density of 0.05-0.2 g/cm³ |
Visibility and Wind Requirements | Maintains visibility, winds below 10 mph (16 km/h), typically 5-10 mph (8-16 km/h) | Reduces visibility, winds exceed 35 mph (56 km/h), typically 40-60 mph (64-97 km/h) |
Precipitation type and formation process distinguish ice storms from snowstorms. Ice storms produce freezing rain or sleet, resulting from air aloft melting snow before it refreezes near the ground. Snowstorms generate snowflakes that form and fall in below-freezing conditions.
Accumulation on surfaces and hazards created vary between ice storms and snowstorms. Ice storms coat surfaces with a layer of ice, exceeding 0.25 inches (6.35 mm), causing damage to trees and power lines. Snowstorms blanket areas with snow, affecting ground transportation and requiring plowing.
Visibility conditions and wind requirements contrast in ice storms versus snowstorms. Ice storms maintain visibility, with winds below 16 km/h (10 mph) needed to sustain the warm air layer aloft. Snowstorms reduce visibility due to falling and blowing snow, accompanied by winds exceeding 56 km/h (35 mph).
What is the difference between an ice storm and freezing rain?
Freezing rain produces ice layers less than 0.25 inches (6.4 mm) thick. Ice storms create accumulations exceeding 0.5 inches (13 mm). Freezing rain occurs at -4°C to 0°C (25°F-32°F), while ice storms span -9°C to 2°C (15°F-35°F). Ice storms cause more disruptions, including power outages and hazardous travel conditions. Both phenomena involve supercooled raindrops freezing upon contact with surfaces.
Freezing rain accumulates at rates of 3-13 mm (0.1 to 0.5 inches) of ice per hour. Ice storms produce ice accumulations exceeding 6.4 mm (0.25 inches). Some ice storm events reach totals of up to 102 mm (4 inches) over a 12- to 24-hour period.
Freezing rain causes slippery conditions and damage. Ice storms result in damage to trees, power lines, and infrastructure. Ice storm impacts include power outages, hazardous travel conditions, and disruptions to daily life.
The National Weather Service issues Freezing Rain Advisories for expected ice accumulation under 6.4 mm (0.25 inches) within 6 hours. Ice Storm Warnings are issued for expected ice accumulation of 6.4 mm (0.25 inches) or more within 12 hours. Ice Storm Warnings indicate potential for power outages, travel conditions, and significant economic losses.
Ice storms occur when atmospheric conditions support prolonged freezing rain. Low-pressure systems move into areas with warm air aloft and cold surface air. Strong high-pressure systems to the north provide a source of cold air for ice storms.
What are fun facts about ice storms?
The fun facts about ice storms are listed below.
- Ice storms: Caused by freezing rain that accumulates as ice on surfaces.
- Glazing: Glazing is the process where super-cold rain freezes on contact during ice storms.
- Ice accumulation: Ice storms deposit up to 279 mm (11 inches) of ice.
- Ice storms in the US: Typically occur during December and January due to cold conditions and cause 15 deaths annually in the United States.
- Stress from ice storms: Extreme cold and weight causes strains on woods and structures.
- Increased weight: Ice from storms increases weight by 30 times on tree branches and power lines.
- Automobile danger: Seventy percent of winter deaths related to snow and ice occur in car accidents, often during ice storms.
- Area coverage: Winter storms, including ice storms, cover larger areas than hurricanes, affecting millions.
- Ice storms impact: Responsible for more lives lost and property damage than hurricanes as per National Weather Service.
- Duration: Ice storms can last for days, causing significant disruptions.
- Synonyms: Ice storms are also called glaze events or silver storms due to the ice layer.
- Historical significance: The media highlighted the 1998 Ice Storm as one of the major winter storms of the 20th century.
- Patterns and shapes: Ice storms form unique patterns and shapes as ice accumulates.
How does an ice storm form?
Ice storms form when subfreezing air traps warm air underneath. Rain falls through air, melting ice crystals. Freezing temperatures near the ground refreeze droplets. Ice accumulates on surfaces, trees, roofs, and cars. Icestorms occur at or below 0°C (32°F). Temperature differences between warm and cold air layers create conditions for ice storm formation.
Supercooled raindrops develop as they pass through the subfreezing air. Water droplets cool below the freezing point, reaching temperatures around -4°C (25°F). The droplets remain liquid due to the lack of freezing nuclei in the air. Freezing occurs when these supercooled raindrops strike the ground or objects. The raindrops freeze upon contact with exposed surfaces that are at or below 0°C (32°F).
Accumulation of freezing rain is a process. Supercooled raindrops fall and freeze on surfaces. Ice builds up over time, with layers growing thicker as more raindrops freeze. Ice accumulations of 6 mm (0.25 inches) or more are considered an ice storm. Exposed surfaces freeze quickly, becoming hazardous. Roads, sidewalks, trees, and power lines become coated with a layer of ice.
Where do ice storms happen?
Ice storms occur in northeastern and midwestern US states. The Great Lakes region, Appalachian Mountains, and Northeast Corridor are prone spots. New York, Massachusetts, Vermont, New Hampshire, Maine, Michigan, Wisconsin, and Minnesota experience 2-5 ice storms annually. The Pacific Northwest and Southern US face ice storms.
The East Coast, including the northeastern United States, is prone to ice storms due to cold-air damming. Cold-air damming occurs when a cold air mass is trapped under a layer of warm air, causing water vapor to freeze into ice. The Great Lakes area experiences 1-2 ice storms per year, with ice accumulation up to 0.5 inches (1.3 cm) per event. The Central United States sees frequent ice storms, while southern regions face these events when conditions align.
Ice storms form in areas with specific geographical conditions, at elevations ranging from sea level to over 1,000 meters (3,300 feet). Freezing rain events are common at higher latitudes, above 35°N. Areas near bodies of water, such as the Great Lakes or the Atlantic Ocean, are susceptible to ice storms. Wind direction from the east or northeast leads to cold-air damming, creating favorable conditions for ice storm formation.
Why do ice storms happen?
Ice storms result from warm air layering over cold air. Supercooled raindrops fall through cold layers, becoming colder and prone to freezing. Raindrops freeze upon contacting surfaces, forming a clear ice coating called glaze. Accumulating ice causes damage to structures and creates hazardous travel conditions that disrupt daily life.
Rain becomes supercooled as it falls through a cold layer of air near the surface. Supercooled raindrops remain liquid despite air temperatures below freezing. Raindrops freeze upon contact with surfaces below freezing temperatures. Ice accumulates on surfaces as raindrops freeze on contact, forming ice layers. Freezing rain accumulates at rates of 1-5 mm/h (0.04-0.2 in/h) during ice storms.
Ice storms form when warm air aloft overlays a shallow layer of cold air near the ground. Warm air rises over cold air layers, causing rain to become supercooled. Rain falls through air layers with near-freezing temperatures. Rain freezes upon impact with objects and the ground during ice storms. Ice accumulation causes disruptions and damage during ice storms. Accumulated ice weight reaches up to 10-20 kg/m² during ice storms.
What causes ice storms?
Ice storms result from freezing rain. Raindrops fall through warm air layers, then cold air near the surface. Raindrops freeze on contact with surfaces, creating a glaze coating. Temperatures range from -10°C to 0°C (14°F to 32°F). Supercooled liquid water droplets in the atmosphere contribute to ice pellet formation. Ice accumulation causes damage and disruptions.
The causes of ice storms are outlined below.
- Ice storms occur: When a warm layer of air sits above a cold layer near the ground due to a warm front over a cold air mass.
- Ice storm formation: Depends on the temperature difference between air layers.
- Ice storm precipitation: Starts as snow, which melts into rain, then becomes supercooled.
- Ice storm supercooled rain: Rain remains liquid below 0°C (32°F) when falling through freezing air.
- Ice storm accumulation: Occurs when supercooled raindrops freeze on contact with surfaces.
- Ice storm surfaces: Ice coats trees, power lines, roads, and structures.
- Ice storm criteria: Defined by at least 0.25 inches (6.35 mm) of ice accumulation by freezing rain.
- Ice thickness during ice storms: Ranges from millimeters to centimeters.
- Ice storm ground temperature: Remains below freezing throughout the event.
- Ice storm duration: Can last several hours or days, disrupting daily life.
Precipitation begins as snow in the atmosphere. Snow melts into rain as it falls through the air layer aloft. Rain becomes supercooled as it passes through a freezing layer of air to the ground. Supercooled raindrops remain liquid despite temperatures below 0°C (32°F).
Freezing rain accumulates when supercooled raindrops hit surfaces. Raindrops freeze upon contact with objects at or below freezing temperatures. Ice coats surfaces in a layer, building up on trees, power lines, roads, and structures.
Ice storms result in accumulations of ice. The U.S. National Weather Service defines an ice storm as freezing rain that accumulates at least 0.25 inches (6.35 mm) of ice. Ice thickness reaches millimeters or centimeters during ice storms.
Temperatures remain below freezing at ground level throughout an ice storm. Freezing rain continues to accumulate as long as the temperature inversion persists. Ice storms last for several hours or days, causing disruptions to daily life.
How often do ice storms occur?
Ice storms occur with varying frequency across regions. Ice storms happen 0-2 times per 25 years in some areas. New England experiences extreme ice storms every 35-85 years and moderate ice storms every 5-10 years. Ice events occur in certain regions. The Midwest frequency band experiences 12-15 hours of freezing rain annually. Canada faces 10-15 winter ice events each year, ranging from light freezing drizzle to severe ice storms. Ice storms occur between December and February. Meteorological agencies issue ice storm warnings when freezing rain or drizzle is expected, alerting the public to hazards. Ice storms have impacts on transportation, infrastructure, and daily life, causing damage and disruption. Understanding ice storm frequency and severity informs preparedness and mitigation efforts.
How to prepare for an ice storm?
Emergency kits are crucial for ice storm preparation. Kits contain flashlights, batteries, radio, first aid supplies, and non-perishable food. Home protection involves insulating pipes and draining hoses. Winter driving kits include ice scrapers and jumper cables. Stay informed about weather conditions. Prepare heat sources. Pack a go-bag with medications and documents.
To prepare for an ice storm, follow the steps outlined below.
- Pack an emergency kit with non-perishable food, water, and medications.
- Include flashlights, batteries, first aid supplies, warm clothing, and blankets in your kit.
- Insulate pipes in areas like garages and basements to protect your home.
- Trim tree branches near power lines.
- Gather heat sources, such as firewood, or ensure heaters have proper ventilation.
- Obtain a battery-powered or hand-crank radio for weather updates and emergency instructions.
- Confirm emergency contact information for family members and authorities.
- Keep vehicles fueled and stocked with emergency supplies like blankets, snacks, and a winter driving kit.
- Use salt or sand to melt ice on walkways and driveways after the storm.
- Carefully remove icicles to prevent injury.
- Monitor and check for damage by inspecting downed power lines, roofs, and gutters.
- Make plans to check on neighbors who might require assistance.
What is an ice storm warning?
Ice storm warnings are weather statements issued by the National Weather Service. Warnings indicate freezing rain will produce ice accumulation, 0.25 inches (6.4 mm) or more within 12 hours. Hazardous conditions and disruptions to daily life are expected. Warnings cover areas where severe icing is imminent or occurring.
Ice storm warning alerts are disseminated through multiple channels. The Emergency Alert System broadcasts warnings on TV and radio. Wireless Emergency Alerts deliver notifications to mobile devices. Media platforms and weather services post warning information. The National Oceanic and Atmospheric Administration (NOAA) Weather Radio broadcasts ice storm warnings to ensure widespread public awareness.
Ice storm warning safety precautions are crucial for protecting life and property. Avoiding travel reduces the risk of accidents on icy roads. Keeping distance from downed power lines and trees prevents injuries. Using flashlights instead of candles minimizes fire hazards during power outages. Keeping phone lines open for emergencies ensures communication with authorities. Staying informed through local news provides up-to-date information on storm developments.
Ice storm warnings are tools for public safety during winter weather. These warnings enable individuals to take steps to minimize storm impacts and stay safe. Black ice, a hazard during ice storms, is addressed in these warnings to alert people about its presence.
What damages can ice storms cause?
Ice storms cause infrastructure damage. Trees weaken, snap, and topple, damaging buildings and vehicles. Power lines and utility poles accumulate ice, disrupting electricity transmission. Communication towers and poles suffer damage. Essential services face disruption. Repair work is dangerous and time-consuming, requiring specialized equipment. Public safety is threatened through hazards.
Structural damage to buildings and bridges occurs as ice adds weight to surfaces. The Insurance Information Institute reports that ice storms cause an average of $1.4 billion in damage per year in the United States. Roofs and structures collapse under the strain of ice, which weighs up to 10 pounds per square foot according to the National Oceanic and Atmospheric Administration (NOAA). Metal surfaces corrode, and building materials deteriorate due to chemical damage from prolonged ice exposure.
Environmental impacts of ice storms are substantial. Up to 100,000 trees are damaged or destroyed in an ice storm event. Branches break and trees collapse under the weight of ice, which accumulates up to 38 mm (1.5 inches) thick on surfaces. While destructive, ice storms foster forest health by killing diseased trees and promoting new growth.
How to protect your car from an ice storm?
To protect your car from an ice storm, follow the steps outlined below.
- Park in a garage or carport to protect from snow and ice accumulation.
- Use buildings or trees as shelter when enclosed spaces are unavailable.
- Cover the vehicle with a car cover or tarp to prevent ice formation.
- Apply windshield, wiper, and mirror covers to protect these areas from ice.
- Apply deicer to locks and door seals to prevent freezing.
- Gas tanks and cold-rated washer fluid protect against freezing.
- Rust-inhibiting coatings shield cars from salt damage.
- Remove ice within 24 hours to avoid damage to paint and mechanical parts.
- Use brushes and plastic scrapers to clear ice without scratching surfaces.
- Park 20 feet away from trees and power lines to avoid damage from falling ice.
- Flip windshield wipers up to prevent them from freezing to the glass.
- Remove loose exterior items to prevent freeze damage.
What countries have the most ice storms in a year?
The countries with the most ice storms in a year are listed in the table below.
Country | Average Ice Storms Per Year | Key Regions Affected | Average Annual Ice Storm Duration (hours) | Average Annual Ice Accumulation (mm) |
Canada | 13.4 | Quebec (35%), Ontario (25%), Maritimes (20%) | 12-24 | 30-50 |
Japan | 11.2 | Hokkaido (40%), Tohoku (30%) | 6-18 | 20-40 |
United States | 10.8 | Northeastern States (Maine, New Hampshire, Vermont, Massachusetts, New York) (60%) | 12-36 | 25-50 |
Russia | 8.1 | Western regions (Leningrad Oblast, Pskov Oblast) (30%), Eastern regions (Primorsky Krai, Khabarovsk Krai) (25%) | 6-24 | 15-30 |
China | 7.3 | Heilongjiang (30%), Jilin (25%), Liaoning (20%) | 6-18 | 10-25 |
Canada experiences the highest frequency of ice storms. Canadian provinces Quebec, Ontario, and the Maritimes are affected, with 12-15 ice storms occurring annually. Quebec averages 5-7 ice storms per year, resulting in substantial economic losses and disruptions. The majority of ice storms occur between December and March, with the most severe events in January and February.
Japan ranks second in ice storm frequency, experiencing 10-12 ice storms. Hokkaido and the Tohoku region are susceptible. Sapporo, located in Hokkaido, averages 5-7 ice storms per year and receives a snowfall of 191 cm (75 in). Ice storms occur between January and March, causing damage and power outages.
The United States follows behind in ice storm frequency. Northeastern states are most affected, with an average of 10-12 ice storms per year. Russia experiences 7-9 ice storms annually, in western and eastern regions. China faces 6-8 ice storms per year, mainly in provinces like Heilongjiang, Jilin, and Liaoning.
What was the worst ice storm in US history?
The Great Blizzard of 1993, known as the “Storm of the Century,” was the worst ice storm in US history. The March 1993 storm affected 26 states, causing 318 deaths, 48 injuries, and $10 billion in damages. Storm brought snowfall, winds, coastal flooding, and snow drifts up to 30 feet.
The 1951 ice storm ranks as one of the costliest on record. Damages from the storm were estimated at over $66 million in 1951 dollars, equivalent to $730 million in today’s currency. The storm left over 1 million households without electricity and disrupted services such as transportation and communication. Ice accumulation reached up to 102 mm (4 inches) in some areas, with ice drifts high 20 feet in certain locations. The weight of the ice caused damage to trees, power lines, and infrastructure.