Freezing rain, ice accumulation, glaze events, and ice storm warnings
This ice storm monitor tracks freezing rain events and dangerous ice accumulation worldwide. Users searching for ice storm warning, freezing rain forecast, or glaze ice can see active warnings, expected accumulation, and impacts on travel and infrastructure.
Freezing rain forms when snow falls through a warm air layer aloft and melts completely, then falls into a shallow cold layer near the surface where the droplets supercool but don't refreeze before reaching the ground. On contact with surfaces below freezing, the supercooled drops instantly form a layer of clear glaze ice. Ice pellets form in the same setup when the cold surface layer is deep enough to refreeze drops in flight, producing small bouncing ice grains rather than glaze.
Ice accumulation of 6 mm produces hazardous driving and walking conditions. Accumulation of 12 mm becomes a damaging ice storm — tree branches break under the weight, power lines sag and snap, and travel becomes essentially impossible. Above 25 mm of ice accumulation, the event qualifies as a major ice storm with widespread infrastructure damage. The 1998 North American Ice Storm produced over 100 mm in places, killing 35 people and leaving millions without power.
Ice storms produce the largest sustained power outages in the historical US record. Heavy ice loading combined with wind brings down distribution lines, transmission towers, and entire forest canopies. Restoration can take weeks across heavily damaged regions because outages affect distribution networks rather than central facilities. Trees with brittle wood, asymmetric crowns, or already weakened limbs face the highest risk; mature ice-storm-damaged forests often show long-term productivity losses.
Glaze ice produces near-zero friction surfaces on roads, sidewalks, and bridges. Black ice — thin clear glaze on asphalt — is particularly dangerous because it's nearly invisible. Bridge decks freeze before adjacent road surfaces because they cool from both sides. Pedestrians sustain serious injuries from falls on iced surfaces, and elderly people face the highest fracture risk. Tire chains help moderately but don't restore safe braking on glaze ice.
ice storm warning, freezing rain, ice storm today, glaze ice, ice accumulation, freezing rain advisory, ice storm near me, power outage ice storm, black ice, ice pellets, freezing rain forecast.