Where The Severe Threat Ramps Up This Weekend

Winter Storm Iona is bringing heavy snowfall across the Great Lakes and Upper Midwest. Heavy snowfall and gusty wind is causing blizzard conditions over the region. Across the southern end of the storm, warm air is mixing in and is helping bring a major severe storm threat, including gusty winds and tornadoes.

(MORE: Severe Forecast)

(MORE: Iona Forecast)

Below you'll find maps that will help you track it all.

Current Radar

Current Winds

Satellite

Alerts

Rain and Snow Forecasts

Instability

CAPE (Convective Available Potential Energy) measures the amount of instability in the atmosphere and is essential for thunderstorm development. The higher the CAPE, the higher the probability of thunderstorm development.

Wind Shear

Wind shear is the change in wind speed or direction with height, a key ingredient in thunderstorm development, especially severe storms.

Cold

Rob Shackelford is a meteorologist and climate scientist at weather.com. He received his undergraduate and master’s degrees from the University of Georgia studying meteorology and experimenting with alternative hurricane forecasting tools.