Snow and ice storms

Overview

Winter storms are a type of storm that forms in the transition zone between subtropical and polar climate regions. In late autumn and winter, when the ocean remains warm but polar regions are cold, bursts of cold polar air collide with warm subtropical air masses, leading to the development of large low-pressure systems. While the wind speeds of winter storms (typically 140-200 km/h) may not reach those of cyclones, they can be just as destructive due to their ability to sweep across much larger areas—sometimes up to 2,000 km wide—and bring additional perils such as heavy snow, freezing rain, and ice storms, all of which have significant impacts on society and human life.

Winter storms are among the seven disaster types that cause billion-dollar losses in the United States. They are also one of the most destructive natural disasters in Europe. For example, during the winters of 1990 and 1999, storm damages in Europe resulted in more than 10 billion euros in insurance payouts, with total economic losses estimated to be about twice that amount. The powerful winter storm Uri, which occurred in 2021, incurred overall losses of around 30 billion dollars, making it the most costly winter storm on record.

The damages from winter storms primarily arise from destruction to buildings, vehicles, and infrastructure. These storms can cause widespread power outages, road closures, supply chain disruptions, and significant health risks. Winter storms bring strong winds, heavy snowfall or freezing rain, and cold temperatures, which together create a range of impacts. As summarized by the IPCC AR6 as below:

"Heavy snowfall is a substantial concern for cities, settlements and key transportation and energy infrastructure. Heavy snowfall can interfere with transportation and cause a loss of both work and school days depending on local snow removal infrastructure. Freezing rain and ice storms can be treacherous for road and air travel, and can knock down power and telecommunication lines if ice accumulation is high. Rain-on-snow events can create a solid barrier that hinders wildlife and livestock grazing that is important to indigenous communities. Shifts in the frequency, seasonal timing and regions susceptible to ice storms alter risks for agriculture and infrastructure."

Data for Risk Analysis

Winter storm data

Dataset	Description	Temporal Location	Data download link
Snowstorm database	A collection of over 500 snowstorms over the US dating back to 1900 and updated operationally. Only storms having large areas of heavy snowfall (10-20 inches or greater) are included. This data has been used to provide input for the calculation of the Regional Snowfall Index (RSI) and the Northeast Snowfall Impact Scale (NESIS) and for analyzing trends of large snowstorms. The data can also be used to make maps of historical snowstorms or for exploratory data analysis of historical storms. Archiving the data as shapefiles allows external users such as emergency managers, researchers, or anyone from snow sensitive entities to use the data directly in a GIS.	Past	Access
Regional snowfall index (RSI)	NOAA's National Centers for Environmental Information is now producing the RSI for significant snowstorms that impact the eastern two thirds of the U.S. It is a regional index. The RSI ranks snowstorm impacts on a scale from 1 to 5, similar to the Fujita scale for tornadoes or the Saffir-Simpson scale for hurricanes. RSI is based on the spatial extent of the storm, the amount of snowfall, and the juxtaposition of these elements with population. Including population information ties the index to societal impacts.		View; Access
Northeast Snowfall Impact Scale (NESIS)	NESIS characterizes and ranks high-impact Northeast snowstorms, like Fujita and Saffir-Simpson Scales characterizing tornadoes and hurricanes respectively. The index differs from other meteorological indices in that it uses population information in addition to meteorological measurements. Thus NESIS gives an indication of a storm's societal impacts. This scale was developed because of the impact Northeast snowstorms can have on the rest of the country in terms of transportation and economic impact. Though it was developed aiming for the Northeast only, NESIS also ranks snow storms over the other regions of the US.
NOAA storm events database	A database that contains storm data and other severe weather events (droughts, wildfires, etc.) from January 1950 to near present. Damage and fatalities are also provided.		Access

Risk assessment model

There are now very little studies on projection of heavy snowfall and ice storms separately in the future. This is because projection of winter storm in general requires resolution beyond the ones currently available for climate models, let alone the difficulty to separate snow and rainfall in the model. Instead, metrics of generally characterizing the storminess and storm track activity is available.

With global warming: revealed a decrease in the number of storms over the mid-latitude regions of Canada. However, intense storms with a longer duration are projected over all regions at the end of the century.

Climate change studies offer contrasting projections regarding the number of winter storms. These scientific studies indicate that the risk of severe winter storms, and possibly also autumn storms, from the North Atlantic to central Europe could increase in the 21st century, while the overall number of storms is likely to decrease.

Numerous risk models are available in the form of either open-source of proprietary.

Munich Re’s NatCatSERVICE is one of the world’s most comprehensive databases for analysing and evaluating losses caused by natural disasters. For this service, Munich Re has for decades been systematically recording in detail all essential information on loss events worldwide. This is stored in a digital catalogue of events and damage. https://www.munichre.com/en/solutions/for-industry-clients/natcatservice.html

• G20 climate risk analysis: https://www.cmcc.it/g20
• climate related economic losses: https://www.eea.europa.eu/en/datahub/datahubitem-view/1fac8253-3df7-4408-b5fa-a6f2dc524182
• Economic losses from climate-related extremes in Europe https://www.eea.europa.eu/en/datahub/datahubitem-view/77389680-ecd2-4f56-926f-8106061a5570

1.

Not much studies on projection of snow storm changes, like intensity, frequency, because of the resolution and it is hard to separate snow and precipitation.

There are projection of winter storm in general. Storminess, Storm track activity.

No data either. But CONUS 404 is in development. We may look forward to it.