Monday, October 30, 2023

A 'White Halloween' Blanket Of Snow Isn't As Weird As It Sounds

Jonathan Erdman

Published: October 30, 2023





 A white Halloween may sound bizarre, and a chance of snow on the holiday is low for most, but it has happened before in parts of the Midwest, Northeast and West.

W​hat it means: Similar to its more famous cousin, the white Christmas, we'll consider a Halloween white if there is at least 1 inch of snow on the ground. However, since snow is fairly rare for many this early in the season, we'll also count any measurable snow - at least 0.1 inch - that falls during the day as a white Halloween.

M​ore widespread this year: A pair of winter storms - named Archer and Bryson by The Weather Channel - each dumped heavy snow over parts of the Rockies and Plains since last week. Then, cold air plunged out of Canada into the Plains. T​hen, we expect some "first snow of the season" in the form of showers in parts of the Great Lakes on Halloween.

T​hat means 2023's version of a white Halloween is likely to be more expansive than usual.

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Article imageSnow cover analysis on the morning of Oct. 30, 2023.

W​hat's typical: Alaska-based climatologist Brian Brettschneider crunched the data to construct the map below, the chance of seeing a white Halloween in any year. A​s you can see, much of the Lower 48 has a less than 5% chance of a white Halloween, based on average weather conditions over many years.

The Rockies have the best chance of a white Halloween in the contiguous United States. Some of the highest elevations in Wyoming and Colorado have anywhere from a one-in-four to one-in-two chance, historically.

Adjacent parts of the Plains as far east as the western and northern Dakotas into northern Minnesota and the western Upper Peninsula of Michigan have probabilities from 10 to 25%, according to Brettschneider. In the East, northern New England and New York's Adirondacks and Catskills have white Halloween odds of about 10% or slightly higher.

Over the past 20 years, an average of only 6% of the contiguous U.S. had snow on the ground on Oct. 31, according to NOAA's national snow analyses. NOAA has compiled historic white Halloween data for almost 300 U.S. cities here.

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R​ecent notable white Halloweens: In the last week of October 2020, snow fell as far south as Midland, Texas, and a severe ice storm knocked out power to hundreds of thousands in Oklahoma. While that snow and ice melted away by Halloween, a brush of snow in the Northeast lingered on the ground that first Halloween of the COVID-19 pandemic.

T​he previous year was the most expansive Halloween snow cover in NOAA records since 2003, from the Rockies to the mid-Mississippi Valley and western Great Lakes, when almost 17% of the contiguous U.S. had snow on the ground. It was also the snowiest Halloween on record in both Madison (4 inches) and Milwaukee, Wisconsin (5.4 inches).

In 2011, a major October snowstorm - dubbed "Snowtober" in social media - dumped more than a foot of snow from northeastern Pennsylvania to southern Maine from Oct. 29-30. Parts of Massachusetts and New Hampshire picked up more than 30 inches. Some of that snow remained on the ground on Halloween.

Trees were damaged and power lines were downed by the heavy, wet snow, knocking out power to more than three million customers, some for more than a week.

Article imageSatellite image from Oct. 30, 2011, showing the area of snow produced by "Snowtober" from West Virginia to southern New England.

Jonathan Erdman is a senior meteorologist at weather.com and has been covering national and international weather since 1996. His lifelong love of meteorology began with a close encounter from a tornado as a child in Wisconsin. He studied physics at the University of Wisconsin-Madison, then completed his Master's degree working with dual-polarization radar and lightning data at Colorado State University. Extreme and bizarre weather are his favorite topics. Reach out to him on X/TwitterFacebook and Threads. 

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

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