Snowmageddon 2010: The Blizzard That Buried Washington Under 32 Inches

How much snow fell, city by city

Snowmageddon was really two storms in one week. The first — February 5–6 — is the one that earned the name. The second — February 9–11 — reloaded on cities that had barely dug out. We pulled both totals, and the February monthly total, straight from NOAA's daily archive for seven airport stations:

Storm totals are sums of daily snowfall on the listed dates from NOAA GHCN-Daily (bad readings excluded), computed this week. The National Weather Service reported a 32.9-inch storm total at Dulles; Philadelphia's 28.5 inches was its second-greatest storm since records began in 1872 (NWS).

Why “Snowmageddon”?

The name was crowdsourced. As the storm bore down, the Washington Post's Capital Weather Gang blog ran a reader poll on February 4 for what to call it; “Snowmageddon” and “Snowpocalypse” stuck. It went national when President Obama used “Snowmageddon” at a Democratic National Committee meeting on February 8, 2010 (Wikipedia). The nickname outlived the snowpiles — it is now shorthand for any paralyzing East Coast blizzard.

Meteorologically, Snowmageddon was a textbook “Miller Type B” storm: a low pressure center tracking over the Ohio Valley stalled against a block to the north and handed off to a new, explosively deepening low along the Carolina coast. That coastal low tapped an enormous moisture feed from both the Gulf of Mexico and the Atlantic, then drew it north over cold air locked in place at the surface — the recipe for two to three feet of snow across the Washington–Baltimore–Philadelphia corridor.

The storm that broke February

One blizzard would have been a top-five storm for these cities. Two in a week rewrote the record books. The February 9–11 follow-up dropped another 19.5 inches on Baltimore, 15.8 on Philadelphia and 15.7 on Harrisburg, piling onto snow that had not melted. Add it all up and February 2010 became, by a wide margin, the single snowiest calendar month ever recorded at these stations in our NOAA data:

• Philadelphia: 51.5 inches in February 2010 — more than its two next-snowiest months combined; the previous record month was January 1996 at 33.9 inches.
• Baltimore: 50.0 inches, versus 40.6 in the next-highest month (February 2003).
• Washington Dulles: 46.1 inches, versus 34.9 (February 2003).
• Reagan National: 32.1 inches, edging February 1979's 30.6.

Philadelphia's snowiest month on record, in a city with snowfall data back to the 1880s, was set in a single week in 2010. That is the distinction Snowmageddon really holds — not the biggest single storm in American history, but the one that turned a normal winter into the snowiest month the Mid-Atlantic has ever measured.

What the snow did

The back-to-back storms were blamed for 41 deaths across Mexico and six U.S. states, and knocked out power to more than 331,000 customers — over 150,000 in Maryland alone — as heavy, wet snow snapped limbs and lines (Wikipedia). The federal government in Washington shut down, closing offices early on Friday, February 5 and staying closed into the following week as the second storm arrived — a rare multi-day closure of the nation's capital. Reagan National and Dulles ground to a halt, Amtrak suspended service, and roofs collapsed under the load across the region.

Where Snowmageddon ranks

By single-storm snowfall, Snowmageddon sits in elite company among Mid-Atlantic blizzards — but it is not alone. The Blizzard of 1996 still holds Philadelphia's all-time single-storm record at 30.7 inches, and the Blizzard of 2016 (Jonas) out-snowed Snowmageddon's single storm in Baltimore and New York. Go further back and the Great Blizzard of 1888 and the Storm of the Century (1993) remain the benchmarks for East Coast winter catastrophe. See the full ranking in our worst blizzards in U.S. history guide. Where Snowmageddon stands apart is the month, not the storm: no other event turned a Mid-Atlantic February into the snowiest month these cities have ever recorded.

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