The snowstorm of October 3 to 6, 2009
A snowstorm NOAA ranked in 1 region on its Regional Snowfall Index, strongest in the Northern Rockies and Plains.
What the offices filed during it
Winter weather episodes east of the Rockies from the day before the storm began to the day after it ended, colored by kind.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The storm by region
Each region’s thresholds are its own, so the same depth of snow counts for more in the South than in the Northeast.
| Region | Index | Category | Area with snow (sq mi) | People under snow | Above the top threshold (sq mi) | People above it |
|---|---|---|---|---|---|---|
| Northern Rockies and Plains | 1.38 | Category 1, Notable | 280,717 | 1,827,539 | 86 | 432 |
The Regional Snowfall Index is NOAA’s ranking of snowstorms east of the Rockies by how much snow fell, over how wide an area and on how many people, region by region: the area and the population above four snowfall thresholds set for each region, weighted against that region’s own history. A storm is scored in each region it reached, on a scale from 1, notable, to 5, extreme.
The toll the offices filed
- Events
- 22
- Deaths
- 0
- Injuries
- 0
- Damage
- $14,000
- Episodes
- 7
Every winter weather episode the Weather Service filed east of the Rockies in these dates. A few may belong to another system on the same days. Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
Episode by episode
- Winter Storm in Wyoming, October 4 to 5, 2009A large trough over Western Wyoming combined with a surface low across Colorado resulted in a major early Fall snowstorm across North Central Wyoming. Heavy, wet snow contributed to scattered power outages and numerous automobile accidents.
- Heavy Snow in Idaho, October 4 to 5, 2009Ten to 30 inches of snow fell in the central mountains of Idaho on October 4th and 5th. The heavy autumn snow caused schools to close in Bellevue with power outages.
- Winter Storm in Montana, October 4 to 5, 2009A closed upper low tracked south from the Pacific Northwest into Utah and then Wyoming. Circulation from this storm brought moisture into Montana where it overran cold air at the surface. Snowfall of greater than 6 inches was reported at elevations above 6000 feet.
- Winter Storm in Montana, October 4 to 5, 2009Low pressure tracking across the Pacific Northwest brought moisture into Montana from the south while cold air was moving into the state from Canada. The result was winter storm conditions, mainly confined to elevations above 5000 feet.
- Heavy Snow and Winter Weather in South Dakota, October 4 to 5, 2009An early fall storm system brought rain and accumulating snowfall to much of western South Dakota. The heaviest snow occurred over the central Black Hills; where Mount Rushmore, Hill City, and Pactola Reservoir received six to eight inches of snow.
- Winter Weather in Wyoming, October 4 to 5, 2009An early fall storm system brought rain and snow to the region. Across northeastern Wyoming, the precipitation began as rain, then changed to snow during the night. Snowfall amounts of four to six inches were reported across the area.
- Winter Weather in South Dakota, October 5 to 6, 2009An early fall storm system brought rain and snow to the region. Precipitation began as rain and changed over to snow. Four to six inches of snow fell across portions of Harding and Perkins Counties.
More
The snowstorm of April 17 to 19, 2009The snowstorm of October 21 to 24, 2009Snow nowEvery winter storm filed
Sources
NOAA NCEI Regional Snowfall Index, and the Storm Events Database for the episodes.