National Snow & Ice - March 2011
During March, an active storm track along the U.S. West Coast and the northern tier of the country led to above-normal precipitation for these regions, while the central and southern regions of the country were drier than normal. The northern and western U.S. were dominated by near- to slightly-below average temperatures. The cool temperatures and active storm pattern led to significant snow accumulations for the high elevations of the western U.S., along the Northern Plains, and into the Northeast. Monthly and seasonal snowfall records were broken in these regions including Williston, North Dakota, which broke a 105-year old seasonal snowfall record, having received 95.1 inches (242 cm) of snow since autumn. Glasgow, Montana received 105.3 inches of snow this winter, besting it's previous seasonal record by 35 inches (89 cm).
Across the West, the annual peak in snow pack water content occurs at the end of March, and the amount of snow pack is a good indicator of the amount of water runoff available to supply water to the major cities in the West during the dry summer period. At the end of the month, almost all river basins had snow packs above normal, with the exception of the Southern Rockies. Locations in the central Sierra Nevada Mountains had roughly 165 percent of normal snow pack at the end of the month. March typically marks the end of the snow season for much of the Southern Plains and the Southeast, and March 2011 was not an exception, with little to no snow falling across those regions due to the arrival of spring-like temperatures. According to data from the Rutgers Global Snow Lab, a NOAA supported facility, there was below average March snow cover across the Ohio River Valley, the High Plains, and the Southern Rockies. Meanwhile, the Sierra Nevada and Cascade mountains had above-average snow cover. The northern Plains, the Great Lakes, and the Northeast also had above average snow cover during March.
Based upon satellite analysis, the contiguous U.S. had a March average snow cover extent 216,217 square miles (0.56 million square km) above the long-term average of 768,343 square miles (1.99 million square km), ranking as the seventh largest March snow cover extent in the 45-year period of record. At the beginning of the month, 43.4 percent of the contiguous U.S. was under snow cover — the high elevations of the West, the Northern and Central Plains, the Great Lakes, and most of the Northeast. The monthly maximum snow cover extent occurred on March 8th, when a storm brought snow to much of the Appalachians, increasing the percent area of snow cover to 44.3 percent. By the end of the month, the percent of the U.S. snow covered decreased to 25.4 percent. Snow cover was limited to the highest mountains in the West, the far northern Plains, most of the Great Lakes, and the Northern New England.
New England Snowfall 7 March
Image Credit: NOHRSC
A late season snow storm hit the Northeast between March 5th and 7th. Snowfall amounts up to 30 inches (76 cm) were reported across northern New York and western Vermont. Burlington, Vermont received 25.8 inches (65.5 cm) of snow, the largest single-storm accumulation on record during March. The storm contributed to Burlington having its sixth snowiest March with 29.3 inches (74.4 cm) for the month and third snowiest winter on record with 127.6 inches (324 cm) for the season, behind 1899/1900 [159.5 inches(405 cm)] and 1970/1971 [145.4 inches(369.3 cm)]. Syracuse, New York received 13 inches (33 cm) of snow, contributing to the fourth snowiest winter there with 173.5 inches (441 cm) for the season. The heavy snow caused significant impacts in the region, including the closure of Interstate Highway 89 and over 50,000 homes losing power during the storm. Please see Global Hazards for additional information.
Satellite Image of landfalling storms
along U.S. West Coast 20 March
A series of large Pacific storms made landfall along the U.S. West Coast between the 18th and 26th of the month. The storms brought incredible amounts of rain and snow from Washington State to Southern California. These storms contributed to many high elevation observation stations having impressive snowfall totals for the month and the winter season. Squaw Valley at Lake Tahoe, California reported 241 inches (612 cm) of snowfall during March 2011. Alpine Meadows, California reported 315 inches (800 cm) of snow on the ground after these storms moved through, and several snow observation stations in the Sierra Nevada received as much as 145 inches (368 cm) during the 9-day period. The snow added to the amount of water contained in the snow pack measured by snow water equivalent (SWE). At the end of March, some high elevation stations in California had SWE values approaching 80 inches (203 cm). For California as a whole, the average snowpack was 48 inches (122 cm) on April 1st, 168 percent of average. At some locations in the Sierra Nevada, the snow depth exceeded the height of the automated weather stations in the SNOTEL network, causing underestimates in the measurement of snow on the ground. Please see Global Hazards for additional information on the impacts of these storms.