MODIS Observes Snowfall from Recent Blizzard

The MODIS False Color imagery produced by SPoRT utilizes one visible and two infrared channels in order to highlight areas where these signatures differ for a particlar phenomena, in this case, snowfall over the Dakotas and eastern Montana.  Prior to the storm, the MODIS False Color product shows snow free conditions in Montana, Wyoming, western South Dakota (with the exception of the Black Hills) and the panhandle of Nebraska.  Following the storm, the MODIS imagery provides a clear separation of cloud cover and snow across these regions, details that may be missed if only a visible image were used, as clouds and snow both appear white.  Furthermore, infrared channel imagery during the period did not provide good discrimination between snow and cloud, as the clouds were low in altitude and similar in brightness temperature to the cold land surface below.

Snowfall in this region is being monitored carefully, as widespread flooding is a concern as the region moves into the Spring season, where rapid snow melt and additional liquid precipitation are likely.  Previously, MODIS False Color data have been used by the Great Falls, MT office of the National Weather Service to support hydrologic monitoring.

MODIS false color imagery on 22 March 2009 at 1940 UTC.

MODIS false color imagery on 25 March 2009 at 2012 UTC.

2 thoughts on “MODIS Observes Snowfall from Recent Blizzard

  1. Unfortunately, there is no quantitative way to determine snow depth from this image. As you pointed out, the darker colors do give some qualitative assessment, although as you get to black you are looking at snow in a forest. WFO Great Falls uses the NOHRSC (National Operational Hydrologic Remote Sensing Center) products (as well as in situ measurements) in tandem with this MODIS product to paint a complete picture of snow depth and extent. As an alternative, SPoRT has a research AMSR-E product that gives an estimate of Snow Water Equivalent.

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