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April 8, 2023 - Snow Western United States
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After a series of at least a dozen atmospheric rivers lashed the Western United States between November 2022 and March 2023, mountain snowpack reached record or near-record levels.
On April 5, 2023, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a false-color image centered on the state of Wyoming. In this type of image, snow appears bright blue, grass is green, open land looks brown, and clouds may appear either white or, if the clouds are high and very cold, may be tinted with bright blue.
A blanket of heavy snow covers almost all of the high mountains in this image, with the exception of an area in northern Idaho, where vegetation predominates. Snow also stretches over part of the Midwest, including South Dakota and North Dakota, and extends northward into Canada. The deep blue waters of the Great Salt Lake, Utah, illustrate the effect of this winter’s exuberant precipitation, even in the lower elevations. In November 2022, the Great Salt Lake hit a new record low, with the water level measured at 4,188.5 feet. By April 6, the level had risen to 4,191.5 feet—a full 3-foot rise—even before the onset of spring runoff.
Early April is the typical peak of snow water equivalent (SWE) in the West. Because SWE estimates the amount of water held in the winter snowpack, the SWE measured on April 1 is used as one of the initial indicators of potential spring and summer water supply. According to the National Integrated Drought Information System (NIDIS), California, Nevada, Utah, and western Colorado all registered record-high SWE. In northwestern Utah, the SWE is 300 percent above the 1991-2020 median. In parts of the eastern Sierra Nevada along the border of California and Utah, SWE peaked at 303 percent of median. In addition, along the northwestern border of Arizona and southeast Nevada, SWE was estimated at 408 percent, while central Arizona reached a full 600 percent of median.
The high snowpack is welcome to drought-plagued portions of the West, but the robust snowpack may trigger spring and summer floods, especially if runoff is rapid. The NIDIS notes that serious drought concerns remain in the parts of the Pacific Northwest, in part due to lack of snow. They also expect Lake Powell to rise significantly by summer, but Lake Mead may continue to fall. Both of those reservoirs will remain at critically low levels, despite the anticipated runoff, due to more than 20 years of drought.
Image Facts
Satellite:
Terra
Date Acquired: 4/6/2023
Resolutions:
1km (800.6 KB), 500m (2.7 MB), 250m ( B)
Bands Used: 7,2,1
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
After a series of at least a dozen atmospheric rivers lashed the Western United States between November 2022 and March 2023, mountain snowpack reached record or near-record levels.
On April 5, 2023, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a false-color image centered on the state of Wyoming. In this type of image, snow appears bright blue, grass is green, open land looks brown, and clouds may appear either white or, if the clouds are high and very cold, may be tinted with bright blue.
A blanket of heavy snow covers almost all of the high mountains in this image, with the exception of an area in northern Idaho, where vegetation predominates. Snow also stretches over part of the Midwest, including South Dakota and North Dakota, and extends northward into Canada. The deep blue waters of the Great Salt Lake, Utah, illustrate the effect of this winter’s exuberant precipitation, even in the lower elevations. In November 2022, the Great Salt Lake hit a new record low, with the water level measured at 4,188.5 feet. By April 6, the level had risen to 4,191.5 feet—a full 3-foot rise—even before the onset of spring runoff.
Early April is the typical peak of snow water equivalent (SWE) in the West. Because SWE estimates the amount of water held in the winter snowpack, the SWE measured on April 1 is used as one of the initial indicators of potential spring and summer water supply. According to the National Integrated Drought Information System (NIDIS), California, Nevada, Utah, and western Colorado all registered record-high SWE. In northwestern Utah, the SWE is 300 percent above the 1991-2020 median. In parts of the eastern Sierra Nevada along the border of California and Utah, SWE peaked at 303 percent of median. In addition, along the northwestern border of Arizona and southeast Nevada, SWE was estimated at 408 percent, while central Arizona reached a full 600 percent of median.
The high snowpack is welcome to drought-plagued portions of the West, but the robust snowpack may trigger spring and summer floods, especially if runoff is rapid. The NIDIS notes that serious drought concerns remain in the parts of the Pacific Northwest, in part due to lack of snow. They also expect Lake Powell to rise significantly by summer, but Lake Mead may continue to fall. Both of those reservoirs will remain at critically low levels, despite the anticipated runoff, due to more than 20 years of drought.
Image Facts
Satellite:
Terra
Date Acquired: 4/6/2023
Resolutions:
1km (800.6 KB), 500m (2.7 MB), 250m ( B)
Bands Used: 7,2,1
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
