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Water and Climate Update December 09, 2021

The Natural Resources Conservation Service produces this weekly report using data and products from the National Water and Climate Center and other agencies. The report focuses on seasonal snowpack, precipitation, temperature, and drought conditions in the U.S.

1BSnow .......................................................................... 2 1BPrecipitation ............................................................... 4 2BTemperature .............................................................. 8

3BDrought .................................................................... 10 4BOther Climatic and Water Supply Indicators ............ 13 6BMore Information ...................................................... 19

Hawaii drenched with record rainfall

A strong low-pressure system produced record rainfall in Hawaii from December 5 to 7. The storm moved from East to West over the island chain dropping the largest amounts of precipitation on southern slopes of the volcanos on the Big Island and Maui, as well as most of O’ahu. Strong winds, heavy rainfall and flooding caused power outages, road closures, and damage to homes and businesses. Flooding damage to the Iwilet Power Substation on O’ahu cut power to downtown Honolulu businesses and residences. At summits of the island volcanoes, blizzard warnings were issued for heavy snow and high winds.

Related:

Deluge triggers flood watches in Hawaii as more rain expected in western islands – Reuters Hawaii under state of emergency as winter storm brings flash flooding and high winds – CBS News Hawaii mountains to see snow after rare blizzard warning - AP Flooding Rains—And Blizzard Conditions—Hit Hawaii – Scientific American Hawaii braces for foot of snow amid blizzard warning – NBC Dangerous storm threatens havoc across Hawaiian archipelago – AP Honolulu records second-highest rainfall total ever on Monday – KITV (HI) Hawaii Declares Emergency as ‘Kona Low’ Storm Brings Flooding - Bloomberg

Water and Climate Update

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1BSnow

Snow water equivalent percent of median map

See also: Snow water equivalent values (inches) map

Alaska snow water equivalent percent of median map

See also: Alaska snow water equivalent values (inches) map

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Current Snow Depth, National Weather Service Snow Analysis

Source: NOAA Office of Water Prediction

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1BPrecipitation

Last 7 Days, NRCS SNOTEL Network

7-day precipitation percent of average map

See also: 7-day total precipitation values (inches) map

Alaska 7-day precipitation percent of average map

See also: Alaska 7-day total precipitation values (inches) map

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Last 7 Days, National Weather Service (NWS) Networks Source: Regional Climate Centers

7-day precipitation percent of normal map for the continental U.S.

See also: 7-day total precipitation values (inches) map

Last 7 Days, National Weather Service (NWS) Networks Source: Regional Climate Centers

7-day precipitation anomaly map for Alaska.

See also: 7-day total precipitation values (inches) map

Water and Climate Update

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Monthly, All Available Data Including SNOTEL and NWS Networks Source: PRISM

Monthly national total precipitation anomaly map

Last 3 Months, All Available Data Including SNOTEL and NWS Networks Source: PRISM

September through November 2021 precipitation anomaly map

Water and Climate Update

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Water Year-to-Date, NRCS SNOTEL Network

2022 water year-to-date precipitation percent of median map

See also:

2022 water year-to-date precipitation percent of average map

2022 water year-to-date precipitation values (inches) map

Alaska 2022 water year-to-date precipitation percent of median map

See also:

Alaska 2022 water year-to-date precipitation percent of average map

Alaska 2022 water year-to-date precipitation values (inches) map

Water and Climate Update

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2BTemperature

Last 7 Days, National Weather Service (NWS) Networks Source: Regional Climate Centers

7-day temperature anomaly map for the contiguous U.S.

See also: 7-day temperature (° F) map

Last 7 Days, National Weather Service (NWS) Networks Source: Regional Climate Centers

7-day temperature anomaly map for Alaska.

See also: 7-day temperature (° F) map

Water and Climate Update

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Monthly, All Available Data Including SNOTEL and NWS Networks Source: PRISM

Monthly national daily mean temperature anomaly map

Last 3 Months, All Available Data Including SNOTEL and NWS Networks Source: PRISM

September through November 2021 daily mean temperature anomaly map

Water and Climate Update

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3BDrought

U.S. Drought Monitor U.S. Drought Portal Source: National Drought Mitigation Center Source: NOAA

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Current National Drought Summary, December 09, 2021 Source: National Drought Mitigation Center

“This U.S. Drought Monitor (USDM) week saw continued deterioration in conditions across areas of the Mid-Atlantic (Virginia, North Carolina) and the Southeast (South Carolina, Georgia) in response to below-normal precipitation (past 30- to 90-day period), declining soil moisture and streamflow levels. Likewise, drought-affected areas expanded and intensified on the map in areas of the South including Louisiana, Arkansas, and Texas as well as in the Southern Plains of Oklahoma, where overall warm and dry conditions have prevailed during the past 30- to 120-day period. Across areas of the Northern Plains, Upper Midwest, and the Northeast, light-to-heavy snowfall accumulations were observed during the past week. The heaviest accumulations (8-18 inches) were centered on northern portions of Minnesota, Wisconsin, and Michigan, while lake-effect snowfall (2 to 8 inches) impacted areas downwind of Lake Erie and Lake Ontario in New York, according to snowfall analysis from the National Weather Service (NWS) National Operational Hydrologic Remote Sensing Center (NOHRSC). Out West, some areas including the North Cascades, Sierra Nevada, and the Northern and Central Rockies, received much-needed snowfall this past week. However, basin-level snowpack conditions remained below normal across the entire western United States. In Hawaii, a Kona Low delivered very heavy rainfall accumulations (highest totals exceeding 16+ inches) leading to widespread flooding, power outages, and damage to infrastructure in areas across the Hawaiian Island this week. Impacts from the multi-day event led Hawaii Governor Ige to declare a state of emergency on December 6. With the meteorological autumn (September-November) coming to a close, the Lower 48 experienced its third warmest fall on record with the largest mean temperature departures from average observed across areas of the Northern and Central Plains, according to NOAA’s National Centers for Environmental Information (NCEI). In terms of fall precipitation, the driest conditions were observed across parts of the Southwest, Texas, Montana, Wisconsin, and the Carolinas.”

USDA Secretarial Drought Designations Source: USDA Farm Service Agency

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Changes in Drought Monitor Categories over Time Source: National Drought Mitigation Center

1 Week

1 Month

6 Months

1 Year

Changes in drought conditions over the last 12 months for the contiguous U.S.

Highlighted Drought Resources

• Drought Impact Reporter

• Quarterly Regional Climate Impacts and Outlook

• U.S. Drought Portal Indicators and Monitoring

• U.S. Population in Drought, Weekly Comparison

• USDA Disaster and Drought Information

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4BOther Climatic and Water Supply Indicators

Soil Moisture Source: NOAA National Centers for Environmental Prediction

Modeled soil moisture percentiles as of November 27, 2021

Soil Moisture Percent of Saturation Source: NRCS SNOTEL and Soil Climate Analysis Network (SCAN) U.S. Soil moisture map at 8 inches depth:

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Soil Moisture Source: NRCS Soil Climate Analysis Network (SCAN)

This chart shows the precipitation and soil moisture for the last 30 days at the Kainaliu SCAN site in Hawaii. Recent precipitation from December 3-7 totaled 3.68 inches, with all sensors showing an increase in soil moisture. The total precipitation for the last 30 days was 3.93 inches.

Soil Moisture Data Portals

• USCRN Soil Moisture

• National Soil Moisture Network

• NOAA Climate Prediction Center Soil Moisture

• NASA Grace

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Streamflow, Drought, Flood, and Runoff Source: U.S. Geological Survey WaterWatch Streamflow Map

WaterWatch: Streamflow, drought, flood, and runoff conditions

Reservoir Storage

Hydromet Teacup Reservoir Depictions Source: U.S. Bureau of Reclamation

• Upper Colorado

• Pacific Northwest/Snake/Columbia

• Sevier River Water, Utah

• Upper Missouri, Kansas, Oklahoma, Texas

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Current California Reservoir Conditions Source: California Department of Water Resources

Current California Reservoir Conditions

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Agricultural Weather Highlights Author: Brad Rippey, Agricultural Meteorologist, USDA/OCE/WAOB

National Outlook, Thursday, December 09, 2021: “For the remainder of today, a weak disturbance crossing the Midwest will generate some light snow in the upper Great Lakes region. Meanwhile, a storm system currently traversing the western U.S. will gradually intensify, reaching the central Plains on Friday and affecting the Great Lakes region during the weekend. The storm will produce varying amounts of snow in the West, heaviest from the Sierra Nevada to the western slopes of the central Rockies. Farther east, accumulating, late-week snow should fall in a narrow band from southeastern Wyoming to Michigan’s Upper Peninsula. Along the storm’s trailing cold front, December 10-11 rainfall totals could exceed an inch in parts of the eastern U.S. Elsewhere, a slow-moving storm system should arrive along the Pacific Coast during the weekend. Late in the weekend and early next week, much needed precipitation should spread southward into central and southern California—and inland across the Great Basin and Intermountain West. The NWS 6- to 10-day outlook for December 14 – 18 calls for the likelihood of near- or above-normal temperatures and precipitation across most of the country. Colder-than-normal conditions will be mostly confined to the Pacific Coast States, while drier-than-normal weather should be limited to parts of the East, mainly along the Atlantic Coast.”

Weather Hazards Outlook: December 11 – 15, 2021 Source: NOAA Weather Prediction Center

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Seasonal Drought Outlook: November 18, 2021 – February 28, 2022 Source: National Weather Service

Climate Prediction Center 3-Month Outlook Source: National Weather Service

Precipitation

Temperature

December-January-February 2021-2022 precipitation and temperature outlook summaries

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6BMore Information

The NRCS National Water and Climate Center publishes this weekly report. We welcome your feedback. If you have questions or comments, please contact us.