This water year recap and drought & climate webinar summary was originally sent via email to the California-Nevada DEWS email list.
Quarterly Climate Impacts and Outlook for the Western Region for June – August 2020. Dated September 2020.
Summer temperatures were well above normal in California, Nevada, the Four Corners and Wyoming. Pacific Northwest and Montana temperatures were near normal or above normal with a few small pockets below normal. Large areas of the West observed a drier than normal summer with southeast California into Arizona being the driest. This is the second year in a row with “missing” monsoon rains.
Quarterly Climate Impacts and Outlook for the Western Region for March – May 2020. Dated June 2020.
Temperatures were above average during spring 2020 throughout much of the West. Widespread drier-than-normal conditions occurred in spring though some regions experienced wetter than normal months.
Quarterly Climate Impacts and Outlook for the Western Region for December 2019 – February 2020. Dated March 2020.
Winter temperatures were above normal for much of the West. Near to below normal temperatures were observed in the Central Rockies states. Scattered areas across the northern tier of the West reported above normal precipitation due to an active, poleward shifted storm track. In contrast, western Oregon and the Southwest observed near-to-below normal precipitation, due to persistent ridging during January and February.
Quarterly Climate Impacts and Outlook for the Western Region for September – November 2019. Dated December 2019.
Autumn temperatures were well below normal across the northern tier of the region while near to above normal temperatures were observed across California and the Southwest. Several areas of the West reported below normal autumn precipitation including northern California, eastern Utah, and western Colorado. Montana, northern Wyoming, northwestern Utah, and the Southwest reported above normal precipitation.
Current Drought Conditions
The 2020 water year (Oct. 2019 - Sept. 2020) started dry in California-Nevada and led to the presence of dry or drought conditions across the region, first in southern Nevada followed by expansion of abnormally dry conditions across both states, according to the U.S. Drought Monitor. Recent precipitation has removed abnormally dry conditions (D0) in parts of southern California and moderate drought (D1) in southern Nevada. As of Dec. 5, 2019, ~82% of the region is in D0 or D1 conditions.
Current Drought Conditions
Over the course of the 2019 Water Year (Oct. 2018 - Sept. 2019), California-Nevada became drought free as the region received above normal precipitation. On Oct. 2, 2018, nearly 50% of California (including extreme drought (D3) in southeastern California) and Nevada was in drought, according to the U.S. Drought Monitor. Conditions worsened slightly in fall 2018, but by the end of March, both states were free of drought. As of Oct. 8, 2019, ~3% of the region is in moderate drought (D1) (Fig. 1) due to dryness in the southwest over the summer.
Quarterly Climate Impacts and Outlook for the Western Region for June – August 2019. Dated September 2019.
Quarterly Climate Impacts and Outlook for the Western Region for March – May 2019. Dated June 2019.
Spring temperatures were variable across the West. The North Pacific storm track remained active through the spring season bringing above normal precipitation to much of the West.
Current Drought Conditions
As California and Nevada move into summer, the region remains drought free as wet conditions continued through the spring. As of June 4 according to the U.S. Drought Monitor, 4.32% of California remains abnormally dry (D0) due to long term drought while Nevada is drought and dryness free.