Summer Precipitation in the West
With a few exceptions, many areas in the Rockies and High Plains have had a drier than normal summer season.
The annual summer thunderstorm pattern, mostly driven by the monsoonal moisture flow from the south was spotty. As you can see in the map below precipitation since late May through late August has been below normal in many areas (brown shading). The red shading highlights the driest areas. Many areas of Wyoming, Montana, Idaho, Utah and Nevada as well as portions of Colorado and New Mexico had a drier than normal summer season.
A few pockets of above normal precipitation were noted in portions of Arizona, eastern and northeastern Montana and portions of Kansas and the Dakotas. Dry conditions were also noted in the Pacific Northwest and California.
Heavier precipitation from this year’s monsoon season in the west was more focused in the eastern and southern areas of the west.
Some of the dryness is reflected by the reservoir storage figures taken in early August.
Only Colorado, Montana and Wyoming have reservoir storage at above levels. With the fall and winter season approaching it looks like Montana, Wyoming and Colorado will head into the next snowpack season with adequate reservoir storage.
Unfortunately, poor reservoir storage continues in California, Arizona, Nevada, New Mexico and Washington.