A series of storms that pummeled the US West recently brought a much-needed boost to local reservoirs, but federal meteorologists warned on Tuesday that long-term drought still plagues the region.
Nine storm systems known as “atmospheric rivers” began battering California and other Western areas with significant precipitation over a three-week period starting in late December, according to an update from the National Integrated Drought Information System (NIDIS).
During these storms, 80 percent of the full seasonal snowpack was deposited in California, the report found. Statewide, the precipitation accumulated over those three weeks amounted to 11.2 inches, or 46 percent of a full year.
The atmospheric rivers vastly improved mountain snowpack across many parts of the West, where snow totals are now well above normal for this time of year, according to NIDIS, a multiagency partnership housed at the National Oceanic and Atmospheric Administration in Colorado.
Exceptions to this include many areas of the Cascades and the Northern Rockies, where accumulation has lagged since the beginning of January, according to the report.
Because it is still early in the snow accumulation season, water totals could end up being moderate if the rest of the winter is dry or relatively high if this influx of precipitation continues, meteorologists explained.
The three-week string of storms improved drought conditions by boosting soil moisture through the West, particularly in California, according to the report.
And although the amount of water in many reservoirs increased, some are still below historical averages for this time of year, NIDIS warned.
Meanwhile, long-term drought persists in parts of the West as reservoir storage shortfalls, such as those in the Colorado River system, and groundwater deficits — particularly in the Northwest — have built up over time, the report observed.
Despite California’s onslaught of rain and snow, 92 percent of the state is still experiencing some level of drought, as is 100 percent of Nevada and 96 percent of Utah.
NIDIS ranks drought levels on a scale from D0 through D4 — beginning with abnormally dry and then ranging from moderate to severe to extreme to exceptional drought.
Pockets of extreme and exceptional drought conditions continue to impact areas of Utah, Nevada, and central and eastern Oregon, according to the update.
While current forecasts indicate that atmospheric river activity could begin again in early February, NIDIS stressed that “storm tracks are still uncertain.”