The U.S. Drought Monitor released March 24 says, from a water supply perspective, there is nearly normal snowpack to melt off and northern Sierra reservoirs are filling. But long-term to extreme drought is still "entrenched" across much of central and southern California.
The weekly update says the heavy precipitation the first two weekends of March and March 20-22, brought "incremental drought relief" in northern California, with some reduction in abnormal dryness and moderate to extreme drought.
The Drought Monitor drought intensity levels are abnormally dry, moderate, severe, extreme and exceptional drought.
In California, there were slight reductions in the percentage of the state in moderate (91 percent) and severe drought (72 percent), but extreme (55 percent) and exceptional drought (34 percent) remained the same from the previous week.
"Higher elevations have received substantial snow; the average water content of the high-elevation Sierra Nevada snowpack has increased to 25 inches, up from 20 inches from the beginning of March," according to the report. "The 25-inch snow-water equivalency translates to 90 percent of the historical average as the traditional peak snowpack date of April 1 approaches. Snowpack is roughly average in the northern Sierra Nevada, but only about three-quarters of average in the southern Sierra. This is consistent with the winter 2015-16 storm track that has been more active across northern California and the northwestern U.S."
While northern California has gotten the benefit of March rain and snow, other parts of the state are still high and dry, "with long-term severe to extreme drought still entrenched across much of central and southern California, as reflected by less frequent storms during the 2015-16 wet season; still-low reservoir levels; less robust mountain snowpack; and continuing groundwater shortages."
In terms of water supply, the report says "the favorable news is that there is a nearly normal snowpack to melt off, in addition to the fact that the state’s reservoirs had already received nearly 6.5 million acre-feet of inflow by February 29. (This figure does not include any March inflow, which has been substantial in northern California.)