Northern California could return to drought by early summer. Nearly 16 percent of the state is already “abnormally dry.” Even though rainfall was close to normal, a warm winter shrank the mountain snowpack to its lowest in more than ten years. According to the California Department of Water Resources, this week, the northern Sierra Nevada has only 18 percent of its usual snowpack. California’s reservoirs are near capacity, but mountain snow is melting quickly which leaves little for continued runoff through the spring. Northern California may cool briefly, but another heat wave could hit by late March. No major rain is expected until April.