April in the West
Although April in the West was generally cool and wet no record-setting events occurred.
Temperatures were generally on the cool side throughout the west with central California 4-5 deg F (2-3 deg C) below normal. Locations east of the Rockies and in the southern Intermountain region were a bit above normal.
Precipitation was well above normal in most of California and below normal in the Southwest. The Northwest and Intermountain regions had scattered regions of above and below normal precipitation.
Mountain snowpack on May 1st was mostly below normal except for the Sierra Nevada of California and higher elevations of the Southwest. Snowpack in the Central Sierra rose from 90% of normal on April 1st to just over 120% of normal by May 1st (barely losing any snow water equivalent) thanks to cool and wet conditions in April.
Significant Events for April 2010
April 27-30: Late Season Winter Storm: A powerful late season winter storm hit California and Nevada with strong winds, heavy rain and heavy mountain snow from the 27th to the 29th. Winds gusted to over 90 mph in western Nevada and eastern California valleys causing numerous trucks to overturn on U.S. 395. Winds in the Reno area hit 95 mph causing lots of local damage and power outages to over 5000 customers and causing 16 flights at Reno Airport to be diverted, cancelled or delayed. Winds in the Sierra crested at 130 mph with heavy snow. Donner Summit measured 25 inches (63.5 cm) of snow throughout the event. Some locations in northwest California received over 6 inches (152 mm) of rain, very unusual for so late in the season. In Montana, up to 4 feet of snow fell in the Mission Mountains and Little Belt Range on the 29th and 30th. Numerous power outages occurred statewide with the combination of heavy snow and strong winds of up to 60 mph. At several locations, new record low barometric pressures for April were recorded.
April 2010 Departure from Normal Temperature and Percent of Normal Precipitation for Western United States