Ice Storm and Heavy Snow in California, December 20 to 21, 1998

In conjunction with the freeze event affecting area agriculture, the combination of moisture and unusally cold air led to the development of black ice on Central San Joaquin Valley roadways. Two fatalities occurred during the evening hours of the 20th in the city of Fresno due to black ice on roadways. In addition over 200 accidents were reported in the Fresno/Madera County area. Some additional vehicular accidents were also reported in Merced and Mariposa Counties due to black ice, including stretches of Highways 59, 99, and 152 on the San Joaquin Valley floor. Snow fell on the San Joaquin Valley floor very early in the morning of the 20th although only recorded as a trace at NWS observing sites beginning around 0700 PST. From the late morning hours until 17:30 PST on the 20th, 8 inches to a foot of new snow fell in the Sierra Nevada Foothill town of Mariposa at approximately the 3000-foot elevation. Over 6,000 local power utility customers went without power the night of the 20th due to the snowfall.