October in the West
Temperatures were above normal throughout the west except for portions of California and Oregon. Parts of Montana and Wyoming had a very warm month. In Cut Bank, MT, and Sheridan, WY, it was the warmest October since 1965 and in Great Falls, MT, it was the warmest since 1974. Generally speaking, it was the average minimum temperatures throughout the west that were above normal leading to far fewer days below freezing that typical Octobers.
Rainfall was well above normal for most of the Great Basin, southern California, southern Utah and northern Arizona. The Pacific Northwest was above normal while much of the Rockies were below normal. Reno, NV, recorded their wettest October on record while Winnemucca, NV, recorded their 2nd wettest in 100 years. San Diego measured their 4th wettest October in 96 years while Santa Barbara their 3rd wettest in 70 years. Oddly enough, the 3 wettest Octobers on record in Santa Barbara have all occurred in the past 7 years.
Significant Events for October 2010
October 3-7: Heavy Rain in Parts of Southwest: A cutoff low that stalled over the Great Basin brought locally heavy rain and severe weather to Nevada, Utah, Arizona and southern California. Up to 5 inches (127 mm) of rain fell in during the 5 day period in portions of south central Utah while location in Nevada picked up over 2 inches (51 mm) of rain. Severe thunderstorms in Bellemont, AZ, near Flagstaff, spawned tornados that damaged or destroyed 14 homes on the 6th. Twenty-one railcars were thrown off the tracks and numerous trucks overturned on the highways.
October 18-21: More Rain in Southwest: Another cutoff low formed over southern Nevada bringing more rain, hail and strong thunderstorms to the Southwest. An EF0 tornado touched down near Kingman, AZ, on the 18th damaging w homes. Heavy hail near Williams, AZ, caused 9 crashes on I-40 injuring 6 people. This event brought nearly 4 inches (102 mm) of rain to parts of southern California causing local flooding and mudslides.
October 23-24: Powerful storm along Pacific Coast: This storm hit northern California and the Sierra Nevada with strong winds of over 130 mph along the mountain crests and heavy rain. One automated weather station in the Sierra measured 11.38 inches (289 mm) of rain in 60 hours with 8.33 inches (212 mm) falling on the 24th.
October 2010 Departure from Normal Temperature and Percent of Normal Precipitation for Western United States