Western Regional Climate Center


November in the West

Several strong, deep troughs passed through the West this month, bringing cold Arctic air and slightly below to well below normal temperatures to areas west of the Rockies. The associated storm systems, however, generally resulted in precipitation values that were below normal. In part, the trajectories of these storms leave many of them with insufficient moisture to produce typical November precipitation.

November’s cool temperatures west of the Rockies were punctuated with warm days in the latter half of the month due to strong ridging. Many locations saw 2-3 days with temperature departures from normal greater than +10 F (5.5 C) around the Thanksgiving holiday. Tonopah, located in southwest Nevada, recorded a monthly average temperature of 36.8 F (2.67 C), tied for 9th coolest average temperature on record. Olympia, Washington was also cooler than normal with a month average of 40.5 F (4.72 C). This is the 12th coldest November on record there, and -2.8 F (1.5 C) below its November normal.

East of the Rockies, temperatures were near to slightly above normal. Colorado Springs, Colorado experienced a warm November at an average temperature of 40.6 F (4.8 C). This is +4.4 F (2.4 C) above normal and the 17th warmest November on a record beginning in 1948.

Dry conditions dominated in the West this month. The Reno, Nevada airport tied its 7th driest November in a record beginning in 1937 with a precipitation total of 0.06 in (1.52 mm). In central Oregon, the Redmond airport station also recorded its 7th driest year on record, with 0.21 in (5.3 mm). Many eastern Oregon and Washington locations received only 50-75% of their normal precipitation amounts. Albuquerque, New Mexico had its 29th driest year on record, receiving 0.13 in (3.3 mm).

Pockets of above-normal precipitation appear in the usually dry Southwest due to cutoff low systems that passed through the area this month. The much-needed precipitation from these systems helped to reduce the severity of the drought in western Arizona, though severe drought persists in New Mexico. San Diego Airport (Lindbergh Field), California experienced its 5th wettest November since 1914. This station received 3.12 in (79.2 mm), well above the station mean of 1.78 in (45.2 mm). Yuma, Arizona received 0.42 in (10.7 mm), tying as the 20th wettest year in a record beginning in 1948. The airport at Rock Springs, Wyoming experienced its 4th wettest November with a total of 1.46 in (37 mm), well above the station mean of 0.52 in (13.2 mm) in a record beginning in 1948. Wyoming also experienced pockets of above normal precipitation.

Significant Events for November 2011

November 8-10: Bering Sea Super Storm: An intense storm developed southeast of Japan on November 7th, and strengthened as it moved across the northern Pacific towards the Bering Sea and western Alaska. The storm’s center dropped close to 50 millibars (1.48 inches of mercury) in 24 hours, reaching a minimum pressure of 944 millibars (27.88 inches) at its center. Waves to 35 ft (10.7 m) and 100 mph (161 kph) winds were recorded offshore as the storm approached. Hurricane force winds and blizzard conditions affected coastal Alaska. Storm surges of up to 10 ft (3 m) affected communities along Alaska’s west coast causing flooding, some structural damage and property loss. Winds of up to 93 mph (150 kph) were recorded at some locations, and many locations along the coast reported minor wind damage and downed power lines. Many locations were without power following the storm, and a subsequent smaller storm complicated rescue efforts. An ice zone connected to land had not yet developed to reduce the impact of large waves striking the coast.

November 12-13: Colorado Blizzard: A trough moved into Colorado and southern Wyoming Saturday bringing strong winds and heavy precipitation to the Rockies area. Gusts at Berthoud Pass reached 113 mph/182 kph and at Pike’s Peak 109 mph/ 175 kph. Other locations reported gusts in the 80-90 mph (129-145 kph) range. Mountain storm snowfall totals ranged from 14-25 in (36-63 cm). Many road closures were in effect due to the hazardous conditions. Some locations experienced power outages, and strong winds caused small wildfires in the Foothills.

November 18: Caughlin Fire in Reno, Nevada: The Caughlin Fire ignited at approximately 12:45 am PST due to arcing power lines and spread rapidly in southwest Reno due to a strong wind event featuring gusts of 45-74 mph (72-119 kph). The low relative humidity and high speed of these winds allowed the fire to spread quickly. The fire destroyed 32 homes, burned over 2000 acres, and voluntary evacuations were posted for 10,000 people.

November 21-24: Pacific Northwest Severe Storm: A winter storm in the Pacific Northwest complicated travel leading into the Thanksgiving holiday. Wind gusts up to 97 mph (156 kph) were recorded along the Oregon coast, and gusts up to 85 mph (136 kph) in passes and canyons. More than 10,000 people were without power at some point during the storm and one fatality was reported in Washington due to a falling tree. Many road closures were reported due to downed trees. Heavy rainfall caused flooding in western Oregon and Washington, and 1-2 ft (30-60 cm) of snow was recorded in the Cascades, northern Rockies, and northern Sierra Nevada.

November 2011 Departure from Normal Temperature and Percent of Normal Precipitation for Western United States

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