February in the West
February was the 3rd consecutive month of widespread above normal temperatures in the West, and the 15th consecutive month for the state of California. Record February temperatures were observed in the Sierra Nevada, Great Basin, and Central Rockies. Precipitation varied widely, having no recognizable pattern across the West, with record February totals in areas of the central and southern Rockies and drier than normal conditions in central and southern California as well as large areas of the Great Basin.
Strong and persistent high pressure anchored over the West this month resulted in a large number or record temperatures. Some of the greatest departures from normal were observed in the northeastern Great Basin and Central Rockies. Idaho Falls, Idaho, with records from 1948, logged its warmest February on record at 36.9 F (2.7 C), 12.9 F (7.2 C) above normal. Salt Lake City, Utah also recorded its warmest February in an 88-year record, averaging 43.9 F (6.5 C), 9.7 F (5.4 C) above normal. Elsewhere in the Great Basin, Elko, Nevada had its warmest February in a 126-year record with an average 40.1 F (4.5 C), 10.2 F (5.6 C) above normal. Bishop, California also set a record for warmest February at 50.3 F (10.2 C); records there began in 1895. Other western locations also experienced a record warm February. In eastern Oregon, Ontario recorded its warmest February in a 71-year record at 43.3 F (6.3 C), 10 F (5.5 C) above normal. Bakersfield, California, set a record for warmest February with an average of 58.9 F (14.9 C); records there date from 1937. Las Vegas, Nevada also set a record for warmest average February temperature in its 68-year record at 60.0 F (15.6 C), 7.1 F (3.9 C) above normal.
Following a warm and dry start to the month, the second half of February brought cold and snowy conditions to the central and southern Rockies. Riverton, Wyoming observed its wettest February on record with a total 1.28 in (33 mm) precipitation, 388% of normal. This February was also the second snowiest at Riverton with 17.8 in (45 cm) of snowfall. Records for Riverton began in 1907. Further south, Boulder, Colorado experienced its wettest and snowiest February in a 123-year record. Boulder received 3.69 in (94 mm) of precipitation, 450% of normal and 54.8 in (140 cm) of snow, 22.7 in (58 cm) greater than the previous record set in 2012. Continuing south, Pueblo, Colorado also saw a wet and snowy February. Precipitation totaled 1.13 in (29 mm), the second wettest in a record that began in 1954. Snowfall totaled 23.5 in (60 cm), shattering the previous February record of 14.4 in (37 cm) set in 1965. A series of storms in early February brought beneficial precipitation to northern California and areas of the Pacific Northwest, helping to improve drought conditions in these areas. At the end of the month, severe to exceptional drought persisted in 67% of California, 48% of Nevada, and 34% of Oregon. At month’s end, snowpack remained meager in the Cascades, with many locations < 25% of normal snow water equivalent (SWE). The Sierra Nevada fared slightly better thanks to a cold storm at the end of the month and had SWE values 20-40% of normal. Throughout the Rockies, basin average SWE values ranged from roughly 80-110% of normal.
Warm conditions were observed across Western and Southcentral Alaska as well as the North Slope. In western Alaska, Kotzebue noted an average temperature of 10.2 F (-12.1 C) for the month, 11.1 F (6.2 C) above average and the 3rd warmest February since records began in 1897. Precipitation was highly variable across the state, though generally below normal in the Southcentral and Southeast regions and parts of the Interior. For the snow season to-date (since July 1), Anchorage has only received 20.5 in (52 cm), making this season the 2nd least snowy on record so far. Normal snowfall at Anchorage by the end of February is 60.3 in (153 cm). The famed Iditarod sled race was altered to accommodate the warmth and dryness. Further south, drier than normal conditions prevailed for much of Hawaii. Hilo and Honolulu recorded 55% and 43% of normal, respectively. Lihue, Kauai recorded its 5th driest February on record at 0.75 in (19 mm). At month’s end, 50% of the state was experiencing moderate drought.
Significant Events for February 2015
February 6-8: Storms impact northern California: A series of two storms brought 1-3 in (25-76 mm) precipitation to the San Francisco Bay Area, 4-8 in (102-203 mm) to northern California, and 5-10 in (127-254 mm) to the Sierra foothills and crest. These storms had generally high snow levels; roughly 10-15 in (25-38 cm) of snow accumulated above 8000 ft (2400 m) with mostly rain below. Strong winds knocked out power to more than 60,000 people in the Bay Area and 5,000 in western Nevada. The storms resulted in cancellation of roughly 250 flights out of SFO. Downed trees, localized flooding, and vehicle accidents associated with the storm were reported in northern California and western Nevada.
February 6: Round Fire near Bishop, California: The Round Fire began during a period of 50-75 mph (80-120 kph) winds event and rapidly burned 7,000 acres (2,800 hectares. The fire destroyed 40 residences and damaged 5 others in the communities of Swall Meadows and Paradise.
February 6-7: Mudslide, flooding in Brinnon, Washington: Following heavy rains, flooding occurred along the Duckabush River, inundating a number of homes. A mudslide also occurred partially closing two roads in the area. Three people were rescued after their truck was swept away by the river.