Western Regional Climate Center


February in the West

February 2017

February was a wetter than normal month for much of the West, rounding out an anomalously wet meteorological winter for the region. Temperatures were above normal across most of the region, with some of the greatest anomalies within and east of the Rockies. Only Washington, northern Idaho, and northwestern Montana saw well below normal temperatures. The Northwest observed abundant precipitation this month, with many locations attaining record monthly totals. In eastern Washington, Spokane recorded 4.39 in (112 mm) precipitation, 330% of normal and it’s second wettest February in a 137-year record. In the Idaho Panhandle, Bonners Ferry saw a record wet February at 7.06 in (179 mm), 455% of normal. Records for Bonners Ferry began in 1907. In southeastern Idaho, February precipitation in Pocatello totaled 3.10 in (79 mm), 320% of normal and the wettest in a 79-year record. Storms continued to batter central and northern California this month, with the greatest anomalies observed in a wide swath paralleling the Interstate-80 corridor. Many long-record stations in this area saw February precipitation totals among the top-20 on record. North of San Francisco, Venado had its wettest February on record at 37.45 in (951 mm), breaking the previous record of 19.24 in (489 mm) set in 2000. Portola, in the northern Sierra Nevada, observed its wettest February on record at 12.36 in (314 mm), 319% of normal and experienced major flooding. Records for Portola began in 1915. Elsewhere in the Sierra, Tahoe City observed its second wettest February in a 115-year record at 16.66 in (423 mm), 293% of normal. Several other scattered locations in the West observed above normal precipitation as well. Castle Hot Springs, Arizona, recorded 5.20 in (132 mm), 251% of normal, the 8th wettest since records began in 1916. In eastern Nevada, Ely logged 1.73 in (44 mm), 231% of normal and the 7th wettest in a 130-year record. February ended with a healthy snowpack across the West. For areas south of Washington and Montana, snowpack was well above normal. The Sierra Nevada saw end of February SWE values of 150-200+% of normal, and the southern Cascades were in the 125-140% of normal range. The central and southern Rockies boasted end of February SWE values in the 150-200% of normal range. Snowpack in the northern Cascades and northern Rockies trailed values seen in other regions, with many basins just shy of or slightly over normal for the end of February. Precipitation across California this month furthered drought amelioration in the central and southern parts of the state. At the end of the month, only 9% of the state had any drought designation, compared to 51% at the start of the month. Portions of Nevada, eastern Oregon, western Utah and small areas of Montana and western Arizona also saw abnormally dry conditions disintegrate this month. A few locations, mainly east of the Rockies, developed abnormally dry conditions during February. High pressure over the inland West during the first two-thirds of the month produced well above normal temperatures. Elko, Nevada, reported a February average temperature of 36.3 F (2.4 C), 6.4 F (3.5 C) above normal. In central Idaho, Stanley observed an average temperature of 22.9 F (-5 C), 7.1 F (4 C) above normal and the 6th warmest in a 102-year record. In the Southwest, Clayton, New Mexico, had its warmest February with complete data since records began in 1896. Temperatures averaged to 45.6 F (7.5 C), 8.1 F (4.5 C) above normal. Temperatures were well above normal in Colorado; Grand Junction observed an average temperature of 41.7 F (5.4 C), 7.2 F (4 C) above normal, the 4th warmest February since records began in 1900. In the southeastern portion of the state, La Junta had its second warmest February since records began in 1945 at 44.2 F (6.8 C), 9.7 F (5.4 C) above normal. In contrast, eastern Washington observed well below normal temperatures with several locations experiencing one of their bottom-10 coldest Februaries. Moses Lake reported an average temperature of 26.7 F (-2.9 C), 8.6 F (4.8 C) below normal and the second coldest February since records began in 1949. Several windward locations in the southeastern Hawaiian Islands observed below normal precipitation this month. Kaneohe, Oahu, and Hilo, Big Island, reported 0% and 64% of normal, respectively. In contrast, Honolulu, Oahu, observed 7.12 in (181 mm) for the month, 358% of normal and the 4th wettest February in a 78-year record. Further north, temperatures were near normal across much of Alaska, with the exception of areas north of the Brooks Range. Utqiaġvik recorded an average temperature of -6.2 F (-21.2 C), 8 F (4.4 C) above normal and the 7th highest since records began in 1901. Some areas in the western part of the state saw below normal temperatures; Bethel observed an average temperature 4.3 F (-15.4 C), 6.8 F (3.8 C) below normal. Precipitation was near to above normal across much of the state, with the greatest departures from normal in the interior and northern portions of the state. Fairbanks logged 1.24 in (31 mm), 295% of normal and the 7th wettest February since records began in 1929.

Significant Events for February 2017

February (all month): Winter storms cause flooding, slope failures in California: Persistent rain on saturated soils led to slope failures that resulted in temporary or permanent closure of many major routes throughout the state. Interstate 80 was at one point closed on both sides of the Sierra Nevada due to debris flows. In Southern California, Interstate 15 near Cajon Pass suffered a lane collapse. The Pfeiffer Canyon Bridge on Highway 1 in Big Sur is collapsing due to landslides. Flooding along a creek in San Jose resulted in mandatory evacuation of 14,000 people and major flood damage.
February (first half of month): Flooding in northern Nevada: Storms with high snow levels produced rain on existing snow, resulting in melting and widespread flooding. Along the Humboldt River, flooding damaged homes and roadways, and the failure of an earthen dam near Wells also caused significant flooding for rural areas.

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