April in the West
Conditions were variable across the West this month, fairly typical of the spring season. Temperatures were within a few degrees of normal across a majority of the West, though well above normal in California. Precipitation was characterized by pockets of both above and below normal precipitation scattered throughout the region. Although a majority of this month’s storm systems favored the Pacific Northwest, some moisture made its way to parts of drought-stricken California and the Southwest, providing temporary irrigation support amid persistent drought.
Periods of strong high pressure over California brought warmer than normal temperatures to the state and adjacent areas. In southern California, temperatures in San Diego averaged to 65.2 F (18.4 C) for the second warmest April in a 76-year record. Further north, Santa Maria recorded an average 60.3 F (15.7 C) for the month, 4.7 F (2.6 C) above normal, tied for warmest April since records began in 1948. In northern California, Ukiah recorded its second warmest April at an average 59.2 F (15.1 C), just behind the record 59.6 F (15.3 C) set in 2013. Records in Ukiah began in 1949. For the year-to-date, 2014 has been the warmest on record at San Diego (63 F/17.2 C), Santa Maria (59.2 F / 15.1 C), and Ukiah (54 F/12.2 C) as well as many other California locations. In Oregon, Medford also had a warm April at 56.2 F (13.4 C), the 9th warmest since records began in 1911. Reno, Nevada, logged its 4th warmest April on record at 54.3 F (12.4 C), 3.4 F (1.9 C) above normal. The average since January for Reno was 46.6 F (8.1 C), the warmest such period in the past 78 years. In the Desert Southwest, Phoenix, Arizona, reported an average 74.8 F (23.8 C) for the month, the 11th warmest April in an 82 year record. Phoenix also saw its warmest start to the year with an average 67.0 F (19.4 C) over the last 4 months. Outside the Southwest, temperatures were generally within 2 F (1 C) of normal for April.
Wet weather continued this month for the Pacific Northwest. In spite of the drought conditions developing in eastern Washington, Seattle has had its 4th wettest start to the calendar year at 23.43 in (595 mm), including 4.18 in (106 mm) this month, 154% of normal. Records for Seattle began in 1948. Elsewhere in the Northwest, Boise, Idaho, measured 2.15 in (55 mm) precipitation this month for the 6th wettest April in the past 75 years. Select locations in Colorado received above normal precipitation as well. Pueblo accumulated 2.06 in (52 mm), 147% of normal and the 9th wettest April in the past 61 years. In California, Sacramento received a beneficial 1.97 in (50 mm) of rain, 152% of normal. At the end of April, snow pack remained near to above normal in a broad swath from Washington southeast to Colorado. To the south and west, despite some reinforcement with this month’s storms, an already meager snowpack continued to deteriorate with the help of above normal temperatures.
Most of this month’s drier than normal areas were in the Southwest. Albuquerque, New Mexico, recorded only 0.01 in (<1 mm) this month, making it the 15th driest April since records began in 1897. For the second month in a row, Las Vegas received no precipitation. Las Vegas has only seen precipitation on one day (February 28, 0.3 in/8 mm) since the start of the year, 16% of the normal 1.89 in (48 mm) for that period and only the 13th driest in a 67-year record. Coastal areas of southern California also saw below normal rainfall; Los Angeles recorded 0.35 in (9 mm), 38% of normal. In northern California, Arcata received 1.84 in (47 mm) of rain this month. This was 42% of normal, making this the 3rd driest April since records began for Arcata in 1945. Across the border in Oregon, light showers throughout the month in Klamath Falls accumulated to only 0.2 in (5 mm), 15% of normal and tie for the 5th driest April in a 67-year record.
Outside the continental US, average temperatures were above normal in western Alaska. Nome saw an April average of 28.4 F (-2 C), the 4th warmest since continuous records began in 1907. This was the 7th consecutive month of above normal average temperatures in Nome. Many locations in Interior and South Central Alaska were drier than normal this month. Anchorage recorded only 0.04 in (1 mm) precipitation, 9% of normal and the 5th driest April in the past 63 years. Further south, drought conditions improved for windward areas of Hawaii while leeward locations were drier than normal. On the windward side of the Big Island, Hilo received 13.37 in (340 mm) of rain, 116% of normal. This month saw the first time since June 2008 that the entire state of Hawaii has been free of D2 (severe drought) designation. In contrast, Lihue, Kauai, received 0.65 in (17 mm), 29% of normal and the 3rd driest April since records began in 1950.
Significant Events for March 2014
April (all month): Drought conditions continue in Southwest: April saw further expansion of drought conditions in California, the Great Basin, Arizona and New Mexico. This is the first time in the 15-year history of the US Drought Monitor that the entire state of California has been designated as D2-D4 (moderate to exceptional drought). Several municipalities in the West are in danger of running out of water in the near future, such as Montecito, in Southern California; Montague, in Northern California; and Monticello, Utah in the Four Corners area. April 29-30: Late season Santa Ana winds, fire in Southern California: Santa Ana winds typically occur October-March, though may be observed any time of year. High winds, high temperatures, and low humidity associated with Santa Ana wind conditions helped a wildfire east of Los Angeles spread rapidly. The Etiwanda fire has burned roughly 1,000 acres (405 hectares) and threatens 1,600 homes. The Santa Ana conditions brought record daily high temperatures to coastal California.