NATIONAL WEATHER SUMMARY

DECEMBER 2014

1-6…Warm and mostly dry weather was reported in the southern Atlantic States and the Deep South. Cold conditions lingered across the nation’s northern tier, especially from Washington to Wisconsin. Weekly temperatures averaged at least 10F below normal at several locations along the Canadian border. Farther south, however, near to above normal temperatures dominated the southern two-thirds of the U.S. In particular, weekly temperatures locally averaged at least 10F above normal from California to the Intermountain West and in parts of the Southeast. Early in the week, warmth prevailed across the South, while frigid conditions lingered across the North. December opened with daily record lows in locations such as Jamestown, ND (-24F); Bozeman, MT (-23F); and

Marquette, MI (-11F). Cold conditions also returned to the Northwest, where record setting lows for December 2 dipped to 19F in Olympia, WA, and 23F in Portland, OR. Farther south, however, numerous daily record highs accompanied and trailed a warm Pacific storm. By December 4, daily record highs included 69F in Sacramento, CA, and 59F in Salt Lake City, UT. Both locations also posted daily records (68 and 58F, respectively) on December 6. Other record setting highs in California for December 6 included 70F in Fresno and 67°F in San Francisco (SFO Airport). Farther north, Quillayute, WA, collected a daily record high (57F) on December 5, shortly after notching consecutive daily record lows (19 and 25F, respectively) on December 1-2. Elsewhere, warmth in the Southeast led to a handful of daily record highs, including readings of 75F (on December 1) in Danville, VA, and 81F (on December 3) in Tallahassee, FL.

 

7-13: Mostly dry weather covered the central and southeastern U.S. across the Plains; in particular, unusually mild weather accompanied the dry conditions. In fact, weekly temperatures averaged at least 10F above normal across a broad area stretching from the Northwest to the upper Midwest, and southward through the High Plains. Cool weather was especially prominent in Florida, where temperatures averaged as much as 10F below normal. Multiple freezes were noted primarily from December 11-13—as far south as northern Florida.  For much of the week, record setting warmth dominated the Pacific Northwest. From December 7-11, Hoquiam, WA, posted five consecutive daily-record highs (56, 56, 59, 60, and 60F). Elsewhere in Washington, Seattle noted four daily record highs during the week, including a reading of 66F on December 10. During the mid to late week period, warmth expanded to other areas of the West. Walla Walla, WA, collected consecutive daily-record highs (71 and 68F, respectively) on December 10-11. Record breaking highs for December 11 climbed to 64F in Pendleton, OR; 64F in Winnemucca, NV; and 63F in Boise, ID. By December 12, daily record highs included 64F in Cheyenne, WY, and 63F in Salt Lake City, UT. Toward week’s end, warmth also reached the Plains. In South Dakota, Rapid City logged consecutive daily-record highs of 71F on December 11-12. Other daily record highs for December 12 soared to 72F in Chadron, NE, and 63F in Great Falls, MT. Elsewhere in Montana, Livingston (64F on December 12) achieved a monthly record high, previously established with maxima of 62F on December 26, 1980, and December 1, 1995. In Wyoming, Casper set a December record with highs of 50F or greater on 11 consecutive days (December 3-13); the previous record of 10 days was set in 1939. Farther east, Dickinson, ND, closed the week with consecutive daily record highs (61 and 60F, respectively) on December 12-13. In Nebraska, monthly records were set on the 13 for the highest minimum temperature in locations such as Grand Island (low of 47F) and Norfolk (46°F).

 

14-20: Dry weather lingered through week’s end in the southern Atlantic region. In contrast, mild, damp covered Wisconsin and elsewhere in the Great Lakes States. Warmth continued to dominate most of the U.S., with weekly temperatures averaging at least 10F above normal in the upper Mississippi Valley. For the most part, unusually cool conditions were limited to Florida’s peninsula, where readings averaged as much as 5F below normal. Warmth lingered early in the week across the nation’s midsection, where Omaha, NE, posted a daily record high (59F on December 14). Omaha also tied a monthly record with a December 14 low temperature of 52F (previously, 52F on December 22, 1877). Elsewhere on the 14th, monthly high minimum temperature records were also set or tied in locations such as Lincoln, NE (53F), and St. Cloud, MN (42F). Later, however, Valentine, NE, netted a daily-record snowfall (3.5 inches) on December 15, shortly after noting seven consecutive highs (from December 7-13) of 50F or greater. Farther west, mid to late week highs surged to daily record levels in locations such as Bellingham, WA (56F on December 18) and Portland, OR (59F on December 20.

 

21-27: Lingering showers dotted northern and central California, but mostly dry weather prevailed in southern California and the Desert Southwest. Farther east, several disturbances crossing the Plains provided beneficial snow in advance of the strongest push of cold air in nearly a month. Late week snow was also reported as far south as Oklahoma and northern Texas, while generally light freezes were noted in California’s Central Valley. Meanwhile, unusual warmth lingered across the eastern half of the U.S., boosting weekly temperatures 10 to 20F above normal in the upper Midwest. In fact, near to near to above normal temperatures dominated the country for the third week in a row. Warmth lingered early in the week across the West, but was gradually replaced by colder conditions. Consecutive daily record highs were reported on December 21-22 in locations such as Yakima, WA (59 and 56F), Montague, CA (60 and 58F); and Klamath Falls, OR (53°F on both days). Other Western daily record highs included 81F (on December 22) in Santa Barbara, CA; 75F (on December 22) in Las Vegas, NV; and 65F (on December 21) in Medford, OR. In advance of colder weather, a wind gust to 92 mph was reported on southern California’s Whitaker Peak on December 21. Whitaker Peak clocked another high gust, to 84 mph, on the morning of December 25. During the mid- to late-week period, notable warmth shifted into the East. By December 24, daily-record highs climbed to 87F in Vero Beach, FL; 70F in Salisbury, MD; and 69°F in Georgetown, DE. Warmth lasted into Christmas morning along the northern Atlantic Coast, resulting in consecutive daily record highs (64 and 63 F, respectively) on December 24-25 in Providence, RI. At week’s end, markedly colder air settled into the northwestern and north-central U.S., resulting in a daily-record low (-19F on December 27) in Laramie, WY. In California’s Central Valley, Hanford reported its first two freezes of the season (32 and 30F, respectively) on December 26-27. Widespread precipitation preceded and accompanied the transition to colder weather.

 

28^th-31: Very cold weather returned to the western and central U.S., accompanied by light precipitation. Readings below -10F occurred throughout the northwestern half of the Plains, while sub-zero temperatures were noted northwest of a line from northern New Mexico to southern Wisconsin. Readings below -10F occurred throughout the northwestern half of the Plains, while sub-zero temperatures were noted northwest of a line from northern New Mexico to southern Wisconsin. For much of the week, warmth prevailed in the Southeast. In Georgia, daily record highs for December 28 reached 80F in Alma and Savannah. Daily records were also set in Florida locations such as Orlando (84F on December 29) and Miami (83F on December 30). Elsewhere in Florida, Vero Beach posted daily record highs (85 and 83F, respectively) on December 29 and January 3. Lakeland, FL, also registered a daily record high (84F) for January 3. Farther west, however, Thermal, CA, collected consecutive daily-record lows (25 and 24F, respectively) on December 29-30. On December 29, Las Vegas, NV, reported a low of 30F it was the latest first freeze on record (previously, December 20, 2012). Las Vegas’ longest freeze-free period (December 13, 2013 – December 28, 2014) ended at 381 days; the previous record had been 378 days from December 8, 2011 – December 19, 2012. December 30-31 featured consecutive daily record lows in Big Piney, WY (-31 and -35F), and Pueblo, CO (-16 and - 17F). Fiercely cold weather on the High Plains led to record-setting lows for December 30 in locations such as Alliance, NE (-28F), and Cheyenne, WY (-22F). Elsewhere in Wyoming on December 30,

Laramie logged a daily-record low of -31F, while temperatures plunged to -40F or lower in parts of Sublette County. A low of -48F was reported in Daniel, WY. High pressure accompanying the cold weather led to all-time barometric pressure records on December 30 in Seattle, WA (30.87 inches, or 1045.5 millibars), and Astoria, OR (30.80 inches, or 1042.9 millibars). Astoria’s record had survived since December 14, 1996, when the pressure reached 30.74 inches (1041.0 millibars).

Jim G. Munley, jr.
http://www.jimmunleywx.com