NATIONAL WEATHER SUMMARY

DECEMBER 2013

1st-7th…A strong cold frontal boundary extended from the southern Plains to the central Great Lakes on Thursday, while an arctic air mass continued to impact the West Coast. A cold front stretched from southern Texas to Lake Erie on Thursday, which pushed an active weather system across the central and eastern thirds of the country. Temperatures were 10 to 30 degrees below normal in the southern Plains, the lower Mississippi Valley and across the Appalachians as Ice storm warnings, winter storm warnings, and flood watches were issued. This cold front triggered freezing rain, sleet and snow showers across Texas, Oklahoma, Kansas, Missouri, Arkansas, Illinois and Indiana. Boise City, Okla., reported a midday total of 2.0 inches of snow, while Sherman, Texas, reported a midday total of 0.10 inches of ice accumulation. Meanwhile, rain and thunderstorms impacted a handful of states, as the strongest thunderstorms moved across the Tennessee Valley and the Ohio Valley. Nashville, Tenn., reported a midday total of 1.80 inches of rain, while Cincinnati, Ohio, reported a midday total of 0.98 inches of rain. The northern Plains and upper Midwest avoided precipitation on Thursday, although frigid, blustery conditions lingered over the two regions. Meanwhile, the western third of the country continued to experience very cold temperatures due to an arctic air mass over the area. Hard freezing warnings were issued across the Central Valley of California and into the desert Southwest, while winter storm warnings were issued along higher terrain. The coldest temperatures affected the Intermountain West and the Great Basin on Thursday, as Walden, CO, recorded a morning low of -32 degrees, and Laramie, Wyo., recorded a morning low of -29 degrees with a wind chill factor of -46 degrees.
A mixture of rain, snow, and freezing rain moved across the Eastern states on Friday as a strong cold front continued to make its way eastward throughout the day. The system pulled moisture in from the Gulf of Mexico, while also pulling cool air in from Canada. This allowed for rain and snow to develop from eastern Texas into the Northeast. 2.60 inches of sleet was reported at Macon, Arkansas, while 7.3 inches of snow was reported southwest of Mammoth Spring, Arkansas. The ice storm moved out of eastern Texas early Friday morning, with overnight sleet accumulation up to 3.5 inches at Little Elm, Texas. The northern side of this system brought heavy snow from Missouri through the Ohio River Valley. Snowfall reports ranged from 12 inches at Chester, Illinois to 9 inches at Frederickstown, Missouri. As this front moved through, it pushed cool air into the Southeast. Temperatures ranged from 15 to 25 degrees below normal across the region. Meanwhile, out West, below normal temperatures continued across the Western states as another strong low pressure system moved in from the Pacific Ocean. This system brought rain and snow showers to northern California and Oregon, with snowfall totals across the Cascades ranging from 3 to 5 inches. Snow levels continued to drop as this system brought more cold air in from the north. Snow levels dropped to 1,000 feet across far northern California and into Oregon.

8th-14th…A cold frontal boundary extended from the Southeast to the eastern portion of the Great Lakes on Monday, while an arctic air mass continued to linger over the Intermountain West, the northern Plains and the upper Midwest. A cold front drove showers and thunderstorms across a handful of states in the Southeast and the Mid-Atlantic on Monday as the front interacted with a warm air mass along the Gulf of Mexico. The strongest showers and thunderstorms impacted Alabama, Georgia, South Carolina, North Carolina and Virginia. Franklin, N.C., reported a midday total of 1.92 inches of rain, while Cartersville, GA, reported a midday total of 1.72 inches of rain. Meanwhile, snow fell across parts of New England due to a low pressure system off of the coast of Massachusetts. Millinocket, Maine, reported a midday total of 1.50 inches of snow, while Bridgton, Maine, reported a midday total of 1.30 inches of snow. An arctic air mass continued to funnel southward across the upper Midwest, the northern Plains and the Intermountain West as wind chill advisories were issued across several states. Yellowstone, WY, recorded a morning low of -27 degrees with a wind chill factor of -39, while Driggs, Idaho, recorded a morning low of -27 with a wind chill factor of -43. A ridge of high pressure kept the West Coast clear of precipitation on Monday, while cold temperatures triggered hard freeze warnings across the Central Valley of California and the desert Southwest.

15th-21st…A cold frontal boundary ushered snow showers across the upper Midwest and Great Lakes on Monday, while the remainder of the country experienced relatively calm weather. A cold front extended from Kansas to Virginia on Monday, which brought cold temperatures to the upper Midwest, parts of the Mississippi Valley, the Ohio Valley and across the Great Lakes. Ely, Minn., recorded a morning low of -23 degrees, while Tomahawk, Wis., recorded a morning low of -22 degrees. Winter storm warnings were also issued along the western portion of Michigan as snow showers approached the region. Snowy weather impacted Minnesota, Wisconsin and Illinois on Monday, as Dunn, WI, reported a midday total of 2.20 inches of snow, while Atkins, Minn., reported a midday total of 1.9 inches of snow. A separate cold front stretched across the Northeast on Monday, which ushered light snow showers across parts of Ohio and New York. The remainder of the Eastern Seaboard experienced relatively calm conditions.
The western third of the country stayed clear of precipitation due to a ridge of high pressure along the eastern Pacific. Temperatures across southern California rose into the 70s and 80s, as San Diego, Calif., recorded a mid-day high of 81 degrees, while Santa Monica, Calif., recorded a midday high of 82 degrees.
A cold frontal boundary extended from the southern Plains to New England on Saturday, while a ridge of high pressure kept the Southwest clear of wet weather. Severe thunderstorm warnings, tornado watches and flood warnings were issued across the southern Plains and parts of the lower Mississippi Valley as a maritime tropical air mass interacted with a continental polar air mass. The strongest thunderstorms moved across
eastern Texas, Oklahoma, Louisiana, Mississippi, Arkansas and Tennessee. Corning, Ark., reported a midday total of 4.62 inches of rain, while Walnut Ridge, AR, reported a midday total of 3.79 inches of rain. Behind the frontal boundary, winter storm warnings were issued across the central Mississippi Valley and into the upper Midwest as cold air triggered widespread freezing rain and snow showers. Marion, MO, reported a quarter of an inch of freezing rain on Saturday. Meanwhile, showers, freezing rain and snow also spread across the Ohio Valley, the Great Lakes and the Northeast. Metropolis, Ill., reported a midday total of 3.12 inches of rain. The remainder of the Eastern Seaboard avoided wet weather and experienced above normal temperatures for this time of year. Punta Gorda, Fla., recorded a midday high of 87 degrees, while Waycross, Ga., recorded a midday high of 86 degrees. Light snow showers also fell in the upper portion of the Intermountain West on Saturday due to a cold frontal boundary over the region. Showers also began to push onshore along western Washington as a shortwave of energy approached the region. The Southwest avoided wet weather due to a high pressure system over the eastern Pacific.

22nd-28th…A cold frontal boundary extended from the northern Plains to the upper Midwest on Wednesday, while a frontal boundary lingered along the southern coast of Florida. The northern portion of the country experience very cold, blustery conditions on Wednesday. Alpena, Mich., recorded a morning low of -16 degrees, while Mt. Washington, N.H., recorded a morning low of -20 degrees. A low pressure system moved over the western portion of the Great Lakes, as winter weather advisories were issued across Minnesota and Michigan. Snow showers pushed across Minnesota, Iowa, Wisconsin, Illinois and Michigan as a result of this system. Luce, Mich., reported a midday total of 12.0 inches of snow, while Manistee, Mich., reported a midday total of 4.60 inches of snow. Meanwhile, a warm frontal boundary stretched across the central and eastern portion of the Great Lakes, as a mixture of rain and snow impacted northeastern Ohio, northwestern Pennsylvania and western New York. To the south, an onshore flow from the Atlantic triggered scattered showers and thunderstorms along the coast of the Carolinas and into western Florida. A similar type of flow pushed across southern Texas from the Gulf of Mexico, which ushered showers across the area. The West Coast stayed clear of wet weather on Wednesday as a ridge of high pressure continued to build over the eastern Pacific. Temperatures in the Lower 48 states Wednesday have ranged from a morning low of -20 degrees at Mt. Washington, NH to a midday high of 84 degrees at Marco Island Airport, FL.
A low pressure system along the western side of the Gulf of Mexico ushered showers and scattered thunderstorms across southern Texas and parts of Louisiana on Friday. An onshore flow also moved across Florida, which triggered showers and thunderstorms over the state. Hebbronville, Texas, reported a midday total of 0.45 inches of rain, while Cotulla, Texas, reported a midday total of 0.40 inches of rain. The majority of the Southeast stayed clear of wet weather due to a ridge of high pressure over the region. Light snow showers moved across parts of the Northeast on Friday, while cold, blustery conditions pushed southward from Canada. Similar conditions swept across the Great Lakes and upper Midwest. Silver Bay, Minn., recorded a morning low of -16 degrees, while Presque Isle, Maine, recorded a morning low of -9 degrees. Along the West Coast, an onshore flow from the Pacific Ocean ushered showers across western Washington and parts of Oregon. Quillayute, Wash., reported a midday total of 0.45 inches of rain. The Southwest continued to experience warm, dry conditions on Friday, as Santa Monica, Calif., recorded a midday high of 80 degrees, while Fullerton, Calif., recorded a midday high of 79 degrees.