All graphics courtesy of USDA, NOAA, Department of Commerce
Repeated rounds of precipitation fell in the Southeast, largely eradicating drought west of the Appalachians and easing drought in the southern Atlantic piedmont region. Late in the week, enough cold air interacted with lingering moisture to produce accumulating snow from the lower Mississippi Valley into the southern Mid-Atlantic region. However, little or no rain fell in Florida, maintaining heavy irrigation demands for citrus and winter vegetables. In addition, weekly temperatures averaged 5-15° F above normal in the Atlantic Coast States.
Meanwhile, lowland flooding gradually subsided from the Mid-South into the lower Midwest, as runoff from the previous week’s downpours moved from tributaries into main-stem rivers. The remainder of the nation’s midsection, including the Plains and upper Midwest, experienced mostly dry weather. Generally cold, dry weather prevailed in the West, except for some early-week snow showers in the Rockies. Temperatures averaged at least 10-20° F below normal across the Intermountain West. A series of freezes affected winter agricultural regions of California and the Desert Southwest, resulting in producers employing protective measures to guard against injury to citrus and vegetables. However, the 2013 cold wave was less severe than a similarly timed event in mid-January 2007.
Elsewhere, early-week temperatures plunged to 0° F or below in the hard red winter wheat belt as far south as eastern Colorado and northwestern Kansas. There was little or no snow on the ground across the central High Plains’ at the height of the cold snap, leaving drought-stressed winter wheat potentially vulnerable to freeze injury. Farther north, freshly fallen snow provided insulation to the northern High Plains’ wheat.