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Exhibit K <br />Climate Page 2 <br />Climatography of the United States No. 60 <br />(updated January 2003) <br />by Nolan J. Doesken, Roger A. Pielke, Sr., Odilia A.P. Bliss <br />CLIMATE OF THE EASTERN PLAINS <br />The climate of the plains is comparatively uniform from place to place, with characteristic features <br />of low relative humidity, abundant sunshine, infrequent rains and snow, moderate to high wind <br />movement, and a large daily and seasonal range in temperature. Summer daily maximum <br />temperatures are often 95°F or above, and 100°F temperatures have been observed at all plain <br />stations. Such temperatures are not infrequent at altitudes below 5,000 feet; above that elevation <br />they are comparatively rare. The highest temperatures in Colorado occur in the Arkansas Valley <br />and lower elevations of South Platte and Republican Rivers. The hottest temperature ever <br />recorded in Colorado was 114°F at Las Animas in July 1, 1933 and at Sedgwick on July 11, <br />1954. Because of the very low relative humidity accompanying these high temperatures, hot days <br />cause less discomfort than in more humid areas. The usual winter extremes in the plains are from <br />zero to -10°F to -15°F but have reached extraordinarily low readings of -30 to -40°F during some <br />of the most extreme cold waves. <br />An important feature of the precipitation in the plains is the seasonal cycle. A very large <br />proportion (70 to 80 percent of the annual total) falls during the growing season from April through <br />September. Cool season precipitation can be important for soil moisture recharge, but midwinter <br />precipitation is light and infrequent. More often, winter brings dry air and strong winds contributing <br />to the aridity of the area. From early March through early June, periodic widespread storms bring <br />soaking beneficial moisture that helps crops and grasslands. Summer precipitation over the <br />plains comes largely from thunderstorm activity and is sometimes extremely heavy. Localized <br />rains in excess of 4" sometimes fall in just a few hours contributing to local flooding. In late May <br />1935 nearly two feet of rain fell along the Republican River in eastern Colorado causing one of <br />the worst floods in state history. June flash floods in 1965 were also devastating. The weather <br />station at Holly in southeast Colorado measured 18.81" of rainfall in that extraordinarily wet <br />month. It is more common, however, to be too dry. Annual average precipitation ranges from less <br />than 12 inches in the Arkansas Valley between Pueblo and Las Animas to almost 18 inches in <br />extreme northeastern and southeastern corners of the state. Many years are drier than average, <br />and some years receive only half or less the long-term average. The region seems almost always <br />in or on the verge of drought. Multi-year drought is common to the area such as the decade-long <br />drought of the 1930s, the severe drought of the mid 1950s and 1970s and the recent intense <br />widespread drought of the early 2000s. <br />At the western edge of the plains and near the foothills of the mountains, there are a number of <br />significant changes in climate. Average wind movement is less, but areas very near the <br />mountains are subject to periodic, severe turbulent winds from the effects of high westerly winds <br />over the mountain barrier. These winds are sometimes referred to as "chinook winds" when they <br />warm, and "bora winds" when they are associated with a strong cold frontal passage downslope <br />off of the mountains. Temperature changes from day to day are not quite as great; summer <br />temperatures are lower, and winter temperatures are higher. Not surprisingly, this milder corridor <br />close to the mountains is where the majority of Colorado's population now lives. Precipitation, <br />which decreases gradually from the eastern border to a minimum near the mountains, increases <br />rapidly with the increasing elevation of the foothills and proximity to higher ranges. The decrease <br />in temperature from the eastern boundary westward to the foothills is less than might be expected <br />with increasing altitude. This results from mountain and valley winds and greater frequency of the <br />chinook. Below the Royal Gorge of the Arkansas River, the mountain and valley winds are <br />persistent enough to modify the climate over a considerable area. Descending air currents <br />frequently prevent the stratification of air necessary for the occurrence of excessive cold. As a <br />consequence, the winter climate is milder near Canon City and Penrose than anywhere else in <br />the State. <br />http://ccc.atmos.colostate.edu/climateofcolorado.php