2011-08-11_PERMIT FILE - M2011042

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/g,6 widespread storms bring soaking beneficial moisture that helps crops and grasslands. Summer precipitation over the plains comes largely from thunderstorm activity and is sometimes extremely heavy. Localized rains in excess of 4" sometimes fall in just a few hours contributing to local flooding. In late May 1935 nearly two feet of rain fell along the Republican River in eastern Colorado causing one of the worst floods in state history. June flash floods in 1965 were also devastating. The weather station at Holly in southeast Colorado measured 18.81" of rainfall in that extraordinarily wet month. It is more common, however, to be too dry. Annual average precipitation ranges from less than 12 inches in the Arkansas Valley between Pueblo and Las Animas to almost 18 inches in extreme northeastern and southeastern corners of the state. Many years are drier than average, and some years receive only half or less the long- term average. The region seems almost always in or on the verge of drought. Multi -year drought is common to the area such as the decade -long drought of the 1930s, the severe drought of the mid 1950s and 1970s and the recent intense widespread drought of the early 2000s. At the western edge of the plains and near the foothills of the mountains, there are a number of significant changes in climate. Average wind movement is less, but areas very near the mountains are subject to periodic, severe turbulent winds from the effects of high westerly winds over the mountain barrier. These winds are sometimes referred to as "chinook winds" when they warm, and "bora winds" when they are associated with a strong cold frontal passage downslope off of the mountains. Temperature changes from day to day are not quite as great; summer temperatures are lower, and winter temperatures are higher. Not surprisingly, this milder corridor close to the mountains is where the