Laserfiche WebLink
<br />. <br /> <br />. <br /> <br />. <br /> <br />, <br /> <br />0729 <br /> <br />with a drainage area of 62. square miles. The confluenc e of this stream <br /> <br /> <br />with the main stem is at river ndle 160 which is upstream from the urban <br /> <br /> <br />area of Trinidad. <br /> <br />CLII'JATE <br /> <br />4. '"leather. - The Purgatoire River originates in a high mountain range <br /> <br /> <br />and flows through a canyon sheltered by mountains. Climatic conditions vary <br /> <br /> <br />considerably between the high mountainous region and the valley downstream <br /> <br /> <br />from Trinidad. The drainage basin above Trinidad is characterized by intense <br /> <br /> <br />local thunderstorms in summer and heavy snowfall in winter months. The in- <br /> <br /> <br />fluence of the topog;aphy of the Purgatoire River watershed, and the geo- <br /> <br /> <br />graphical locatj.on with respect to the paths of invading air masses from the <br /> <br /> <br />several source regions, result in the occurrences of several storm types or <br /> <br />combinations of storm types over the watershed. These storms may be divided <br />into two classifications: the frontal storm resulting from frontal activity <br />of two or more air masse,; and the thunderstorm (local summer storm) result- <br />ing from either orographic or convective lifting or a combination of both. <br />The frontal storms are further subdivided into two types, a cyclonic wave <br />developing on a cold front or on a stationary front, and a second type which <br /> <br /> <br />is characterized by a front aloft; either of these types may cover a large <br /> <br /> <br />area. The former generally produces moderate precipitation intensities and <br /> <br /> <br />shows the effects of orographic influence; during the latter type, precip- <br /> <br /> <br />itation intensities may be high at random locations within the general <br /> <br /> <br />storm area tending to indicate a series of local storms although general <br /> <br /> <br />precipitation occurs over relatively large areas. The change from summer <br /> <br /> <br />to winter is characterized by the sudden disappearance of thunderstorm <br /> <br /> <br />activity followed by the clear winter weather that dominates this area <br /> <br /> <br />between frontal passages. Storms during the summer months are usually of the <br /> <br /> <br />thunderstorm type and are rnost active during July and August. The surface <br /> <br /> <br />winds associated with summer thunderstorms are usually 30 to 40 miles per <br /> <br />2 <br /> <br />~'I..d') .GIJDIX B- <br /> <br />," ~ 0'" <br /> <br />