1999-03-08_PERMIT FILE - M1999025

Home Browse Search

• 1997 GRAND JUNCTION, t COLORADO Grand Junction is located at the junction of the t Colorado and Gunnison Rivers. It is on the wes= slope of the Rockies, in a large mountain valley. The area has a clima_e marked by the wide seasonal range usual to interior localities at this ' lot etude. Thanks, however, to the protective topography of the vicinity, sudden and severe weather changes are very infrequent. The valley floor slopes from 9,800 feet near Palisade [o 4,900 feet at the west end near Fru it a. Mountains are on all sides at distances of Erom 10 to 60 miles and reach heights of 9,000 to over 12,000 feet. This mountain valley location, with attendant ' valley breezes, provides protection from spring and fall frosts. This results in a growing season averaging 191 days in the city. This varies considerably in the outlying districts. IL is ' about the same in the upper valley around ?alisade, and 3 to 9 weeks shorter near the river west of Grand Junction. The growing season is suffice ent ly long co permit commercial growth of almost all Eru its except citrus varieties. Summer ' grazing of cattle and sheep on nearby mountain ranges is extensive. The interior, co nCinental location, ringed by ' mountains on ail sides, results in quite law precipitation ~n all seasons. Consequently, ag ri cu lCUre a dependent on irrigatron. Adequate supplies of water are available from mountain snows and ra=ns. Summer ra irs occur chiefly as t (GJT) scattered light showers and thunderstorms which develop over nearby mountain S. Wl rater snOw'S die fairly frequent, but are mostly light and quick to melt. Even [he infrequent snows of from 9 to 8 inches seldom remain on the ground for prolonged periods. Bl rz zard conditions in the valley are extremely rare. Temperatures above 100 degrees are infrequent, and about one-third of the winters have no readings below zero. Summer days with maximum temperatures in the middle 90s and minimums rn the low 60s are common. Rel at.ve humrd icy is very low during the summer, with values similar to ocher dry locations such as the southern parts of New Mexico aad Arizona. Spells of Cold wrnLer weather are somet rmes prolonged due Lo cold air becomtng trapped in the valley. Winds are usually very light during the coldest weather. Changes in winter are normally gradual, and abrupt changes are much less frequent than in eastern Colorado. Cold waves are rare. Sunny days predominate in all seasons. The prevailing wind is from the east-southeast due co the valley breeze effect. The strongest winds are assoc faced with thunderstorms or with pre-frontal weather. They usually are from the south or southwest.