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<br />VIATER SUPPLY OUTLOOK FOR- UPPER COLORADO BAS:, 16 1984'
<br />C. fOLOn.
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<br />COLORADO RIVER abeve CISCO, UTAH: Numerous storms continually dumped significant
<br />amcun1;S of snow 1;hroughout western Colorado during December. The mountain snowpack
<br />is at record high levels for this date. The water supply outlook projects much
<br />above normal with streanu'lows expected between 140 to 200 percent. The potential
<br />for some low land flooding is very real, particularrJ those areas which experienced
<br />problems last spring. However, dewnstream flows are not anticipated to De quite
<br />as high as last year. It is still early in the year and significant depart~es
<br />from normal could alter the forecasts. If the early ~J period of January continues,
<br />then the threat of snow melt fleoding this spring will be reduced.
<br />
<br />.
<br />
<br />as of January 1, 1984
<br />
<br />?recipi1;a1;ion during the month of December averaged 250% with new monthly prec~p~-
<br />tation records reported at Breckenridge, Cedaredge, Glenwood Sprir~s, Hamilton,
<br />Ha:fden, Marvine Ranch, Ouray, ?lacerville, p:rrarrJ.d, Sa~gen-:'3, Silverton e..nd T',,=ll1.l-
<br />ride. The 6.53 inches for Glenwood Springs, 467% of normal, was also the wettest
<br />month ever recorded dating back to 1900.
<br />
<br />Seasonal accurnmulations, October through December, range from 140% along the
<br />Continental Divide to over 200% in the upper ~bite and Yampa River drainages
<br />southward to the Grand Mesa.
<br />
<br />The mountain snowpack is tremendous. Of the 75 snow courses which were read in
<br />Colorado by the Soil Conservacion Service on January 1, 50 were records for this
<br />time 0:" year, scme dating back to 19 J8. The average basin snolllpack for several
<br />of the drainages in western Colorado include: Upper Colorado msinstem - 222%,
<br />Vfuite and Yampa - ::'03% end the Gunnison basin 229% of the new 20-year (1961-1980)
<br />normal.
<br />
<br />Runoff since the start of the water year on Dccober 1 has been above normal re-
<br />ilecting last years much above normal flow, and an abundance of groundwaoer flow
<br />still remaining. Seasonal runoff, October tnru December, ranges from 125 to 140%
<br />in ~eadwater ~reas to l65% in lower reaches of the basin. The ~otal flow i~~o Lake
<br />Powell since October 1 has bee~ 2.05 million acre-feet, 165% of average.
<br />
<br />Reservoir storage on December ;1, 1983 in the four ~ajor reservoirs above Ci~cQ,
<br />Utah (Lake Granby, Green MOill1tain, Dillon and Blue !'Jlesa) is 1.!...4 lC.i2.12.::::'~ 3.'2:'e-
<br />ieet, 85% of capacity, 132% of average and 150,000 acre-feet more than last yea~
<br />at chis time. Storage in Lake Powell is 22.7 million, nearly the same as last
<br />year and 91% of capacity, The April-July inflow forecast to Lake Powell is 13.0
<br />million acre-feet, 174% of the new 10-~ear (1961-1980) average of 7,~6 million.
<br />ac..r_e~f.eet .
<br />
<br />GREEN RIVER BASIN:
<br />G~ee~ River basin.
<br />next 3 to 4 mon~hs,
<br />from 117 to 156% in
<br />
<br />Water year 1983 was a record breaking year for runoff in the
<br />If near or above normal precipitation pattern occ~s over t~~
<br />anoT.her big yea!' is likely. Forecasts as Qf Januar.f l range
<br />the Green River above Fla~ing Gorge an1 145 to 234% belcw
<br />
<br />NOAA-NATIONAL 'IrEATHER SERVICE
<br />Colorado Basin River Forecast Center, Salt Lake City, Utah
<br />Gera::'d Williams, Hydr81ogis. t in Charge
<br />ph'Jfll~ 1- 801- 50-4. - 51liS
<br />~ 5/30
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