Snowpack
Snowpack over the State varied from just above normal to below
normal. Only a few drainages and individual sites record above
normal snow water equivalent. The northwest portion of the State
varied from 15 percent above normal in the Wind River drainage to
8 percent below normal in the Big Horn basin. The northeast part
of Wyoming varied from 94 percent of average in the Tongue River
drainage to 83 percent of average in the Powder River drainage.
The southeast portion of the State was 80 to 90 percent of normal
at the end of January. Generally, the southwest part of the State
is 80 to 90 percent of average; the Henrys Fork drainage was about
63 percent above normal. The Bear River drainage appears to have
near normal SWE.
Precipitation
Basins across Wyoming received above average precipitation across
the State, except in the Black Hills. January precipitation in the
Black Hills was only 86 percent of average for the month. The
Upper North Platte received 162 percent of average during the
month. Twelve of the 13 basins were above average for the month of
January. The following table displays the major river basins and
their departure from normal.
Basin | Departure from Normal |
Basin | Departure from Normal |
Snake River | +44% | Upper North Platte River | +62% |
Yellowstone & Madison | +44% | Lower North Platte | +19% |
Wind River | +31% | Little Snake River | +28% |
Big Horn | +17% | Upper Green River | +32% |
Shoshone & Clarks Fork | +56% | Lower Green River | +30% |
Powder & Tongue River | +12% | Upper Bear River | +51% |
Belle Fourche & Cheyenne | -14% |
Streams
Runoff is expected to vary from average to just below average
across the state. The northwestern part of the state is expected
to have yields varying from average to about 15 percent below
average. The northeast portion of Wyoming varies from near average
(part of the Powder River drainage) to about 30 percent below
average (Belle Fourche drainage). In most cases, the southeast
portion of the state will be near average to about 15 percent below
normal -- some drainages will be 30 to 45 percent below normal. The
southwest varies from 80 to 85 percent of average, with the Thomas
Fork drainage forecast to be about 25 percent below normal..
Reservoirs
Reservoir storage varies from well below to well above average,
however, the majority are above average for this time of the year.
Even a below average runoff should fill most reservoirs. See
following table for further information about reservoir storage.
Major Reservoirs in Wyoming
B A S I N W I D E R E S E R V O I R S U M M A R Y FOR THE END OF JANUARY 1998 BASIN AREA CURRENT AS LAST YR AS AVERAGE AS CURRENT AS CURRENT AS RESERVOIR % CAPACITY % CAPACITY % CAPACITY % AVERAGE % LAST YR -------------------------------------------------------------------------------- ALCOVA 85 85 85 100 100 ANGOSTURA 94 77 80 118 123 BELLE FOURCHE 98 87 57 173 113 BIG SANDY 60 0 46 129 0 BIGHORN LAKE 68 61 62 110 112 BOYSEN 92 91 97 95 101 BUFFALO BILL 83 79 64 129 104 BULL LAKE 64 53 57 111 120 DEERFIELD 101 99 84 120 103 EDEN 30 0 35 85 0 ENNIS LAKE NO REPORT FLAMING GORGE AVERAGE NOT ESTABLISHED FONTENELLE 51 43 57 90 118 GLENDO 81 62 65 124 130 GRASSY LAKE 53 86 71 75 62 GUERNSEY 35 33 15 234 106 HEBGEN LAKE 74 69 65 114 108 JACKSON LAKE 77 82 57 137 95 KEYHOLE 89 76 51 176 117 PACTOLA 96 97 83 116 99 PALISADES 92 85 75 123 108 PATHFINDER 93 85 54 171 110 PILOT BUTTE 69 75 52 132 92 SEMINOE 84 70 46 183 121 SHADEHILL 50 50 60 82 100 TONGUE RIVER 8 27 40 19 28 VIVA NAUGHTON RES 59 64 68 87 92 WHEATLAND #2 64 52 41 157 124 WOODRUFF NARROWS AVERAGE NOT ESTABLISHED GLENDO PROJECT USERS 84 82 65 129 103 KENDRICK PROJECT 84 82 68 123 103 NORTH PLATTE PROJ 97 72 57 171 135