Snowpack
Conditions vary across the State as of February 1. The northwest and western
portions of the State are near average to well above average. The Shoshone
and Upper Yellowstone Basins are well above average. The southern and
eastern areas of Wyoming are average to below in percent of normal snow
water equivalent (SWE). The Bighorn River basin is a little above average,
while on the other side of the Bighorn Mountains, the Powder-Tongue River
basin is below average.
Precipitation
Most basins across Wyoming received above average precipitation for the
month of January. Eleven of the 13 basins were above average for the month.
The following table displays the major river basins and their departure from
normal for January 1999.
Basin | Departure from normal | Basin | Departure from normal |
Snake River | +08% | Upper North Platte River | +70% |
Yellowstone & Madison | +43% | Lower North Platte River | +27% |
Wind River | +03% | Little Snake River | +12% |
Bighorn | +33% | Upper Green River | -16% |
Shoshone & Clarks Fork | +63% | Lower Green River | -16% |
Powder & Tongue River | +13% | Upper Bear River | +04% |
Belle Fourche & Cheyenne | +75% |
Streams
Runoff is expected to vary greatly across the state. The northwestern part
of the state is expected to have yields varying from average to slightly
above average. The northeast portion of Wyoming should be well above
average -- because of very high precipitation during the early part of the
water year (Oct-Sep). In most cases, the southeast portion of the state will
vary from 20 to 38 percent below normal (LaPrele Creek drainage is expected
to be about 38 percent below normal). The southwest portion of Wyoming
varies from near average to about 15 percent below average. The Bear River
will produce 15-25 percent below average yields.
Reservoirs
Reservoir storage is generally above average for this time of the year.
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 1999 BASIN AREA CURRENT AS LAST YR AS AVERAGE AS CURRENT AS CURRENT AS RESERVIOR % CAPACITY % CAPACITY % CAPACITY % AVERAGE % LAST YR ------------------------------------------------------------------------------ ALCOVA 84 85 85 100 100 ANGOSTURA 95 94 80 118 101 BELLE FOURCHE 94 98 57 165 95 BIG SANDY 81 60 46 174 135 BIGHORN LAKE 64 68 62 103 93 BOYSEN 96 92 97 98 104 BUFFALO BILL 69 83 64 107 83 BULL LAKE 64 64 57 113 101 DEERFIELD 95 101 84 113 94 EDEN NO REPORT ENNIS LAKE 70 72 83 84 97 FLAMING GORGE AVERAGE NOT ESTABLISHED FONTENELLE 52 51 57 92 103 GLENDO 80 81 65 122 98 GRASSY LAKE 85 53 71 119 159 GUERNSEY 38 35 15 254 109 HEBGEN LAKE 82 74 65 125 110 JACKSON LAKE 72 77 57 127 93 KEYHOLE 92 89 51 180 102 PACTOLA 94 96 83 113 98 PALISADES 85 92 75 115 93 PATHFINDER 87 93 54 161 94 PILOT BUTTE 71 69 52 135 103 SEMINOE 72 84 46 157 86 SHADEHILL 68 67 60 113 101 TONGUE RIVER NO REPORT VIVA NAUGHTON RES 74 59 68 109 126 WHEATLAND #2 63 64 41 155 98 WOODRUFF NARROWS AVERAGE NOT ESTABLISHED GLENDO PROJECT USERS 85 84 65 131 101 GLENDO PROJECT USERS 85 84 65 131 101 NORTH PLATTE PROJ 81 97 57 144 84