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. Snow water equivalents (SWE) in the southern and
eastern areas of Wyoming vary from slightly above average to
below average. 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
All the basins across Wyoming received above average
precipitation for the month of February. Six of the 13 basins
received over 150 percent of average precipitation for the month.
The following table displays the major river basins and their
departure from normal for February 1999.
| Basin | Departure from normal | Basin | Departure from normal |
| Snake River | +56% | Upper North Platte River | +17% |
| Yellowstone & Madison | +54% | Lower North Platte River | +20% |
| Wind River | +55% | Little Snake River | +47% |
| Bighorn | +31% | Upper Green River | +58% |
| Shoshone & Clarks Fork | +45% | Lower Green River | +59% |
| Powder & Tongue River | +13% | Upper Bear River | +79% |
| Belle Fourche & Cheyenne | +45% |
Streams
Runoff is expected to vary greatly across the state. Yield from
the northeast portion of Wyoming should be near average -- yield
varies from 84 to 119 percent of average (mean is 106%). In most
cases, the southeast portion of the state will be about 10
percent below normal -- yield estimates range from 58 to 119
percent of normal. The southwest portion of Wyoming varies from
81 to 114 percent of average -- mean estimated yield is 103
percent of average. Portions of Bear River are expected to
produce about 20 percent below normal volume of runoff. The
northwest part of the State is expected to yield about 16 percent
more than normal -- yields vary from 93 to 130 percent of normal.
Reservoirs
Reservoir storage is generally above average for this time of the
year. See following table for further information about
reservoir storage.
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 FEBRUARY 1999
BASIN AREA CURRENT AS LAST YR AS AVERAGE AS CURRENT AS CURRENT AS
RESERVIOR % CAPACITY % CAPACITY % CAPACITY % AVERAGE % LAST YR
------------------------------------------------------------------------------
ALCOVA 86 86 85 100 100
ANGOSTURA 99 98 83 119 101
BELLE FOURCHE 94 99 63 148 95
BIG SANDY 86 62 48 180 138
BIGHORN LAKE 59 64 60 99 92
BOYSEN 92 89 93 99 104
BUFFALO BILL 68 81 61 112 83
BULL LAKE 64 63 56 115 103
DEERFIELD 97 100 87 112 97
EDEN NO REPORT
ENNIS LAKE 74 71 83 89 104
FLAMING GORGE AVERAGE NOT ESTABLISHED
FONTENELLE 42 39 50 84 108
GLENDO 89 88 76 118 101
GRASSY LAKE 86 51 72 119 168
GUERNSEY 43 53 30 143 80
HEBGEN LAKE 77 72 66 117 107
JACKSON LAKE 74 77 57 130 96
KEYHOLE 92 91 53 175 102
PACTOLA 95 98 84 113 97
PALISADES 74 86 76 98 86
PATHFINDER 90 96 58 155 94
PILOT BUTTE 70 69 56 124 101
SEMINOE 69 82 40 172 84
SHADEHILL 68 69 61 111 99
TONGUE RIVER 11 10 44 26 111
VIVA NAUGHTON RES 72 55 66 110 131
WHEATLAND #2 62 64 44 141 97
WOODRUFF NARROWS AVERAGE NOT ESTABLISHED
GLENDO PROJECT USERS 87 86 69 126 101
KENDRICK PROJECT 81 84 68 120 97
NORTH PLATTE PROJ 86 97 60 144 88
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