Drought eliminated across NW Wyoming
Record or near-October record precipitation eliminates remaining drought across northwest Wyoming
by National Weather Service
November 13, 2016
A much wetter than normal October across western Wyoming eliminated remaining moderate /d1/ drought conditions over northwest Wyoming. Moderate to severe /d2/ drought remained over the northeast corner of Wyoming, where October was drier and much warmer than normal.
The Snake River Basin had their wettest October over the last 122 years with a basin-wide average precipitation of 6.78 inches, or 320% of the 20th century average. Yellowstone Basin had its 2nd wettest October since 1895 with basin-wide average precipitation of 5.47 inches or 291% of the 20th century average. Old faithful set a new record for wettest October with 8.18 inches of precipitation, shattering the old record of 4.46 inches in 1908.
Summary of Impacts:
River and Streamflow Conditions:
28 day average streamflows across Wyoming showed much above normal conditions across most of western Wyoming with near normal to above normal conditions across the rest of the state.
Fire Weather Impacts:
Fuels remained critically dry and susceptible to rapid fire growth across Natrona county and southern Johnson county where unseasonably mild and dry conditions prevailed in October. Two week and one month evaporative demand drought index (EDDI) values (a measure of the thirst of the atmosphere) showed flash drought conditions potentially developing over this area and much of eastern Wyoming.
Below are the cumulative precipitation amounts from selected locations across west and central Wyoming in 2016.
Note: Basin-wide percent of averages are based on 20th century (1901-2000) averages. Specific locations percent of averages are based on 1981-2010 normals.
LOCATION PRECIPITATION % OF AVERAGE
AND DROUGHT (INCHES)
CONDITION JAN-OCT 2016
-------- ----------------- ---------
Yellowstone Basin Avg., 20.87, 93
0 Old Faithful - 21.85, 110
Snake Basin Avg., 27.67, 106
Afton - 19.17, 124
Moose - 17.98, 109
Green And Bear Basin Avg. - 14.38, 124
Big Piney Airport - 11.51, 193
0 Evanston Airport - 6.93, 66
Fossil Butte N.M. - 14.51, 154
Green River - 14.32, 191
Rock Springs (Fire Dp) -13.99, 162
Bighorn Basin Avg. - 14.47, 110
Cody - 11.63, 119
Greybull Airport - 6.82, 98
Powell Field Station - 6.27, 97
Thermopolis - 13.90, 133
Worland Airport - 8.79, 126
Powder/Tongue Basin Avg. -13.97, 101
Buffalo Airport - 11.55, 92
Kaycee - 10.82, 94
Sheridan Airport - 14.67, 114
Lower Platte Basin Avg - 13.36, 98
Casper Airport - 13.88, 123
0 Cheyenne Airport - 13.97, 94
Wind River Basin Avg. - 16.20, 123
Dubois - 10.95, 121
Lander Airport - 18.90, 168
Riverton Airport - 13.09, 152
Riverton (Downtown) - 13.56, 175
Upper Platte Basin Avg. - 11.98, 104
Jeffrey City - 11.46, 127
Statewide Average - 14.70, 106
| STATION'S DROUGHT INTENSITY (LEFT COLUMN):|
| 3 - LOCATION IN EXTREME DROUGHT/D3/ |
| 2 - LOCATION IN SEVERE DROUGHT /D2/ |
| 1 - LOCATION IN MODERATE DROUGHT /D1/ |
| 0 - LOCATION ABNORMALLY DRY /D0/ |
| - NONE |
| (M) MISSING PRECIPITATION DATA IN RECORD |
La Nina advisory has been issued as La Nina conditions had developed across the tropical Pacific ocean in October. La Nina conditions are favored to persist during winter 2016-17. The winter outlook for Wyoming considers La Nina conditions to remain through the period.
The winter (December-January-February) outlook for Wyoming shows an elevated chance of above normal temperatures across roughly the southwest third of the state. The rest of the state has equal chances of above normal, normal or below normal temperatures; or no clear climate signal. The winter precipitation outlook showed an elevated chance of above normal precipitation roughly along and north of a Kemmerer to Casper line with the greater than 40 percent chance of above normal precipitation along and north of a Powell to West Yellowstone line.
The seasonal drought outlook showed no areas of drought development across west and central Wyoming through the end of January 2017.
Hydrologic Summary and Outlook:
Reservoir storages across Wyoming were in relatively good condition for October and early November. Notable exceptions were Palisades Reservoir (14% full) and Glendo Reservoir (38% full).
Reservoir Data for November 10TH:
Reservoir Percent Full
Boysen - 88.6
Buffalo Bill - 70.5
Bull Lake - 22.0
Pathfinder - 83.8
Upper Green River Basin
Big Sandy - 50.0
Fontenelle - 68.0
Flaming Gorge - 85.0
Upper Snake River Basin
Grassy Lake - 85.0
Jackson Lake - 58.0
Related Web Sites
Additional information on current drought conditions may be found at the following web addresses:
To report effects of the drought in your area, please go to the drought impact reporter at: http://droughtreporter.unl.edu/ and click on submit a report.
Information for the media may be found at:
NWS Riverton Drought Page:
Wind River Indian Reservation and Surrounding area climate and drought summaries:
USGS Wyoming Drought Watch:
U.S. Drought Monitor:
NOAA Drought Page:
Climate Prediction Center (CPC):
Additional River and Reservoir Information:
NWS Advanced Hydrologic Prediction Service (AHPS):
Water Resource Data System (WRDS)
The drought monitor is a multi-agency effort involving NOAA’s National Weather Service and National Climatic Data Center, the USDA, state and regional center climatologists and the National Drought Mitigation Center. Information for this statement has been gathered from NWS and FAA observation sites, state cooperative extension services, the USDA, USACE and USGS.
For more information, contact:
Climate/Drought Focal Point
National Weather Service
12744 West US Highway 26
Riverton, WY 82501