U.S Drought Monitor for Wyoming
Upper Green in moderate drought conditions
by National Weather Service
September 15, 2008
The latest U.S. drought monitor for Wyoming released on September 11 showed the area of moderate /d1/ to severe /d2/ drought had remained unchanged since July. The area classified as severe drought was confined to the northwest two-thirds of Sweetwater County and southeast Lincoln County. Most other areas in southwest Wyoming with the exception of the Upper Green River Basin remained in moderate drought. The northeast quarter of Wyoming was free of drought with most of northwest Wyoming classified as abnormally dry.
Summary of Impacts:
State and local actions
No drought impacts were reported across west and central Wyoming during August and the first half of September.
River and Streamflow Conditions
Streamflows in the moderate to severe drought areas of southwest Wyoming were mostly near normal. Only the Green River near LaBarge was running below normal compared to a 30-year average.
Fire Weather Impacts
The two largest wildfires of the summer, the Gunbarrel fire 40 miles west of Cody and the New Fork fire 19 miles north of Pinedale were left smoldering after early September rains brought over one inch of precipitation to these fires. Fire crews were mostly mopping up hot spots on these fires and area closures had been lifted. The Gunbarrel fire was 85 percent contained as of September 11th.
Early September precipitation helped mitigate critical fuel conditions across west and central Wyoming. The east slopes of the Wind River Mountains was the only area still classified as critical or as having fuel characteristics favorable for large fire growth as of September 10th.
The BLM has specific burning restrictions in effect across Johnson County as well as normal year-round restrictions. Check with the Buffalo BLM office for specific restrictions in Johnson County. These are the only known restrictions in effect by federal agencies. Most of Wyoming/s counties have year-round restrictions regarding fireworks, burning notifications etc. Please contact specific counties for information regarding any restrictions.
Precipitation for August was highly variable due to typical hit-and-miss thunderstorms with precipitation amounts across west and central Wyoming ranging from a trace at a few locations in the eastern Big Horn Basin to 4.58 inches at Afton. Areas in severe drought across southwest Wyoming mostly had below normal precipitation in August, but an estimated 1 to 3 inches of rain has fallen over the area since September 1st. The Rock Springs airport has received 1.27 inches of rain during the first half of September. Wyoming had the 41st driest August over a 114 period of record, or near normal precipitation overall. Wyoming also had the 31st warmest August on record, or above normal temperatures overall.
Below are the total precipitation amounts from selected locations across west and central Wyoming for August 2008:
Casper (airport) : 0.72 August Precipitation, 99% average
Lander (airport) : 0.84 August Precipitation, 147% average
Riverton (airport) : 0.59 August Precipitation, 137% average
* Rock Springs (airport) : 0.26 August Precipitation, 45% average
^Big Piney: 1.14 August Precipitation, 143 % average
Buffalo: 0.09 August Precipitation, 10% average
Cody: 0.88 August Precipitation, 98% average
Dubois: 0.65 August Precipitation, 76% average
* Flaming Gorge: 0.10 August Precipitation, n/a
* Fontenelle Dam: 0.50 August Precipitation, 69% average
* Fossil Butte Nat Mon: 0.13 August Precipitation, 12% average
* Green River: 0.60 August Precipitation, 95% average
Jackson: 0.17 August Precipitation, 13% average
Kaycee: 0.36 August Precipitation, 41% average
* Kemmerer: 1.50 August Precipitation, 138% average
Lake Yellowstone: 0.41 August Precipitation, 24% average
* LaBarge: 0.44 August Precipitation, 50% average
Mammoth (Yellowstone) : 0.30 August Precipitation, 32% average
Old Faithful: 0.23 August Precipitation, 44% average
Powell Field Station: 0.18 August Precipitation, 35% average
Riverton Downtown: 0.51 August Precipitation, 104% average
* Rock Springs: 0.42 August Precipitation, n/a
Thermopolis: 0.07 August Precipitation, 14% average
^Wamsutter: 1.01 August Precipitation, n/a
Worland: - August Precipitation, 0% average
* location in severe drought /d2/
^ location in moderate drought /d1/
The 8 to 14 day outlook valid September 21st through the 27th calls for above normal temperatures across all of Wyoming with the greatest probability across the southeast half of the state. Below normal precipitation is forecast over the southwest half of Wyoming September 21st through the 27th with the northeast half expected to receive near normal precipitation.
The outlook for October, November and December calls for above normal temperatures across roughly the eastern two-thirds of Wyoming or east of the continental divide and equal chances of above...below or normal temperatures across the west. The precipitation outlook for this same period calls for equal chances of above below or normal precipitation or no clear climate signal across the entire area.
Enso-neutral conditions were observed in the pacific during the summer and these conditions are expected to continue through the end of 2008 into spring 2009.
Hydrologic summary and outlook:
Fontenelle Reservoir was 81 percent full. During the April through July period Fontenelle received 582000 acre-feet inflow, which is 68 percent of average. Based on the latest inflow forecast from the Colorado River Basin Forecast Center inflows will be slightly below average through the fall and winter months.
Boysen Reservoir was 85 percent full.
Pathfinder Reservoir was 34 percent full.
Buffalo Bill Reservoir was 82 percent full as of September 13.
Next Issuance Date
This product will be updated on Wednesday, October 15, 2008 or sooner if necessary in response to significant changes in conditions.
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, questions or comments about this drought information statement, please contact:
Climate/Drought Focal Point
National Weather Service
12744 West US Highway 26
Riverton, WY 82501