Drought conditions continue to intensify
by National Weather Service - Riverton Wyoming
July 16, 2012
Wyoming had the driest June on record. Drought conditions continue to intensify over most of west and central Wyoming.
The latest U.S. drought monitor for Wyoming released on July 12th showed extreme drought /d3/ across Sweetwater county, and expanding into far southern Fremont County, and far eastern Lincoln and Uinta counties. Severe drought /d2/ had expanded across much of southern and eastern Wyoming, or roughly from a Kemmerer to Lander to Midwest line and south. Moderate drought /d1/ had expanded to cover most of north central Wyoming. Abnormally dry /d0/ conditions were observed across most of northwest Wyoming with the exception of northern Yellowstone National Park. One year ago, Wyoming was 100 percent free of drought or abnormally dry conditions. Abnormally dry /d0/ or moderate /d1/ drought conditions developed more rapidly through the spring after a below normal winter snowpack and a very warm and dry spring. Rock Springs had the warmest and driest spring (March-May) on record. June 2012 was the driest on record in Wyoming since 1895 with a state average of 0.45 inches of precipitation. June 2012 was also the 6th warmest over the last 118 years in Wyoming.
Summary of impacts
River and Streamflow conditions
28-day average streamflow conditions on July 11th showed much below normal or below normal streamflows at most stations in areas classified as moderate drought /d1/ or higher. Streamflows were closer to normal in the northwest or in the Upper Green River Basin, Snake River Basin, Upper Yellowstone and Madison River basins, Upper Wind River Basin.
Fire weather impacts
Fuels were classified as critical in all areas across west and central Wyoming. As of July 11th, fire danger was classified as very high to locally extreme across most areas in moderate drought /d1/ or higher, most of southern and central Wyoming. Fire danger was moderate across the northwest. Contact your local county officials for the latest burning restrictions.
An El Nino Watch has been issued by the climate prediction center. Chances have increased for El Nino beginning in July-September 2012. Enso-neutral conditions prevailed in May and June following the dissipation of La Nina in April.
The 8-14 day outlook for July 20-26 shows above normal temperatures across Wyoming with the greatest chance across the north. Precipitation is also expected to be below normal during this period with the greatest chance across the northern two-thirds of the state.
The 90-day outlook for July, August and September shows a chance for above normal temperatures across most of Wyoming with the greatest likelihood across the southwest. The precipitation outlook for this period shows a slight chance of below normal precipitation across northwest Wyoming with equal chances of above, below or near normal precipitation across the rest of the state.
The U.S. seasonal drought outlook issued on July 5th showed that drought conditions were likely to persist or intensify through September across all areas in Wyoming that are currently in drought. Drought conditions are not currently forecast to develop in northwest Wyoming.
Hydrologic summary and outlook
The following reservoir data was obtained on July 11th.\
BOYSEN 81.1 Percent Full
PATHFINDER 64.2 Percent Full
BULL LAKE 98.2 Percent Full
BUFFALO BILL 98.5 Percent Full
FONTENELLE 92.0 Percent Full
FLAMING GORGE 83.0 Percent Full
JACKSON LAKE 99.0 Percent Full