HIGHLIGHTS:
- Wyoming April 2019 precipitation was 115 to 120 percent of average
- Current water year precipitation is averaging 110 to 115 percent of normal across Wyoming…
- Mountain snowpack across Wyoming is 90 to 100 percent of median…
- Near normal to slightly above normal snowmelt streamflow volumes are still expected across several major basins in Wyoming…
- Total reservoir capacity across Wyoming continues to be 75 to 80 percent by early May
Synopsis:
April 2019 precipitation totals across Wyoming were 115 to 120 percent of average. Precipitation numbers varied between 160 percent of normal over the Snake and Upper Green River Drainages (west to west central Wyoming) to near 80 percent of average over the Big Horn River Basin (north central Wyoming). Current water year (October 2018 – April 2019) precipitation across Wyoming is averaging 110 to 115 percent of average.
Mountain snowpack across Wyoming was 90 to 100 percent of median by early May. Snowpack “water” numbers and/or SWEs were the highest across basins in western to northwestern Wyoming—varying between 110 to 120 percent of median. SWEs across watersheds in north central Wyoming were 65 to 80 percent of median.
Near normal to slightly above normal (95 to 105 percent) snowmelt streamflow volumes are still expected across several major basins across Wyoming. Above average snowmelt streamflow volumes are expected across the Shoshone, Upper Bear, Upper North Platte, and Laramie Watersheds. Several rivers and creeks along the Tongue and Powder River Basins are forecasted to have below normal streamflow volumes during the upcoming snowmelt season.
Total reservoir capacity across Wyoming continues to be 75 to 80 percent by early May. Reservoir storages across Wyoming remain above average at 115 to 120 percent for early May.
Note: This may be the LAST water supply outlook and graphic for WY2019—all dependent of snowpack conditions in early June.
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Other hydrological information for Wyoming can be found at the NOAA hydrology website:
http://www.weather.gov/riw/local_hydrology
Monthly Wyoming Hydrologic Summary and Graphics:
(updated monthly around the 15th of every month)
http://www.weather.gov/media/riw/hydro/hydro_report.pdf
Wyoming Drought Information Page:
(updated at least once a month)
http://www.weather.gov/riw/drought
Wyoming Graphical Water Supply Outlook:
(updated by the 10th of every month—January-June)
http://www.weather.gov/images/riw/hydro/watersupply.png
Wyoming Average Precipitation by Basin:
(updated monthly)
http://www.weather.gov/images/riw/hydro/wyomingprecip.png
Wyoming Spring Snowmelt Runoff Flood Potential Graphic:
(updated around the 20th of the month—February-April—sometimes May)
http://www.weather.gov/images/riw/hydro/floodoutlook.png
Current and Forecast Wyoming Streamflows and/or River Stages:
http://water.weather.gov/ahps2/index.php?wfo=RIW
http://water.weather.gov/ahps2/index.php?wfo=CYS
http://waterdata.usgs.gov/wy/nwis/rt <http://waterdata.usgs.gov/wy/nwis/rt>