April 2012 Wyoming Spring Snowmelt Flood Potential Outlook---issued April 23, 2012

Quick Synopsis:


Above average basin temperatures in March and April has drastically decreased the mountain snowpack and associated snow water equivalents (SWEs) across Wyoming.   Below average precipitation in March and April has also been a main factor in the declining SWE numbers.  The only substantial snowpack to cause significant snowmelt runoff is currently between 9,000 and 10,000 feet.   Mountain snowpack  “water” numbers continue to be the highest across the western and eastern slopes of the Big Horn Mountains---but  are much lower than in late March.  


Unless weather and hydrological trends—especially above average basin temperatures---change drastically, this will be the LAST graphical outlook of the season.   





...Moderate potential for snowmelt runoff flooding is expected along headwater locations along the eastern Big Horn (Shell Creek, Tensleep Creek) Watershed...


…All other headwater locations across Wyoming can expect a generally low potential for flooding due to springtime snowmelt...


Other hydrological information for Wyoming can be found at the NOAA hydrology website:



Monthly Wyoming Hydrologic Summary and Graphics can be found at:




The current Wyoming Spring 2012 Snowmelt Runoff Flood Potential Outlook graphic:

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