Riverton, Wyoming Severe Thunderstorm Warning

Widely scattered convection was developing over central Wyoming Tuesday afternoon, aided by up slope flow and strong southwesterly winds aloft.  The NOAA/CIMSS ProbSevere model indicated a 71% probability of the storm over northern Fremont county Wyoming to produce severe weather in following 60 minutes (Figure 1) at 1956 UTC 6 May 2014.  The probability continued to increase as the radar estimated intensity correspondingly increased.  The NWS in Riverton, WY issued a severe thunderstorm warning on this storm at 2013 UTC 6 May 2014.  The ProbSevere model could have been used to potentially increase lead-time on the issuance of a severe thunderstorm warning.  The storms that warranted a severe thunderstorm warning have since weakened, the largest reported hail size was 0.75".

Figure 1. NOAA/CIMSS ProbSevere and KRIW 0.5 degree reflectivity valid 1956 UTC 6 May 2014.

-Sieglaff