GSL Slip Renters and Marina Users. Severe Thunderstorm Warning! -> Hurricane Force Warning. A Severe thunderstorm is building in the west desert and is tracking for the south end of Great Salt Lake. At 8pm this is a significant and still developing thunderstorm. NOAA has issued a Severe Thunderstorm Warning for the Tooele Valley. Great Salt Lake Marina has issued a Hurricane Force Warning for the southern half of Great Salt Lake. This system could produce strong gusty winds, lightning, heavy rain, and possibly a cyclone. The storm has yet to pass over the Stansbury Mountains and could be diminished as it does so lessening its effect over the lake. This event should expire by 10pm tonight. This thunderstorm has formed on the outer edge of a pinwheel monsoonal system over New Mexico. It could spawn a few more storms over the night. Dave Shearer Harbormaster Great Salt Lake State Marina