Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 456 PM EDT Tue Jun 17 2014 Valid 00Z Wed Jun 18 2014 - 00Z Fri Jun 20 2014 ...Unseasonably cold conditions expected for portions of the Intermountain West and Rockies...with snow possible in the higher elevations... ...A cold front pushing out into the Northern Plains could threaten the region with flash flooding and severe weather... ...Heavy rains and strong to severe thunderstorms will be possible along a wavy frontal boundary stretched from the Upper Midwest to the Northeast/northern Mid-Atlantic states... Widespread shower activity will continue beneath an anomalously deep upper low spinning over the northwestern corner of the Nation. The upper vortex should keep conditions unseasonably cold across portions of the Intermountain West and Rockies...and temperatures should even be low enough to support June snows in some of the highest elevations of Montana...Idaho...Wyoming...and Utah. As the upper low in the Northwest gradually lifts northeastward...an organized line of convection should fire up ahead of a strong cold front pushing out across the Northern Plains Tuesday night. Strong dynamics combined with an unstable environment will make flash flooding and severe weather a possibility with developing storms...and the threat should progress east with the boundary while it crosses into the Upper Mississippi Valley Wednesday night into Thursday. On the northern fringe of a warm and muggy airmass in place from the Southern/Central Plains to the Southeast and Mid-Atlantic region...a wavy frontal boundary stretched from the Upper Midwest to the Northeast will serve as a focal point for showers and thunderstorms the next few days. Developing storms will be moving into the ripe and juicy airmass in place to the south of the front...allowing for heavy downpours...damaging winds...large hail...and even isolated tornadoes. Across the southern tier...a dry line pushing out across Texas should help ignite afternoon convection while shower and thunderstorm activity will continue across Florida the next few days. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php