Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 459 AM EDT Tue Jun 18 2013 Valid 12Z Tue Jun 18 2013 - 12Z Thu Jun 20 2013 ...A strong closed low will bring a threat for severe weather and heavy rainfall across the Upper Intermountain West... ...An enhanced wildfire danger is expected over much of the southwestern states... ...Below normal temperatures are in the forecast across the Northeast... An anomalous upper low which has lingered offshore of the Pacific Northwest during the past several days will finally shift inland. Accompanying this system will be a well-defined frontal zone which should remain the site for an active period of precipitation. The activity is expected to be rather showery in nature given the cold core low circulating overhead. Some of the convection may become locally severe, particularly during the peak heating of the day. Additionally, an increased risk for flash flooding is possible on Wednesday given the antecedent conditions in place. An unsettled weather pattern should continue through Thursday given the rather slow motion of this upper disturbance. The other aspect of this powerful Pacific system is the enhanced risk for wildfires. A strong frontal zone crossing the Intermountain West will be accompanied by a rather tight pressure gradient leading to gusty winds, particularly in the mountain passes. This combination of hot/dry air with windy conditions will increase the chances for wildfire development across the southwestern U.S. In anticipation of this event, a large number of forecast offices have issued red flag warnings which cover this threat through Thursday. To view the latest information on this feature, please visit the Storm Prediction Center website at www.spc.noaa.gov/products/fire_wx/overview.html. Looking out to the east coast, a fairly defined upper trof will slowly work its way toward the western Atlantic which should eventually drag a cold front offshore and along the Gulf Coast. Given the sharp thermal contrast along this boundary, numerous showers and thunderstorms are forecast to break out with the best activity across the southeastern U.S. In its wake, a much cooler air mass will spill in from Canada keeping high temperatures only in the 70s the next couple of days over the northeastern states. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php