Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 338 AM EDT Tue Jul 22 2014 Valid 12Z Tue Jul 22 2014 - 12Z Thu Jul 24 2014 ...There is a slight risk of severe thunderstorms over parts of the Central Plains/Middle Mississippi Valley and Upper Great Lakes... ...There is a slight risk of severe thunderstorms over parts of the Northern High Plains... A front extending from the Upper Great Lakes to the Central Plains will move eastward to the Northeast/Mid-Atlantic Coast and southward to the Tennessee Valley/Southern Plains by Wednesday evening. The system will produce showers and thunderstorms along and ahead of the boundary over the Upper Great Lakes moving to New England/Mid-Atlantic and expanding into the Ohio/Tennessee Valleys by Wednesday. Meanwhile, upper-level energy over the Central Gulf Coast and upper-level impulses over the Southeast will trigger showers and thunderstorms over the region through Tuesday evening. On Wednesday the showers and thunderstorms will retreat to the Lower Mississippi Valley Coast and along the Southeast Coast, too. In addition, an upper-level low will slowly come onshore over the Pacific Northwest by Wednesday evening. The energy and the general upper-level troughing will aid in producing showers and thunderstorms over parts of the Northern Intermountain Region to the Northern High Plains through Wednesday. Rain will also develop along parts of the Pacific Northwest Coast. Elsewhere, diurnal heating and monsoonal moisture will produce showers and thunderstorms over parts of the Southern Rockies during the late afternoon and evening on Tuesday and Wednesday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php