Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 324 AM EDT Wed Oct 19 2016 Valid 12Z Wed Oct 19 2016 - 12Z Fri Oct 21 2016 ...Severe thunderstorms and heavy rain possible today across portions of the Mid-Mississippi valley... ...Above average temperatures to continue today for much of the central and eastern U.S... ...Rain expected to spread back into the Pacific Northwest by late today... A stationary frontal boundary will bring scattered to numerous showers and thunderstorms from the southern plains to the Ohio valley today. Some thunderstorms could be severe across portions of the Mid-Mississippi valley. Please refer to products issued by the Storm Prediction Center for more details on the severe weather threat. Additionally, some storms could produce heavy rainfall. On Thursday, the front will begin to advance eastward as an upper-level disturbance crossing the Rockies today moves into the plains. The frontal system will spread rain across the lower Great Lakes and into the Northeast on Thursday, with thunderstorms farther south from the Ohio valley to the Southeast. Friday morning should be rainy across much of the Mid-Atlantic and Northeast as the low pressure system begins to deepen. Ahead of the cold front, temperatures will be above average once again today across much of the central and eastern U.S. Temperatures will be most anomalous from the Tennessee valley to the Northeast, where high temperatures will be 10 to 20 degrees above average. As the cold front moves east it will usher a cooler Canadian air mass into the central and eastern U.S. The warm temperatures will hang on into Thursday across the East, however, before the front moves through on Friday. Rain showers are forecast to once again spread into the Pacific Northwest by late today ahead of an incoming frontal system. As the system moves inland on Thursday, rain will move into the northern Intermountain Region, with snow for the highest elevations. Another Pacific front will approach the coast by Friday morning, with the potential for more showers along the coast. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php