Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 PM EDT Sun Apr 09 2017 Valid 00Z Mon Apr 10 2017 - 00Z Wed Apr 12 2017 ...A strong low pressure system will track eastward across the Upper Mississippi Valley and Great Lakes over the next few days, bringing a variety of weather impacts... A strong cold front sinking southward from Canada has combined with another strong cold front tracking eastward across the Plains earlier today, and has now evolved as a single frontal boundary which will slowly track across the Great Lakes and southward across the central U.S. overnight and Monday. The northern extent of the front should reach the Northeast by Tuesday, while the southern extent will make it into the Lower Mississippi Valley during this time. Scattered showers and thunderstorms will continue to develop along and ahead of the frontal passage, with best coverage expected during the afternoon on Monday, stretching from Texas northeast into the Great Lakes. The Storm Prediction Center has outlined a Slight Risk area for severe thunderstorms from the Upper Midwest southward into central Oklahoma for this afternoon into the overnight. They have also highlighted a Slight Risk area for central and northwest Texas, as well as for parts of the Upper Great Lakes region for Monday/Monday night. Please refer to the Storm Prediction Center Website (www.spc.ncep.noaa.gov) for more information. Across the north-central U.S., the remnants of the cold front sinking southward from Canada will allow for much colder temperatures to mix with precipitation chances, impacting the Northern Rockies eastward into the Upper Great Lakes. A combination of rain and snow will be possible over the next couple of days in this region. Accumulating snow will continue along the lee side of the Rockies and portions of the Northern Plains this evening and into tonight. Winter Weather Advisories and Winter Storm Warnings remain in effect across central and Southern Montana as well as northern Wyoming into the overnight as a result. Drier and windy conditions are expected elsewhere across the central and southern U.S. behind the frontal passage. Another Pacific cold front will move inland and across the Pacific Northwest on Monday, bringing yet another round of coastal rain and mountain snow to much of this region and northern California tonight, then spreading inland into the Intermountain West and Northern Rockies over the next couple of days. The rain and snow amounts should be lighter than what was observed over the past few days. Finally, for the eastern U.S. and Deep South, a high pressure ridge will remain in control for another couple of days. This will keep sunny to partly cloudy skies in place across the region, with warming conditions expected through the first part of the work week. High temperatures in the 70s and 80s should be widely present. Also of note, the strong surge of warm air will make it all the way into the northern U.S. just ahead of the cold front (a lot of what is fueling the unstable airmass and thunderstorm chances). The Upper Great Lakes region could see near record breaking high minimum temperatures on Monday morning just before the cold front passage, with much of the Northeast seeing the same by Tuesday morning. Wix/Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php