Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 358 PM EDT Mon Apr 10 2017 Valid 00Z Tue Apr 11 2017 - 00Z Thu Apr 13 2017 ...Rain and thunderstorms for Texas and the Upper Midwest, slowly spreading eastward over the next few days... ...A wintry mix of snow, rain, and ice will impact portions of the Upper Mississippi Valley and Upper Great Lakes through Tuesday... ...More rain and higher elevation snow is expected to impact the Pacific Northwest over the next few days... An extensive cold front stretching from central Texas northeast through the Upper Great Lakes this afternoon will continue a slow shift eastward over the next few days while maintaining decent strength. Along and just ahead of this front will be an area of good moisture and lift, conducive to producing showers and thunderstorms, some of which could be strong. The Storm Prediction Center has outlined a portion of the Upper Midwest/Upper Great Lakes region as being in a Slight Risk for severe thunderstorm Development through this evening, with a Severe Thunderstorm Watch in place. An area spanning from South-Central Texas northeast into the Ark-La-Tex region is also highlighted in a Slight Risk area for this time frame. Please refer to the Storm Prediction Center website (www.spc.ncep.noaa.gov) for more information. The Weather Prediction Center has also outlined portions of Southern and Eastern Texas as being in a Slight Risk for excessive rainfall conducive to producing flash flooding through this evening as well. Please refer to the Weather Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php this threat. A flash flood watch has been issued in this area as a result. A surface low pressure system will travel northeast with the front, crossing the Great Lakes overnight as it continues Northeast. Abundant moisture will be found wrapping around this low, on the backside of the frontal passage and in the cold sector as a much cooler airmass shifts southward from Canada. As such, this precipitation is anticipated to fall as a mixture of rain, snow, and ice across the Upper Mississippi Valley and Upper Great Lakes tonight into Tuesday before tapering off. A Winter Weather Advisory is in effect through Tuesday morning for far northern Wisconsin in response to accumulating snow and freezing rain chances. Several low pressure systems are expected to impact the Pacific Northwest over the next few days. One system that continues to move inland across the Northern Rockies and into the Northern Plains will result in snow showers through this evening, before tapering off overnight as it tracks farther eastward. Otherwise, a more potent system should begin impacting the shore by midweek, bringing mainly widespread rain from Northern California northward into the Pacific Northwest and Northern Great Basin starting Tuesday afternoon/evening. Highest elevations will likely see snow. Across the eastern U.S., mostly sunny and warm conditions are expected ahead of the approaching cold front to the west through Tuesday. Scattered showers and isolated thunderstorms arrive by the middle of the week. Shower and thunderstorm chances will also begin filling back in across the Southern U.S. during midweek as well. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php