Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 416 PM EDT Mon Apr 10 2017 Valid 00Z Tue Apr 11 2017 - 00Z Thu Apr 13 2017 ...Rain and thunderstorms spreading from Texas into the Upper Midwest, slowly shifting 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 decent 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 also 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 outlined portions of Southern and Eastern Texas as being in a Slight Risk for excessive rainfall conducive to producing flash flooding through this evening in addition to the severe weather threat. Please Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php more information on 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 through Tuesday. Abundant moisture will be found wrapping around this low, located behind the cold frontal passage and interacting with a much cooler airmass that is shifting 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 across these areas through this evening, before tapering off overnight as it tracks farther eastward. A more potent system should begin reach 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. Otherwise, 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. Some high temperature records, including daily high minimum temperature and high maximum temperature, may be met or exceeded across portions of the Northeast Tuesday. Record high minimum temperature records may also be met or exceeded along the Northeast and northern Mid-Atlantic coastline for Wednesday morning as well. Shower and thunderstorm chances will eventually begin filling back in across the Southern and central U.S. during midweek ahead of another developing system. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php