Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 316 AM EST Fri Nov 23 2018 Valid 12Z Fri Nov 23 2018 - 12Z Sun Nov 25 2018 ...Widespread precipitation to impact the western U.S., with flash flooding and debris flows possible over burn scars... ...Widespread rain is expected in the Mississippi Valley on Friday, spreading to the East on Saturday... ...Light frozen precipitation possible in the Southern and Central Appalachians Friday night into Saturday morning... ...After record lows expected for the Northeast and northern Mid-Atlantic this morning, will return to near normal by the end of the weekend... Multiple frontal systems along with upper level disturbances will move across the western U.S. over the next few days. This will bring an increased amount of precipitation in the area--with rain in the lower elevations and snow in the higher elevations of the Pacific Northwest, northern California, and across the Intermountain West. Although this rainfall is beneficial particularly for northern California since it had been so dry, burn scars from the fires could create hazardous weather and lead to flash flooding. In addition, debris flows are also a hazard. This widespread precipitation is expected to last through Saturday morning. Furthermore, winter storm warnings and winter weather advisories are in effect for today across the higher elevations of the Cascades, Sierra Nevada mountain range, and across the Intermountain West as heavy snow will impact these areas. By Saturday evening and into Sunday morning, precipitation will shift to portions of the northern and central Rockies in addition to the northern/central Plains as the surface low moves from the Plains toward the Mississippi Valley. This system will bring snow to portions of the Plains, middle to upper Mississippi Valley, and Great Lakes late in the weekend and into early next week. On Friday, showers and thunderstorms will develop ahead of a cold front pushing across the Mississippi Valley today. This front is expected to move quickly, thus excessive rainfall is not a threat at this time. To the south, a low pressure system developing in the western Gulf Coast will bring showers and thunderstorms to the western and central Gulf Coast. By Saturday, precipitation will increase across areas from the Southeast northward into the Great Lakes and Mid-Atlantic. Most of this precipitation will be rainfall. However, light snow and freezing rain could be possible tonight into Saturday morning--making travel conditions slick temporarily. Most of the precipitation will clear our across the Southeast and Great Lakes late Saturday--with moderate rainfall continuing across the Mid-Atlantic and Northeast overnight into Sunday morning. After low temperature records expected Friday morning across the northern Mid-Atlantic and Northeast, temperatures will begin to rebound slowly over the weekend. Although temperatures will still remain below normal through Saturday, by Sunday high temperatures will be near average for this time of year. Below normal temperatures of 5 to 15 degrees below normal are forecast for the central U.S. Finally, the western U.S. will be slightly below normal due to the unsettled weather across the region. Reinhart/Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php