Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 234 PM EST Thu Jan 31 2019 Valid 00Z Fri Feb 01 2019 - 00Z Sun Feb 03 2019 ...Heavy rain along the coast and heavy snow in the Sierra Nevada expected in California... ...Temperatures finally rebound as Arctic airmass moves away from the north and eastern U.S... Heavy rain that has been impacting the southern California coast will wind down by later tonight and into Friday morning as the upper low moves into northern Mexico. Some light showers/higher elevation snow is possible in Arizona on Friday morning associated with this system. However, a digging trough will begin to approach the West Coast by Friday afternoon. Precipitation will start that morning, increasing significantly by the afternoon. Most of the heavy precipitation in the Pacific Northwest and northern California will occur on Friday as a frontal system moves over the region. Snow is expected for the Washington Cascades, with even lighter amounts for the Oregon Cascades and higher elevation in northern California. Precipitation will increase significantly on Saturday--bringing heavy rain along the coast along with very heavy snowfall for the Sierra Nevada. Flash flooding and debris flows will be a concern particularly near burn scar areas. Additionally, snow total accumulations from Friday afternoon through the weekend in the Sierra Nevada could reach 5 feet for elevation above 5000 feet! Monitor all local watches, warnings and advisories with this event at www.weather.gov. The end life-threatening cold that has gripped the Upper Midwest and Great Lakes, in addition to the Ohio Valley, Mid-Atlantic, and Northeast, is finally near as the upper low causing this begins to lift northward into eastern Canada. By Friday, temperatures in the Upper Midwest will finally rebound to well above zero--with high temperatures making it into the teens and low 20s. By Saturday, high temperatures will be in the 30s and even low 40s. Additionally, the central Plains will see temperatures in the low 60s--which is nearly 20-25 degrees above normal. Elsewhere, the snow downwind of the Great Lakes will finally begin winding down by tonight and into tomorrow. A clipper system will deliver light snow along the central Appalachians and portions of the Mid-Atlantic by Friday afternoon--with some light showers stretching into the lower Mississippi Valley. A wavy frontal boundary in the Gulf of Mexico will provide focus for showers and possible embedded thunderstorms for the western Gulf Coast through Saturday. Reinhart Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php