Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 259 PM EST Thu Mar 03 2016 Valid 00Z Fri Mar 04 2016 - 00Z Sun Mar 06 2016 ...Heavy rain over parts of the Olympic Peninsula, northern California and the Sierras... ...Flash flooding possible Friday and Saturday for northern California and the Sierras... ...Snow for parts of the Upper Great Lakes southeastward to the Mid-Atlantic Coast... A low pressure system tracking across the Gulf states and the Southeast has generated showers and thunderstorms from Louisiana to the central Appalachians and portions of the Ohio Valley. Areas of precipitation will taper from the west and spread to the north and east tonight and into Friday as the system pushes offshore into the Atlantic Ocean. Cold air entrenched over portions of the Mid-Atlantic will aid in transitioning the rain to snow this evening for the central Appalachians/Mid-Atlantic region. Accumulations of 1 to 4 inches is forecast and numerous Winter Weather Advisories are in effect. A clipper system will pass through the Great Plains Friday bringing another shot of cold air and light precipitation. Rain is expected across from the Northern Plains/Upper Midwest to the Ohio Valley/northern Appalachians. Multiple Pacific fronts will approach and pass through the Pacific Northwest and parts of the Northern Intermountain West over the next few days. A long duration of an anomalous moisture fetch will stream aid in high rainfall amounts for the portions of the Pacific Northwest and the California. Higher elevation snow will also persist into the weekend. week. The Olympic Peninsula may see rainfall amounts up to 6.5 inches over the next three days. Coastal areas of northern California could see rain amounts exceeding 7 inches. The Sierras have forecast amounts ranging from 5 to 9 inches. Excessive rainfall may lead to rapid runoff and flashing flooding. Additional information on the lash flood potential can be found on WPC's Excessive Rainfall Outlooks section of the webpage. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php