Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 344 PM EDT Wed Mar 21 2018 Valid 00Z Thu Mar 22 2018 - 00Z Sat Mar 24 2018 ...Another nor'easter impacting the Mid-Atlantic northward into coastal New England... ...Heavy rainfall with higher elevation snow to continue across California... The fourth nor'easter is currently underway in the Atlantic and is expected to move northward along the eastern seaboard over the next few days. The snowfall impacting the Mid-Atlantic will begin to taper off this evening as the surface low of the nor'easter pulls away from the region--with all the snow coming to an end by tonight. Lingering snow showers are possible along the central Appalachians. Meanwhile, the Northeast and New England will have an increase in snowfall rates this evening and into tonight due to the proximity of the surface low. The axis of heavy snow will shift to coastal New England by early Thursday morning. By Thursday afternoon, the low will move into the Canadian Maritimes--with snow being confined mostly to Maine and finally coming to an end by Thursday night. Meanwhile, an axis of moisture will continue to deliver copious amounts of precipitation to California. Heavy rainfall will occur especially in southern California. The heavy rainfall coupled with burn scars could lead to flash flooding and debris flows. Because of this, a high risk for excessive rainfall is in effect through Friday morning. In addition, heavy snow is expected for the Sierra Nevada where snowfall accumulations of 2 to 4 feet are expected with localized amounts up to 5 feet possible! Precipitation will finally taper off along the Sierra Nevada mountains and southern California by Friday morning. The Pacific Northwest and Great Basin will also experience rain and higher elevation snow--with coverage increasing across these regions by Thursday afternoon and continuing into Friday. Reinhart Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php