Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 259 AM EST Thu Mar 09 2017 Valid 12Z Thu Mar 09 2017 - 12Z Sat Mar 11 2017 ...Heavy snow possible from the Northern Rockies into the Northern Plains over the next couple of days... ...Heavy rain possible over parts of the Pacific Northwest today... ...Scattered showers and thunderstorms possible across the Southern Plains and deep South over the next few days... ...Snow possible over parts of the Northern Mid-Atlantic, Central Appalachians, and Northern Ohio Valley Thursday evening into Friday... A persistent east/west front across the Northwest will be followed by cold front moving onshore on Friday morning. A plume of moisture associated with the boundary will aid in producing rain over parts of Northern California and Pacific Northwest through Friday. In addition, snow will develop over the higher elevations of the Northern Rockies into parts of the Northern High Plains through Friday morning. Snow will then taper off across the Rockies and move farther southeast into the Central Plains. Winter Weather Warnings and Advisories are in effect for much of the Northern Rockies and portions of the Northern Plains for the expected heavy snow. Meanwhile, warm moist flow from the Gulf of Mexico will interact with a fast moving cold front pushing southward across the eastern U.S. This will allow for scattered showers and thunderstorms over parts of the Southern Plains today, expanding northeastward into parts of the Ohio Valley by Thursday afternoon, and across the southeast Thursday night into Friday. Furthermore, snow and rain will develop over the northern Ohio Valley expanding into the Central Appalachians and Northern Mid-Atlantic overnight Thursday into Friday morning thanks to return flow off of the Atlantic and falling temperatures behind the cold front. Elsewhere, a secondary push of colder northeast flow across the Upper Great Lakes will aid in triggering lake induced snow showers over parts of the area overnight Thursday into Friday. This airmass will spread eastward and aid in producing snow showers downwind of the Lower Great Lakes by Friday. High pressure will be in control across much of California and the Southwest, keeping conditions dry over the next few days. Ziegenfelder/Wix Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php