Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 408 PM EDT Sat Oct 26 2019 Valid 00Z Sun Oct 27 2019 - 00Z Tue Oct 29 2019 ...There is a critical to extreme fire weather threat over parts of Northern/Central California... ...There is slight risk of excessive rainfall over parts of the Southern Appalachians... ...Heavy snow for parts of the Central Rockies/High Plains... A deep storm over the Western Ohio Valley will move northeastward to the Great Lakes on Sunday evening as a new low develops over Southern New England. On Monday the new low will move eastward out over the Western Atlantic. A strong stream of moisture will move northward out of the Eastern Gulf of Mexico and the Atlantic moving into the Ohio Valley and the Southeast. Rain will develop over the Ohio Valley into the Great Lakes that will move into parts of Canada on Sunday. In addition, heavy rain will develop over parts of the Southern/Central Appalachians overnight Saturday that will move northeastward into New England by Sunday evening, then off the Northeast Coast by Monday. The heavy rain associated with the system will produce areas of scattered flash flooding that will be mainly localized over parts of the Southern Appalachians. During this time period, showers and thunderstorms will develop over parts if the Southeast and move mostly off the coast by Monday. A front extending from the Upper Mississippi Valley to the Central High Plains then westward to Northern California will move eastward to the Great Lakes/Western Ohio Valley into the Middle Mississippi Valley and southward to the Southern Plains, the Southwest, and Southern California Sunday into Monday. In the wake of the front, cold high pressure will move into the Northern/Central Rockies from Western Canada by Monday. Temperatures associated with the high pressure will be 20 to 30 degrees below average over the Northern/Central Rockies and Northern/Central High Plains by Sunday evening. As the high pressure moves in, upslope flow will aid in producing snow over the Northern/Central High Plains and Northern/Central Rockies. Winter Storm Warning and Winter Weather Advisories are posted over the region from Saturday evening into Monday morning. As the high pressure builds in, a strong pressure gradient will develop over Northern California into parts of the Great Basin and Northern/Central Rockies that will produce high winds over the region. Low relative humidity, warm temperatures, and a long with strong winds will lead to Critical to Extreme fire weather conditions over Northern California Saturday evening into Monday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php