Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 AM EDT Thu Oct 22 2020 Valid 12Z Thu Oct 22 2020 - 12Z Sat Oct 24 2020 ...Winter weather from Northern Rockies to Upper Midwest; rain and thunderstorms across Mississippi/Tennessee/Ohio Valleys... ...There is a Slight Risk of severe thunderstorms over the Middle Mississippi Valley; there is a Slight Risk of excessive rainfall over parts of the Upper Great Lakes... ...Cold air dives south through Plains while warm air lingers in the East... ...Critical Fire Risk will be over parts of Northern California and over Southern Rockies/High Plains... Low pressure over the Central High Plains will move northeastward to near James Bay in Canada by Friday evening. The system will produce heavy rain across parts of the Upper Great Lakes on Thursday into Friday morning. The WPC has issued a Slight Risk of excessive rainfall over parts of the Upper Great Lakes. The heavy rain associated with the system will produce mainly localized areas of scattered flash flooding in which the most vulnerable areas will be urban areas, roads, and small streams. Isolated significant areas of flash flooding are possible. In addition, the SPC has issued a Slight Risk of severe thunderstorms over the Middle Mississippi Valley, likewise, on Thursday into Friday morning. The severe thunderstorms will have the main hazards of frequent lightning, severe thunderstorm wind gust, hail, and a limited threat of tornadoes. In addition, the storm in the Plains will produce snow from the Northern Rockies to the Upper Great Lakes. Up to six inches of snow will fall over parts of the Upper Mississippi Valley. The winter weather will produce hazardous driving conditions with slippery roads and increased stopping distance along with other hazards. A second storm will move into the Pacific Northwest on Friday that will produce rain and higher elevation snow over the area. Furthermore, additional snow will develop over the Northern Rockies producing snow 12 to 18 inches with both storms through Friday. Again the winter weather will produce hazardous driving conditions with slippery roads and increased stopping distance along with other hazards. A strong area of high pressure will build over the Plains between systems. The high will stream cold continental Canadian air into the Plains with high temperatures reaching 10-30 degrees below average. Meanwhile, temperatures over the eastern third of the country will be 10 to 25 degrees above average. The threat for fire weather continues over Northern California will be a Critical Fire Risk as dry/windy conditions are forecast to persist. The above average temperatures over the Southern Plains will contribute to the Critical Fire Risk for parts of Eastern New Mexico and the Texas Panhandle. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php