Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 239 PM EST Wed Nov 20 2019 Valid 00Z Thu Nov 21 2019 - 00Z Sat Nov 23 2019 ...Heavy mountain snow over the Central/Southern Rockies as well as the Great Basin/Southwest... ...Heavy snow over the Upper Mississippi Valley/Upper Great Lakes... ...There is a moderate risk of excessive rainfall over parts of the Southwest... ...There is a critical risk of fire weather over parts of Northern/Central California... A long stretch of warmer and drier conditions over parts of Northern/Central California has primed that area for potential spread of wildfires and this airmass is expected to persist through Thursday. As such, there is a critical risk for fire weather across Northern California through Thursday morning. For the Southwest U.S., heavy mountain snow and moderate to heavy rain in the lower elevations is expects as a deep upper-level low tracks east across the region. The precipitation shield will shift into the Southern/Central Rockies/High Plains as the front approaches. The intensity and during of some of these downpours will likely lead to numerous flash flooding of many streams and potentially affecting larger rives through Thursday morning. Much of West-Central and Southern Arizona has a Slight to Moderate Risk for Excessive Rainfall. Low pressure over the Central High Plains will move northeastward to the Great Lakes by Thursday evening and the associate front will move off the Northeast Coast by Friday evening. The system will produce rain and snow over parts of the Central/Northern Plains into the Upper Mississippi Valley/Upper Great Lakes overnight Wednesday into Thursday evening. The snow will end over the Upper Great Lakes/Upper Mississippi Valley by Friday morning. Light snow will fall across the higher terrain of the Northeast Wednesday night into Thursday. As the front moves across the Northeast areas of rain/freezing rain will develop overnight Thursday into Friday afternoon. Rain will move into parts of the Northeast overnight Thursday into Friday morning that will change over to snow on Friday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php