Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 310 AM EST Wed Dec 07 2016 Valid 12Z Wed Dec 07 2016 - 12Z Fri Dec 09 2016 ...Heavy snow possible over the Sierras... ...Heavy snow possible in downwind favored areas from the Great Lakes... ...Rain/freezing rain possible over interior portions of the Pacific Northwest/Northern California... ...Temperatures will be 15 to 35 degrees below average over the Northern/Central Rockies and High Plains... Deep low pressure just north of the Great Lakes will slowly move northeastward to just east of James Bay by Thursday evening. The energy will produce snow over parts of the Northern Plains to the Upper Great Lakes through Thursday with the snow ending over the Northern Plains and the Upper Mississippi Valley on Thursday afternoon into evening. The associated upper-level low will pass just north of the Keweenaw Peninsula on Wednesday that will aid in producing the heaviest snow over that region of the Great Lakes. The lake effect/enhanced snow will move into the Lower Great Lakes on Thursday morning into evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php