Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 243 AM EST Tue Jan 19 2021 Valid 12Z Tue Jan 19 2021 - 12Z Thu Jan 21 2021 ...No let up expected to the damaging wind and fire weather threat across much of California over the next two days... ...Active Lake effect snow showers expected with locally heavy snowfall totals downwind of the Great Lakes... ...Heavy snows likely Tuesday across the Southern Rockies... There is not expected to be any significant changes to the weather pattern affecting California over the next two days. A developing low pressure system off the Southern California coast and strengthening high pressure from the Northern Rockies into the Great Basin will produce strong winds across much of the state of California Tuesday and Wednesday. High winds warnings and advisories continue in effect across much of California where wind gusts may reach 70-80 mph at higher elevations and 50 to 70 mph in valleys and along the coast. These high winds have the potential to produce widespread downed trees and tree limbs, significant property damage and numerous power outages. In addition, the combination of the high winds and low relative humidities will continue to support a significant fire weather, especially along coastal sections from San Francisco to San Diego. The only potential beneficial part of this weather pattern is the increased chances of rainfall for portions of Southern California into southern Arizona Tuesday night into Wednesday as the above mentioned area of low pressure pushes slowly eastward off the northern Baja. Rainfall totals here are not expected to be heavy with the greatest totals associated with this area of low pressure remaining to the southeast across northwest Mexico. An active lake effect snow pattern expected across all of the Great Lakes on Tuesday and over the lower Great Lakes on Wednesday. This will support locally heavy snowfall accumulations downwind of Lakes Erie and Ontario across portions of western and northwestern New York State where lake effect snow warnings are currently in effect. Locally heavy snows also possible downwind of Lake Superior across portions of the Upper Peninsula of Michigan, and downwind of the northern portion of Lake Michigan across the northern portion of the Lower Peninsula of Michigan where winter weather advisories are currently in effect. Heavy snow are also likely Tuesday across portions of the Southern Rockies where accumulations in excess of a foot are possible across the San Juan mountains of southwest Colorado and also the Sangre De Cristo range from south-central Colorado down into northern New Mexico. Oravec Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php