Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 259 AM EST Tue Dec 12 2017 Valid 12Z Tue Dec 12 2017 - 12Z Thu Dec 14 2017 ...Improving but still elevated fire weather conditions for Southern California... ...Coastal storm to bring wintry conditions to portions of the Northeast today and tonight... ...Locally heavy lake effect snowfall to continue downwind of the Great Lakes... Strong high pressure over the West is expected to gradually weaken into mid-week which should lessen the wildfire threat across Southern California but keep warm temperatures in place. Gusty winds and low relative humidities will continue to pose elevated fire weather conditions today, with a diminished but non-zero threat for Wednesday. Low pressure will organize and strengthen over the lower Great Lakes today, dragging a cold front across the East Coast. Much colder temperatures will filter in behind a strong cold front for the East Coast tonight into Wednesday with expected high temperatures on Wednesday 10 to 20 degrees below average from Florida to the Great Lakes. Meanwhile, as the low pressure center continues to wrap up tonight into Wednesday morning over New England, moderate snowfall is expected for portions of upstate New York into interior portions of New England with a wintry mix possible from central Massachusetts to the coast of Maine. Winter Storm Warnings and Winter Weather Advisories are in effect for these locations through Wednesday morning given the anticipated deteriorating conditions. Cold air blowing across the relatively warm Great Lakes will continue to produce lake effect snow showers with the greatest snowfall accumulations through Thursday across southwestern Lower Michigan and east of lakes Erie and Ontario where local totals over a foot will be possible. The north-central U.S. and upper Mississippi Valley will see a series of weak clipper systems move through the region tonight and Wednesday night. In advance of the first clipper, downslope winds will generate high temperatures across the central and northern High Plains in the 50s and 60s, well above average for mid-December. Colder temperatures will reside farther north and east in this pattern with the clipper systems generating light snow or a wintry mix across the eastern Dakotas into Minnesota but with any accumulations generally below an inch. Otto Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php