Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
225 PM EST Tue Jan 19 2021
Valid 00Z Wed Jan 20 2021 - 00Z Fri Jan 22 2021
...Damaging winds and critical fire weather to come to an end across
California on Wednesday...
...Multiple rounds of snow showers across the Great Lakes and Northeast
with locally heavy snowfall totals downwind of the Great Lakes...
The weather pattern responsible for damaging winds and critical fire
weather across California is expected to gradually weaken by Wednesday
evening. A developing low pressure system off the Southern California
coast and strengthening high pressure from the Northern Rockies into the
Great Basin is fueling strong winds across much of the state of California
tonight and into Wednesday. High Wind warnings and advisories continue
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 high winds and low relative humidities
will continue to support a significant fire weather risk, especially along
coastal sections from San Francisco to San Diego. The only potentially
beneficial part of this weather pattern is the increased chances of
rainfall for portions of southern California into southern Arizona through
Thursday morning as the aforementioned area of low pressure pushes slowly
eastward off the northern Baja. Rain could be heavy at times across far
southeastern California and southwest Arizona, where Flash Flood Watches
have been issued.
Meanwhile, an active lake effect snow pattern is expected across much of
the Great Lakes through Thursday. Two separate systems are forecast to
cross the region over the next few days, the first will exit overnight,
while the second enters on Thursday. This will support locally heavy
snowfall accumulations mainly downwind of Lake Erie and Lake Ontario,
where Lake Effect Snow Warnings are currently in effect. Locally heavy
snow is also possible downwind of Lake Superior across portions of the
Upper Peninsula of Michigan, and downwind of Lake Michigan as well. There
will also be the potential for upslope snow showers across the central
Appalachians, with 2 to 4 inches of snowfall possible.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php