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.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php