Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
324 AM EDT Wed Nov 03 2021

Valid 12Z Wed Nov 03 2021 - 12Z Fri Nov 05 2021

...Another round of light to moderate Lake Effect snow accumulations
expected across portions of Michigan and New York...

...Quasi-stationary boundary to bring heavy rain to portions of the
Southern Plains today...

...Unseasonably cool temperatures to persist across the Central and
Eastern US as above average temperatures dominate out West...

Anticyclonic flow around a large region of high pressure centered over the
Midwest is serving to force cool Canadian air southward over the Great
Lakes. As this cold air moves over the warm, unfrozen waters it is
expected to interact with shortwave forcing both at the surface and aloft,
creating conditions favorable for the development of Lake Effect rain and
snow downwind of the Great Lakes through Thursday. Light to moderate snow
accumulations of 3-6" are currently forecast for portions of the Michigan
Upper Peninsula and extreme northern Wisconsin, while a slightly lighter
2-5" are in store for Upstate New York east of Lake Ontario and along the
New York/Pennsylvania border east of Lake Erie. Winter Weather Advisories
remain in effect for these affected locations through the late morning.
Out West a stationary boundary curving through the Rockies will also serve
as the focal point for the development of both rain and snow over central
Colorado and southern Wyoming today. Unlike its eastern counterpart,
moderate to heavy snow accumulations in this part of the country will be
isolated higher elevations above 8500 ft, where additional accumulations
of 4-6" remain possible through mid-morning.

In the neighboring Southern Plains, the southern edge of the previously
mentioned stationary front is forecast to bring showers and thunderstorms
to much of the region through Thursday morning. As the front and an
associated low pressure wave slowly meander through southern Texas,
anywhere from 1-2+" of rain are expected to fall over the southern and
eastern parts of the state in 24 hours. These rainfall totals combined
with the potential for rainfall rates of 1.5-2"/hr and localized flash
flooding has prompted the Weather Prediction Center to issue a Marginal
Risk of Excessive Rainfall for portions of south/southeast Texas through
Thursday morning.

Meanwhile, a series of low pressure systems approaching the Pacific
Northwest will bring moderate amounts of coastal rain and high elevation
snow to the region throughout the period. High winds will accompany the
first system as it moves onshore tonight, with gusts as strong as 60 to 75
mph possible over portions of southern Oregon and northern California,
where scattered High Wind Watches and Warnings as well as Wind Advisories
will go into effect this evening. The trailing cold front associated with
this first system is forecast to remain intact as it moves further inland,
bringing light rain and high elevation snow to the Northern Great Basin
and Northern Rockies on Thursday.

Temperature-wise, unseasonably cool weather is expected to persist
throughout the Central and Eastern US as surface high pressure dominates
and draws cold air south. The greatest hit to daily maximum temperatures
will be felt in the Southern Plains, Lower Mississippi Valley, and the
Carolinas where highs are forecast to sit 20 to 25 degrees below normal as
they struggle to escape the 40s and 50s. Furthermore, near to below
freezing overnight lows will be possible in the Middle Mississippi Valley,
Ohio Valley, Mid-Atlantic, and extreme southern New England, where a
mixture of Freeze Watches and Warnings as well as Frost Advisories have
been put into effect. In stark contrast to the cold spell to the east,
temperatures from the West Coast to the Northern Plains are forecast to
remain around or just above average today. Thanks to a building
upper-level ridge, high temperatures across these regions are expected to
rise on Thursday to 10 to 15 degrees warmer than normal.

Zavadoff

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