Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
332 AM EDT Tue Nov 02 2021

Valid 12Z Tue Nov 02 2021 - 12Z Thu Nov 04 2021

...Lake Effect snow accumulations possible across portions of Michigan and
New York through the early afternoon...

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

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

Cyclonic flow around a deep low pressure system over eastern Canada is
serving to force cool Canadian air southward over the Great Lakes. When
combined with shortwave instability at the surface and forcing via a
passing cold front, this cold air advection is expected to produce a
favorable environment for a rain shower/Lake Effect snow mix over portions
of Michigan and Upstate New York over the next couple days. While only
light accumulations are expected over higher terrain in New York, parts of
Northern Michigan could see widespread totals of 2+" today with isolated
higher amounts of 5-8+", particularly in the Upper Peninsula where Winter
Weather Advisories are currently in effect. Out West a stationary boundary
curving through the Rockies will also serve as the focal point for the
development of both rain and snow. Unlike its eastern counterpart,
moderate to heavy snow accumulations in this part of the country will be
primarily isolated to higher elevations above 8000 ft.

In the neighboring Southern Plains, the southern edge of the
aforementioned stationary boundary is forecast to bring showers and
thunderstorms to much of the region through Thursday morning. On Wednesday
the front and an associated low pressure wave are expected to remain
virtually motionless over Texas, delivering moderate to heavy rainfall to
the eastern portion of the state. With rainfall totals of 2-3+" in 24
hours possible in some areas, the Weather Prediction Center has issued a
Marginal Risk of Excessive Rainfall for portions of eastern Texas
effective Wednesday morning through Thursday morning. Meanwhile, a series
of low pressure systems approaching the Pacific Northwest will bring light
rain and high elevation snow to the region throughout the period.

Temperature-wise unseasonably cool weather is expected to persist
throughout the Central and Eastern US as surface high pressure dominates
and pulls cold air south. The greatest hit to daily maximum temperatures
will be felt in the Central and Southern Plains where highs are forecast
to sit 20 to 25 degrees below normal as they struggle to escape the 40s
and 50s. Less extreme temperature departures of 10 to 15 degrees below
average are also expected throughout the Northern Plains, Midwest, Ohio
Valley, and Northeast. In stark contrast to the cold spell to the east,
temperatures from the Rockies to the West Coast are forecast to remain
around average on Tuesday before warming up on Wednesday. Thanks to a
building upper-level ridge, high temperatures across these regions are
expected to rise to 5 to 10 degrees above average. 

Zavadoff

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