Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
420 AM EDT Mon Oct 11 2021

Valid 12Z Mon Oct 11 2021 - 12Z Wed Oct 13 2021

...Severe weather and heavy rain over the southern Plains this morning
will spread towards the Great Lakes tonight...

...A powerful low pressure system is forecast to bring heavy mountain
snow, high winds and freezes to various parts of the West...

...Another severe weather outbreak anticipated for the central to southern
Plains on Tuesday...

The stage is set for a large and powerful low pressure system to form over
the mid-section of the country as an outbreak of cold air is surging into
the Pacific Northwest behind a sharp cold front.  The coldest air of the
season to date will be ushered into the western states today and into
Tuesday behind the sharp front, bringing high winds from the Great Valley
of California to the Desert Southwest, where High Wind Warnings and Wind
Advisories have been issued in advance for a heightened risk for hazardous
wind gusts.  An impressive upper-level trough will then interact with the
front to produce the first significant winter storm of the season for the
northern and central Rockies on Tuesday into early Wednesday.  Latest
snowfall forecast indicate anywhere from 12 to 24 inches (locally higher
amounts possible) in the northern Rockies, including ranges such as the
Wasatch, Uinta, Absaroka, Teton, Wind River, and Big Horns.  In addition,
high winds will likely result in blowing and drifting of the snow during
the height of the storm over parts of the northern and central Rockies
Tuesday night into early Wednesday.

In the meantime, a low pressure system currently bringing severe weather
and heavy rainfall across the central and southern Plains this morning
will head northeastward and reach the Great Lakes by Tuesday morning.  The
severe storms should be most intense this morning over the Plains but they
should gradually weaken with time as they reach the Mississippi Valley,
the Midwest, and eventually the Great Lakes later today and tonight.  On
Tuesday, the threat of severe storms will gradually come to an end over
the Great Lakes as the low pressure system weakens and heads into Canada.

Meanwhile, the large and powerful low pressure system will set the stage
for yet another severe weather outbreak for much of the central to
southern Great Plains later on Tuesday and into early Wednesday. The Storm
Prediction Center has issued an Enhanced Risk for severe weather from
southern Nebraska and central Kansas to parts of the Oklahoma and Texas
Panhandle.  Excessive Rainfall is also possible in parts of the Great
Plains on Tuesday. While severe weather erupts in the Plains and
cold/snowy conditions take hold of the West, the East remains under the
influence of large scale upper level ridging, allowing above normal warm
temperatures to stick around from the Plains to the East Coast.  A stalled
front with pesky low pressure systems are forecast to linger just off the
East Coast, with the associated rainfall expected to stay largely
offshore.  On the West Coast, some record low temperatures are possible
especially on Tuesday morning.  By later on Tuesday, the next wave of
Pacific moisture is forecast to reach the Pacific Northwest.

Kong/Mullinax


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