Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 PM EDT Wed May 18 2022

Valid 00Z Thu May 19 2022 - 00Z Sat May 21 2022

...Low pressure system will spread showers/thunderstorms across the
Northeast and Mid-Atlantic with more severe storms to follow over the
upper Midwest next couple of days...

...Early-season heat continues in Southern/Central Plains while heat
begins to build and expand up the East Coast...

...Cold air surges into the West on Thursday followed by mountain snows
down into the central Rockies by Friday...

...Critical fire danger continues over portions of the Southwest into the
Central/Southern Plains...

An increasingly active weather pattern is in store through the next couple
of days as a deep low pressure system pushes onshore over southwestern
Canada followed by a strong surge cold air through the western U.S. 
Precipitation associated with the low pressure system will continue to
spread into the Pacific Northwest and reach into the northern Rockies in
the form of showers and a few thunderstorms across coastal
Washington/Oregon and snow over the higher elevations.  This system is
forecast to re-invigorated over the northern Plains and into the Canadian
Prairies on Thursday, with showers and thunderstorms expanding across the
region, some of which are expected to be heavy and reach severe criteria. 
By Thursday night, additional energy arriving from a cold upper trough in
the western U.S. will trigger another round of showers and a decent chance
of severe thunderstorms, mostly likely across the upper Midwest as a low
pressure wave intensifies along a front.  The front is forecast to stall
on Friday, keeping the best chances of showers and storms from across
Missouri through the Midwest and into the Great Lakes.

Behind the low pressure system, a strong surge of cold air is forecast to
sweep through much of the western U.S. for the next couple of days.  In
addition to the arrival of much colder air, the associated upper trough
will bring an episode of mountain snows down the northern and central
Rockies as well as the nearby foothills/High Plains.  The most notable
location will be over Colorado where near record high temperatures in the
90's on Thursday will be followed by a drastic cool down and the
development of wintry precipitation on Friday.

Meanwhile, showers and thunderstorms will focus around a low pressure
system moving through the Midwest/Ohio Valley today. Localized heavy
rainfall leading to flash flooding is possible over much of Kentucky,
where a Slight Risk of excessive rainfall is in effect. Some thunderstorms
may turn severe, especially over west-central Kentucky where a Slight Risk
of severe thunderstorms is in effect. Wind and hail will be the primary
threats with storms that materialize. Additional severe thunderstorm
activity is marginally possible along the attendant cold front over
portions of the Middle Mississippi Valley, around an upstream system
moving through eastern North Dakota and the Upper Midwest, and another
system gliding across the eastern Colorado and the Southern Plains.

Upper-level ridging will continue a trend of record warmth in the
Central/Southern Plains over the next couple of days. High temperatures in
the 90s and 100s will be 20-30 degrees above average for many parts of
north-central Texas, Oklahoma and the Central Plains through Thursday.
These temperatures will either tie or break many existing records. There
will be little respite for parts of north-central Texas and central
Oklahoma in the evenings as lows are forecast to remain in the 70s over
the next couple of days. A retrograding ridge will jut into the Southeast
from the western Atlantic late Thursday into Friday leading the East Coast
to experience a significant warm up heading into the weekend. Much of the
West will be warmer than normal today and Thursday, as well. Strong winds
will overlap a very dry airmass over the Southwest leading to a Critical
Risk of fire weather for much of the 4 corners region on Thursday.

Kong/Kebede

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