Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
446 PM EDT Thu May 19 2022

Valid 00Z Fri May 20 2022 - 00Z Sun May 22 2022

...Heat is expected to intensify and expand up the East Coast the next
couple of days as heat becomes less intense over the southern Plains...

...Drastically colder air will surge across the western U.S., culminating
with a late-season wintry weather event over the central Rockies/High
Plains late Friday into Saturday...

...Heavy rain and severe thunderstorm threats across the upper Midwest and
the Ohio Valley into tonight will be more focused near a stalled front
from the southern Plains to the Great Lakes Friday and Saturday...

...Critical fire danger continues from the Southwest into the
central/southern High Plains before the arrival of cold air this weekend...

An increasingly active weather pattern is expected to transpire as a
significant surge of cold air moving through the western U.S. will collide
with a large dome of heat that is forecast to shift from the South to the
East Coast.  In the meantime, clusters of thunderstorms associated with a
pair of frontal boundaries could become severe and result in locally heavy
rain across the upper Midwest and into the Ohio Valley through tonight. 
These activities will tend to diminish as they move across the Northeast
and the Mid-Atlantic on Friday.  However, new rounds of heavy rain and
severe thunderstorms are expected to develop across the upper Midwest on
Friday as a low pressure system intensifies over the northern Plains ahead
of the surge of cold air arriving from the western U.S.  By late Friday
into Saturday, the potential for heavy rain and severe thunderstorms will
be focused near a stalled front extending from the southern Plains to the
Great Lakes.

The aforementioned surge of cold air associated with a digging upper
trough will overspread much of the western U.S. with unseasonably cold
temperatures together with a round of heavy mountain snows, first from the
northern Rockies and then down to the Colorado Rockies by Friday.  6-10
inches of snow with locally higher amounts are possible for the
aforementioned areas by Saturday morning.  Strong and gusty winds are also
expected in these areas into the High Plains as the low pressure system
intensifies.  By Friday into Saturday, the surge of cold air will bring a
dramatic drop of temperatures from the 90s down to freezing across the
central High Plains where a late-season winter weather event is forecast
to develop.  Potential exists for more than a foot of snow across the
higher elevations of the Colorado Rockies while accumulating snowfall can
be expected down into the central High Plains.

Meanwhile, a heat wave is forecast to intensify and expand up the East
Coast during the next couple of days under a strengthening upper-level
ridge.  Increasingly warm southwesterly wind flow around the Bermuda high
will send afternoon temperatures to record levels.  Much of the
Mid-Atlantic, Carolinas and Ohio/Tennessee Valley will experience highs
well into the 90s on Friday, and reaching into interior New England by
Saturday.  Across the southern Plains, the heat is expected to become less
intense as the cold air approaches from the north.  However, highs are
still into the 90s across much of the South on Saturday.

Temperatures will remain above average over much of the southern/central
Plains today as high pressure glides across the Southern Plains. Highs
will be in the 90s and 100s for a large swath extending north-south from
west-central Texas up to Nebraska, which will tie or break existing high
temperature records. These temperatures will be 20-30 degrees above
average. This sustained heat wave, which began days ago, lead to the
issuance of Excessive Heat Warnings for parts of central Texas including
Abilene and San Angelo this afternoon. Extreme heat will significantly
increase the potential for heat related illnesses, particularly for those
working or participating in outdoor activities.  Farther west, a Critical
Fire risk remains in effect for much of New Mexico, Colorado, southern
Utah and northern Arizona today as windy/dry conditions fuel the fire
threat.   Red Flag warnings are in effect for these areas before the surge
of cold air reaching into the northern portion of these areas by this
weekend.

Kong/Kebede

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