Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
1148 PM EDT Thu May 19 2022

Valid 12Z Fri May 20 2022 - 12Z Sun May 22 2022

...Record breaking heat is expected to intensify and expand up the East
Coast over 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
in a late-season wintry weather event over the central Rockies/High Plains
late tonight into Saturday...

...Heavy rain and severe thunderstorm threats will focus near a stalled
front from the southern Plains to the Great Lakes today 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. Scattered showers and thunderstorms are expected to move
across the Great Lakes and Northeast today. Isolated severe thunderstorms
may form over parts of the Southern Plains and Lower/Middle Mississippi
Valley this evening due to diurnal heating and instability along a cold
front pushing through the region.

The 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 today. 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. 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 this weekend 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 today, and
reaching into interior New England by Saturday. High temperatures are
forecast to be between 20-30 degrees above average for much of the
Mid-Atlantic and Northeast on 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. 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 arrives over the northern
portions of these areas this weekend.

Kebede/Kong

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