Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Mon May 30 2022

Valid 12Z Mon May 30 2022 - 12Z Wed Jun 01 2022

...An outbreak of severe thunderstorms and tornadoes is likely on this
Memorial Day across parts of northeast South Dakota, southeast North
Dakota, and western and northern Minnesota...

...Severe weather concerns will shift from the northern Plains and upper
Mississippi Valley today down to the southern High Plains and lower
Missouri Valley on Tuesday...

...Colder temperatures and unsettled weather will continue across parts of
the Intermountain West with locally heavy snowfall today for the northern
Rockies...

...Critical fire weather concerns will remain in place today across the
Southern Rockies and Southern High Plains...

The big story for this Memorial Day holiday will the likelihood of a
significant severe weather outbreak across parts of the northern Plains
and the upper Mississippi Valley as a strong upper trough ejecting across
the Intermountain West edges east out across the Plains and allows for a
very strong area of low pressure for this time of the year to advance from
western Kansas this morning northward up across the Red River Valley
tonight before moving into southwest Ontario on Tuesday.

Widespread showers and thunderstorms are expected along and east of the
path of this low center, and there is the expectation of seeing these
thunderstorms turn severe given the strength of low pressure and its
interaction with very moist and unstable air surging north ahead of a cold
front. In fact, numerous severe thunderstorms are expected that will
likely produce large to giant hail, damaging winds and tornadoes,
including the potential for a couple of intense and long-track tornadoes.
The area with the greatest risk of seeing these hazards will be across
areas of northeast South Dakota, southeast North Dakota and through
western and northern Minnesota where the Storm Prediction Center has
highlighted a Moderate Risk of severe weather for today and tonight.

In addition to the severe weather, the showers and thunderstorms will
produce heavy rainfall and there will be concerns for areas of flash
flooding across the central and northern Plains and especially the Red
River Valley area where the Weather Prediction Center has indicated a
Moderate Risk of excessive rainfall. Locally a few inches of rain is
expected across parts of central and eastern North Dakota and possibly
reaching into parts of northwest Minnesota as this low center approaches
and crosses the region going through tonight. The threat for severe
weather and locally heavy rainfall will shift south on Tuesday and will
include areas of the southern Plains northeastward through the lower
Missouri Valley as a cold front makes progress advancing off the east
across the Plains and Midwest.

Meanwhile, a broad upper trough is forecast to remain in place across much
of the Intermountain West through Tuesday, and this will maintain a large
area of below normal temperatures and unsettled weather. In fact, high
temperatures today will be much as 20 to 30 degrees below normal across
areas of the northern Great Basin and the northern Rockies. Widespread and
locally heavy shower activity is expected, and with the colder
temperatures and lowering snow levels, heavy snowfall will continue for
the higher terrain. Storm total snowfall amounts going through Tuesday of
1 to 3 feet are expected for parts of the Absoroka and Big Horn mountains
where the heaviest precipitation is expected. Gradually warming
temperatures and a drying trend are expected for these areas by the middle
of the week as the upper trough weakens and the energy pulls away to the
northeast.

Some of the cooler temperatures across the West over the next couple of
days will be spilling down through the southern High Plains and the
southern Rockies which will be welcome news as there remains at least one
more day of critical fire weather concerns given hot and very dry
conditions along with gusty winds. As a cold front crosses the region,
lowering temperatures will help to reduce the fire danger heading toward
the middle of the week.

Elsewhere, aside from some scattered showers and thunderstorms across the
Florida Peninsula, and the Gulf Coast, generally dry and tranquil weather
will remain in place across the East for a couple more days. However, the
heat and humidity will be on the increase as high pressure offshore of the
East Coast drives southerly flow up from the Gulf of Mexico. This will
yield widespread above normal temperatures with many areas seeing
temperatures ranging from the upper 80s to the mid 90s. The front upstream
across the Plains and Midwest that will be driving severe weather concerns
over the next couple of days will encroach on the East by midweek, and
this will eventually increase the threat of showers and thunderstorms.
While many areas of the East will be briefly rather hot, cooler
temperatures will be noted over New England as a backdoor cold front
slowly sinks south from southeast Canada.

Orrison

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