Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
417 PM EDT Tue May 21 2024

Valid 00Z Wed May 22 2024 - 00Z Fri May 24 2024

...There is a Moderate Risk of severe thunderstorms over parts of the
Middle Mississippi Valley on Tuesday and the Southern Plains/ Lower
Mississippi Valley on Wednesday...

...There is a Slight Risk of excessive rainfall over parts of the
Upper/Middle Mississippi Valley and Upper Great Lakes on Tuesday and
Southern Plains/Lower Mississippi Valley on Wednesday and Thursday...

...Heavy snow over the higher elevations of the Northern Rockies and
Northern Intermountain Region on Tuesday evening and Wednesday evening...

On Tuesday evening, a front extending from the Upper/Middle Mississippi
Valley to the Southern High Plains will move eastward to the Northeast
Coast by Thursday evening. The southern half of the boundary moves
northward as a warm front over the Southern Plains on Thursday, then
dissipates by Thursday evening.

The front will fire showers and severe thunderstorms over Iowa, southwest
Wisconsin, northern Missouri, and northwestern Illinois.  Therefore, the
SPC has issued a Moderate Risk (level 4/5) of severe thunderstorms over
parts of the Middle Mississippi Valley and a small part of the Upper
Mississippi Valley through Wednesday morning.  The potential hazards
associated with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, hail, and a few tornadoes. There will be the
added threat of EF2- EF5 tornados and severe thunderstorm wind gusts of 65
knots or greater over the region. Moreover, there will be an additional
threat of hail two inches or greater over parts of the Mississippi Valley
and the Central/Southern Plains.

Furthermore, the showers and thunderstorms will cause heavy rain to
develop over parts of Minnesota, western Wisconsin, northern Iowa, and
adjacent areas. Therefore, the WPC has issued a Slight Risk (level 2/4) of
excessive rainfall over the Upper Mississippi Valley and Upper Great Lakes
through Wednesday morning.  The associated heavy rain will create mainly
localized areas of flash flooding, with urban areas, roads, small streams,
and low-lying areas the most vulnerable. Additionally, showers and severe
thunderstorms will develop southward over parts of the Southern Plains.
Moreover, showers and thunderstorms will develop over parts of the Central
Plains and Middle Mississippi Valley. 

On Wednesday, as the front moves southward and eastward over the Southern
Plains, the system will produce showers and severe thunderstorms over
parts of the Southern Plains and Lower Mississippi Valley. Therefore, the
SPC has issued an Enhanced Risk (level 3/5) of severe thunderstorms over
parts of the area from Wednesday into Thursday morning.  The hazards
associated with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, hail, and a few tornadoes. In addition, there
will be an added threat of hail two inches or greater over parts of the
region.

Moreover, some of the showers and thunderstorms will produce heavy rain
over parts of the Southern Plains and Lower Mississippi Valley. Therefore,
the WPC has issued a Slight Risk (level 2/4) of excessive rainfall over
the Lower Mississippi Valley and Southern Plains from Wednesday into
Thursday morning.  The associated heavy rain will create mainly localized
areas of flash flooding, with urban areas, roads, small streams, and
low-lying areas the most vulnerable.

On Thursday, the threat of severe thunderstorms decreases slightly as the
boundary moves northward over the Southern Plains/Lower Mississippi
Valley.  Therefore, the SPC has issued a Slight Risk (level 2/5) of severe
thunderstorms over the Central/Southern Plains and the Lower Mississippi
Valley on Thursday morning.  The hazards associated with these
thunderstorms are frequent lightning, severe thunderstorm wind gusts,
hail, and a few tornadoes.

Similarly, the showers and thunderstorms will produce heavy rain over
parts of the Southern Plains/Lower Mississippi Valley. Therefore, the WPC
has issued a Slight Risk (level 2/4) of excessive rainfall over the Lower
Mississippi Valley and Southern Plains on Thursday.  The associated heavy
rain will create mainly localized areas of flash flooding, with urban
areas, roads, small streams, and low-lying areas the most vulnerable.

Meanwhile, another front will move over the Pacific Northwest overnight
Tuesday, advancing to Upper Mississippi Valley and then to the Southwest
by Thursday evening. The system will produce rain over parts of the
Pacific Northwest overnight Tuesday. As the boundary moves farther inland,
the snow levels will lower, producing snow at higher elevations over the
Northwest. Overnight Wednesday, the rain and higher-elevation snow will
move into the Northern Intermountain Region, producing heavy snow at the
higher elevations. On Thursday, the rain and higher-elevation snow will
move into the Northern Rockies. The system will create areas of heavy snow
over the highest elevations.


Ziegenfelder


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