Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
357 AM EDT Thu Apr 20 2023

Valid 12Z Thu Apr 20 2023 - 12Z Sat Apr 22 2023

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

...There is a Slight Risk of excessive rainfall over parts of the
Middle/Lower Mississippi Valley, Tennessee Valley, and the Southern Plains
on Thursday and Friday...

...Moderate to heavy snow over parts of the Northern Plains/Upper
Mississippi Valley on Thursday; snow over the Cascades, Northern
Intermountain Region, and Northern/Central Rockies on Thursday and
Friday...

On Thursday, a front extending from the Middle Mississippi Valley to
Southern Plains then westward to the Southwest, will slowly move eastward
to the Lower Great Lakes roughly southward to the Central Gulf Coast by
Saturday morning. In addition, moisture will flow northward over the
Southern Plains, Middle/Lower Mississippi Valley, and the Great Lakes.

As a result, on Thursday, showers and severe thunderstorms will develop
over parts of the Southern Plains and Middle/Lower Mississippi Valley as
the front moves onto the Mississippi Valley. Therefore, the SPC has issued
a Slight Risk of severe thunderstorms over parts of the Southern Plains
and Middle/Lower Mississippi Valley through Friday morning. The hazards
associated with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, hail, and a few tornadoes. Additionally, there is
a greater risk of two-inch or greater hail over parts of the Southern High
Plains.

Moreover, heavy rain will accompany the thunderstorms over parts of the
Southern Plains and Middle/Lower Mississippi Valley. Therefore, the WPC
has issued a Slight Risk of excessive rainfall over parts of the Southern
Plains and Middle/Lower Mississippi Valley through Friday morning. The
associated heavy rain will create localized areas of flash flooding,
affecting areas that experience rapid runoff with heavy rain.
Additionally, showers and thunderstorms will develop over parts of the
Great Lakes on Thursday.

Furthermore, on Thursday, moderate to heavy snow will develop over parts
of the Northern Plains and Upper Mississippi Valley, continuing into
Friday morning. On Friday, the snow will become moderate over parts of the
Northern Plains and Upper Mississippi Valley.

Moreover, on Friday, the threat of severe thunderstorms decreases slightly
to a marginal threat along the Western/Central Gulf Coast. However, heavy
rain will accompany the thunderstorms over parts of the Tennessee Valley
to the Central Gulf Coast. Therefore, the WPC has issued a Slight Risk of
excessive rainfall over parts of the Tennessee/Lower Mississippi Valleys
from Friday into Saturday morning. The associated heavy rain will create
mainly localized areas of flash flooding, with urban areas, roads, and
small streams the most vulnerable.

In the meantime, on Friday, rain with embedded thunderstorms will move
across the Great Lakes into the Ohio Valley, moving into the Lower Great
Lakes on Friday afternoon, and into the Central Appalachians overnight
Friday.

Meanwhile, on Thursday, onshore flow and upper-level energy will create
coastal rain and higher-elevation snow, in the Cascades, over the Pacific
Northwest and Northern California. The light snow will extend into the
Northern Intermountain Region, Northern Rockies, and parts of the Central
Rockies through to Saturday. Elsewhere, onshore flow will create showers
and thunderstorms over parts of Florida through Saturday morning.


Ziegenfelder


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