Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
321 AM EDT Fri Apr 18 2025
Valid 12Z Fri Apr 18 2025 - 12Z Sun Apr 20 2025
...Moderate to heavy snow over parts of the Central Rockies on Friday and
Saturday...
...There is a Slight Risk of excessive rainfall over parts of the Middle
Mississippi Valley and Southern Plains on Friday and a Moderate Risk of
excessive rainfall over parts of the Middle Mississippi Valley and
Southern Plains on Saturday...
...There is a Slight Risk of severe thunderstorms over parts of the Ohio
Valley to the Southern Plains on Friday and from the Middle/Lower
Mississippi Valley to the Southern Plains on Saturday...
A front extending from the Upper Midwest to the Central Plains and then
across the Central Rockies into the Southwest will move eastward off the
Northeast Coast and then from the Mid-Atlantic to the Southern Plains by
Sunday morning. On Friday, the system will produce showers and severe
thunderstorms from the Ohio Valley to the Southern Plains. Therefore, the
SPC has issued a Slight Risk (level 2/5) of severe thunderstorms over
parts of the Ohio Valley to the Southern Plains through Saturday morning.
The hazards associated with these thunderstorms are frequent lightning,
severe thunderstorm wind gusts, hail, and a few tornadoes. Furthermore,
there is an added threat of hail, two inches or greater, over the Southern
Plains.
In addition, the showers and thunderstorms will produce heavy rain over
parts of the Middle Mississippi Valley and Southern Plains on Friday.
Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive
rainfall over parts of the Middle Mississippi Valley into the Southern
Plains through Saturday 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.
Further, showers and thunderstorms will develop over parts of the Great
Lakes on Friday and continue into Saturday. Rain with embedded
thunderstorms will develop over parts of the Northeast by Friday evening.
Moreover, the upper-level low associated with the front on Friday will
produce moderate to heavy snow over parts of the Central Rockies. Rain
will also develop over the lower elevations of the Southwest and Central
High Plains.
On Saturday, as the front moves southeastward, showers and severe
thunderstorms will develop over parts of the Middle/Lower Mississippi
Valley and Southern Plains. Therefore, the SPC has issued a Slight Risk
(level 2/5) of severe thunderstorms over parts of the Middle/Lower
Mississippi Valley and Southern Plains from Saturday into Sunday morning.
The hazards associated with these thunderstorms are frequent lightning,
severe thunderstorm wind gusts, hail, and a few tornadoes. Additionally,
there is an added threat of hail, two inches or greater, over the Southern
Plains.
The threat of excessive rainfall will increase on Saturday over parts of
the Middle Mississippi Valley into the Southern Plains. Therefore, the WPC
has issued a Moderate Risk (level 3/4) of excessive rainfall over parts of
the Middle Mississippi Valley into the Southern Plains from Saturday into
Sunday morning. Numerous flash flooding events are possible and many
streams may flood, potentially affecting larger rivers.
Moreover, showers and thunderstorms will develop from the Ohio Valley to
the Northeast on Saturday, ending over the Northeast by Sunday morning.
Furthermore, on Saturday, the upper-level low over the Central/Southern
Rockies will produce moderate to heavy snow over parts of the region.
Lower-elevation rain will also develop over parts of the Central/Southern
High Plains on Saturday. The snow will end over the region by Sunday
morning.
Meanwhile, late Friday night, a new front will move onshore over the
Pacific Northwest and move eastward to the Northern High Plains to the
Northern Intermountain Region/Great Basin by Sunday morning. The system
will produce rain and the highest-elevation snow over parts of the
Cascades and Northern Intermountain Region overnight Saturday into Sunday
morning.
Ziegenfelder
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php