392
FXUS01 KWBC 170801
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Sat Aug 17 2024

Valid 12Z Sat Aug 17 2024 - 12Z Mon Aug 19 2024

...There is a Slight Risk of excessive rainfall over parts of the
Mid-Atlantic on Saturday/Sunday and Southwest/Eastern Great Basin
on Saturday...

...There is a Slight Risk of severe thunderstorms over parts of
the Pacific Northwest, Great Basin, and Ohio Valley on Saturday
and southern Mid-Atlantic to Southeast/Lower Mississippi Valley on
Sunday...

...There are Excessive Heat Warnings and Heat Advisories over
parts of the Southern Plains and Lower Mississippi Valley...

A front extending from the Great Lakes/Ohio Valley across the
Middle Mississippi Valley and then to the Central High Plains will
move eastward to the Mid-Atlantic/Southeast Coast and southward to
the Southern Plains by Monday. On Saturday, showers and
thunderstorms will develop along and ahead of the boundary from
the Great Lakes/Ohio Valley to the Tennessee/Lower Mississippi
Valleys.

Additionally, upper-level energy will intersect a pool of tropical
moisture over the northern Mid-Atlantic, producing heavy rain.
Therefore, the WPC has issued a Slight Risk (level 2/4) of
excessive rainfall over parts of the northern Mid-Atlantic through
Sunday 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.

Furthermore, the boundary will trigger showers and severe
thunderstorms over parts of southwestern Ohio, eastern Kentucky,
and extreme north-central Tennessee. Therefore, the SPC has issued
a Slight Risk (level 2/5) of severe thunderstorms over parts of
the Ohio/Tennessee Valleys through Sunday morning. The hazards
associated with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, hail, and a few tornadoes.

Moreover, upper-level energy and a plume of monsoonal moisture
will aid in creating showers and thunderstorms with heavy rain
over parts of southern Utah and northwestern Arizona. Therefore,
the WPC has issued a Slight Risk (level 2/4) of excessive rainfall
over parts of the Great Basin/Southwest through Sunday 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.

In addition, the energy will produce showers and severe
thunderstorms over parts of the Great Basin. Therefore, the SPC
has issued a Slight Risk (level 2/5) of severe thunderstorms over
parts of the Great Basin through Sunday morning. The hazards
associated with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, and a minimal threat of hail and
tornadoes.

Also, an upper-level low over the Pacific Northwest Coast and
associated energy will develop showers and severe thunderstorms
over parts of Oregon and Washington State on Saturday. Therefore,
the SPC has issued a Slight Risk (level 2/5) of severe
thunderstorms over parts of the Pacific Northwest through Sunday
morning. The hazards associated with these thunderstorms are
frequent lightning, severe thunderstorm wind gusts, hail, and a
minimal threat of tornadoes.

On Sunday, as the front moves into the Mid-Atlantic, Southeast,
and Lower Mississippi Valley, showers and severe thunderstorms
will develop along and ahead of the boundary. Therefore, the SPC
has issued a Slight Risk (level 2/5) of severe thunderstorms over
parts of the southern Mid-Atlantic to Southeast/Lower Mississippi
Valley from Sunday through Monday morning. The hazards associated
with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, hail, and a minimal threat of tornadoes.

Further, a strong pool of moisture will be over the Mid-Atlantic
on Sunday, aiding in producing showers and thunderstorms with
heavy rain over parts of the northern Mid-Atlantic. Therefore, the
WPC has issued a Slight Risk (level 2/4) of excessive rainfall
over parts of the northern Mid-Atlantic from Sunday through Monday
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.

Moreover, monsoonal moisture and daytime heating will create
showers and thunderstorms over parts of the Southwest, Eastern
Great Basin, and Central Rockies from late afternoon into late
evening on Sunday. Additionally, the upper-level low over the
Northwest will produce rain, with maybe an embedded thunderstorm
over the region on Sunday.

  Meanwhile, upper-level ridging over parts of the Southern Plains
and Lower Mississippi Valley will produce high temperatures in the
upper-90s to low-100s with dew points in the low to mid-70s have
prompted Excessive Heat Warnings and Heat Advisories over parts of
the Southern Plains and Lower Mississippi Valley. The sweltering
summer heat will continue over the south. A prolonged stretch of
high temperatures in the upper 90s and triple digits will be
focused over portions of the Southern Plains and Gulf Coast
through Monday. Low temperatures in the low-80s/upper-70s are also
forecast along the Gulf Coast, providing little relief from the
heat overnight. Moreover, the combination of summer heat and high
humidity will support daily maximum heat indices near 110F. People
spending more time or effort outdoors or in a building without
cooling are at an increased risk of heat-related illness.


Ziegenfelder



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


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