Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Sat Jul 20 2024

Valid 12Z Sat Jul 20 2024 - 12Z Mon Jul 22 2024

...A break in the heat continues for much of the eastern two-thirds of the
country but heat will intensify in the interior Pacific Northwest through
this weekend...

...Scattered thunderstorms continue across the South and Southeast as
monsoonal thunderstorms linger across the Four Corners region...

...Scattered thunderstorms over the central Plains today will gradually
shift in the southern Plains by Monday while a cold front will bring new
rounds of thunderstorms across the northern tier states...

A cool air mass settling in across the eastern two-thirds of the country
will offer an extended reprieve from the heat through the next few days. 
Afternoon high temperatures will only reach into the 70s and 80s today
from the northern and central Plains eastward through the Atlantic coast
with the exception of the Sunshine State and the coastal plain of Georgia
and South Carolina where highs will remain in the 90s.  Texas will have
highs into the 90s to near 100 this afternoon but will cool down into the
70s and 80s by Monday.  In contrast, the heat across the western U.S. is
expected to persist, with high temperatures once again exceeding 100
degrees across much of the region.  The interior Pacific Northwest will
feel the heat intensify, with afternoon readings possibly reaching 110
degrees at the hottest locations by Sunday afternoon along with little
overnight relief.  Daily highs across the Southwest will generally hover
in the 110s. Please continue to practice heat safety in this persistent
and prolonged heat wave in the western U.S. through the next couple of
days.  A Pacific cold front will approach the West Coast on Monday,
lowering the heat only slightly for inland sections.

The upper level pattern will be slow to change across the lower 48 through
the next few days. A nearly stationary front will remain draped across the
South and into the Mid-Atlantic region, keeping the cooler air north of
the boundary and the warm, moist air to the south. The front will also
help focusing and triggering scattered thunderstorms from the Gulf Coast
to the Southeast through the next few days.  For the Southwest/Four
Corners region, monsoonal moisture will continue to support on-and-off
thunderstorms through the weekend.  These storms will keep an elevated
threat for isolated to scattered flash flooding and severe weather, which
may result from the strongest of the storms.  Meanwhile, scattered
thunderstorms over the central Plains today will gradually shift into the
southern Plains by Monday as a weak low pressure wave slowly digs
southward.  Across the northern tier states, a cold front arriving from
central Canada will bring new rounds of thunderstorms from the northern
Plains through northern New England during the next couple of days.

Kong


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