Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 PM EDT Sun Jul 31 2022

Valid 00Z Mon Aug 01 2022 - 00Z Wed Aug 03 2022

...Heavy rain is likely to continue the flash flood risk over the southern
Mid-Atlantic, central/southern Appalachians, and into parts of the
Ohio/Tennessee Valley through this evening...

...Anomalous monsoonal moisture over the Southwest to continue the threat
of flash flooding over the next few days...

...Some severe thunderstorms will be possible across the Upper Midwest
this evening and into the Ohio Valley on Monday, before returning to the
Upper Midwest on Tuesday...

...Excessive heat persists over the Pacific Northwest on Monday, while
spreading into the northern Plains to start the month of August...


A lingering frontal boundary draped across the Mid-Atlantic and Ohio
Valley is finally forecast to begin lifting northward tonight and produce
continuing concerns for flash flooding. Parts of southeastern Kentucky are
most at risk to flash flooding this evening as soils remain overly
saturated from previous drenching rainfall from the past week. Additional
storms containing intense rainfall rates are likely to create instances of
flash flooding if they pass over this region, prompting a Moderate Risk
(level 3/4) of Excessive Rainfall to remain in effect over southeast
Kentucky through tonight. Elsewhere, a Slight Risk (level 2/4) of
Excessive Rainfall extends along the same boundary from the southern
Mid-Atlantic to the lower Mississippi Valley. Here, scattered chances for
flash flooding exist. Flooding can be particularly dangerous and hard to
see at night, residents are advised to plan ahead before traveling and
never drive through a flooded roadway. By Monday, the overall heavy rain
threat is expected to diminish as thunderstorm activity becomes more
scattered and less organized. However, there remains a concern for
additional flash flood chances over susceptible terrain along the
central/southern Appalachians and into eastern Kentucky/Tennessee.

The other area contending with heavy rainfall chances is over the
Southwest and associated with the summer monsoon. Anomalous moisture in
place throughout the Southwest and into the central Great Basin will aid
thunderstorm development and the potential for numerous downpours. In
order to highlight the flash flooding concern, a Slight Risk of Excessive
Rainfall is in effect through tonight from southern Nevada and Utah to
south-central Arizona and western New Mexico, including parts of southeast
California. Areas near recent burn scars, slot canyons, urban corridors,
and other vulnerable terrain are most at risk for flooding impacts. The
current plume of monsoonal moisture is expected to gradually lift
northward on Monday into the Great Basin and eventually spread into the
northern Rockies by Tuesday, where isolated flash flooding is possible.

Hazardous weather in the form of severe thunderstorms are also possible
heading into the beginning of August for some parts of the Nation. An
advancing cold front located over the Midwest and central Plains this
evening may spark a few strong thunderstorms capable of containing
damaging wind gusts, isolated tornadoes, and large hail. Thus, the Storm
Prediction Center has issued a Slight Risk (level 2/5) of severe weather
over portions of eastern Minnesota and northwestern Wisconsin.
Additionally, a few tornadoes and damaging wind gusts cannot be ruled out
across North Carolina and southern Virginia tonight as thunderstorms form
along a warm front. By Monday, as the aforementioned cold front over the
Midwest advances eastward, severe thunderstorms are possible over the Ohio
Valley and into parts of the Mid-Mississippi Valley. Damaging wind gusts
are expected to be the primary hazard associated with these storms.
Fast-forwarding to Tuesday, a separate system entering the northern Plains
will potentially produce another round of severe thunderstorms in/around
Minnesota.

Record-breaking summer heat will remain a major weather story across the
Pacific Northwest on Monday, but relief is on the way as the well above
normal temperatures shift eastward into the northern Plains by Tuesday.
The anomalous upper-level ridge currently located over this Northwest is
forecast to be suppressed by strong upper-level energy entering western
Canada. This will allow for temperatures over Washington and Oregon to
return to near normal by Tuesday. However, highs are still anticipated to
reach into the upper 90s and low 100s across the Columbia Basin on Monday,
which may threaten daily high temperature records. For the northern
Plains, highs 10 to 20 degrees above average are expected over Montana,
the western Dakotas, and western Nebraska on Monday, which equates to
highs right around 100 degrees. By Tuesday, excessive heat consolidates
over South Dakota and surrounding states, where highs are forecast to
reach into the triple digits.

Snell

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