Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
428 PM EDT Tue Jul 30 2024
Valid 00Z Wed Jul 31 2024 – 00Z Fri Aug 02 2024

…There is an Enhanced Risk of severe thunderstorms over parts of the
Central Plains and Middle Mississippi Valley on Tuesday evening and
Wednesday with a Slight Risk of severe thunderstorms over parts of the
Ohio Valley on Thursday…

…There is a Slight Risk of excessive rainfall over parts of the Middle
Mississippi Valley and Ohio/Tennessee Valleys on Tuesday evening and
Wednesday…

…There is a Slight Risk of excessive rainfall over parts of Northern New
England and Southwest on Wednesday and over parts of the Ohio Valley on
Thursday…

…There are Excessive Heat Watches over parts of the Pacific Northwest
and Excessive Heat Warnings/Advisories over parts of the Central/Southern
Plains, Middle/Lower Mississippi Valley, Ohio/Tennessee Valleys, and the
Southeast.

A front with a wave of low pressure over the Northern High Plains will
move slowly eastward to the Ohio Valley/Great Lakes by Thursday. The
associated boundary will aid in triggering showers and severe
thunderstorms over parts of the Central Plains, Middle Mississippi Valley,
and parts of the Ohio/Tennessee Valleys. Therefore, the SPC has issued an
Enhanced Risk (level 3/5) of severe thunderstorms over the Central Plains
and Middle Mississippi Valley through Wednesday morning. The hazards
associated with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, hail, and a few tornadoes. Also, there is a
threat of severe thunderstorm wind gust of 65 knots, or greater over parts
of the Central Plains, Middle Mississippi Valley and hail two inches, or
greater over parts of the Central Plains.

In addition, showers and thunderstorms will create heavy rain over parts
of the Middle Mississippi Valley and Ohio/Tennessee Valleys. Therefore,
the WPC has issued a Slight Risk (level 2/4) of excessive rainfall over
parts of the Middle Mississippi Valley and Ohio/Tennessee Valleys through
Wednesday 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.

A second area of severe thunderstorms is forecast over parts of the
Northern Plains. Therefore, the SPC has issued a Slight Risk (level 2/5)
of severe thunderstorms over parts of the Northern Plains through
Wednesday morning. The hazards associated with these thunderstorms are
frequent lightning, severe thunderstorm wind gusts, hail, and a few
tornadoes.

As the wave of low-pressure moves eastward overnight Tuesday into
Wednesday, the system will create showers and severe thunderstorms over
parts of the Middle Mississippi Valley. Therefore, the SPC has issued an
Enhanced Risk (level 3/5) of severe thunderstorms over the Middle
Mississippi Valley from Wednesday through Thursday morning. The hazards
associated with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, hail, and a few tornadoes. Moreover, there is an
increased threat of severe thunderstorms wind gust of 65 knots or greater
over parts of the Central/Southern Plains and Upper/Middle Mississippi
Valley. Additionally, there is a threat of hail two inches or greater over
parts of the Northern/Central Plains and Upper Mississippi Valley.

Furthermore, showers and thunderstorms will produce heavy rain over parts
of the Northern Plains, Upper/Middle Mississippi Valley, and Ohio Valley.
Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive
rainfall over parts of these areas from Wednesday through Thursday
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, upper-level energy and a plume of moisture moving over New
England will produce areas of heavy rain. Therefore, the WPC has issued a
Slight Risk (level 2/4) of excessive rainfall over parts of Northern New
England from Wednesday through Thursday 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.

Similarly, upper-level energy and a plume of moisture will create areas of
heavy rain over parts of the Southwest. Therefore, the WPC has issued a
Slight Risk (level 2/4) of excessive rainfall over parts of the Southwest
from Wednesday through Thursday 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.

On Thursday, the wave of low pressure continues to move eastward,
producing showers and severe thunderstorms over parts of the Ohio Valley.
Therefore, on Thursday, the SPC issued a Slight Risk (level 2/5) of severe
thunderstorms over parts of the Ohio Valley. The hazards associated with
these thunderstorms are frequent lightning, severe thunderstorm wind
gusts, hail, and a few tornadoes.

Likewise, the showers and thunderstorms will create heavy rain over parts
of the Ohio Valley/Great Lakes. Therefore, the WPC has issued a Slight
Risk (level 2/4) of excessive rainfall over parts of the Ohio Valley/Great
Lakes on Thursday. 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.

Meanwhile, upper-level ridging will build over the Pacific Northwest,
spawning Excessive Heat Watches over parts of the region. The upper-level
ridging will aid in creating intense and widespread heat across portions
of the West late this week. High temperatures 10-15 degrees above normal
are expected across the Northwest and Northern High Plains later this
week, where several daily record high temperatures are forecast.

Moreover, the upper-level high will develop over the central portion of
the country, which will foster Excessive Heat Warnings/ Heat Advisories
over parts of the Central/Southern Plains, Middle/Lower Mississippi
Valley, Ohio/Tennessee Valleys, and the Southeast. The associated
dangerous heat, with high temperatures exceeding 100F and heat indices
near 110F, persists over the South-Central Plains and Mid-South through
Thursday. Multiple days of Major to Extreme HeatRisk are forecast for
portions of the southern Plains to the Southeast. These levels of heat
mean health impacts become more likely in general, and may occur in ANYONE
without adequate hydration or cooling

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Tue Jul 30 2024
Valid 12Z Tue Jul 30 2024 – 12Z Thu Aug 01 2024

…Daily scattered flash flooding and severe weather from the Mid-Atlantic
into the Northern Plains/Midwest…

…Dangerous mid-summer heat wave to expand across the Central U.S. and
Southeast; more hot weather across the West…

An active, unsettled pattern will continue across the eastern half of the
Lower 48 as an elongated frontal system with access to abundant moisture
and instability leads to repeat bouts of thunderstorms through midweek.
This will maintain a daily threat of scattered (level 2/5) flash flooding
and severe weather from the Mid-Atlantic, Ohio/Tennessee Valley, Midwest,
and Northern Plains through Thursday. Daily isolated flash flooding
chances should also continue across the Southwest tied to the monsoon.

Thunderstorms aside, heat will become the big story over the Central and
Southeast U.S. this week as an upper-level high strengthens. Forecast high
temperatures Monday and Tuesday are expected to soar into the triple
digits over the Central Plains, with upper-90s to low 100s to the west
over much of the High Plains, and mid-to upper 90s for the Middle and
Lower Mississippi Valley. High humidity values over the Mississippi Valley
and eastern portions of the plains will lead to heat indices in the
105-110 degree range, potentially as high as 115 for some locations, with
widespread Excessive Heat Warnings and Advisories in place. Warm morning
lows only dropping into the mid- to upper 70s will provide little relief
from the heat overnight. This combination of hotter temperatures to the
west, higher heat indices to the east, and the multi-day duration of this
heat wave will increase the danger not only to more sensitive groups, but
also the general public, particularly those without adequate air
conditioning.

West of the Continental Divide, a troughing pattern and associated cool
weather over the West will give way to widespread warm weather by Thursday
as a stationary Pacific front washes away beneath widespread height rises
across the region. By Friday, we can expect high temperatures in the 90’s
and triple digits across much of the West which could challenge numerous
records across the region. Unfortunately, smoke from area wildfires will
also continue to plague parts of the West, particularly over portions of
the northern Great Basin, resulting in poor air quality and areas of
reduced visibility.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Mon Jul 29 2024
Valid 12Z Mon Jul 29 2024 – 12Z Wed Jul 31 2024

…Flash flooding possible in the Ohio/Tennessee Valleys and
central/southern Appalachians through early this week…

…Scattered severe thunderstorms forecast across portions of the Northern
Plains Monday and Upper Midwest Tuesday…

…Dangerous mid-summer heat wave to begin expanding across the central
U.S. on Monday…

Bouts of thunderstorms are expected to continue over portions of the
Ohio/Tennessee Valleys and spread further into the central/southern
Appalachians to start off the work week. An active upper-level pattern
featuring at least a couple shortwaves and an approaching surface frontal
system from the west will help to focus storm development over the
Ohio/Tennessee Valleys and eventually into the southern Appalachians
Monday. Plentiful moisture in place will also continue to lead to the
threat of heavier rain rates, with increasing storm coverage into the
evening and potential back building/repeated rounds of storms raising the
chance for locally heavy rainfall totals. As such, a Slight Risk of
Excessive Rainfall (level 2/4) is in place for the threat of some
scattered flash flooding. In addition, sufficient instability/shear will
be in place over the Ohio Valley for a couple more intense storms, as well
as the threat for a more organized storm complex later Monday evening. The
Storm Prediction Center has included a Slight Risk (level 2/5) for severe
weather as well mainly for the threat of damaging winds. A similar pattern
will be in place on Tuesday, with the focus shifting further into the
southern and central Appalachians as the upper-level energy and surface
frontal system move eastward. Another Slight Risk of Exessive Rainfall is
in effect here for additional instances of flash flooding. Outside of the
flash flooding threat, scattered thunderstorms with moderate to locally
heavy rainfall are expected more broadly over the Midwest/Southeast
Monday, and also over portions of New England as a coastal low approaches.
Rain chances will expand over the Mid-Atlantic/Northeast as the system
approaches from the west on Tuesday. Forecast high temperatures across the
East will vary depending on cloud/storm coverage, with mostly mid-80s to
low 90s expected.

Some additional storms will be possible further west along the frontal
boundary into the Upper Midwest and Northern Plains. Embedded upper-level
energy will help to trigger one round of storms over the Northern Plains
on Monday. Stronger upper-level flow will lead to more deep-layer shear
here than further east, with another Slight Risk of severe weather for the
threat of some very large hail as well as significant damaging winds if
storms consolidate/grow upscale into an organized system later in the
evening. Another round of severe weather is possible downstream over the
Upper Midwest Tuesday as yet another upper-level impulse helps to trigger
storms along the frontal boundary. Very high moisture will lead to strong
to extreme instability, with a Slight Risk in place for the chance of more
damaging winds.

Outside of the severe weather threat, heat will become the big story more
broadly over the central U.S. over the next few days as an upper-level
high strengthens/expands over the region. Forecast high temperatures
Monday and Tuesday are expected to soar into the low to mid-100s over the
Central Plains, with upper-90s to low 100s to the west over much of the
High Plains, and mid- to upper 90s for the Middle and Lower Mississippi
Valley. High humidity values over the Mississippi Valley and eastern
portions of the plains will lead to heat indices in the 105-110 degree
range, potentially as high as 115 for some locations, with widespread
heat-related warnings/advisories in place. Warm morning lows only dropping
into the mid- to upper 70s will provide little relief from the heat
overnight. This combination of hotter temperatures to the west, higher
heat indices to the east, and the multi-day duration of this heat wave
will increase the danger not only to more sensitive groups, but also the
general public, particularly those without adequate air conditioning.

A stagnant troughing pattern over the West will keep temperatures mostly
below average across the region, especially over portions of the Pacific
Northwest and northern Great Basin/Rockies. Forecast highs Monday-Tuesday
range between the 60s and 70s along the Pacific Coast, the 70s and 80s in
the Pacific Northwest and northern Great Basin/Rockies, the 80s and 90s
for interior California and the central Great Basin/Four Corners Region,
and 100s in the Desert Southwest. A cold front passing through the Pacific
Northwest will bring some rain chances on Monday, spreading into the
northern Rockies Tuesday. Smoke from area wildfires will also continue to
plague parts of the West, particularly over portions of the northern Great
Basin, resulting in poor air quality and areas of reduced visibility.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Sun Jul 28 2024
Valid 12Z Sun Jul 28 2024 – 12Z Tue Jul 30 2024

…Flash flooding possible in the Ohio/Tennessee Valleys Sunday, spreading
into the central/southern Appalachians by Monday…

…Severe thunderstorms expected across portions of the Northern/Central
Plains with flash flooding into the Upper Midwest Sunday…

…Cooler than normal for much of the West with monsoonal thunderstorms
for portions of the Southwest…

A lingering frontal boundary snaking through the Ohio/Tennessee Valleys
deeper into the Southeast and off the Atlantic coast will continue to help
trigger scattered showers and thunderstorms over the next couple of days.
An upper-level wave passing over the Ohio/Tennessee Valleys will provide a
focus for more numerous storms on Sunday, possibly into the
central/southern Appalachians as well, with very moist, southerly Gulf
flow leading to some locally heavy downpours. A Slight Risk of Excessive
Rainfall (level 2/4) is in effect for the threat of some scattered
instances of flash flooding, particularly where storms may have the
tendency to backbuild/repeat over areas in vicinity of the frontal
boundary. Then, as the upper-level wave continues east on Monday, the
focus for storms will spread further into the central/southern
Appalachians, with another Slight Risk of Excessive Rainfall in effect for
additional instances of flash flooding. High temperatures broadly across
the Ohio Valley into the Southeast and along the Gulf Coast will remain at
or a bit below average given widespread clouds and storms, with highs
generally in the mid-80s to low 90s.

A frontal system passing slowly through the Northern/Central Plains and
the Upper Midwest will bring storm chances to these regions Sunday.
Plentiful moisture, instability, and strong upper-level flow overhead
leading to sufficient deep-layer shear is expected to result in some more
intense, organized storms. Initially isolated storms/supercells over
portions of South Dakota, central Nebraska, and northwestern Kansas may
produce some large hail and damaging winds. Eventual upscale growth into
an organized convective system Sunday evening may bring a damaging wind
threat downstream into southwestern Minnesota and northwestern Iowa. The
Storm Prediction Center has highlighted these areas with a Slight Risk
(level 2/5) of severe weather. The expanding coverage of storms heading
eastward, as well as plentiful moisture to lead to heavy rainfall rates,
will also bring the threat of flash flooding into Iowa. Additional storms
will continue ahead of the front over Minnesota through early morning
Sunday, with another round of storms expected Sunday night. Repeated
storms bringing heavy rainfall on top of already wet antecedent conditions
will lead to the risk of some scattered flash flooding here as well. A
Slight Risk of Excessive Rainfall extends from portions of Minnesota
southward into Iowa to cover these threats. The system will continue into
the Great Lakes region Monday, bringing showers and storms with moderate
to locally heavy rainfall. High temperatures ahead of the front will be
rather hot, running 10-15 degrees above average for some locations, with
80s to near 90 in the Upper Midwest and 90s to low 100s southwestward into
the Central Plains and southern High Plains. A few near
record-tying/breaking highs will be possible in the southern High Plains
Monday.

An upper-trough over the West will keep temperatures below average for
most of the region. Forecast highs Sunday-Monday range between the 60s and
70s along the Pacific Coast; 70s and 80s in the Pacific Northwest; 80s and
90s in the Great Basin, Four Corners Region, and interior California; and
the 100s into the Desert Southwest. Some Monsoonal storms will continue
over parts of the Southwest, particularly southeastern
Arizona/southwestern New Mexico, with an isolated threat of flash
flooding. A storm system approaching the Pacific Northwest will bring some
shower chances here as well. Smoke from wildfires will also continue to
plague parts of the West, particularly over the northern Great
Basin/Rockies, resulting in poor air quality and areas of reduced
visibility. Elsewhere, conditions will be trending hotter across most of
the Northeast, with 80s and low 90s forecast. A coastal low approaching
southern New England is looking more likely to bring cooler temperatures
and some rain chances over the next couple of days.