Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0759 PM CDT Fri Aug 14 2026

Valid 150100Z - 151200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE CENTRAL PLAINS INTO THE MID MISSISSIPPI VALLEY...MID-ATLANTIC
AND INTERMOUNTAIN WEST...

...SUMMARY...
Thunderstorms with isolated severe wind gusts and hail will be
possible this evening into the overnight across parts of the mid
Missouri and mid Mississippi Valleys. Isolated severe gusts and hail
will also be possible in parts of the Mid-Atlantic, central Plains
and Intermountain West.

...Mid Missouri and Mid Mississippi Valleys...
The latest water vapor imagery shows a broad anticyclonic flow
pattern in place from the Great Plains to the Appalachians. An
embedded mid-level shortwave trough appears to be located from
south-central Iowa into far northwest Missouri. Ahead of this
feature, surface dewpoints across far southern Iowa and northern
Missouri are in the upper 70s F. The RAP currently has an
east-to-west corridor of strong instability in north-central
Missouri, where MLCAPE is estimated to be in the 3000 to 4000 J/kg
range. Along the instability gradient in northern Missouri,
low-level flow will increase this evening, fueling the development
of numerous thunderstorms. Some RAP forecast soundings near the
instability gradient this evening have effective shear in the 25 to
30 knot range with 850 to 500 mb lapse rates around 6.5 C/km. This
should support a hail threat with the stronger elevated storms. An
isolated potential for severe gusts may also develop if any of the
cells can remain surface-based. The severe threat is expected to
continue into the overnight period.

...Mid-Atlantic...
West-northwesterly mid-level flow is evident on water vapor imagery
over the eastern U.S. At the surface, dewpoints are in the 70s F
from the Mid-Atlantic southward into the Carolinas, where the RAP
has MLCAPE in the 2000 to 3000 J/kg range. Scattered thunderstorms
are ongoing along the northern edge of the stronger instability over
eastern Virginia. Near this convection, the WSR-88D VWP at Wakefield
has 0-6 km shear of 30 to 35 knots which could support a marginal
severe threat for another hour or two this evening. Severe wind
gusts and hail will be possible.

...Central Plains...
Southwesterly mid-level flow is currently in place over much of the
central U.S. At the surface, a quasi-stationary front is located
from eastern Colorado into central Kansas. Surface dewpoints near
the front are from the mid 60s to mid 70s F, and the RAP has MLCAPE
in the 2000 to 3000 J/kg range. Along the western edge of the
stronger instability, scattered thunderstorms are ongoing across
eastern Colorado. RAP forecast soundings just ahead of the storms
near the Colorado-Kansas state line this evening have 0-6 km shear
around 40 knots with 700-500 mb lapse rates around 7 C/km. This will
support a marginal severe threat. A few severe wind gusts and hail
will be possible with the stronger cells.

...Intermountain West...
Water vapor imagery currently shows southwesterly mid-level flow
over the Intermountain West with a subtle shortwave trough moving
into the region from the southwest. Ahead of this feature, an axis
of moderate instability is located from northwestern Arizona into
southeast Nevada, along which the RAP has MLCAPE in the 1000 to 1500
J/kg range. Scattered thunderstorms are ongoing near the instability
axis early this evening. RAP forecast soundings just downstream from
the storms early this evening have 0-6 km shear around 30 knots
along with 700-500 mb lapse rates near 7.5 C/km suggesting a
potential for isolated severe wind gusts.

..Broyles.. 08/15/2026

Day 1 Convective Outlook AMEND 1
NWS Storm Prediction Center Norman OK
0532 PM CDT Fri Aug 14 2026

Valid 142000Z - 151200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
MIDWEST AND SOUTHEAST VIRGINIA...

AMENDED FOR INCREASED SEVERE PROBABILITIES IN SOUTHEAST VIRGINIA

...SUMMARY...
Severe thunderstorms remain possible this afternoon and evening
across parts of the mid Missouri and mid Mississippi Valleys, as
well as southeast Virginia. Isolated severe wind gusts may also
still occur in parts of the central Plains and from the Ohio Valley
to the Mid-Atlantic, as well as parts of the Northeast and
Southwest.

...Southeast Virginia...
Supercells which have developed across parts of southeast VA appear
to be anchored to a surface boundary, and they should continue to
pose some threat for large hail this evening as they track
southeastward. Although low-level flow remains modest, locally
greater effective SRH is present near this boundary, and a brief
tornado appears possible. Otherwise, scattered damaging winds may
also occur across parts of southeast VA with a loosely organized
cluster moving east-southeastward over the next few hours. See
Mesoscale Discussion 1982 for more details on the near-term severe
threat across this region.

..Gleason/Squitieri.. 08/14/2026

.PREV DISCUSSION... /ISSUED 1143 AM CDT Fri Aug 14 2026/

...Mid Missouri and mid Mississippi Valleys...
Thunderstorms have largely weakened through the early morning across
the middle Missouri Valley, with more of a lingering persistence
across Illinois/Indiana. Scattered showers remain rather common,
however, regionally with semi-prevalent cloud cover. Multiple MCVs
persist regionally at midday, including across central Iowa, and
more prominently near the Nebraska/Iowa border. Regional WSR-88D
data from Omaha/Des Moines/Davenport continue to sample enhanced
westerlies (35-50 kt) between 4-8 km AGL in association with these
MCVs.

Primary severe risk across this region today will be linked to the
amount of air mass recovery and associated destabilization that 
occurs along the southern periphery of the residual convection and
ahead of the aforementioned slow-moving MCVs. Ample low-level
moisture is in place, and differential heating between the residual
cloud debris may yield an effective warm-front-like zone across
southern Iowa or near the Iowa/Missouri border. The airmass along
and south of this is forecast to destabilize and become moderately
to strongly unstable by the late afternoon. This should result in
renewed thunderstorm development by late afternoon into evening,
with sufficient deep-layer shear to support organized updrafts and
potentially some initial supercells. Modestly enhanced low-level
winds/SRH could yield a tornado risk. Strong wind gusts will
otherwise be possible with water-loaded downdrafts, as well as with
any bowing segments through this evening.

...Ohio Valley/Central Appalachians/Mid-Atlantic...
Outflows/differential heating across the lower Ohio Valley will
influenced thunderstorm redevelopment this afternoon, while storms
are starting to develop/increase across the Appalachians vicinity.
Vertical shear will generally be weak, but strong updrafts and ample
moisture will yield the potential for wet microbursts regionally.

...Central High Plains...
A shortwave trough currently moving through the Lower Colorado River
Valley is forecast to continue northeastward through the Four
Corners. Ascent associated with this wave will combine with
orographic lift in the foothills of the Rockies to support scattered
convective initiation by early afternoon. Thunderstorms will then
move northeastward into the moderately buoyant airmass over the
central High Plains. Deep-layer shear will be modest but sufficient
for a few organized updrafts capable of hail and damaging gusts.

...Northeast States...
Influenced by strong northwesterly flow aloft, a few stronger to
locally severe relatively low-topped storms may occur this afternoon
across northern/upstate New York into southern New England, with
strong/gusty winds as the primary hazard as convection progresses
southeastward.

...Lower Colorado River ...
With a moist air mass across the region, strong heating will support
afternoon airmass destabilization, yielding moderate buoyancy this
afternoon. Slightly stronger mid-level flow is anticipated over the
southern Nevada vicinity, supporting the potential for isolated
strong wind gusts.

Day 3-8 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0448 PM CDT Fri Aug 14 2026

Valid 161200Z - 221200Z

...Synopsis...
Mid/upper troughing near the West Coast will wane as the upper ridge
across the central US retrogrades westward by early Day 4/Monday,
allowing drier conditions to infiltrate much of the Great Basin and
Cascades. A mid-level short wave arriving early next week along with
residual monsoonal moisture could bring additional thunderstorms to
portions of the Northern Rockies Day 4/Monday, while also promoting
dry and breezy conditions across portions of the northern Great
Basin. Forecast uncertainty increases Day 6 onward as ensemble
spread reduces predictability in the longer term across the western
U.S. as fuels likely rebound to the drier side from recent monsoon
moisture.

...Day 4/Monday...
...Central Idaho and the Northern Rockies...
The aforementioned short wave moving into the Northwest, lingering
monsoonal moisture and daytime heating will promote a favorable
convective environment across portions of the Northern Rockies,
central ID and perhaps into northeastern OR on Day 4/Monday.
However, preceding days of showers and thunderstorms and good
overnight RH recoveries could temporarily reduce fuel receptiveness
leading up to this event. Although critical probabilities were not
introduced for this outlook, the dry thunderstorm threat will be
monitored for inclusion in future outlooks once assessment of
rainfall distribution becomes clearer.

...Northwestern California, southern Oregon and northwestern
Nevada...
The same short wave and attendant mid-level speed max will likely
bring dry and breezy conditions to parts of the northern Great Basin
into northwestern CA on Day 4/Monday. A relative minimum of rainfall
has been observed in this area over the last several days of
monsoon-related showers and thunderstorms across the broader western
U.S. A warming and drying trend is expected with the arrival of
stronger west/southwest winds. This coupled with existing dry fuels
will increase fire weather concerns, where 40 percent critical
probabilities were introduced for northeastern CA, northwestern NV
and southern OR for Day 4/Monday.

...Day 5/Tuesday - Southern Plains...
Expanding drought and continued above normal 100F+ temperatures will
most likely stay in place through next week across portions of the
Southern Plains. Increasing southerly winds are expected to evolve
south of a nascent Central Plains surface low/trough over portions
of the northwest TX and western OK. South winds of 15-20 mph
collocated with low afternoon RH and very dry fuels will bring an
enhanced fire weather concern to the area Day 5/Tuesday, with 40
percent critical probabilities introduced.

..Williams.. 08/14/2026

...Please see www.spc.noaa.gov/fire for graphic product...