167 
ACUS01 KWNS 161244
SWODY1
SPC AC 161242

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0742 AM CDT Sun Aug 16 2026

Valid 161300Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE OHIO VALLEY...CENTRAL APPALACHIANS...MID-ATLANTIC...AND CENTRAL
HIGH PLAINS...

...SUMMARY...
Thunderstorms with damaging wind gusts will be possible from this
afternoon into early evening over parts of the Ohio Valley and
Mid-Atlantic. Large hail and isolated severe wind gusts will also be
possible in parts of the central High Plains.

...Lower MO Valley through the OH Valley into the Mid-Atlantic...
Satellite and regional radar imagery shows several vorticity maxima
embedded within the moderate westerly flow aloft that extends from
the central Plains across the OH Valley and into the Mid-Atlantic.
The strongest vorticity maximum is currently moving through
north-central KS and south-central NE, while more subtle maxima
exist across western IL, southwestern Lower MI/far northern IN, and
western PA. Each of these features will likely contribute to showers
and thunderstorms later today. The most consequential of these
storms will likely occur in tandem with the western IL and
southwestern Lower MI waves as they interact with a moist and
diurnally destabilized airmass from the middle OH Valley into the
Mid-Atlantic. Airmass destabilization appears likely by the early
afternoon, with renewed thunderstorm development anticipated from
southeast Lower MI into southern IN. Moderate vertical shear will be
in place, supporting a predominantly multicellular mode. Mid-level
winds may increase slightly throughout the afternoon, and a
supercell or two is possible over southern OH. A trend towards
clustering and the development of linear segments is anticipated
over time, with damaging gusts as the primary risk throughout the
day.

These storms will continue eastward across WV into Mid-Atlantic
during the late afternoon/early evening. Moderate buoyancy will
support storm persistence and the potential for continued damaging
gusts. Additional thunderstorm development is possible ahead of
these clusters in areas of low-level convergence during the
afternoon. Moderate vertical shear could support a few more
organized storms, with water-loaded downbursts as the primary severe
risk. A tornado or two is also possible, particularly across
northern VA where southerly surface winds could result in adequate
low-level hodograph curvature. 

Farther west (across the Lower MO Valley), the well-defined
vorticity maximum currently over north-central KS/southern-central
NE is forecast to be east of the region by the late afternoon, but
airmass destabilization in its wake is uncertain. If the airmass can
recover, additional thunderstorms are likely along a cold front
moving into the region this evening. Strong buoyancy will support
robust updrafts, but modest vertical shear will keep storm
organization limited. If thunderstorms form, a few strong gusts are
possible across this region this evening.

...Northern/Central High Plains...
Scattered thunderstorm development in anticipated this afternoon
across the northern and central High Plains. Thunderstorms over the
northern High Plains will be supported by low-level convergence
along the western edge of the moist airmass over the Plains.
Moderate vertical shear could support a few supercells capable of
hail and strong gusts, but modest buoyancy should keep the overall
severe threat isolated. 

Thunderstorm development farther south across the central High
Plains will result from a combination of moist low-level easterlies,
westerly flow aloft and orographic effects. Here, more cellular
development over the high terrain and immediate foothills could pose
a risk for large hail before transitioning towards more linear
structures with strong gusts as the primary severe risk.

..Mosier/Dean.. 08/16/2026

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260816T1244.txt



471 
ACUS01 KWNS 160557
SWODY1
SPC AC 160556

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1256 AM CDT Sun Aug 16 2026

Valid 161200Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE OHIO VALLEY...CENTRAL APPALACHIANS...MID-ATLANTIC AND CENTRAL
HIGH PLAINS...

...SUMMARY...
Thunderstorms with severe wind gusts will be possible from this
afternoon into early evening over parts of the Ohio Valley and
Mid-Atlantic. Large hail and isolated severe wind gusts will also be
possible in parts of the central High Plains.

...Ohio Valley/Mid-Atlantic...
A mid-level shortwave trough, embedded in west-northwesterly flow,
will move through the Ohio Valley today. Ahead of the shortwave
trough, a moist airmass will be in place from the Ohio Valley
southeastward to the Mid-Atlantic Coast. Surface dewpoints along
this west-northwest to east-southeast corridor will be in the 70s F,
which will contribute to the development of moderate instability by
midday. At the surface, a cold front will advance eastward into the
Ohio Valley, as a pre-frontal trough moves into the central
Appalachians. These two features will focus convective development
during the day. A complex of storms appears likely to form over the
higher terrain in West Virginia, and move east-southeastward into
the lower elevations of Virginia and Maryland during the mid to late
afternoon.

RAP forecast soundings from West Virginia into the Virginia in the
late afternoon have 0-6 km shear in the 25 to 30 knot range. Some
directional shear is present in the low-levels and 0-3 km lapse
rates are steep approaching 7 C/km. This environment will support a
wind-damage threat with organized multicells. Isolated supercells
with severe gusts will also be possible. The threat may continue
into the early evening across parts of the Mid-Atlantic.

Further west into parts of the lower Ohio Valley, a very moist
airmass will also be in place. Surface dewpoints in the 70s F will
contribute to the development of moderate instability. Scattered
thunderstorms are expected to form along zones of low-level
convergence during the afternoon. Although large-scale ascent will
be weaker further west, the thermodynamic environment will be
sufficient for isolated severe gusts.

...Central High Plains...
At mid-levels, a ridge will move through the Intermountain West
today as flow remains westerly over much of the central U.S. As
surface temperatures warm, scattered thunderstorms will develop in
the foothills of the central Rockies. These storms will move
eastward into the lower elevations of eastern Colorado and western
Nebraska. RAP forecast soundings across the central High Plains by
late afternoon have moderate instability (MLCAPE around 2500 J/kg),
0-6 km shear near 35 knots and 700 to 500 mb lapse rates in the 7 to
7.5 C/km range. This should support a threat for large hail and
isolated severe gusts with rotating storms and organized line
segments. The threat will likely persist into the evening across
parts of the central High Plains.

..Broyles/Lyons.. 08/16/2026

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260816T0557.txt



051 
ACUS01 KWNS 160052
SWODY1
SPC AC 160051

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0751 PM CDT Sat Aug 15 2026

Valid 160100Z - 161200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL HIGH PLAINS...

...SUMMARY...
Thunderstorms with severe wind gusts and isolated large hail will be
possible this evening across parts of the central Plains. Isolated
severe wind gusts may also occur this evening into tonight across
parts of the lower Missouri and Ohio Valleys.

...Central Plains/Lower Missouri Valley...
A mid-level shortwave trough is evident on water vapor imagery over
eastern Colorado within west-southwesterly flow. Ahead of this
feature, a moist airmass is present across the central Plains.
Surface dewpoints in eastern Colorado and western Kansas are in the
60s F, and the RAP has MLCAPE in the 1500 to 3000 J/kg range. Along
the western edge of moderate instability, scattered thunderstorms
are ongoing from western Nebraska southward into the Oklahoma
Panhandle. In addition to moderate instability, RAP forecast
soundings early this evening downstream from the storms near Dodge
City and Hill City and have 0-6 km shear around 30 knots with 0-3 km
lapse rates near 7.5 C/km. The steep low to mid-level lapse rates
are evident on the Dodge City 00Z sounding. This environment should
support an isolated severe threat for several more hours this
evening as the storms move across the central Plains. Severe wind
gusts and hail will be the primary threats...see MCD 1992. During
the overnight period, a convective cluster or line segment is
forecast to move east-northeastward across northern Kansas and
southern Nebraska, potentially reaching far northwest Missouri late
in the period. Isolated severe gusts will be possible with these
storms.

...Ohio Valley...
A mid-level shortwave trough is evident on water vapor imagery over
the Ohio Valley within west-northwesterly flow. At the surface, a
moist axis is located from central Illinois southeastward into
eastern Kentucky, along which surface dewpoints are in the 70s F.
Near the moist axis, the RAP has MLCAPE in the 2500 to 3500 J/kg
range. To the east and northeast of the strongest instability,
scattered thunderstorms are currently ongoing ahead of the shortwave
trough in western Ohio and northern Kentucky. The Wilmington, Ohio
00Z sounding has 0-6 km shear around 30 knots with a surface
dewpoint in the mid 70s F, and precipitable water near 2.15 inches.
This moist and unstable environment should support a potential for
isolated severe wet downbursts with the stronger multicells early
this evening.

..Broyles.. 08/16/2026

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260816T0052.txt



799 
ACUS01 KWNS 151942
SWODY1
SPC AC 151941

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0241 PM CDT Sat Aug 15 2026

Valid 152000Z - 161200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE
OHIO VALLEY AND PARTS OF THE CENTRAL HIGH PLAINS...

...SUMMARY...
Thunderstorms with severe wind gusts and isolated large hail remain
possible from late afternoon into the evening across the central
High Plains. Severe wind gusts may also still occur this afternoon
through early evening across parts of the Ohio Valley and Southeast.

...20Z Update...
The previous forecast (see below) remains generally on track, with
only minor changes made to the 20Z Day 1 Convective Outlook Update
to reflect the latest observations and latest guidance consensus.
There were considerations to add a Category 1/Marginal Risk for
severe wind/hail over portions of the Pacific Northwest into the
northern Rockies given appreciable cool temperatures aloft
overspreading a heated boundary layer. Nonetheless, vertical wind
shear should remain quite weak. Therefore, while a 50+ kt gust or
instance of 1+ inch hail may occur with any of the stronger storms,
the severe threat should be very sparse, precluding severe
probabilities this outlook.

..Squitieri.. 08/15/2026

.PREV DISCUSSION... /ISSUED 1135 AM CDT Sat Aug 15 2026/

...Front Range/Central High Plains...
Modestly strong southwesterly flow aloft coupled with strong
daytime heating, low-level upslope flow, and orographic lift will
support another day of thunderstorms regionally. These thunderstorms
should gradually move off the higher terrain into the central High
Plains later this afternoon, where a moderately
buoyant airmass will be in place. Around 30-35 kt of effective
bulk shear is expected over the region, which will support a mixed
mode with supercells and multicell line segments. Isolated large
hail is possible with any supercells, while severe wind gusts will
be possible with both supercells and line segments. The severe
threat should persist into the evening as this complex of storms
moves eastward through the central High Plains including
west/southwest Kansas.

...Midwest/Middle Ohio Valley...
Thunderstorms have generally weakened since the overnight, although
scattered showers/some thunderstorms and plentiful cloud cover
continue in areas progressively north of the Ohio River. An MCV is
readily apparent in observational data as it continues to move into
northwest Indiana, with an enhanced belt (40+ kt) of westerly winds
associated with the MCV per regional WSR-88D VWP data. 

As clouds thin/abate, a gradual increase in renewed thunderstorm
coverage and intensity is expected later this afternoon. Mid-level
lapse rates will be poor, but dewpoints in the 70s F will support
moderate buoyancy, particularly in areas where cloud cover does not
overly inhibit diurnal heating, which will tend to generally be
southward toward the Ohio River. Strong updrafts and high
precipitable water will support the potential for wet microbursts
capable of producing damaging gusts, and some enhancement to the
low-level winds could also yield a brief tornado.

...Central Appalachians/Carolinas/Georgia...
A very moist airmass, characterized by dewpoints in the low to mid
70s, is in place regionally. Strong heating will destabilize the
airmass by the early afternoon, resulting in a large reservoir of
moderate buoyancy. Thunderstorm development is anticipated within
this destabilized airmass across the higher terrain of the central
Appalachians as well as any area of low-level convergence across the
remainder of the region. Vertical shear will be weak, and limited
storm organization is anticipated. Even so, the moderate buoyancy
could still support updrafts/downdrafts strong enough to produce
occasional damaging gusts.

...Central Plains/Mid Missouri Valley to Mid Mississippi Valley...
Elevated thunderstorms are expected again tonight, initiated by both
an approaching cold front and warm-air advection. Ample low-level
moisture and moderate buoyancy will be in place, but vertical shear
will be marginal. Isolated strong to severe storms are expected, but
a predominantly elevated and clustered storm mode should limit the
overall severe potential.

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260815T1942.txt



751 
ACUS01 KWNS 151636
SWODY1
SPC AC 151635

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1135 AM CDT Sat Aug 15 2026

Valid 151630Z - 161200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE FRONT
RANGE/CENTRAL HIGH PLAINS AND MIDDLE OHIO VALLEY...

...SUMMARY...
Thunderstorms with severe wind gusts and isolated large hail are
possible from late afternoon into the evening across the central
High Plains. Severe wind gusts may also occur this afternoon through
early evening across parts of the Ohio Valley and Southeast.

...Front Range/Central High Plains...
Modestly strong southwesterly flow aloft coupled with strong
daytime heating, low-level upslope flow, and orographic lift will
support another day of thunderstorms regionally. These thunderstorms
should gradually move off the higher terrain into the central High
Plains later this afternoon, where a moderately
buoyant airmass will be in place. Around 30-35 kt of effective
bulk shear is expected over the region, which will support a mixed
mode with supercells and multicell line segments. Isolated large
hail is possible with any supercells, while severe wind gusts will
be possible with both supercells and line segments. The severe
threat should persist into the evening as this complex of storms
moves eastward through the central High Plains including
west/southwest Kansas.

...Midwest/Middle Ohio Valley...
Thunderstorms have generally weakened since the overnight, although
scattered showers/some thunderstorms and plentiful cloud cover
continue in areas progressively north of the Ohio River. An MCV is
readily apparent in observational data as it continues to move into
northwest Indiana, with an enhanced belt (40+ kt) of westerly winds
associated with the MCV per regional WSR-88D VWP data. 

As clouds thin/abate, a gradual increase in renewed thunderstorm
coverage and intensity is expected later this afternoon. Mid-level
lapse rates will be poor, but dewpoints in the 70s F will support
moderate buoyancy, particularly in areas where cloud cover does not
overly inhibit diurnal heating, which will tend to generally be
southward toward the Ohio River. Strong updrafts and high
precipitable water will support the potential for wet microbursts
capable of producing damaging gusts, and some enhancement to the
low-level winds could also yield a brief tornado.

...Central Appalachians/Carolinas/Georgia...
A very moist airmass, characterized by dewpoints in the low to mid
70s, is in place regionally. Strong heating will destabilize the
airmass by the early afternoon, resulting in a large reservoir of
moderate buoyancy. Thunderstorm development is anticipated within
this destabilized airmass across the higher terrain of the central
Appalachians as well as any area of low-level convergence across the
remainder of the region. Vertical shear will be weak, and limited
storm organization is anticipated. Even so, the moderate buoyancy
could still support updrafts/downdrafts strong enough to produce
occasional damaging gusts.

...Central Plains/Mid Missouri Valley to Mid Mississippi Valley...
Elevated thunderstorms are expected again tonight, initiated by both
an approaching cold front and warm-air advection. Ample low-level
moisture and moderate buoyancy will be in place, but vertical shear
will be marginal. Isolated strong to severe storms are expected, but
a predominantly elevated and clustered storm mode should limit the
overall severe potential.

..Guyer/Chalmers.. 08/15/2026

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260815T1636.txt