Clearpost.online It's your post, so post it!

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0752 AM CDT Wed Jul 20 2022

Valid 201300Z - 211200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER EASTERN LOWER
MICHIGAN INTO THE OHIO VALLEY...

...SUMMARY...
Damaging thunderstorm gusts, isolated hail and a tornado or two are
possible over eastern Lower Michigan into the Ohio Valley.

...Synopsis...
The CONUS portion of the large-scale mid/upper-level pattern will
continue to be dominated by an expansive anticyclone centered over
western NM, and covering much of the Southwest and southern Plains. 
Mean troughing will persist over the Eastern States and Great Lakes,
with the main shortwave influence being a co*pact cyclone now
centered over western Lake Superior.  The associated midlevel low
has begun to fill with the low-level cyclone now occluded; this
process will continue through the period.  By 00Z, the 500-mb low
should reach portions of ON just east of Lake Superior and north of
Lake Huron, with trough southwestward over UIN.  By 12Z, the low
should devolve into an open-wave trough extending from the southern
tip of James Bay to near a TOL-CVG line.

The surface map at 11Z showed an occluded low just north of the
northern part of Lake Superior in ON, with occluded/cold front
arching across Upper MI, southeastern WI, northeastern MO,
northwestern OK, and the TX Panhandle.  The surface low will
continue to progress eastward with the midlevel cyclone center
nearly stacked above.  The cold front should reach northwestern OH,
southern portions of IL/IN, the Ozarks, south-central OK, and
northwest TX by 00Z, with a weak low (hybrid frontal-wave and heat
low) reasonably progged over southern OK.  By 12Z, the cold front
should extend from western parts of NY/PA across central KY, western
TN, and central AR, beco*ing quasistationary across southeastern OK
and north TX.

...Eastern Lower Michigan to Ohio Valley...
Scattered thunderstorms are expected to develop from midday through
this evening near the cold front, and perhaps along one or two
nearly parallel bands of low-level convergence ahead of the front. 
Convection initially should be in the form of supercells and
multicells, evolving to a mix of broken to continuous line(s) of
convection over time.  Development should be earlier over eastern
Lower MI, then trending toward later in the afternoon into evening
across the Ohio Valley region. Damaging to severe gusts should be
the main concern, with sporadic large hail and a marginal tornado
threat as well.

Even though the low/trough aloft will be weakening with time, its
co*pact and progressive nature will ensure strong height falls
shifting eastward across the Lake Huron vicinity into southern ON.
The southern portions of favorable large-scale ascent and
enhancement of mass response/wind fields should extend southward to
near the Ohio Valley.  This will contribute to effective-shear
magnitudes in the 35-45-kt range across the immediately prefrontal
warm sector.  Winds will veer with height in low levels -- more with
northern extent -- contributing to curved hodographs.  However,
hodograph size will be limited somewhat over most of the area by
lack of greater speeds.  Diurnal heating and rich low-level moisture
-- manifest by surface dew points co*monly in the upper 60s to mid
70s F -- will help to boost MLCAPE into the 2500-3500 J/kg range
over southern parts of the "slight" area, trailing off to a narrower
corridor of 1500-2500 J/kg preconvective MLCAPE across eastern Lower
MI and northeastern OH.  Convection should diminish tonight over the
Appalachians as more-stable boundary-layer air is encountered.

...Mid-South to Red River Valley...
Farther southwest near the front, weak but sufficient low-level
convergence and intense diurnal heating should contribute to
isolated to scattered thunderstorms. A hot and deeply mixed boundary
layer with lapse rates near dry adiabatic will be co*mon along and
ahead of the front, especially in the Red River region into parts of
AR, where surface temperatures will exceed 100 F.  MLCAPE values
should range from around 1000-2000 J/kg, atop similar DCAPE values,
supporting strong/locally severe downdrafts.  Though vertical shear
will be weak, flow will veer strongly with height, curving to a
substantial northerly co*ponent in upper levels.  This should
encourage southward to southeastward storm motions off the front and
into the hot boundary layer, prior to evening diabatic cooling. 
Some clustering and localized enhancement of wind potential is
possible, but too dependent on details at mesobeta and finer scales
to assign any greater unconditional probabilities at this time.

...South-central Rockies/High Plains...
Widely scattered thunderstorms are expected to develop this
afternoon from the southern parts of the Front Range down through
the Sangre de Cristos, moving east-southeastward to southeastward
across the adjoining High Plains and Raton Mesa regions.  Low-level 
moisture and mid/upper support (so close to the strong high) each
will be meager.  Still, activity will be supported by strong heating
of elevated terrain, preferentially eroding MLCINH, followed by
translation of resulting high-based thunderstorms over deep,
well-mixed subcloud layers.

Forecast soundings in the preconvective environment east of the
mountains show inverted-V low-level thermodynamic profiles, with
surface dewpoints mixed down into the 40s to low 50s still
supporting around 500 J/kg MLCAPE (and about 2-3 times that value of
DCAPE).  Vertical shear will be very weak, but aggregation of
outflows may foster some forward-propagational organization to the
wind potential, with isolated severe gusts embedded in the
convective regime, until it weakens this evening atop increasing
near-surface stability.

...Northern Plains...
Isolated to widely scattered thunderstorms are possible this
afternoon, offering marginally severe hail and gusts from the most
intense cells.  Activity will be supported by difluent flow aloft
and weak DCVA ahead of a northern-stream perturbation over MB, and
an associated surface trough in northwest flow.  Dewpoints in the
upper 50s to mid 60s F and diurnal heating will weaken MLCINH
substantially by heating through the afternoon, with steep low-level
lapse rates and a well-mixed boundary layer. A pocket of 500-1200
J/kg MLCAPE should develop in the preconvective environment across
most of the region.  Despite the nearly unidirectional nature of
deep-tropospheric flow, enough speed shear is apparent to support
30-40 kt effective-shear magnitudes in support of some organization
to the convection, which may grow upscale into a small co*plex over
eastern ND or western MN with continued strong/isolated severe wind
potential, before weakening late this evening.

..Edwards/Mosier.. 07/20/2022