Mesoscale Discussion 2324
NWS Storm Prediction Center Norman OK
0536 PM CDT Mon Sep 21 2026

Areas affected...parts of North Texas

Concerning...Severe potential...Watch unlikely 

Valid 212236Z - 220100Z

Probability of Watch Issuance...5 percent

SUMMARY...Strong wind gusts may affect parts of the Metroplex later
this evening. Isolated damaging gusts cannot be ruled out.

DISCUSSION...A cluster of storms that formed in southern OK
continues to push south/southeast across the Red River, with the
stronger storm moving through Gainesville TX. Other cells are also
developing along the outflow, extending into northern Wise and Jack
counties.

Meanwhile, an older outflow boundary is pushing north and extends
from Dallas to Hood counties. This area has become relatively hot
today, with upper 90s to near 100 F temperatures. Surface analysis
also indicates a low between the storms to the north and
northward-moving outflow to the south.

Given the steep low level lapse rates ahead of these storms (which
are substantial in height), and possibility of increased surface
convergence/colliding outflows, it seems possible at least strong
outflow will affect the Metroplex later this evening, with perhaps
locally damaging gusts assuming storm cores continue to develop as
they approach out of the north.

..Jewell/Guyer.. 09/21/2026

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

ATTN...WFO...FWD...

LAT...LON   33209804 33389793 33409753 33579687 33679656 33519629
            33129610 32919615 32749693 32559743 32359781 32499802
            32719808 32919813 33129806 33209804 

MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0256 PM CDT Mon Sep 21 2026

Valid 212000Z - 221200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE SOUTHEAST INTO CENTRAL APPALACHIANS AND OVER THE TEXAS SOUTH
PLAINS...

...SUMMARY...
Isolated damaging wind gusts remain possible this afternoon from
parts of the Southeast into the southern and central Appalachians.
An isolated risk for large hail and severe gusts is also forecast
over parts of the Texas South Plains later today.

...20z Update...
No changes were made to the existing outlook with this update cycle
as the forecast remains on track. See MCD #2323 and the discussion
below for additional information.

..Chalmers/Wendt.. 09/21/2026

.PREV DISCUSSION... /ISSUED 1125 AM CDT Mon Sep 21 2026/

...Southeast/Southern and Central Appalachians...
Recent radar and satellite imagery reveals a trio of MCVs over the
OH Valley, with perhaps another MCV farther southwest in the
Mid-South vicinity. These vorticity maxima are north/west of an
arcing cold front that extends from southern VA west-northwest into
northern KY and then back southwestward through northern AR and 
central OK into the TX South Plains. A moist airmass persists south
of this boundary, with dewpoints in the low 70s across much of
Southeast, TN Valley, and Carolinas. The front is forecast to slowly
shift southward today, interacting with the moist, diurnally
destabilized, and moderately buoyant airmass to support scattered
thunderstorms. Vertical shear will be weak, and largely
multicellular, outflow-dominant storm mode is anticipated. Even so,
ample moisture is in place (i.e. PW values over 2" sampled on the
12Z BMX sounding), and sporadic stronger downdrafts may yield a
strong to locally severe gusts (50 to 60 mph). Highest thunderstorm
coverage is expected from southeast TN and northwest GA through
northern AL into central/southern MS and eastern LA.

...TX South Plains into north-central/northeast TX...
Western periphery of the front described in the previous section
intersects a weak low over far southeast NM. A moist airmass exists
along and south of this boundary, with dewpoints ranging from the
low 60s over the TX South Plains to the low 70s across much of
central and eastern TX. Easterly flow will help maintain this
moisture amid strong heating over the TX South Plain vicinity,
contributing to airmass destabilization and moderate buoyancy by
this afternoon. Low-level convergence along the front (and/or
residual outflow) and near the surface low will likely result in
scattered thunderstorm development. Vertical shear will be modest,
but any stronger, more persistent thunderstorms may yield an
isolated risk for large hail/severe gusts before dissipating during
the evening. 

A secondary area of higher thunderstorm coverage appears likely over
northeast TX this afternoon/evening. Here, differential heating
and/or outflow from ongoing thunderstorms could result in an area of
increased low-level convergence within a warm, moist, and moderately
unstable airmass this afternoon. Isolated water-loaded downbursts
capable of producing damaging wind gusts are possible. Anticipated
limited severe coverage precludes introducing low wind probabilities
in this area.

Day 3-8 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0402 PM CDT Mon Sep 21 2026

Valid 231200Z - 291200Z

...Discussion...
An upper low will transition into the Great Lakes region and Ohio
Valley on Day 3/Thursday, supporting precipitation chances and much
cooler temperatures along/east of the Appalachians. Meanwhile, a
shallow cold front will slowly progress southward through southern
Texas and the Deep South. Hot and mostly dry conditions will
continue across the lower Mississippi Valley through the forecast
period as upper ridging rebuilds over the ArkLaTex, contributing to
forecast ERCs approaching the 90-95th percentile; but, prevailing
light winds should suppress overall fire weather concerns.

Guidance is in general agreement for ridging to build over the
central CONUS late in the workweek as an upper trough evolves across
the Eastern Pacific and impinges upon the Northwest. The overall
pattern indicates stronger southwest winds may return to the
portions of the northern Great Basin, Pacific Northwest, and
Northern Rockies on Days 4-5/Thursday-Friday; however, an expected
marginal fuelscape should limit a broader fire weather threat. If
fuels guidance trends drier, critical probabilities may be needed in
future outlook cycles.

..Elizalde-Garcia.. 09/21/2026

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