Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1236 AM CDT Thu Sep 10 2026

Valid 101200Z - 111200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE
SOUTHERN HIGH PLAINS TO THE SOUTHERN MID-ATLANTIC COAST...

...SUMMARY...
Sporadic damaging wind gusts appear possible from the southern
Plains to the southern Mid-Atlantic coast Thursday afternoon and
evening. Isolated occurrences of large hail may occur over portions
of south-central Colorado into northeast New Mexico and perhaps
portions of the Oklahoma and Texas Panhandles Thursday afternoon and
evening.

...Synopsis...

A short-wave trough initially over the upper MS and mid MO Valleys
Thursday morning will continue east into the Great Lakes and OH
Valley with a preceding belt of enhanced mid-level flow extending
into the Mid-Atlantic. Elsewhere, a vorticity maximum (possible MCV)
is forecast to progress from western KS into the Ozark Plateau by
Thursday night. At the surface, a cool front is expected to advance
through the Mid-Atlantic during the forecast period with the western
extension of the boundary settling more slowly south through the OH
Valley, Ozark Plateau, and southern Plains. The location of the
surface front is likely to be modulated by clusters of thunderstorms
that are expected to be ongoing Thursday morning from portions of
the OH Valley into the southern Plains.


...Southern Plains to the southern Mid-Atlantic coast...

To the south of residual cloudiness and lingering showers and
thunderstorms, a hot air mass is expected to develop by afternoon
with temperatures well into the 90s to around 100 F over the
southern Plains into the lower MS Valley, and upper 80s to mid 90s
from the TN Valley to Mid-Atlantic. While mid-level lapse rates will
remain generally less than 7 C/km, the daytime heating coupled with
dewpoints in the 60s to low/mid 70s will yield a moderately unstable
air mass by afternoon with MLCAPE ranging from 1500-2500+ J/kg.

The 00Z models indicate a gradual increase in thunderstorm coverage
and intensity through the afternoon, aided by forcing for ascent
associated with the mid-level disturbances mentioned in the
synopsis, as well as convergence along the synoptic front and any
existing outflow boundaries. The strongest mid/upper-level wind
field and resultant vertical shear are expected to largely remain to
the north of the effective warm sector. However, 30-35 kt of
deep-layer shear is forecast along the front over portions of the OH
Valley into the southern Mid-Atlantic, where some storm organization
appears possible with the primary hazard being damaging wind gusts.
Vertical shear will diminish with southwestward extent from the TN
Valley into the OK-TX Red River Valley; however, the presence of a
relatively deep, well-mixed boundary layer will be supportive of
sporadic damaging winds with isolated severe gusts.


...Raton Mesa Vicinity...

Upslope flow of a moist boundary layer beneath mid-level lapse rates
of 7-8 C/km will yield moderate afternoon instability with MLCAPE of
1000-1500 J/kg. Isolated to widely scattered thunderstorm
development is anticipated by mid afternoon along the high terrain
amidst a vertically veering wind profile with up to 30-35 kt of
deep-layer shear. The given environment will be supportive of
multicell and supercell storm modes with an associated risk for
large hail.

..Mead/Chalmers.. 09/10/2026

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1238 AM CDT Thu Sep 10 2026

Valid 111200Z - 121200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL
NEBRASKA INTO THE UPPER MIDWEST...

...SUMMARY...
Severe thunderstorms are possible across portions of Nebraska to the
Upper Midwest late Friday afternoon into Friday night.

...Nebraska/eastern Dakotas/Minnesota/Wisconsin...

An upper shortwave trough will move across the northern Plains and
Upper Midwest on Friday. As this occurs, a belt of enhanced
southwesterly flow will overspread the region, particularly from the
Dakotas into MN/WI. Cooling aloft will also support steepening
midlevel lapse rates atop a moistening boundary layer in which
increasing southerly low-level flow will transport 60s dewpoints
northward across the region. A surface low is forecast to develop
and shift east across SD, with a surface cold front shifting
southeast through period. This front will be oriented from northeast
to southwest from northwest MN/eastern ND into central SD near the
surface low by mid to late afternoon. A dryline will extend
southward from the surface low over central SD through central NE.
Corridors of moderate instability are forecast along/ahead of the
front, and thunderstorm development is expected by late
afternoon/early evening across northern MN.

Vertically veering wind profiles will support initial supercell
storms capable of all hazards, including damaging wind, large hail,
and a couple of tornadoes. Some hail greater than 2 inch diameter is
possible if supercell mode can be maintained. Given strong linear
ascent along the surface boundary, and an increasing southwesterly
low-level jet during the evening, initial supercells are likely to
cluster and/or grow upscale into line of convection spreading
east/northeast through the nighttime hours. 

Convective coverage is a bit more uncertain, and overall severe
potential more conditional, with southward extent into eastern SD/IA
and central NE. Large-scale ascent will be weaker further south, and
this could be problematic for overcoming inhibition from warmer
850-700 mb temperatures, especially through early evening. As the
surface cold front overtakes the dryline in NE overnight, elevated
convection could develop within a low-level warm advection regime.
Whether storms develop during the early evening or overnight, some
severe risk from damaging gusts and hail will be possible.

..Leitman.. 09/10/2026