RSS Mesoscale Discussions from Storm Prediction Center
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0744 AM CDT Fri Jun 19 2026
Valid 191300Z - 201200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
TEXAS INTO THE SOUTHEAST...CENTRAL PLAINS...UPPER MIDWEST...AND
SIERRA INTO THE NORTHERN GREAT BASIN...
...SUMMARY...
Isolated strong to severe thunderstorms may produce gusty winds and
hail today across parts of the the Upper Midwest and central Plains.
Other strong thunderstorms may produce occasional damaging winds
from north Texas/southern Oklahoma into portions of the Southeast,
and separately across parts of the Sierra into the northern Great
Basin.
...Texas into the Southeast/Carolinas...
An expansive area of convection has developed this morning across
north-central TX/southern OK, aided by modest low-level warm
advection and a weak mid-level disturbance. Both low-level and
deep-layer shear remain weak across this region (generally less than
20-25 kt), which should tend to limit updraft organization and
overall thunderstorm severity through the rest of the morning. But,
a very moist airmass and substantial reservoir of instability are
present ahead of this ongoing convection and south of a surface cold
front extending across TX into the ArkLaTex and lower MS Valley.
Current expectations are for an isolated severe/damaging wind threat
to persist downstream into the afternoon across these areas as the
moist airmass undergoes additional destabilization with daytime
heating. Considered including higher wind probabilities, but
confidence in a more organized/severe MCS remains low owing to the
weak deep-layer shear. Additional thunderstorms have also formed
south into central/south-central TX this morning. This activity may
also pose some risk for severe winds with the stronger cores as it
develops east-southeastward through the day, even though shear and
overall updraft organization will remain modest.
The Marginal Risk extending into the Southeast/eastern Carolinas has
been generally adjusted southward to account for the position of the
cold front, and expectations that the isolated damaging wind risk
will likely remain confined along/south of this boundary. Stronger
low/mid-level flow associated with the remnants of Arthur over the
eastern Carolinas this morning is forecast to quickly shift offshore
through the day. An isolated severe wind and brief tornado threat
may exist along/ahead of ongoing precipitation across this region,
although instability will remain limited.
Scattered to numerous thunderstorms will likely develop this
afternoon across parts of the FL Peninsula, with a preferential
focus along the Atlantic Coast sea breeze given modest westerly flow
aloft. While low/mid-level winds and related shear are expected to
remain weak, the strongest cores could still become capable of
producing occasional damaging winds as low-level lapse rates steepen
with daytime heating.
...Upper Midwest...
An upper low will remain over northern Manitoba/Ontario today, with
a broad fetch of moderate northwest flow aloft across the northern
Rockies/Plains. An embedded mid-level shortwave trough is forecast
to move across the Dakotas and toward the upper MS Valley by this
evening, with weak surface low pressure into northern MN. Strong
surface heating along with generally 50s surface dewpoints and
convergence near a cold front will lead to scattered storms across
much of MN and western WI. Forecast soundings show cold profiles
aloft over northern areas, though effective bulk shear will be
somewhat weaker with northward extent. Deep-layer shear will be
stronger over southern MN, but instability will not be as favorable
farther south. Even so, cells that develop this afternoon and
evening and track southeastward may be capable of producing severe
hail given the cool mid-level temperatures. Occasional
severe/damaging winds may also occur.
...Central Plains...
Beneath modest northwest flow aloft, surface low pressure will
develop over southeast CO today, with southeasterly low-level winds
across the central Plains. This will aid modest low-level warm/moist
advection, with 50s to perhaps low 60s surface dewpoints across KS,
eastern CO, and southern NE. It remains uncertain if any
thunderstorms will develop later today across this region, but the
influence of the upper trough over the northern Plains may yield a
few elevated cells. Additional warm/moist advection this
evening/overnight may also support isolated convective development.
Hail appears to be the primary risk, with moderate
instability/deep-layer shear and somewhat steepened mid-level lapse
rates potentially supporting supercells. However, confidence in
sustained convection remains too low to include greater severe
probabilities.
...Sierra/Northern Great Basin...
As a weak mid-level shortwave trough advances inland from the
eastern Pacific, isolated to scattered high-based thunderstorms
should develop later today across parts of the northern Sierra
Mountains into adjacent portions of the Great Basin. While low-level
moisture will remain limited, a very deeply mixed boundary layer and
some mid-level moisture/cooling aloft ahead of the shortwave trough
should support weak instability and thunderstorm potential. This
activity could become strong given some deep-layer shear, with
isolated severe gusts/outflow possible.
..Gleason/Broyles.. 06/19/2026
Read more
