RSS Mesoscale Discussions from Storm Prediction Center
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0730 AM CDT Mon Jul 13 2026
Valid 131300Z - 141200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHEAST AND MONTANA...
...SUMMARY...
Thunderstorms with isolated strong to severe winds may occur this
afternoon and evening across parts of the Southeast and Montana.
...Southeast...
A very weak mid-level trough will persist over the Deep South and
Carolinas today, with modest westerly flow. Although rich low-level
moisture remains present across these areas, multiple days of
convective overturning has resulted in rather poor lapse rates
aloft. This, along with persistent cloudiness, should limit to some
degree how much instability will develop this afternoon with
filtered daytime heating. Deep-layer shear will also remain weak,
and thunderstorms should generally be disorganized. Some loose
clustering may eventually occur with convection spreading eastward
from the central Gulf Coast towards the FL Peninsula, where
low-level lapse rates should become steepened by peak afternoon
heating. Isolated damaging winds appear possible with the strongest
cores from parts of FL into eastern GA and SC ahead of the weak
mid-level trough.
...Montana...
Mid/upper-level ridging will extend from the southern/central
Rockies to the northern Plains/Upper Midwest through the period,
with a belt of enhanced southwesterly mid-level flow over
western/central MT. High-based thunderstorms may develop this
afternoon across parts of southwest into central MT amid a deeply
mixed boundary layer. While low-level moisture and related
instability are both expected to remain limited, some risk for
occasional strong to severe gusts may accompany this convection as
it spreads northward through the early evening before weakening.
...Arizona...
Showers and isolated thunderstorms are still ongoing this morning
across parts of southern AZ. While mid-level east-southeasterly flow
will persist today across much of AZ on the southern periphery of
prominent upper ridging, it remains unclear how much destabilization
will occur in the wake of this morning's convection. Whether
convection will be able to spread westward off the higher terrain of
southeast AZ and the Mogollon Rim is also uncertain. Have therefore
not included low severe wind probabilities with this update.
..Gleason/Thornton.. 07/13/2026
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