995
ACUS01 KWNS 110551
SWODY1
SPC AC 110549

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1249 AM CDT Sat Oct 11 2025

Valid 111200Z - 121200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE INTERIOR WEST AND ALONG THE NORTH CAROLINA COAST...

...SUMMARY...
Isolated severe thunderstorms are possible this afternoon into the
evening across the eastern Great Basin and the Colorado Plateau. A
brief tornado and a severe gust are possible over the Outer Banks of
North Carolina during the early morning Sunday.

...Great Basin Region...

Early-morning satellite imagery depicts a notable upper low off the
OR Coast shifting east in line with latest model guidance.
Associated upper trough will advance inland by sunrise and into the
northern inter mountain/Great Basin by 12/00z as stronger midlevel
flow rotates through the base of the trough into UT. During the
latter half of the period an intensifying 500mb jet will eject
across northwest CO into southern WY as the trough becomes negative
tilted.

PW values are seasonally high across northern Mexico into the CO
Plateau as a dominant downstream upper ridge maintains favorable
deep layer south-southwesterly trajectories across this portion of
the U.S. While profiles are quite moist across this region, lapse
rates are necessarily weak and this will limit buoyancy ahead of the
trough. Even so, a strongly forced frontal zone will surge across
the interior west to a position along the ID/WY border, arcing
southwest across central UT into southern NV by late afternoon.
Scattered convection should easily develop ahead of the upper
trough, and a few robust updrafts could attain weak supercell
characteristics, the strongest of which may generate some hail/wind.


Southern influence of stronger midlevel flow will extend into
central AZ by peak heating. While temperatures are not forecast to
be that warm, favorably upslope flow into the Mogollon Rim may
encourage a few robust updrafts at this lower latitude. Strong
deep-layer shear suggests the most robust updrafts could exhibit
rotation. Have extended MRGL Risk into this region to account for a
few supercells. Isolated damaging winds are the primary concern
across AZ.

...NC Outer Banks...

Slow-moving upper trough over the FL Peninsula will encourage a
surface low to deepen off the Carolina Coast during the latter half
of the period. This feature may approach the southern NC Coast by
12/12z which will prove favorable for lower 70s surface dew points
to advect inland as easterly low-level flow strengthens after 06z.
While lapse rates will remain poor, some buoyancy increase is
expected with 70s dew points - more than adequate for lightning
discharge with deeper updrafts. Forecast shear profiles suggest at
least a low risk for a brief tornado and gusty winds with any
supercells that form in this environment.

..Darrow/Weinman.. 10/11/2025

$$