209
ACUS01 KWNS 181247
SWODY1
SPC AC 181246

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0746 AM CDT Sat Oct 18 2025

Valid 181300Z - 191200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE ARKLATEX
AND OZARKS INTO PARTS OF THE LOWER/MID MS VALLEYS...

...SUMMARY...
Scattered severe thunderstorms are possible mainly this afternoon
into tonight across parts of the Ark-La-Tex, Ozarks, mid to lower
Mississippi and lower Ohio Valleys.  Damaging winds, a few tornadoes
and hail may occur.

...Synopsis...
A vigorous mid/upper-level trough will dig southeastward across the
central/northern Plains later today.  Water-vapor imagery this
morning shows a potent shortwave trough over the southern High
Plains and this feature will quickly move toward the ArkLaTex by
early evening.  The combination of these systems will eventually
result in development of a deep and progressive trough becoming
established over the MS Valley by early Sunday morning.  Morning
surface analysis places a low over northern OK and frontal zone
extending northeast.  The low will develop northeast during the
period and eventually reach Lower MI by early Sunday morning.

...Eastern TX/OK into parts of the lower/mid MS Valley...
Morning radar/satellite imagery shows the initial shower/storm
development over western MO/eastern KS into parts of west TX.  This
activity will likely increase in coverage and intensity from
southern MO into eastern OK/TX through midday, as the ejecting
shortwave trough approaches the region.  A plume of 60s deg F
surface dewpoints and some diurnal destabilization will lead to
moderate buoyancy by afternoon.  As storms gradually develop,
strengthening deep-layer shear will support storm organization.
Some initial supercell development could pose a threat for hail with
some tornado/damaging wind potential also perhaps accompanying this
activity.  Increasing ascent and upscale growth into convective
bands/lines will favor a continued risk for damaging gusts and
possibly some embedded brief tornado potential.

Prior forecast thinking of reduced buoyancy centered over eastern
AR/western TN may result in storms weakening as they move into this
area.  However, a notable increase in the low-level jet may support
some reintensification of storms during the evening near and east of
the lower MS Valley towards evening and into tonight.  A continued
threat for damaging winds and possibly a couple of tornadoes may
persist overnight near and north of the central Gulf Coast vicinity.

...Parts of the Ohio Valley/Midwest...
Latest model guidance generally shows scattered storms developing
later this afternoon coincident with diurnal destabilization.
Initial storm development over the MO/IL/western KY vicinity will
tend to grow upscale into a forced thunderstorm band later this
evening/overnight as forcing for ascent increases and overspreads
the region from the west.  The magnitude of the severe threat may be
limited by scant instability, but strong ascent and strong
deep-layer flow/shear will support some potential for damaging gusts
and perhaps a brief tornado or two.

..Smith/Bentley.. 10/18/2025

$$