Valid 300100Z – 301200Z
…THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN PLAINS AND ARKLATEX…
Marginally severe thunderstorms are possible late tonight across
parts of Oklahoma and North Texas into western Arkansas, southwest
Missouri and far southeast Kansas.
The latest water vapor imagery shows an upper-level low across the
northwestern U.S with a broad cyclonic flow pattern across the
Desert Southwest. A lead shortwave trough is present in the southern
Rockies with southwest mid-level flow over the southern Plains. A
plume of mid-level moisture is evident in the flow across west Texas
and parts of Oklahoma. At the surface, a moist airmass is located
across central and east Texas. A southern Plains low-level jet will
advect low-level moisture northward into eastern Oklahoma tonight.
Destabilization will take place mostly above 700 mb with forecast
soundings increasing MUCAPE into the 1000 to 2000 J/kg range.
Thunderstorm development is expected to occur tonight along the
instability axis due to lift associated with the southern Plains
low-level jet and approaching upper-level system. Scattered
thunderstorms, mostly elevated in nature, are forecast to initiate
from central Oklahoma into southeast Kansas with this activity
spreading eastward into southwest Missouri and northwestern Arkansas
later tonight. The instability combined with effective shear of 40
to 45 kt and steep mid-level lapse rates may be enough for hail with
the stronger updrafts. A few marginally severe wind gusts will also
be possible mainly across north Texas and far southeast Oklahoma
where convection may become surface-based.