...Day 5/Sat - Southern Plains to the Ozarks vicinity...
Low-amplitude west/southwest mid/upper flow is forecast across the
southern Plains to the Mid-South vicinity for much of the diurnal
period on Saturday. By 00z, forecast guidance suggests a shortwave
trough will eject from the southern Rockies into the southern
Plains, and eventually impinging on the Ozarks/Mid-South area by
Sunday morning. A very moist and unstable airmass is forecast over
the southern Plains vicinity ahead of this feature as a surface warm
front lifts northward through the day. Increasing ascent may not
arrive until after 00-03z, limiting convective initiation until the
nighttime hours. If storms can develop during the day across
portions of OK/TX, all hazards severe potential will exist.
Otherwise, thunderstorm potential may be more likely during the
evening/overnight from north TX into southeast OK and AR as
large-scale ascent increases and a 65-75 kt 500 mb jet overspreads
the region. The north and west bounds of severe potential are a bit
uncertain, so this area may shift in subsequent outlooks.
...Day 6/Sun - Ozarks to the Lower OH and TN Valleys...
An upper shortwave trough will progress across the region on Sunday.
Forecast guidance depicts a 50-60 kt southwesterly 700 mb jet
overspreading the region during the day. Meanwhile, a surface low
will intensify over MO/IL, shifting northeast along the OH River
through the period. A very moist and unstable airmass is depicted
ahead of the low and attendant south/southeastward-progressing cold
front. Intense severe thunderstorms will likely accompany this
system. Consistency among deterministic guidance, favorable synoptic
pattern, as well as CSU/NSSL ML output, support introduction of 15
percent probabilities for Sunday.