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ACUS03 KWNS 050731

SWODY3

SPC AC 050730



Day 3 Convective Outlook  

NWS Storm Prediction Center Norman OK

0230 AM CDT Sun May 05 2024



Valid 071200Z - 081200Z



...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF

THE MID-SOUTH INTO THE OHIO VALLEY...



...SUMMARY...

Scattered severe thunderstorms appear possible Tuesday from the

Mid-South northeastward into parts of the Ohio Valley.



...Synopsis...

A large, closed upper cyclone over the northern Plains should move

little on Tuesday. A lead mid-level shortwave trough with attendant

enhanced mid-level jet is forecast to move quickly northeastward

across the Upper Midwest and Great Lakes through the day. The

southern fringe of this shortwave trough and modest large-scale

ascent should overspread parts of the Mid-South into the OH Valley

Tuesday afternoon. At the surface, a deep low over ND should slowly

occlude, while a weak secondary low develops northeastward in tandem

with the shortwave trough across parts of the Upper Midwest and

Great Lakes. A moist and unstable airmass should exist along and

southeast of a convectively reinforced surface front, generally

extending northeastward from the ArkLaTex vicinity into parts of the

mid MS and OH Valleys.



...Mid-South into the Ohio Valley...

A line of thunderstorms will probably be ongoing Tuesday morning

over parts of AR/MO/IL, associated with convection that developed on

Monday across the Plains. This activity may tend to weaken though

the morning. But, it could still pose an isolated strong/gusty wind

threat. Weak to moderate instability should develop ahead of and to

the southwest of these early-day thunderstorms, with greater

instability forecast across the Mid-South and lower OH Valley.

Deep-layer shear is forecast to be strong enough to support

organized convection, including some supercells. However, with

mid-level flow generally aligned with the forecast position of the

surface boundary, tendency may be for clusters/bowing line segments

to prevail.



Regardless, scattered strong to severe thunderstorms should spread

east-northeastward across the OH Valley Tuesday afternoon and

evening, posing a threat for mainly damaging winds and severe hail.

Across the Mid-South/TN Valley into AR, the severe threat appears

more conditional, owing to this region generally being displaced to

the south of the better forcing aloft. An isolated threat for severe

hail may develop late in the period (early Wednesday morning) across

the Ozarks as low-level flow/ascent increases with a strengthening

low-level jet.



Given latest model trends and the likelihood for morning convection

across the mid MS Valley, it appears that the potential for

appreciable destabilization and severe thunderstorms is lower across

much of IA, MO, and IL. Have therefore reduced severe probabilities

across these areas.



..Gleason.. 05/05/2024



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