Mesoscale Discussion 0168
NWS Storm Prediction Center Norman OK
0921 AM CDT Thu Mar 12 2020
Areas affected...Central MO...Far Southwestern IL
Concerning...Severe potential...Watch possible
Valid 121421Z - 121615Z
Probability of Watch Issuance...40 percent
SUMMARY...Elevated thunderstorms capable of hail will continue
eastward across central/east-central MO over the next few hours.
Trends will be monitored for possible watch issuance.
DISCUSSION...Recent surface analysis places a low over eastern KS
with a warm from extending eastward from this low into west-central
MO and then southwestward into south-central MO/north-central AR.
Thunderstorms have recently developed north of this surface boundary
amidst strong warm-air advection/isentropic ascent promoted by
moderate to low/mid-level flow across OK. Recent mesoanalysis
depicts a 40-45 kt 850mb jet extending across eastern OK into far
southwest MO. This jet is expected to progress gradually eastward
over the next few hours just ahead of the mid-level trough also
progressing eastward.
Expectation is for these elevated storms to continue
eastward/southeastward over the next few hours. Current storm motion
estimate is east-southeastward at 40-45 kt, taking this cluster to
MO/IL border by 17Z. Moderate instability (i.e. MUCAPE around 1000
J/kg) and strong deep-layer shear (i.e. 0-6 km bulk shear around 60
kt) supports organized updrafts. Given the currently elevated storm
character, primary threat with any organized updrafts for the next
few hours will be hail. Threat for damaging wind gusts will increase
with eastern extent as the storms become closer to northward-moving
warm front.
A higher probability for surface-based storms is anticipated farther
east across southern IL, southern IN, MO boothill, and far western
KY later this afternoon. This threat will be addressed in later
outlooks and MDs.
..Mosier/Hart.. 03/12/2020
