ACUS01 KWNS 191636

SWODY1

SPC AC 191634



Day 1 Convective Outlook  

NWS Storm Prediction Center Norman OK

1134 AM CDT Wed Aug 19 2026



Valid 191630Z - 201200Z



...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF

THE MID AND LOWER MISSOURI VALLEY...THE MID MISSISSIPPI VALLEY...AND

SOUTHERN ARIZONA...



...SUMMARY...

Thunderstorms capable of severe wind gusts and hail will be possible

this afternoon across the lower to mid Missouri Valley, the mid

Mississippi Valley, and southern Arizona.



...Mid MO Valley...

Radar/visible satellite mosaic imagery depicts a small cluster of

severe thunderstorms immediately ahead of a migratory shortwave

trough moving southeast over the mid MO Valley.  Some heating

downstream of this activity will result in temperatures warming and

the airmass gradually destabilizing amid filtered sunshine.  Gradual

upscale growth is underway and should continue into the early

afternoon.  Large hail and severe gusts 60-70 mph will be the

primary severe hazards as this cluster moves into adjacent portions

of NE/MO/IA later this afternoon.  



...Ozarks into the Mid MS Valley...

Residual showers/thunderstorms from an overnight MCS over the

southeast MO into western KY vicinity will slowly dissipate this

afternoon with greater heating ensuing in the wake of these storms. 

Models continue to show moderate destabilization by late this

afternoon ahead of the MO Valley upper vort.  Weak low-level

convergence along an upstream cold front will support thunderstorm

development within this destabilized airmass this evening. 

Strengthening mid-level flow will result in moderate to strong

deep-layer vertical shear supportive of supercells.  Models vary

regarding the propensity for cellular mode to be maintained beyond

the initial storm development phase, casting doubt on supercell

longevity and tornado potential.  Nonetheless, some strengthening of

850-mb flow during the evening may enable some mesocyclone potential

to persist, and an accompanying isolated risk for a tornado or two. 

Otherwise, storms will tend to cluster with eastward extent, with

the threat for damaging gusts persisting within these bowing line

segments.



...Ohio Valley...

A somewhat secondary area of late afternoon/early evening

thunderstorm development is anticipated from central IL into central

IN and central OH.  Moderate buoyancy and strong westerly flow aloft

supports the potential for isolated supercells capable of large hail

and isolated damaging gusts.



...Central/Southern High Plains...

A seasonably moist airmass will undergo strong heating/mixing and

result in moderate buoyancy by mid-late afternoon. Thunderstorm

development is expected across the higher terrain before then

progressing eastward into the lower elevations.  Moderate

northwesterly flow aloft will support organized storms

structures, and large hail is possible along the Foothills.

Steep lapse rates and large temperature-dewpoint depressions will

lead to outflow-dominant storms capable of severe gusts with the

more intense cores/outflow.



...AZ...

The presence of monsoon moisture will support moderate buoyancy

across the lower elevations of south-central AZ during the late

afternoon.  Scattered storms are expected to eventually develop

towards the early evening.  Trends in model guidance showing a

cluster potentially evolving within an adequately moist/inverted-V

environment lend confidence in introducing a level 1 intensity

highlight for peak gusts in the 70-80 mph range.



...Southeast into northern FL...

A very moist airmass analyzed late this morning (mid to upper 70s F

surface dewpoints) will remain in place along the Gulf Coast. Strong

heating is anticipated, with high temperatures in the upper 90s

across much of the region.  As surface temperatures warm, moderate

instability will develop, with scattered thunderstorms expected amid

modest low-level convergence from MS into western/southern AL and

across the FL Panhandle into northern FL.  The deep low-level

moisture combined with steep low-level lapse rates will support an

isolated wind-damage threat during the mid to late afternoon.



..Smith/Wendt.. 08/19/2026



$$