ACUS01 KWNS 201959

SWODY1

SPC AC 201957



Day 1 Convective Outlook  

NWS Storm Prediction Center Norman OK

0257 PM CDT Sat Jun 20 2026



Valid 202000Z - 211200Z



...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF

THE CENTRAL PLAINS...



...SUMMARY...

Severe thunderstorms remain likely across parts of the central

Plains mainly this afternoon and evening. Large to very large hail,

severe winds (some 75+ mph), and a few tornadoes are possible.



...20z Update WY/NE/CO/KS...

Scattered severe storms are likely over much of the central High

Plains this afternoon and evening. Incipient convection is

developing over the higher terrain/foothills and should spread

eastward into a moist and destabilizing air mass. Aided by strong

ascent from an upper trough and mid-level jet (observed via 18z

RAOBs), supercells and organized clusters remain likely. All hazards

are expected, with a focus for a few more persistent supercells and

a strong tornado or two along a notable differential heating axis in

southwestern NE. With time upscale growth into and MCS is likely

tonight with a risk for damaging winds into the central Plains.

Minor adjustments were made to the probabilities for the latest

observed trends. For short term information see MCD #1212.



...Great Basin...

Scattered thunderstorms have developed over parts of NV and southern

ID along a diffuse frontal zone. While moisture is limited, enough

instability beneath the passing upper trough will support the

potential for a few severe gusts. 5% wind probabilities were

extended westward. See MCD #1213 for more info.



...Southeast...

Scattered to widespread thunderstorms continue across much of the

Gulf Coast and Southeast States this afternoon. Sporadic damaging

gusts remain possible with the stronger clusters across northern FL

and southern LA. Weak shear will preclude much if any storm

organization. 5% wind probabilities were adjusted to better match

damaging wind potential.



..Lyons.. 06/20/2026



.PREV DISCUSSION... /ISSUED 1109 AM CDT Sat Jun 20 2026/



...Central Plains...

Water vapor imagery shows a shortwave trough over ID/UT tracking

eastward toward the central High Plains.  Southerly/southeasterly

low-level winds ahead of this feature over parts of eastern

CO/western NE/KS will help to maintain a moist and moderately

unstable air mass across the region, especially as low clouds

continue to burn off and afternoon heating commences.  Scattered

thunderstorm development is expected by mid-afternoon over central

WY down into central CO in favored terrain/convergence areas.  This

activity will spread eastward into a progressively more

moist/unstable air mass and intensify into supercells.  A corridor

of favorable vertical shear will develop later today from northeast

CO into southwest NE/northwest KS for isolated tornadoes. 

Otherwise, very large hail and damaging winds will be the main

concerns.  Activity is likely to organize upscale during the evening

and spread across KS with a damaging wind risk persisting much of

the night.



...Southeast...

A very moist and moderately unstable air mass is present again today

over much of the southeast US.  Most CAM solutions suggest scattered

afternoon thunderstorms across this area, including along the FL

east coast.  Dewpoints in the 70s and PWAT values around 2 inches,

coupled with strong daytime heating and steep low-level lapse rates

suggest a risk of locally gusty/damaging wind gusts in the most

intense cores.



$$