Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1115 AM CDT Thu May 21 2026
Valid 211630Z - 221200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING OVER PARTS OF EASTERN COLORADO....
...SUMMARY...
Thunderstorms capable of producing large hail and isolated severe
gusts should occur across parts of the central/southern High Plains
this afternoon and evening. A tornado or two may also occur.
...High Plains...
Water vapor imagery shows an upper trough moving across western
WY/CO. This feature will spread weak/broad large scale forcing for
ascent across much of the High Plains from SD to NM this afternoon.
At the surface, southerly low level winds have resulted in an axis
of 40s/50s dewpoints along this corridor. Low clouds are slowly
eroding, which should result in moderate CAPE values and aid in the
development of widely scattered afternoon thunderstorms.
Isolated storms will likely form first over parts of eastern NM.
This activity will build slowly eastward toward west TX with a risk
of large hail.
By mid/late afternoon, storms will likely develop off the Raton and
Palmer ridges, spreading eastward toward western KS this evening.
Shear profiles in this area will be stronger than farther south,
supporting longer-lived storms capable of large hail, damaging
winds, and perhaps a tornado or two.
An isolated cell or two may also produce occasional severe hail over
parts of eastern WY and into the Black Hills region later this
afternoon.
...Carolinas/VA...
Clear skies are leading to strong heating over parts of southern VA
into part of NC/SC. Scattered afternoon thunderstorms are expected
to form in this zone, with steep low-level lapse rates and
sufficient CAPE supporting a risk of gusty/damaging winds in the
strongest cells.
..Hart/Lyons.. 05/21/2026
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