858
ACUS01 KWNS 210553
SWODY1
SPC AC 210552
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1252 AM CDT THU MAY 21 2026
VALID 211200Z - 221200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
EASTERN COLORADO...
..SUMMARY
THUNDERSTORMS WITH A THREAT FOR LARGE HAIL, ISOLATED SEVERE GUSTS
AND POSSIBLY A TORNADO ARE EXPECTED IN PARTS OF EASTERN COLORADO
FROM MID AFTERNOON TO EARLY EVENING. ISOLATED LARGE HAIL WILL ALSO
BE POSSIBLE IN PARTS OF THE SOUTHERN HIGH PLAINS THIS AFTERNOON.
..CENTRAL AND SOUTHERN HIGH PLAINS
AN UPPER-LEVEL TROUGH WILL MOVE EASTWARD INTO THE CENTRAL ROCKIES
TODAY. AHEAD OF THE TROUGH, A LEE SURFACE LOW WILL FORM OVER EASTERN
COLORADO. AS SURFACE TEMPERATURES WARM, CONVECTION WILL INITIATE IN
THE HIGHER TERRAIN NEAR DENVER AND COLORADO SPRINGS. FROM THIS
CONVECTION, STORMS WILL DEVELOP AND MOVE EASTWARD INTO THE CENTRAL
HIGH PLAINS DURING THE AFTERNOON. IN EASTERN COLORADO, A
NORTH-TO-SOUTH AXIS OF INSTABILITY WILL BE IN PLACE BY AFTERNOON,
WHERE MODEL FORECASTS HAVE MLCAPE PEAKING AROUND 1500 J/KG. IN
ADDITION, LATE AFTERNOON RAP FORECAST SOUNDINGS IN EASTERN COLORADO
HAVE 0-6 KM SHEAR IN THE 45 TO 55 KNOT RANGE WITH 700-500 MB LAPSE
RATES NEAR 8 C/KM. THIS WILL BE FAVORABLE FOR SUPERCELLS WITH LARGE
HAIL AND ISOLATED SEVERE GUSTS. IF A SUPERCELL CAN BECOME LOCALLY
DOMINANT, THEN A TORNADO WILL ALSO BE POSSIBLE. THE SEVERE THREAT
WILL LIKELY PERSIST INTO EARLY EVENING.
FURTHER SOUTH INTO THE SOUTHERN HIGH PLAINS, AN AXIS OF INSTABILITY
WILL BE IN PLACE BY AFTERNOON. THE STRONGEST INSTABILITY IS FORECAST
ON THE CAPROCK OF WEST TEXAS, WHERE 0-6 KM SHEAR IS FORECAST TO BE
AROUND 30 KNOTS. THIS, ALONG WITH 700-500 MB LAPSE RATES NEAR 7
C/KM, MAY BE ENOUGH FOR AN ISOLATED LARGE HAIL THREAT.
..BROYLES/SQUITIERI.. 05/21/2026
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