217
ACUS11 KWNS 012144
SWOMCD
SPC MCD 012143
NEZ000-SDZ000-COZ000-WYZ000-012315-
MESOSCALE DISCUSSION 1536
NWS STORM PREDICTION CENTER NORMAN OK
0443 PM CDT TUE JUL 01 2025
AREAS AFFECTED...PORTIONS OF FAR EASTERN WYOMING...WESTERN SOUTH
DAKOTA AND NEBRASKA...INTO FAR NORTHEAST COLORADO
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 012143Z - 012315Z
PROBABILITY OF WATCH ISSUANCE...60 PERCENT
SUMMARY...INITIAL THUNDERSTORMS ACROSS PARTS OF THE HIGH PLAINS
SHOULD CONTINUE TO INTENSIFY THIS AFTERNOON/EVENING. DAMAGING GUSTS
AND HAIL ARE POSSIBLE.
DISCUSSION...AS OF 2140 UTC, REGIONAL RADAR AND VISIBLE IMAGERY
SHOWED THUNDERSTORM DEVELOPMENT WAS UNDERWAY FROM EASTERN WY, INTO
NORTHERN CO AND WESTERN NE/SD. WEAK ASCENT FROM A SUBTLE SHORTWAVE
TROUGH AND STRONG DIURNAL HEATING WILL CONTINUE TO SUPPORT STORM
DEVELOPMENT THROUGH THIS AFTERNOON INTO THIS EVENING. INITIAL STORMS
WILL LIKELY BE HIGH-BASED AS DEEP MIXING HAS REDUCED DEWPOINTS INTO
THE UPPER 40S IN SPOTS. WITH TIME, STORMS SHOULD GRADUALLY MOVE
EAST/SOUTHEASTWARD INTO MORE MOIST/UNSTABLE CONDITIONS. 1500-2000
J/KG OF MLCAPE AND MID-LEVEL LAPSE RATES NEAR 8 C/KM WILL BE MORE
THAN SUFFICIENT TO SUPPORT STRONG UPDRAFTS. DEEP-LAYER SHEAR, WHILE
NOT OVERLY STRONG (25-35 KT) WILL FAVOR SUPERCELLS AND ORGANIZED
MULTI CELLS CAPABLE OF HAIL (SOME POTENTIAL NEAR 2 INCHES IN
DIAMETER) GIVEN THE STEEP LAPSE RATES AND BUOYANCY. DAMAGING WINDS
ARE ALSO LIKELY WITHIN THE DEEPER-MIXED BOUNDARY LAYER.
OBSERVATIONAL TRENDS AND CAM GUIDANCE SUGGESTS STORMS WILL CONTINUE
TO MATURE ALONG AND SOUTH OF THE BLACK HILLS INTO WESTERN NE THIS
EVENING. THE SEVERE THREAT SHOULD INCREASE AS CONVECTION DEVELOPS
AND SPREADS EAST/SOUTHEASTWARD. SOME CLUSTERING IS POSSIBLE WITH
TIME, THOUGH SUBTLE FORCING FOR ASCENT SUGGESTS LOWER STORM COVERAGE
IS PERHAPS MORE LIKELY. GIVEN THE INCREASING SEVERE RISK, CONDITIONS
ARE BEING MONITORED FOR A POSSIBLE WEATHER WATCH.
..LYONS/GUYER.. 07/01/2025
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...LBF...UNR...GLD...BOU...CYS...
LAT...LON 40780354 42130366 43750417 44910414 45000323 44340183
42390103 41220103 40630165 40350279 40780354
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
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