065
ACUS11 KWNS 212357
SWOMCD
SPC MCD 212356
NDZ000-SDZ000-MTZ000-220200-
MESOSCALE DISCUSSION 1748
NWS STORM PREDICTION CENTER NORMAN OK
0656 PM CDT MON JUL 21 2025
AREAS AFFECTED...SOUTHEAST MONTANA...FAR NORTHEAST
WYOMING...SOUTHWEST NORTH DAKOTA...NORTHWEST SOUTH DAKOTA
CONCERNING...SEVERE THUNDERSTORM WATCH 535...
VALID 212356Z - 220200Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 535
CONTINUES.
SUMMARY...A GREATER THREAT FOR SEVERE WIND GUSTS MAY DEVELOP ALONG
AND NORTH OF THE SOUTH DAKOTA/NORTH DAKOTA BORDER THIS EVENING.
DISCUSSION...INITIAL SUPERCELLS HAVE ALREADY GROWN UPSCALE INTO A
SMALL LINEAR SEGMENT IN SOUTHEAST MONTANA. STRONG BUOYANCY EXISTS
JUST SOUTHEAST OF THIS ACTIVITY, SOUTH OF A MODIFIED OUTFLOW
BOUNDARY FROM MORNING CONVECTION. GIVEN THE EXPECTED STRENGTHENING
OF THE LOW-LEVEL JET IN THE DAKOTAS THIS EVENING, THIS BOUNDARY AND
GREATER MOISTURE/BUOYANCY WILL LIKELY SHIFT NORTHWARD OVER TIME. THE
FAVORABLE WIND SHEAR WITHIN THE REGION SHOULD ALLOW THIS ACTIVITY TO
PROPAGATE ALONG THE THETA-E GRADIENT SO LONG AS THE LINEAR SEGMENT
DOES NOT MOVE TOO FAR NORTH TOO QUICKLY (OUTRUNNING THE INCREASING
BUOYANCY). IT IS NOT EXACTLY CERTAIN HOW FAR NORTH THE GREATER
BUOYANCY WILL MOVE THIS EVENING, BUT AREAS NEAR AND NORTH OF THE
SOUTH DAKOTA/NORTH DAKOTA BORDER WILL BE MONITORED FOR AN INCREASING
THREAT OF SEVERE WIND GUSTS INTO THE EVENING.
..WENDT.. 07/21/2025
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...BIS...UNR...BYZ...GGW...
LAT...LON 47390179 47010113 46220145 45720291 45540365 45160512
45130610 45230643 45610663 46260685 46790571 47110445
47390179
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
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