599
ACUS03 KWNS 121927
SWODY3
SPC AC 121926
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0226 PM CDT TUE AUG 12 2025
VALID 141200Z - 151200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH
DAKOTA INTO NORTHWEST MINNESOTA...
..SUMMARY
SEVERE STORMS PRODUCING HAIL AND WIND ARE POSSIBLE MAINLY FROM
EASTERN NORTH DAKOTA INTO NORTHWEST MINNESOTA THURSDAY AFTERNOON AND
EVENING.
..SYNOPSIS AND DISCUSSION
A MATURE MID-LATITUDE CYCLONE IS FORECAST TO BE OVER CENTRAL
ALBERTA/SASKATCHEWAN EARLY THURSDAY MORNING BEFORE THEN CONTINUING
GRADUALLY EASTWARD AND ENDING THE PERIOD OVER THE CENTRAL
SASKATCHEWAN/MANITOBA BORDER VICINITY. EXTENSIVE SURFACE TROUGHING
WILL PRECEDE THIS SYSTEM, LIKELY EXTENDING FROM CENTRAL SASKATCHEWAN
INTO THE CENTRAL HIGH PLAINS EARLY THURSDAY. PRIMARY SURFACE LOW
ASSOCIATED WITH THIS SYSTEM IS FORECAST TO OCCLUDE OVER CENTRAL
SASKATCHEWAN WHILE A SECONDARY LOW DEVELOPS OVER SOUTHERN MANITOBA
AND MOVES EASTWARD/NORTHEASTWARD INTO FAR NORTHWESTERN ONTARIO.
AS THE SECONDARY SURFACE LOW MOVES EAST, AN ATTENDANT COLD FRONT IS
EXPECTED TO MOVE EASTWARD/SOUTHEASTWARD ACROSS THE DAKOTAS AND
WESTERN MN. A VERY MOIST AIRMASS, CHARACTERIZED BY DEWPOINTS IN THE
UPPER 60S/LOW 70S, WILL PRECEDE THIS FRONT. THIS LOW-LEVEL MOISTURE
BENEATH STEEP MID-LEVEL LAPSE RATES WILL RESULT IN VERY STRONG
BUOYANCY (3000+ J/KG OF MLCAPE). DESPITE AMPLE LOW-LEVEL MOISTURE,
SUBSTANTIAL CAPPING WILL LIKELY PERSIST ACROSS MUCH OF THE NORTHERN
PLAINS GIVEN THE VERY WARM LOW/MID-LEVEL TEMPERATURES (ON THE ORDER
20 TO 25 DEG C AT 850 MB). FORCING ALONG THE FRONT SHOULD BE STRONG
ENOUGH TO OVERCOME THIS CAPPING ACROSS EASTERN ND, WITH UNCERTAINTY
REGARDING STORM DEVELOPMENT AND COVERAGE INCREASING WITH SOUTHERN
EXTENT ACROSS SD. THE STRONG BUOYANCY AND MODERATE VERTICAL SHEAR
WILL SUPPORT LARGE TO POTENTIALLY VERY LARGE HAIL WITH THE INITIALLY
MORE CELLULAR STORMS. WARM AND DRY LOW TO MID-LEVELS SUGGEST STRONG
DOWNDRAFTS ARE POSSIBLE WITH MATURE STORMS AS WELL. UPSCALE GROWTH
IS UNCERTAIN GIVEN THE PREVAILING CAPPING AND MORE LIMITED BUOYANCY
DOWNSTREAM INTO MN.
..MOSIER.. 08/12/2025
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page