785
FXUS63 KBIS 010003
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
703 PM CDT SUN MAY 31 2026
KEY MESSAGES
- MARGINAL RISK (LEVEL 1 OUT OF 5) SEVERE WEATHER THROUGH THIS
EVENING OVER MUCH OF SOUTH CENTRAL NORTH DAKOTA.
- MARGINAL (LEVEL 1 OUT OF 5) TO SLIGHT RISK (LEVEL 2 OUT OF 5)
OF SEVERE WEATHER ON TUESDAY.
- LOW TO MEDIUM CHANCES OF SHOWERS AND THUNDERSTORMS WEDNESDAY
THROUGH THE REMAINDER OF THE WEEK.
UPDATE
ISSUED AT 655 PM CDT SUN MAY 31 2026
SHOWERS AND THUNDERSTORMS CONTINUE ALONG AN OCCLUDED FRONT
ARCING FROM SOUTH CENTRAL NORTH DAKOTA BACK NORTHWEST INTO
NORTHWESTERN ND. MODIFIED POPS TO BETTER CAPTURE LATEST RADAR
AND TRENDS/CAM OUTPUT. BEST INSTABILITY AND ENVIRONMENT FOR
STRONGER STORMS (ALBEIT PULSE/SHORT LIVED STRONGER UPDRAFTS)
RESIDES FROM ACROSS PORTIONS OF EASTERN SOUTH DAKOTA INTO PARTS
OF SOUTH CENTRAL NORTH DAKOTA. A FEW ROBUST STORMS ACROSS EMMONS
COUNTY, THOUGH SUB-SEVERE AND NOT EXPECTING ANYTHING MORE THIS
EVENING. NST PARAMETER INCREASING ALONG THE FRONT, SO SOMETHING
WE WILL WATCH GOING FORWARD THIS EVENING. PUSH OF WESTERLY WINDS
IN THE WAKE OF THE OCCLUDED FRONT AS IT PUSHES EAST TONIGHT WILL
SEE CONVECTION ENDING WEST TO EAST NOW THROUGH EARLY MONDAY
MORNING.
DISCUSSION
ISSUED AT 350 PM CDT SUN MAY 31 2026
SURFACE LOW WILL RETREAT INTO SOUTHERN CANADA TONIGHT, PUSHING A
COLD FRONT ACROSS THE STATE FROM WEST TO EAST THIS EVENING
THROUGH TONIGHT. ISOLATED TO SCATTERED THUNDERSTORMS ARE
EXPECTED AS THIS FRONT MOVES THROUGH. SPC HAS MAINTAINED A
MARGINAL RISK FOR SEVERE WEATHER IN SOUTH CENTRAL NORTH DAKOTA.
THIS AREA HAS MODEST CAPE 1000 TO 2000 J/KG WITH AMPLE HEATING
AND INCREASED DEWPOINTS IN THE 60S TODAY. SHEAR IS LACKING
TODAY, WITH EFFECTIVE SHEAR 25 TO 30 KNOTS. SHEAR VECTOR IS
ANGLED TO THE FRONT INDICATING MULTICLUSTER STORMS THE LIKELY
STORM MODE TODAY. MID LEVEL LAPSE RATES ALSO LOOK LACKING TODAY,
ALTHOUGH STEEP LAPSE RATES ARE FOUND IN THE LOWER LEVELS. GIVEN
MODEST CAPE AND SOME SHEAR, PULSE MULTI CELL STORMS COULD BRING
WINDS GUSTS UP TO 60 MPH WINDS AND HAIL UP TO QUARTER SIZE
THROUGH THIS EVENING. WITH STEEP LOW LEVEL LAPSE RATES AND
INCREASED CAPE IN THESE LOWER LEVELS, PERHAPS A NON-SUPERCELL
FUNNEL CLOUD IS POSSIBLE THROUGH THIS EVENING. THE LACK OF LOW
LEVEL SHEAR SHOULD LIMIT THIS THREAT. OTHERWISE LOOK FOR A
BREEZY SOUTHEAST WIND TO BECOME A BREEZY WESTERLY WIND DURING
FRONT PASSAGE. PRECIPITATION WILL PUSH EASTWARD THROUGH THE
NIGHT. COOLER TEMPERATURES WILL MOVE IN BEHIND THIS FRONT
TONIGHT WITH LOWS IN THE 40S WEST TO LOWER 50S EAST. A COOLER
POST FRONTAL DAY IS THEN EXPECTED FOR MONDAY. LOOK FOR BREEZY
WESTERLY WINDS THROUGH THE DAY, ESPECIALLY IN THE NORTHWEST.
PRECIPITATION CHANCES SHOULD BE MINIMAL WITH PERHAPS SOME LIGHT
CHANCES IN THE NORTH ALONG THE STALLED FRONT. LOOK FOR HIGHS IN
THE 60S NORTHWEST TO NEAR 80 SOUTHEAST. UPPER UPPER LOW STALLED
IN CANADA APPROACHES WESTERN ND MONDAY NIGHT. THIS COULD RETURN
CHANCES FOR SHOWERS AND THUNDERSTORMS IN THE WEST. LOWS WILL
REMAIN COOL IN THE 40S TO LOWER 50S.
UPPER LOW REMAINS IN THE AREA FOR TUESDAY AND WEDNESDAY. WARMING
TEMPERATURES AND INCREASE MOISTURE FROM A SOUTHERLY FLOW WILL
BRING MODEST INSTABILITY TO THE AREA. SHEAR WILL ALSO BE
INCREASED FROM THE UPPER LEVEL LOW ALOFT. THE RESULT COULD BE
ONE TO TWO DAYS OF SEVERE WEATHER ACROSS THE STATE. TUESDAY
CURRENTLY HAS A MARGINAL TO SLIGHT RISK ACROSS MUCH OF THE
STATE. STRONG WIND AND LARGE HAIL ARE THE LIKELY MAIN THREATS
FOR TUESDAY. A SHEAR VECTOR ANGLED TO PARALLEL TO THE FRONTAL
BOUNDARY COULD LIMIT THE DISCRETE SUPERCELL POTENTIAL AND THE
STRONGER HAZARDS ASSOCIATED WITH THAT. ALTHOUGH THAT COULD
CHANGE GIVEN THIS SETUP IS STILL A FEW DAYS OUT. THE INCREASED
AMOUNTS OF INSTABILITY WITH THIS SYSTEM COULD ALSO PROVIDE FOR A
PROLONGED SEVERE WEATHER THREAT, WITH SOME CAMS STARTING
CONVECTION LATE MORNING AND CONTINUING THROUGH THE EVENING.
INCREASED PWATS OVER AN INCH ARE ALSO FORECAST FOR TUESDAY.
WITH NEAR SATURATED SOILS THIS COULD LEAD TO SOME LOCALIZED
FLOODING ESPECIALLY IN CENTRAL AND EASTERN PORTIONS. WPC
CURRENTLY HAS A MARGINAL RISK FOR EXCESSIVE RAIN. SIMILAR
CONDITIONS MAY BE FOUND ON WEDNESDAY ALTHOUGH SEVERE WEATHER AND
HEAVY RAIN THREAT MAY SHIFT EASTWARD WITH THE UPPER LOW
SHIFTING EASTWARD. LOWS THROUGH MID WEEK WILL REMAIN IN THE
UPPER 40S TO UPPER 50S, WHILE HIGH IN THE 70S TO LOWER 80S CAN
BE EXPECTED.
ZONAL FLOW ALOFT COULD CONTINUE THE SUMMER LIKE PATTERN FOR
LATE IN THE WEEK AS TEMPERATURES REMAIN ABOVE NORMAL. THIS
COMBINED WITH WEAK DISTURBANCES IN THE WESTERLY FLOW COULD BRING
DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS. CSU-MLP SHOWING
LIMITED THREAT FOR SEVERE WEATHER, WITH PERHAPS SOME ISOLATED
ACTIVITY POSSIBLE DURING THE UPCOMING WEEKEND.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 649 PM CDT SUN MAY 31 2026
MOSTLY CLOUDY TONIGHT WITH A MIX OF VFR TO LOW VFR/MVFR
CEILINGS. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THIS EVENING FOR MAINLY CENTRAL AND EASTERN TAF SITES
(KBIS, KMOT, AND KJMS), WITH CHANCES DECREASING OVERNIGHT. MOST
SITES HAVE PROB30 MENTION FOR SHOWERS/THUNDERSTORMS. MVFR TO
PERHAPS SOME IFR CEILINGS LATE TONIGHT, WITH THE SKY TRENDING
SKC FOR MONDAY. VFR CONDITIONS EXPECTED DURING THE DAY MONDAY.
BREEZY SOUTHERLY WIND THIS EVENING WILL BECOME WESTERLY TONIGHT
INTO TOMORROW WEST TO EAST.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...NH
DISCUSSION...ANGLIN
AVIATION...NH
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