432
FXUS63 KBIS 011950
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
250 PM CDT MON JUN 1 2026
KEY MESSAGES
- MARGINAL RISK (LEVEL 1 OF 5) FOR SEVERE WEATHER THIS AFTERNOON
AND EVENING OVER FAR SOUTHWEST NORTH DAKOTA.
- MARGINAL (LEVEL 1 OUT OF 5) TO SLIGHT RISK (LEVEL 2 OUT OF 5)
OF SEVERE WEATHER ON TUESDAY.
- MEDIUM TO HIGH CHANCES FOR PRECIPITATION CONTINUE WEDNESDAY
MAINLY OVER CENTRAL NORTH DAKOTA INCLUDING THE JAMES RIVER
VALLEY WHERE A SLIGHT RISK (LEVEL 2 OUT OF 5) EXISTS.
- LOW TO MEDIUM CHANCES OF SHOWERS AND THUNDERSTORMS THURSDAY THROUGH
THE REMAINDER OF THE WEEK.
DISCUSSION
ISSUED AT 250 PM CDT MON JUN 1 2026
THE PASSAGE OF A LOW PRESSURE SYSTEM ACROSS THE SOUTHERN
CANADIAN PRAIRIES WILL CHARACTERIZE CONDITIONS ACROSS THE REGION
OVER THE NEXT FEW DAYS. FOR TODAY, THE LOW IS PROGGED TO LINGER
OVER SOUTHWESTERN SASKATCHEWAN. GUSTY SOUTHWEST WINDS ARE FOUND
ACROSS NORTHWESTERN AND PORTIONS OF NORTH CENTRAL NORTH DAKOTA
AS THE PRESSURE GRADIENT TIGHTENS BETWEEN THIS LINGERING LOW AND
A CENTER OF HIGH PRESSURE MOVING NORTH OUT OF SOUTH DAKOTA.
SUSTAINED SPEEDS AROUND 20 TO 25 MPH AND GUSTS UP TO 35 MPH ARE
FORECAST FOR THE NORTHWEST, WITH SPEEDS MORE GENERAL AROUND 10
TO 15 MPH AND GUSTS UP TO 25 MPH ELSEWHERE. THE SKY IS EXPECTED
TO BECOME PARTLY TO MOSTLY CLOUDY AS MID LEVEL CLOUDS MOVE IN
FROM THE NORTHWEST. HIGHS THIS AFTERNOON ARE FORECAST FROM THE
UPPER 60S NORTHWEST TO UPPER 70S AND LOWER 80S IN THE SOUTH
CENTRAL.
LATE THIS AFTERNOON INTO THIS EVENING, CHANCES FOR SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO INCREASE ACROSS THE WEST AS THE
PREVIOUSLY MENTIONED LOW PRESSURE SYSTEM BEGINS TO MOVE FURTHER
TO THE NORTH, LOFTING A SURFACE TROUGH ACROSS THE MONTANA
BORDER. INTERROGATION OF CAM SOUNDINGS DURING THIS PERIOD
REVEALS FAIRLY STRONG BULK SHEAR ACROSS MUCH OF THE SOUTHWEST,
MODEL VALUES AROUND 55 TO 65 KNOTS THIS EVENING. INSTABILITY IS
EXPECTED TO BE COMPARABLY LIMITED DURING THIS PERIOD, WITH
MODEL MUCAPE MAXING OUT AROUND 1000-1250 J/KG IN THE EARLY
EVENING, AND DIMINISH RAPIDLY AFTER SUNSET. THAT BEING SAID,
THERE IS BRIEF PERIOD IN THE LATE AFTERNOON, EARLY EVENING WHERE
A STRONGER TO MARGINALLY SEVERE STORM MAY LOFT MOVE INTO FAR
SOUTHWESTERN NORTH DAKOTA. THE MAIN HAZARDS EXPECTED WOULD BE
QUARTER SIZED HAIL AND ISOLATED GUSTS UP TO 60 MPH. AS OF THIS
FORECAST CYCLE, SPC HAS A LEVEL 1 OF 5 RISK FOR ISOLATED SEVERE
STORMS IN FAR SOUTHWEST FOR TODAY. AFTER THE SEVERE RISK
DIMINISHES THROUGH THE EVENING, CHANCES FOR SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO SPREAD FROM WEST TO EAST
OVERNIGHT. OTHERWISE, GUSTY SOUTHWEST WINDS ARE EXPECTED TO
DIMINISH THROUGH THE EVENING AND OVERNIGHT AS THE LOW CENTER
BEGINS TO MOVE TO THE NORTHEAST, TURNING SOUTH SOUTHEASTERLY
THROUGH TUESDAY MORNING. LOWS ARE FORECAST IN THE MID TO UPPER
40S WEST TO THE LOWER 50S CENTRAL.
WITH THE SURFACE LOW EXPECTED TO BECOME STATIONARY IN SOUTHERN
SASKATCHEWAN TUESDAY MORNING, WITH THE TRANSITION OF THE
INVERTED SURFACE TROUGH INTO A WEAK COLD FRONT THROUGH THE DAY,
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE IN AREAL
COVERAGE THROUGH THE MORNING AND AFTERNOON. WITH THE POSITION OF
THE LOW, BETTER MOISTURE INFLUX WILL DRIVE DEWPOINTS INTO THE
LOWER 60S PORTIONS OF THE WEST AND MUCH OF CENTRAL NORTH DAKOTA
BY THE EARLY AFTERNOON. CAMS CONTINUE TO ADVERTISE INCREASING
AHEAD AND ALONG THE COLD FRONT AS IT MOVES FROM WEST TO EAST
ACROSS THE FORECAST AREA TUESDAY AFTERNOON AND EVENING, WITH
MODEL MUCAPE VALUES PEAKING WELL INTO THE 3000-3500 J/KG RANGE,
AND BULK SHEAR AROUND 35 KNOTS UP TO 55 KNOTS OVER PORTIONS OF
THE FAR WEST AND NORTH. ORIENTATION OF THE SHEAR VECTORS APPEAR
TO ONLY SLIGHTLY OFF PARALLEL FROM THE COLD FRONT, WHICH
INDICATES THAT STORM MODE WOULD MAINLY BE CLUSTERED. MODEL DCAPE
VALUES ACROSS PORTIONS OF THE SOUTH CENTRAL ALSO BEGIN TO PEAK
INTO THE 1000-1500 J/KG RANGE AS WE HEAD INTO THE EARLY EVENING.
WITH THIS IN MIND, THE MAIN EXPECTED HAZARDS WITH ANY SEVERE
STORM THAT DOES DEVELOP WOULD BE HAIL UP TO THE SIZE OF GOLF
BALLS, AS WELL AS WIND GUSTS APPROACHING 70 MPH. AN ISOLATED
TORNADO IS ALSO POSSIBLE ACROSS PORTION OF THE NORTH CENTRAL,
WITH NEAR SURFACE SHEAR VALUES PEAKING AROUND 20-25 KNOTS WHILE
LOW LEVEL SRH JUMPS TO AROUND 150-200 M2/S2 IN THE LATE
AFTERNOON, EARLY EVENING. THE WINDOW FOR TORNADIC DEVELOPMENT IS
EXPECTED TO BE SOMEWHAT BRIEF, WOULD HIGHLY DEPEND ON HOW WELL
THE ENVIRONMENT RECOVERS FROM POTENTIAL CONVECTION EARLIER IN
THE AFTERNOON. THE SPC HAS PLACED PORTIONS OF WESTERN AND MUCH
OF CENTRAL NORTH DAKOTA UNDER A LEVEL 2 OF 5 RISK FOR SCATTERED
SEVERE THUNDERSTORMS FOR TUESDAY. MOVING INTO THE OVERNIGHT
PERIOD, WHILE THE OVERALL SEVERE THREAT IS EXPECTED TO DIMINISH,
SHOWERS AND A FEW THUNDERSTORMS ARE EXPECTED TO CONTINUE AS THE
COLD FRONT MOVES TOWARD EASTERN NORTH DAKOTA. OF NOTE IS THE
POTENTIAL FOR HEAVY RAINFALL. WITH HIGH PWATS AROUND 1.3 TO 1.4
INCHES, AND WITH THE SLOW MOVING NATURE OF THIS SYSTEM, MUCH OF
CENTRAL NORTH DAKOTA HAS MEDIUM TO HIGH CHANCES FOR AT LEAST 1
INCH OF RAINFALL TUESDAY THROUGH WEDNESDAY MORNING, WITH LOCALLY
HEAVIER AMOUNT ANTICIPATED WHERE THUNDERSTORMS DEVELOP. WPC HAS
PLACE MUCH OF THE CENTRAL NORTH DAKOTA IN A SLIGHT RISK FOR
EXCESSIVE RAINFALL FOR TUESDAY.
CONDITIONS ON WEDNESDAY WILL LIKELY DEPEND ON HOW QUICKLY THE
AFOREMENTIONED COLD FRONT IS ABLE TO EXIT TO THE EAST FOR THE
FORECAST AREA. WITH THE SASKATCHEWAN LOW PROGGED TO SLOWLY MOVE
EASTWARD THROUGH THE DAY WEDNESDAY, MORE MOISTURE IS EXPECTED TO
STREAM IN FROM THE SOUTH SOUTHEAST ACROSS THE FORECAST AREA,
AND BULK SHEAR VALUES AROUND 40 TO 55 KNOTS ARE ADVERTISED BY
THE CAMS. IF THE COLD FRONT IS SLOW TO EXIT OUT TO THE EAST, ANY
ONGOING SHOWERS AND CONVECTION THAT ARE ONGOING ON CENTRAL
NORTH DAKOTA MAY PERK UP IN THE LATE MORNING AND AFTERNOON.
THUS, SPC HAS PLACED MUCH OF CENTRAL NORTH DAKOTA INTO A LEVEL 2
OF 5 RISK FOR SEVERE THUNDERSTORMS AGAIN ON WEDNESDAY.
BEHIND THE EXITING LOW, ZONAL FLOW IS GENERALLY EXPECTED OVER
THE NORTHERN PLAINS THROUGH THE REMAINDER OF WORKWEEK. A
DECENTLY STRONG SHORTWAVE IS PROGGED TO MOVE ACROSS NORTH DAKOTA
LATE THURSDAY INTO FRIDAY, PROMOTING ANOTHER ROUND OF SHOWERS
AND THUNDERSTORMS ACROSS THE FORECAST AREA INTO THIS PERIOD.
BEHIND THIS SHORTWAVE, THERE IS DECENT AGREEMENT ON COMPARABLY
DRIER WEATHER ON SATURDAY AS A TRANSIENT SHORTWAVE RIDGE MOVES
ACROSS THE REGION. WITH FLOW ALOFT THEN PROGGED TO TURN
SOUTHWESTERLY SUNDAY INTO EARLY NEXT WEEK, ANOTHER PERIOD OF
ACTIVE WEATHER CAN BE ANTICIPATED.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 250 PM CDT MON JUN 1 2026
VFR CEILINGS AND VISIBILITY IS FOUND AT ALL TERMINALS TO BEGIN THE
18Z TAF PERIOD. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE
ACROSS THE WEST LATE THIS AFTERNOON AND EVENING, SPREADING ACROSS
INTO CENTRAL NORTH DAKOTA THROUGH TUESDAY MORNING AND THE END OF THE
TAF PERIOD. COVERAGE IN THUNDERSTORMS DURING THIS PERIOD IS FAIRLY
UNCERTAIN, THUS HAVE LIMITED PROB30 TO THE WESTERN TERMINALS OF KXWA
AND KDIK AT THIS TIME. WHERE THUNDERSTORMS DEVELOP, GUSTY AND
ERRATIC WINDS SHOULD BE ANTICIPATED. GUSTY SOUTHWEST WINDS THIS
AFTERNOON WILL QUICKLY DIMINISH THROUGH THE EVENING, TURNING SOUTH
THEN SOUTHEASTERLY THROUGH THE OVERNIGHT PERIOD.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...ADAM
AVIATION...ADAM
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page