258
FXUS63 KBIS 070300
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1000 PM CDT SAT JUN 6 2026
KEY MESSAGES
- A WIND ADVISORY REMAINS IN EFFECT SOUTH AND WEST OF THE
MISSOURI RIVER THROUGH THIS EVENING.
- ISOLATED TO SCATTERED SEVERE THUNDERSTORMS OVER NORTHWEST AND
FAR SOUTHWEST NORTH DAKOTA TONIGHT.
- SCATTERED TO NUMEROUS SEVERE THUNDERSTORMS OVER MUCH OF
WESTERN AND CENTRAL NORTH DAKOTA LATE SUNDAY AFTERNOON AND
SUNDAY NIGHT.
- EXCEPT FOR A BRIEF BREAK ON MONDAY, A MORE ACTIVE SEVERE
WEATHER PATTERN LOOKS TO CONTINUE NEXT WEEK.
UPDATE
ISSUED AT 951 PM CDT SAT JUN 6 2026
AT THIS TIME THE STRONGEST STORMS REMAIN OVER NORTHEAST MONTANA
ABOUT TO PUSH INTO NORTH DAKOTA WHERE A NOTABLE WAVE IS LIFTING
THROUGH SOUTHWEST FLOW ALOFT. THIS ALSO COINCIDES WHERE THE
STRONGEST INSTABILITY (~3000 J/KG) IS ALSO NOTED. TO THE SOUTH
OVER SOUTHWEST MONTANA INTO FAR SOUTHWEST NORTH DAKOTA,
SECONDARY AREA OF CONVECTION, THOUGH NOT AS ROBUST, CONTINUES
AFFILIATED WITH INCREASING LOW LEVEL JET.
OVER THE NEXT FEW HOURS EXPECT THE NORTHERN STORMS TO INTENSIFY
ELEVATING THE ONGOING SEVERE THREAT AS THEY PASS THROUGH
NORTHWEST NORTH DAKOTA. AS FOR THE SOUTHERN STORMS, WILL HAVE TO
SEE HOW THE TREND CONTINUES WITH THE ENHANCING JET, BUT THINK
THE FOCUS WILL LEAN MORE TO THE NORTH.
UPDATE
ISSUED AT 641 PM CDT SAT JUN 6 2026
SO FAR THIS EVENING THE STRONGEST STORMS HAVE REMAINED OVER
SASKATCHEWAN, WITH A SPLITTING STORM FORMING JUST NORTH OF THE
BORDER NEAR ESTEVAN. INVERTED TROUGH REMAINS ORIENTATED MORE OR
LESS ALONG A LINE FROM GLENDIVE TO SYDNEY TO CROSBY, WITH SOME
CUMULUS BUBBLING ALONG IT. GUIDANCE NOW LEANS A LITTLE TOWARDS
INITIATION OVER OUR AREA BEING DELAYED A TAD, MORE TOWARDS 8-9
PM CDT. ATMOSPHERE DOES REMAIN SET FOR STRONG CONVECTION,
THOUGH, WITH CAPE VALUES REMAINING AROUND 3000 J/KG, WITH FAIR
DEEP LAYER SHEAR VALUES AROUND 35-40KTS, GREATEST ALONG THE
MONTANA BORDER. STRONG WINDS REMAINS THE GREATEST CONCERN GIVEN
FORECAST SOUNDING PROFILES BUT LARGE HAIL REMAINS ON THE TABLE.
DISCUSSION
ISSUED AT 248 PM CDT SAT JUN 6 2026
THIS AFTERNOON, SHALLOW RIDGING ALOFT WAS MOVING OVER EASTERN
NORTH DAKOTA, WHILE UPSTREAM OF THE FORECAST AREA A DEEP CLOSED
LOW WAS ANALYZED OVER THE PACIFIC NORTHWEST. AT THE SURFACE, LOW
PRESSURE WAS LOCATED IN NORTHEAST WYOMING, WITH SOUTHERLY LOW-
LEVEL FLOW ACROSS NORTH DAKOTA. A TIGHTENING PRESSURE GRADIENT
IS PRODUCING STRONG SOUTHEAST WINDS, AND A WIND ADVISORY IS IN
EFFECT THROUGH LATE THIS EVENING FOR AREAS SOUTH AND WEST OF THE
MISSOURI RIVER.
MOSTLY QUIET WEATHER IS EXPECTED FOR THE REMAINDER OF THE
DAYTIME HOURS, WITH EYES ON A SHORTWAVE MOVING THROUGH MONTANA
AND CONVECTION DEVELOPING WEST OF THE FORECAST. LATEST CAMS RUNS
ARE IN RELATIVELY GOOD AGREEMENT ON THE MAIN AREA OF STORMS
EXTENDING ACROSS NORTHWEST NORTH DAKOTA LATE THIS EVENING AND
INTO THE OVERNIGHT HOURS ALONG A SURFACE TROUGH, WITH
POTENTIALLY SOME ADDITIONAL SHOWERS AND THUNDERSTORMS ACROSS THE
SOUTHWEST WHERE THE ENVIRONMENT IS LESS FAVORABLE. IN THE
NORTHWEST, WE CONTINUE TO ADVERTISE HAIL UP TO THE SIZE OF PING
PONG BALLS AND WINDS UP TO 70 MPH. FORECAST PARAMETERS ARE A BIT
TOUGH, WITH STRONGER SHEAR TO THE WEST AND HIGHER INSTABILITY TO
THE EAST, BUT THE NARROW AREA OF OVERLAP FAVORED ACROSS
NORTHWEST NORTH DAKOTA WOULD BE SUPPORTIVE OF SEVERE
THUNDERSTORMS IF THEY DEVELOP AND CAN SURVIVE CAPPING ADVERTISED
IN FORECAST SOUNDINGS.
NUMEROUS SEVERE THUNDERSTORMS ARE POSSIBLE ON SUNDAY (LEVEL 3
OUT OF 5) WHICH IS AN UPGRADE FROM THE PREVIOUS SHIFT. SHARP
SOUTHWEST FLOW ALOFT WILL OVERLAP WITH ANOTHER SURFACE LOW AND
ASSOCIATED FRONTS FROM EASTERN MONTANA THROUGH MUCH OF NORTH
DAKOTA. AHEAD OF THE COLD FRONT WILL BE A VERY WARM AND MOIST
AIRMASS, WITH FORECAST DEW POINTS IN THE UPPER 50S TO LOWER 60S
AND STRONG SOUTHEAST WINDS ACROSS CENTRAL AND EASTERN NORTH
DAKOTA, WHICH WILL LIKELY NEED ANOTHER WIND ADVISORY. AS THE
FRONT MOVES EAST THROUGH THE AFTERNOON AND EVENING, A BIG
QUESTION IS THE POTENTIAL CAPPING INVERSION AND IF TEMPERATURES
WILL HEAT UP ENOUGH TO OVERCOME THE CAP. RIGHT NOW, FORECAST
HIGH TEMPERATURES ARE IN THE MID TO UPPER 90S ACROSS CENTRAL
NORTH DAKOTA, SLIGHTLY LOWER IN THE JAMES RIVER VALLEY, AND IN
THE MID TO UPPER 80S ACROSS THE WEST BEHIND THE FRONT.
CONVECTIVE TEMPERATURES ARE GENERALLY FROM 94 TO 97 F, SO IT
WILL BE CLOSE. IF ANY INITIAL SUPERCELLS DEVELOP, THEY WOULD
LIKELY BE ACROSS NORTHERN NORTH DAKOTA, AND BULK SHEAR VECTORS
PARALLEL TO THE FRONT WOULD FAVOR DISCRETE CELLS. THESE STORMS
WOULD BE WHERE THE PRIMARY LARGE HAIL (UP TO 2 INCHES) AND
POTENTIAL TORNADO THREAT WOULD BE, ALTHOUGH LOW-LEVEL SRH IS
STILL SOMEWHAT MARGINAL. HIGH-RES GUIDANCE IS PRETTY SPLIT ON
WHAT DEVELOPS IN THE LATE AFTERNOON, BUT IS COMING INTO MORE
AGREEMENT ON STORMS MOVING INTO SOUTHWEST NORTH DAKOTA IN THE
EVENING. THE MEAN WIND QUICKLY TURNS SOUTHERLY ALONG AND BEHIND
THE FRONT WHICH WOULD FAVOR UPSCALE GROWTH AND A WIND THREAT.
DETERMINISTIC GUIDANCE IS ADVERTISING DCAPE OVER 1000 J/KG AND
0-3KM SHEAR AROUND 25 KNOTS, SO STICKING WITH THE 70 MPH WIND
SPEED IN MESSAGING FOR NOW ALTHOUGH CAN SEE THIS HAVING TO BE
INCREASED IF WE GET MORE CONFIDENT IN LINEAR MODE AND THE 0-3KM
SHEAR INCREASES A BIT MORE.
WE GET A BREAK FROM PRECIPITATION CHANCES ON MONDAY AS THE
UPPER LOW LIFTS TO THE NORTHEAST, WITH A BRIEF REPRIEVE FROM THE
HOT AND HUMID AIRMASS FROM THIS WEEKEND. FORECAST HIGHS ON
MONDAY ARE IN THE MID 70S TO LOWER 80S, WITH LIGHT SURFACE WINDS
AS A WEAK SURFACE HIGH PASSES THROUGH THE REGION.
TUESDAY IS THE NEXT DAY TO PAY ATTENTION TO FOR POTENTIAL SEVERE
THUNDERSTORMS. PERSISTENT SOUTHWEST FLOW COMBINED WITH A SURFACE LOW
AND ATTENDANT UPPER WAVE IS A FAVORABLE SYNOPTIC SETUP FOR
CONVECTION, AND ALTHOUGH IT'S STILL EARLY, DETERMINISTIC GUIDANCE IS
ADVERTISING A VERY SUFFICIENT ENVIRONMENT FOR SEVERE THUNDERSTORMS
TO DEVELOP, WITH FORECAST DEW POINTS IN THE 60S ACROSS MUCH OF
THE STATE. CSU MACHINE LEARNING PROBABILITIES HAVE JUMPED UP
SIGNIFICANTLY FROM YESTERDAY, SO WILL BE INTERESTING TO SEE HOW
THIS TRENDS THE NEXT FEW DAYS. NSSL ML PROBABILITIES ARE ALSO
MODEST AND HIGHLIGHT MOST OF NORTH DAKOTA FOR THIS PERIOD.
AS THE SYSTEM FROM TUESDAY CONTINUES TO MOVE THROUGH ON WEDNESDAY,
SEVERE WEATHER PROBABILITIES SHIFT FURTHER TO THE EAST. NBM
PRECIPITATION CHANCES KEEP LOW TO MEDIUM PROBABILITIES OF SHOWERS
AND THUNDERSTORMS THROUGH WEDNESDAY AND INTO THURSDAY, ALTHOUGH A
LACK OF INSTABILITY WILL LIMIT THE SEVERE WEATHER POTENTIAL FOR THE
FORECAST AREA. FLOW ALOFT TURNING MORE NORTHWESTERLY WILL ALSO HELP
COOLER AIR FILTER INTO THE REGION, WITH WIDESPREAD HIGHS IN THE 60S
AND 70S BY LATE IN THE WEEK. EXTENDED OUTLOOKS TILT TOWARDS BELOW
NORMAL TEMPERATURES THROUGH THE MIDDLE OF THE MONTH.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 641 PM CDT SAT JUN 6 2026
SCATTERED THUNDERSTORMS POSSIBLE THIS EVENING OVER NORTHWEST AND
FAR SOUTHWEST NORTH DAKOTA, POSSIBLY SPREADING INTO NORTH
CENTRAL NORTH DAKOTA BETWEEN 06Z AND 12Z. PRIMARILY OVER
NORTHWEST NORTH DAKOTA INCLUDING THE KXWA TERMINAL, SOME STORMS
COULD BE SEVERE. MAINLY VFR CONDITIONS THEN EXPECTED THROUGH
MID-DAY SUNDAY. LATER SUNDAY AFTERNOON AND EVENING, SHOWERS AND
THUNDERSTORMS DEVELOP OVER THE AREA, WITH MANY POSSIBLY BECOMING
SEVERE, PRIMARILY AFTER 21Z. LARGE HAIL AND DAMAGING WIND GUSTS
WILL BE POSSIBLE.
SOUTHEAST WINDS GUSTING TO 40KTS WILL CONTINUE OVER PARTS OF
SOUTHWEST NORTH DAKOTA THROUGH THIS EVENING BEFORE TAPERING OFF.
IN ADDITION, LOW LEVEL WIND SHEAR WILL BE A CONCERN LATER THIS
EVENING AT THE KBIS, KMOT, AND KDIK TERMINALS. SOUTHERLY WINDS
WILL BE ON THE INCREASE ON SUNDAY, ESPECIALLY OVER THE JAMES
RIVER VALLEY INTO PARTS OF SOUTH CENTRAL NORTH DAKOTA, POSSIBLY
GUSTING AROUND 40 KTS.
BIS WATCHES/WARNINGS/ADVISORIES
WIND ADVISORY UNTIL MIDNIGHT CDT /11 PM MDT/ TONIGHT FOR
NDZ017>020-031>033-040>044-059>062.
UPDATE...JJS
DISCUSSION...JONES
AVIATION...JONES
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