237
FXUS63 KBIS 280055
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
755 PM CDT SAT JUN 27 2026
KEY MESSAGES
- NUMEROUS SEVERE THUNDERSTORMS ARE POSSIBLE THROUGH TONIGHT.
EXPECTED HAZARDS INCLUDE DAMAGING WINDS TO 80 MPH, ALONG WITH
A FEW TORNADOES POSSIBLE. HAIL UP TO TENNIS BALL SIZED IS
POSSIBLE WITH ANY DISCRETE STORMS THAT FORM.
- ADDITIONAL ISOLATED TO SCATTERED SEVERE THUNDERSTORMS ARE
POSSIBLE SUNDAY THROUGH MONDAY.
- NEAR TO ABOVE NORMAL TEMPERATURES ARE FAVORED THIS WEEKEND
THROUGH THE MIDDLE OF NEXT WEEK, WARMING TO WELL ABOVE NORMAL
HEADING INTO THE FORTH OF JULY HOLIDAY WEEKEND.
UPDATE
ISSUED AT 755 PM CDT SAT JUN 27 2026
** MESOSCALE UPDATE **
THE RISK OF 70-90+ MPH WINDS IS RAPIDLY INCREASING IN SOUTHWEST
ND AND IS FORECAST TO RAPIDLY EXPAND EAST-NORTHEAST ACROSS WEST
CENTRAL, THE REST OF SOUTHWEST, AND INTO PARTS OF CENTRAL ND IN
THE NEXT 1-2 HOURS.
MERGING SUPERCELLS AND AN INCREASINGLY-LINEAR CONVECTIVE MODE IS
OCCURRING IN AN ENVIRONMENT CHARACTERIZED BY STRONG BOUYANCY
AND DEEP-LAYER SHEAR, AND 0-3-KM BULK SHEAR ON THE ORDER OF 30
KT IN THE FACE OF LARGE DCAPE. THE REQUISITE ENVIRONMENTAL AND
STORM MODE CONSIDERATIONS FOR A BOW ECHO ARE BECOMING REALIZED.
FORWARD-PROPAGATING CORFIDI VECTORS SUGGEST THE LINEAR, BOWING
COMPLEX WILL RAPIDLY MOVE EAST-NORTHEAST WITH A FORWARD SPEED
ON THE ORDER OF 50 KT. RECENT WOFS RUNS SUGGEST THE DAMAGING TO
DESTRUCTIVE WIND RISK WILL CONTINUE, WITH POTENTIAL FOR
LOCALIZED GUSTS UP TO AROUND 100 MPH POSSIBLE IN WESTERN ND THE
NEXT 1-2 HOURS.
CJS
UPDATE
ISSUED AT 657 PM CDT SAT JUN 27 2026
** MESOSCALE UPDATE **
THE SEVERE STORM RISK IS RAPIDLY INCREASING IN WESTERN ND AND IS
EXPECTED TO SPREAD EASTWARD THE NEXT SEVERAL HOURS, WITH AN
INITIAL RISK OF LARGE TO VERY LARGE HAIL AND TORNADOES, AND A
TRANSITION IN MID-LATE EVENING TO THE MAIN HAZARDS BEING FROM
DAMAGING WINDS AND POTENTIAL LINE-EMBEDDED TORNADOES.
THUNDERSTORMS ARE RAPIDLY DEVELOPING FROM NORTHEASTERN MT INTO
SOUTHWESTERN ND AND NORTHWESTERN SD AS OF 2345Z, WITH ADDITIONAL
UPSTREAM CONVECTION IN SOUTHEASTERN MT ALSO APPROACHING AND
MERGING INTO THIS ACTIVITY. THESE STORMS ARE FORMING ALONG A
SURFACE TROUGH AND AS STRONGER FORCING FOR ASCENT APPROACHES.
EARLIER ATTEMPTS AT CONVECTIVE INITIATION IN WEST CENTRAL ND,
E.G., MCKENZIE AND BILLINGS COUNTIES, FAILED MULTIPLE TIMES,
LIKELY AS A RESULT OF A RESIDUAL WARM NOSE ALOFT SHOWN ON
RAP/HRRR FORECAST SOUNDINGS. THAT WILL BE ERODED WITH THE
APPROACHING FORCING FOR ASCENT AS CAMS HAVE LONG BEEN
FORECASTING, AND AS EVEN RECENT WOFS CYCLES HAVE SUPPORTED.
DEEP-LAYER SHEAR ON THE ORDER OF 40-50 KT AND STRONG BOUYANCY
WITH MLCAPE ON THE ORDER OF 3000-4000 J/KG SUPPORTS ROTATING
AND INTENSE UPDRAFTS IN WESTERN ND THIS EVENING. BACKED
SOUTHEAST FLOW HAS RESULTED IN LOW-LEVEL HODOGRAPHS BECOMING
MORE CURVED IN THE LAST HOUR, WHICH IS BEGINNING TO AND WILL
CONTINUE TO FAVOR RIGHT-MOVING SUPERCELLS IN WESTERN ND.
OCCASIONAL LEFT-MOVING SPLITS MAY CONTINUE TO SURVIVE, BUT MAY
BE LESS PREVALENT THAN THEY WERE IN SOUTHEASTERN MT 1-2 HOURS
AGO GIVEN THE RECENT TRENDS IN HODOGRAPH SHAPES. GIVEN THE
SUPERCELL-FAVORABLE SETTING, RICH BOUNDARY LAYER MOISTURE
ALONG/NORTH OF A TRIPLE POINT IN FAR NORTHWESTERN SD INTO
SOUTHWESTERN ND, A TORNADO RISK IS PRESENT AND IS EXPECTED TO
INCREASE THE NEXT FEW HOURS AS STORMS MOVE FURTHER EAST-
NORTHEAST INTO AN ENVIRONMENT THAT CONTAINS GREATER LOW-LEVEL
SRH AND RELATED HIGHER EFFECTIVE STP VALUES. THIS SAME THEME
WILL BE PRESENT WITH STORMS THAT MOVE INTO WEST CENTRAL AND
NORTHWESTERN ND INTO AN ENVIRONMENT THAT CONTAINS INCREASING
AMOUNTS OF LOW-LEVEL SHEAR AND RELATED SRH.
LARGE TO VERY LARGE HAIL IS EXPECTED WITH SUPERCELLS THROUGH
MID-EVENING, THOUGH GRADUAL UPSCALE GROWTH WILL RESULT IN A
SHIFT TOWARD DAMAGING WINDS AT SOME POINT BY AROUND 9 PM CDT.
CAMS AND RECENT WOFS CYCLES CONTINUE TO SUGGEST ONE OR MORE
BOWING SEGMENTS WITH DAMAGING WINDS WILL DEVELOP IN WESTERN ND
BY MID EVENING. SOME TORNADO RISK IS APT TO OCCUR EVEN WITH
UPSCALE GROWTH AND MORE LINEAR STRUCTURES GIVEN THE CAPE-SHEAR
AND LOW-LEVEL SHEAR SETTING.
CJS
UPDATE
ISSUED AT 414 PM CDT SAT JUN 27 2026
WINDS IN THE SOUTHCENTRAL AND SOUTHEAST REMAIN BREEZY, YET BELOW
WIND ADVISORY CRITERIA. ABUNDANT CLOUD COVER SHOULD LIMIT MIXING
FOR THE REST OF THE AFTERNOON. THUS WILL CANCEL THE WIND
ADVISORY.
A TORNADO WATCH IS NOW IN EFFECT FOR PORTIONS OF WESTERN NORTH
DAKOTA FROM 4 PM CDT / 3 PM MDT TO MIDNIGHT CDT / 11 PM MDT.
DESTABILIZATION IS TAKING PLACE ACROSS WESTERN ND WITH CLEARING
SKIES. CUMULUS CLOUDS ARE STARTING TO FORM, ALTHOUGH BILLOW
CLOUDS STILL SHOWING SIGNS OF A STABLE PBL. IN FAR SOUTHEASTERN
MT, SLIGHTLY MORE CU AGITATION IS BEING NOTED, WITH SOME ORPHAN
ANVILS. OVERALL THIS WESTERN AND ESPECIALLY SOUTHWESTERN AREA
WILL BE THE AREA TO MONITOR FOR THE NEXT FEW HOURS. ANY DISCRETE
CELLS THAT FORM IN THIS AREA WILL BE CAPABLE OF ALL HAZARDS
INCLUDING TORNADOES AND LARGE HAIL. THE WATCH DOES REACH TO THE
CANADIAN BORDER. THE NORTHWEST HAS MORE OF A CONDITIONAL THREAT
FOR SUPERCELLS, ALTHOUGH PARAMETERS FOR TORNADOGENESIS ARE QUITE
CONCERNING. OVERALL A TORNADO THREAT IS ANTICIPATED FOR THE
NEXT FEW HOURS. CONVECTION FURTHER INTO MT WILL BE THE NEXT AREA
TO MONITOR AS THE WAVE PRODUCING THIS COULD LEAD TO MORE LINEAR
CONVECTIVE THREAT THIS EVENING INTO TONIGHT. THE ALTERNATE IS
ANY DISCRETE CELLS THAT FORM ALSO GO LINEAR THIS EVENING.
OVERALL AN ACTIVE SEVERE WEATHER EVEN IS EXPECTED AND MOST WILL
WANT TO STAY WEATHER AWARE.
DISCUSSION
ISSUED AT 122 PM CDT SAT JUN 27 2026
WIND ADVISORY REMAINS FOR SOUTHCENTRAL AND SOUTHEASTERN PORTIONS
THROUGH THIS AFTERNOON. THIS IS MAINLY FOR SUSTAINED WINDS
AROUND 30 MPH WITH GUSTS UP TO 45 MPH. ISOLATED TO SCATTERED
SHOWERS WILL LINGER THROUGH THIS AFTERNOON. HIGHS TODAY ARE
FORECAST TO WARM INTO THE UPPER 70S TO UPPER 80S FOR MOST AREAS,
ALTHOUGH COULD BE SLIGHTLY LOWER THAN FORECAST TO AREAS WITH
ABUNDANT CLOUD COVER.
WE CONTINUE TO MONITOR FOR THE THREAT OF SEVERE WEATHER LATER
THIS AFTERNOON THROUGH TONIGHT. SPC'S LATEST UPDATE KEEPS THE
OUTLOOKS FOR SEVERE WEATHER SIMILAR TO THIS MORNING, ALTHOUGH
THERE ARE SOME UPDATES TO THE HAZARD THREATS. SPC HAS INCREASED
THE TORNADO PROBABILITIES TO 5 TO 10 PERCENT IN THE WEST WITH AN
INTENSITY LEVEL 1 NOW IN PLACE. MEANWHILE THE HAIL AND WIND
THREATS REMAIN ELEVATED, WITH THE AN INTENSITY LEVEL 1 WIND
THREAT EXPANDED ACROSS MUCH OF THE WEST. SHEAR AND INSTABILITY
REMAIN ABUNDANT TODAY THROUGH TONIGHT. THE CONCERNS WILL BE
STORM MODE, SOME INITIAL CAPPING, AND TIMING OF THE LOW. LATEST
CAMS PREDICTING TWO SCENARIOS. SCENARIO 1 SEES THE CAPPING
BREAKING DOWN AROUND MID TO LATE AFTERNOON, ALLOWING A SUPERCELL
THREAT TO FLOURISH IN THE WEST BEFORE STORMS QUICKLY BECOME
LINEAR. THIS SCENARIO WOULD BE THE MOST CONCERNING AS SUPERCELLS
WOULD BE IN A FAVORABLE ENVIRONMENT FOR TORNADOES AND LARGE
HAIL UP TO THE SIZE OF TENNIS BALLS. LINEAR MODE WOULD TAKE OVER
IN THE EVENING WITH THIS SCENARIO WITH WINDS IN EXCESS OF 80
MPH AS THE STORMS MOVE FROM WEST TO EAST. THE SECOND SCENARIO
HAS LESS SUPERCELL DEVELOPMENT LATE THIS AFTERNOON AND HAS
STORMS GOING LINEAR QUICKER THIS EVENING. THERE STILL WOULD BE A
BRIEF TORNADO AND LARGE HAIL THREAT, YET THE BIGGER THREAT
WOULD BE WIND GUSTS OF 80 MPH OR HIGHER. WHICH SCENARIO ENDS UP
PLAYING OUT IS STILL UNCERTAIN. 18Z SOUNDING AT WFO BIS SHOWING
A STOUT CAP IN PLACE CURRENTLY. SPC MESO ANALYSIS PAGE SHOWING
THIS CAP LESSONING IN THE HIGHWAY 85 CORRIDOR LATER THIS
AFTERNOON. THUS IT'LL COME DOWN TO THE TIMING OF THE WAVE IN
THIS AREA. OF NOTE IS SOME CONVECTION STARTING TO DEVELOP WITH
THIS WAVE IN MONTANA. WILL CONTINUE TO MONITOR AND ALL SHOULD
PREPARE FOR THE THREAT OF SEVERE WEATHER THROUGH TONIGHT AS ONCE
THE LINE OF STRONG CONVECTION FORMS IT WILL PUSH EASTWARD
THROUGH THE NIGHT. WPC ALSO SHOWING A MARGINAL TO SLIGHT RISK
FOR EXCESSIVE RAINFALL THROUGH TONIGHT. THERE COULD BE SOME
LOWER CLOUDS AND FOG TONIGHT BEHIND THE MENTIONED THUNDERSTORMS
ESPECIALLY IN THE WEST. CONFIDENCE WAS NOT HIGH ENOUGH TO
INCLUDE FOG AT THIS TIME.
TODAY'S UPPER WAVE MOVES EAST FOR SUNDAY, ALTHOUGH THE BROAD
UPPER LOW WILL LINGER ACROSS THE REGION. SOME MORNING CONVECTION
MAY LINGER, WITH ENOUGH ELEVATED INSTABILITY AND SHEAR AROUND
TO MAKE FOR AN ISOLATED STRONG TO SEVERE THUNDERSTORM THREAT
WITH HAIL AND WIND THE MAIN THREAT. AN AXIS OF INSTABILITY THEN
RETURNS SUNDAY AFTERNOON AND EVENING MAINLY ALONG HIGHWAY 83
AND EASTWARD. AMPLE SHEAR WILL ALSO BE IN PLACE. LIFT FOR
THUNDERSTORMS WILL BE THE LIMITING FACTOR FOR SUNDAY AFTERNOON
AND EVENING AS THE UPPER LOW MAY BE TO FAR WEST OR NORTHWARD.
HOWEVER, GIVEN THE GENERAL UNSETTLED PATTERN CHANCES FOR SHOWERS
AND THUNDERSTORMS WILL CONTINUE. SPC HAS MAINTAINED A MARGINAL
TO SLIGHT RISK IN THESE AREAS FOR SEVERE WEATHER WIND LARGE HAIL
AND WINDS THE MAIN THREAT. SPC HAS ADDED A INTENSITY LEVEL 1
FOR HAIL FOR SUNDAY IN THEIR AFTERNOON UPDATE TODAY. CSU-MLP
DOES HAVE SOME LOW TORNADO RISK TOMORROW, MORE SO IN EASTERN ND.
LCLS MAY BE A TOUGH HIGH FOR THIS THREAT. OTHERWISE LOOK FOR
BREEZY WINDS TO CONTINUE FOR SUNDAY WITH HIGH TEMPERATURES IN
THE MID 70S TO MID 80S. A SECONDARY WAVE MAY ROTATE THROUGH
SUNDAY NIGHT, PERHAPS BRINGING ANOTHER ROUND OF ELEVATED
THUNDERSTORMS TO THE AREA. AN ISOLATED SEVERE THREAT IS POSSIBLE
WITH THESE NIGHTTIME STORMS GIVEN A STRONG SHEAR, INCREASING
LOW LEVEL JET, AND MODEST INSTABILITY. LOWS SUNDAY NIGHT WILL BE
IN THE 50S WEST TO 60S EAST.
BROAD UPPER LOW REMAINS TO OUR WEST FOR MONDAY, WHILE A SURFACE
LOW KICKS OUT OF THE SOUTHERN ROCKIES AND TRACKS NORTH NORTHEAST
THROUGH THE REGION. THE RESULT WILL BE CONTINUED UNSETTLED
WEATHER WITH SHOWERS AND THUNDERSTORMS LIKELY. SPC HAS A BROAD
MARGINAL RISK ACROSS THE AREA FOR ISOLATED SEVERE WEATHER. SHEAR
AND INSTABILITY WILL ONCE AGAIN BE HIGH, ALTHOUGH THE TIMING OF
THE STRONGEST SHEAR AND INSTABILITY REMAINS UNCERTAIN. THIS IS
MAINLY DEPENDENT ON THE TRACK OF THE SURFACE LOW. CURRENT
FORECAST HAS THIS LOW TRACKING THROUGH EARLIER IN THE DAY
MONDAY, WHICH MAY LIMIT THE SEVERE WEATHER THREAT FOR OUR CWA
AND SHIFT THE AFTERNOON AND EVENING THREAT EASTWARD. ALL HAZARDS
ARE POSSIBLE FOR THESE EASTERN AREAS, ALTHOUGH MUCH THE MARGINAL
RISK IS FOR A HAIL AND WIND THREAT. THE EARLY PASSAGE OF A COLD
FRONT COULD BRING COOLER TEMPERATURES MONDAY, WITH HIGHS IN THE
70S WEST TO 80S EAST. PRECIPITATION CHANCES ARE THEN MORE
CONFINED TO THE NORTH MONDAY NIGHT, WITH LOWS IN THE 50S TO
LOWER 60S. UPPER LOW AND SURFACE LOW LOOK TO BECOME WELL STACKED
IN SOUTHERN CANADA FOR TUESDAY, BRINGING COOLER AND BREEZY TO
WINDY CONDITIONS TO THE STATE. SHOWER AND THUNDERSTORM CHANCES
WILL BE LIMITED AND MAINLY IN THE NORTH AND SOUTHEAST AS A
RESULT. LOWER INSTABILITY WILL LIMIT THE SEVERE WEATHER THREAT,
ALTHOUGH SOME HIGHER AMOUNTS OF SHEAR WILL REMAIN.
UPPER LOW MOVES NORTH MID WEEK WITH A BROAD AREA OF HIGH
PRESSURE SETTLING IN ACROSS THE EASTERN US. AS A RESULT UNSTABLE
AND WARMING SOUTHWEST FLOW WILL BE FOUND STARTING MID WEEK. LOOK
FOR TEMPERATURES TO START WARMING BACK INTO THE 80S TO LOWER 90S
FOR MOST AREAS. WINDS WILL GENERALLY BE LIGHT WITH THIS PATTERN.
CSU-MLP SHOWING AT LEAST AN ISOLATED THREAT FOR SEVERE WEATHER
EACH DAY WITH THIS PATTERN. LOOKING AHEAD TO THE 4TH OF JULY
HOLIDAY WEEKEND, CLUSTERS INDICATE A SECONDARY BUILDING OF THE
MENTIONED BROAD RIDGE COULD MOVE INTO THE AREA. WHERE CLUSTERS
DIFFER IS HOW FAR EAST A PACIFIC NORTHWEST TROUGH MOVES INTO THE
INTERIOR US. FURTHER EASTWARD WILL BRING MORE UNSETTLED
SOUTHWEST FLOW TO THE REGION, WHILE FURTHER WESTWARD BRINGS MORE
RIDGING AND LESS CHANCES FOR PRECIPITATION. EITHER WAY THE
FORECAST WILL MAINTAIN SLIGHT TO CHANCE POPS FOR AFTERNOON AND
EVENING THUNDERSTORMS EACH DAY. CSU-MLP ALSO SHOWING AT LEAST AN
ISOLATED THREAT FOR SEVERE WEATHER AS WELL THROUGH THE WEEKEND.
THERE REMAINS MODERATE TO HIGH CONFIDENCE IN ABOVE NORMAL
TEMPERATURES FOR THE HOLIDAY WEEKEND WITH HIGHS CURRENTLY
FORECAST IN THE 80S AND 90S. NBM TEMPERATURE SPREADS START
GETTING SLIGHTLY MORE BROAD DURING THE HOLIDAY WEEKEND, ALTHOUGH
EVEN THE 25TH PERCENTILE IS RIGHT AROUND NORMAL FOR THIS TIME
OF YEAR. HEAT RISK PRODUCTS SHOWING AT LEAST MODERATE HEAT
IMPACTS POSSIBLE AND WILL BE WORTH MONITORING CLOSER TO NEXT
WEEKEND.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 705 PM CDT SAT JUN 27 2026
TONIGHT: MAIN CONCERN IN THE SHORT TERM WILL BE FOR SCATTERED
TO WIDESPREAD STORMS TO ROLL THROUGH FROM W TO E, SOME OF WHICH
WILL LIKELY BE SEVERE. SEE UPDATE SECTION ABOVE FOR DETAILED
THREATS. THE PRIMARY WINDOW FOR SEVERE STORMS LOOKS TO BE 01-06Z
FROM W TO E. FLIGHT CATEGORY REDUCTIONS INTO MVFR AND EVEN IFR
(BOTH CIGS AND VSBYS) WILL BE POSSIBLE IN THE STRONGEST STORMS.
EVEN OUT AHEAD OF THE STORMS WILL BE SOME MVFR CIGS. MOST OF THE
STRONGER STORMS WILL BE OUT OF THE AREA BY 07Z, BUT SOME OF THE
CAMS HAVE ISOLATED WEAKER REDEVELOPMENT OFF AND ON FOR MAINLY
XWA MOT AND PERHAPS BIS THROUGH DAWN. BEHIND THESE SHOWERS AND
THUNDERSTORMS WILL BE SOME LOWER CLOUDS - GENERALLY IN THE MVFR
TO PERHAPS IFR RANGE FOR CIGS, BUT CONFIDENCE IN EXACT COVERAGE
IS LOW DUE TO THE EFFECTS THE CONVECTION COULD HAVE ON THIS
DEVELOPMENT. WINDS WILL BE BREEZY OUT OF THE ESE-SE AHEAD OF AND
BEHIND THE MAIN LINE OF STORMS.
SUNDAY: MVFR TO IFR CIGS MAY CONTINUE INTO SUN AM, BUT AGAIN,
CONFIDENCE ON EXACT COVERAGE/PERSISTENCE REMAINS UNCERTAIN. ANY
LOW CLOUDS SHOULD GRADUALLY LIFT AND SCATTER LATE AM INTO EARLY
AFTN. WINDS WILL GRADUALLY TURN FROM SE TO SSW THROUGH THE DAY
AND REMAIN ON THE BREEZY SIDE, ESP. FOR THE AFTERNOON.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...CJS
DISCUSSION...ANGLIN
AVIATION...THIES NWS HASTINGS
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