584
FXUS63 KBIS 272037
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
337 PM CDT SUN JUL 27 2025
KEY MESSAGES
- AN ISOLATED SEVERE THUNDERSTORM RISK EXISTS LATE THIS
AFTERNOON AND THIS EVENING WESTERN AND CENTRAL NORTH DAKOTA,
WITH THE MAIN HAZARDS LARGE HAIL UP TO PING PONG BALL SIZE
HAIL AND DAMAGING WINDS UP TO 60 MPH.
- ISOLATED TO SCATTERED SEVERE THUNDERSTORMS ARE POSSIBLE MONDAY
IN WESTERN AND SOUTH CENTRAL NORTH DAKOTA.
- TEMPERATURES REMAIN BELOW NORMAL (MOSTLY IN THE 70S) THROUGH
THE WORK WEEK.
DISCUSSION
ISSUED AT 136 PM CDT SUN JUL 27 2025
CURRENTLY, SKIES WERE PARTLY CLOUDY ACROSS WESTERN AND CENTRAL
ND. A THUNDERSTORM THAT DEVELOPED OVER SOUTHEAST MONTANA AND
MOVED INTO SOUTHWEST ND A LITTLE EARLIER THIS AFTERNOON HAS NOW
DISSIPATED. WE REMAIN MOIST AND UNSTABLE ACROSS MOST OF THE
FORECAST AREA, ALTHOUGH THE FAR SOUTHWEST IS RELATIVELY DRY WITH
DEWPOINTS IN THE MID 50S. THERE IS A FRONTAL BOUNDARY DRAPED
ACROSS SOUTHEAST ND, WITH SCATTERED THUNDERSTORMS OVER THE FAR
SOUTHEAST PORTION OF THE STATE. GENERALLY WEAK SURFACE HIGH
PRESSURE WAS LOCATED OVER WESTERN AND CENTRAL ND. THERE IS
ABOUT 1500-2000 J/KG OF MLCAPE ACROSS WESTERN AND CENTRAL ND BUT
FORECAST SOUNDINGS INDICATE SOME WEAK MID-LEVEL CAPPING
REMAINING. SPC MESO-ANALYSIS SHOWS THE CAP ERODING OVER
NORTHWEST PORTION OF THE STATE. EFFECTIVE SHEAR IS GENERALLY
AROUND 30 KNOTS WEST TO 40 KNOTS CENTRAL. CAMS ARE NOT SHOWING
MUCH IN THE WAY OF CONVECTION THROUGH THE REST OF THIS AFTERNOON
AND EARLY EVENING. HOWEVER WITH BOUNDARIES LINGERING BEHIND
OVERNIGHT AND EARLY MORNING CONVECTION, THE AFOREMENTIONED
INSTABILITY AND SHEAR, IF A STORM COULD BREAK THE CAPPING, A
STRONG TO SEVERE STORM WOULD BE POSSIBLE WITH THE MAIN THREATS
BEING WINDS TO 60 MPH AND HAIL UP TO PING PONG BALL SIZE. IF I
WERE TO GUESS, WITH THE DISSIPATING CIN NORTHWEST, THIS WOULD BE
A GUESS FOR THE MORE LIKELY AREA FOR CI LATE AFTERNOON OR EARLY
EVENING, AND WITH THE SOUTHWEST (WITH DRIER AIR IN PLACE) THE
LEAST LIKELY. HOWEVER, CAN'T REALLY ELIMINATE ANY AREA FOR
POSSIBLE CONVECTION. COVERAGE DOES LOOK TO BE MINIMAL,
ESPECIALLY WHEN COMPARED TO LAST NIGHT.
LATER TONIGHT AND THROUGH THE DAY MONDAY WE SEE A MORE POTENT
IMPULSE IMPACTING THE LOCAL AREA. CAMS SHOW A GENERAL TIMEFRAME
OF 08-12 UTC WHEN CONVECTION MAY MOVE INTO THE WEST. THIS IS
FROM A WAVE CURRENTLY OVER THE WESTERN U.S. THAT TRACKS ACROSS
THE NORTHERN ROCKIES AND INTO THE NORTHERN HIGH PLAINS TONIGHT
AND ACROSS THE FORECAST AREA ON MONDAY. CONVECTION COULD
CONTINUE THROUGH THE DAY ON MONDAY AS THE WAVE TRACKS ALONG THE
INTERNATIONAL BORDER. THE AFTERNOON AND EVENING HOURS WOULD BE
THE FAVORED TIMEFRAME FOR STRONG TO SEVERE CONVECTION, BUT
AGAIN, I DON'T THINK YOU CAN COMPLETELY RULE OUT SEVERE MORNING
CONVECTION EITHER. AS WE DO GET INTO THE AFTERNOON HOURS, THINK
THE SEVERE POTENTIAL WILL DISSIPATE ACROSS THE NORTH, AND
EVENTUALLY IN THE SOUTH MONDAY EVENING. SPC HAS A SLIGHT RISK
OVER PORTIONS OF THE SOUTHWEST AND SOUTH CENTRAL. THIS WOULD
SEEM REASONABLE GIVING THE CURRENT TIMING. ALTHOUGH INSTABILITY
LOOKS TO DIMINISH IN THE SOUTH THROUGH THE AFTERNOON/EVENING
TIMEFRAME, THERE SHOULD BE A WINDOW WHEN WE WOULD SEE SUFFICIENT
INSTABILITY, COMBINED WITH STRONG SHEAR, TO SUPPORT LARGE HAIL
TO THE SIZE OF GOLF BALLS AND WINDS TO 70 MPH. THIS WINDOW WILL
BE GREATER TO THE SOUTH OF THE FORECAST AREA, BUT A LOT WILL
DEPEND UPON THE EVOLUTION OF THE AFOREMENTIONED SHORTWAVE AND
IT'S ATTENDANT SURFACE BOUNDARY AS WE GO THROUGH THE OVERNIGHT
HOURS AND MONDAY MORNING. PERHAPS IT'S A LITTLE SLOWER AS WE SEE
A GREATER AREA OF STRONG INSTABILITY AND SHEAR ACROSS WESTERN
AND CENTRAL ND, RESULTING IN A LONG AFTERNOON AND EVENING OF
STRONG TO SEVERE CONVECTION. ON THE OTHER HAND, PERHAPS THE
PROGRESSION OF THE SYSTEM IS SUCH THAT STRONG TO SEVERE
CONVECTION IS MOSTLY TO OUR SOUTH. FOR THE TIME BEING, INCLUDING
AT LEAST A PORTION OF THE SOUTHWEST AND SOUTH CENTRAL WITHIN
THE SLIGHT RISK (LEVEL 2 OF 5) FOR SEVERE STORMS SEEMS
REASONABLE.
ONCE CONVECTION (WHEREVER IT IS) ENDS ON MONDAY AFTERNOON OR
EVENING, IT LOOKS LIKE THE THREAT FOR STRONG TO SEVERE STORMS
WILL BE LIMITED TO THE SOUTHWEST PORTION OF THE STATE ON
TUESDAY. THEN GOING THROUGH THE REST OF THE WORK WEEK THE THREAT
FOR SEVERE STORMS LOOKS TO BE MINIMAL, AND IF ANY, ALSO
CONFINED TO THE SOUTHWEST PORTION OF THE STATE. TEMPERATURES
THROUGH THE WORK WEEK ARE EXPECTED TO REMAIN BELOW NORMAL
(MAINLY IN THE 70S TO LOWER 80S) UNTIL POSSIBLY TRENDING BACK
UP BY THE WEEKEND.
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
ISSUED AT 1138 AM CDT SUN JUL 27 2025
MVFR CEILINGS HAVE DEVELOPED IN MINOT EARLY THIS AFTERNOON AND
WILL INCLUDE A PERIOD OF MVFR CIGS TO BEGIN THE TAF AT KMOT.
OTHERWISE VFR CONDITIONS AT REMAINING TAF SITES. ISOLATED
AFTERNOON AND EVENING THUNDERSTORMS ARE POSSIBLE AGAIN TODAY,
BUT WITH A VERY LOW PREDICTABILITY. MVFR CIGS/VSBYS AND GUSTY
ERRATIC WINDS CAN BE EXPECTED WITH ANY THUNDERSTORMS THAT WOULD
DEVELOP, OTHERWISE MOSTLY VFR CONDITIONS THIS AFTERNOON AND
EVENING. LATER TONIGHT AND INTO MONDAY MORNING, AREAS OF MVFR
CIGS AND SHOWERS AND THUNDERSTORM ACTIVITY IS FORECAST OVER
NORTHERN PORTIONS OF THE FORECAST AREA.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...TWH
AVIATION...TWH
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