421
FXUS63 KBIS 291745
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1245 PM CDT TUE JUL 29 2025
KEY MESSAGES
- ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS PARTS OF
WESTERN NORTH DAKOTA THIS AFTERNOON AND EARLY EVENING.
EXPECTED HAZARDS INCLUDE HAIL AS LARGE AS HALF DOLLARS AND
WIND GUSTS UP TO 60 MPH.
- BELOW AVERAGE TEMPERATURES, ALONG WITH PERIODIC ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS, ARE EXPECTED THIS WEEK
WITH HIGHS MOSTLY IN THE 70S AND LOWS MOSTLY IN THE 50S.
UPDATE
ISSUED AT 1245 PM CDT TUE JUL 29 2025
MOSTLY QUIET TO START THE AFTERNOON, WITH WIDELY SCATTERED LOW
CLOUDS AND EARLY AFTERNOON TEMPS GENERALLY IN THE 70S. WE ARE
STARTING TO SEE A BIT MORE CONVECTIVE DEVELOPMENT, MAINLY OUT IN
EASTERN MONTANA, BUT A STORM IS STARTING TO DEVELOP ON THE
ND/MT STATE LINE NORTHWEST OF WILLISTON.
SPC MESOANALYSIS PAGE HIGHLIGHTS 0-6KM SHEAR OF 50-60 KNOTS
ACROSS MOST OF THE FORECAST AREA, WITH INCREASING INSTABILITY AS
HIGHER-BUOYANCY AIR DRIFTS IN FROM EASTERN MONTANA. STILL A BIT
OF CAPPING IS BEING ADVERTISED, BUT THIS SHOULD START TO
DECREASE THROUGH THE AFTERNOON WITH A WEAK IMPULSE AND NEUTRAL
TO FALLING MID-LEVEL HEIGHTS. NO CHANGES IN OUR THINKING FOR
SEVERE WEATHER POTENTIAL, WITH ISOLATED SEVERE STORMS POSSIBLE
THIS AFTERNOON AND INTO THE EVENING.
UPDATE
ISSUED AT 905 AM CDT TUE JUL 29 2025
BROAD SURFACE HIGH CENTERED OVER CENTRAL SASKATCHEWAN, WITH
MODERATE AMOUNT OF CLOUD COVER EXTENDING ACROSS THE FORECAST
AREA. SEEING A FEW AREAS OF RADAR RETURNS AND OCCASIONAL
LIGHTNING STRIKES IN THE FAR SOUTHWEST, SO MAIN CHANGE WITH THIS
UPDATE WAS TO ADD IN 20 POPS OVER THE NEXT FEW HOURS IN LINE
WITH THESE TRENDS.
SPC DID UPDATE THE DAY 1 OUTLOOK TO SHIFT OUTLINED AREA OF
ISOLATED SEVERE STORMS TO OVER PARTS OF WESTERN NORTH DAKOTA,
GENERALLY FROM WILLISTON AREA SOUTH TO THE SD STATE LINE,
ENCOMPASSING OUR WESTERN 2 TIERS OF COUNTIES. UPDATED HWO AND
OUTLOOK GRAPHIC TO ACCOUNT FOR CHANGES.
UPDATE
ISSUED AT 554 AM CDT TUE JUL 29 2025
PATCHY FOG HAS DEVELOPED MAINLY IN PARTS OF THE JAMES RIVER
VALLEY, WITH MORE LOCALIZED DEVELOPMENT IN PARTS OF WESTERN
THROUGH CENTRAL ND. WIDESPREAD MID TO HIGH CLOUDS HAVE LIKELY
HELPED PREVENT MORE WIDESPREAD FOG FORMATION. STILL, COVERAGE
MAY EXPAND OVER THE NEXT COUPLE HOURS BEFORE RAPIDLY DISSIPATING
THIS MORNING. ALL IN ALL, THE FORECAST REMAINS ON TRACK.
DISCUSSION
ISSUED AT 333 AM CDT TUE JUL 29 2025
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE
TODAY THROUGH THIS EVENING MAINLY FOR THE WESTERN HALF OF THE
STATE. OVERALL, INSTABILITY IS EXPECTED TO REMAIN LOW ACROSS
MOST OF THE STATE, WHILE NO OBVIOUSLY STRONG FORCING MECHANISM
IS PRESENT. THAT SAID, THE RAP DOES SHOW A CORRIDOR OF MUCAPE
UP TO 2000 J/KG IN FAR WESTERN ND, ALONG WITH 35 TO 50 KTS OF 0
TO 6 KM BULK SHEAR. IN ADDITION, DESPITE OVERALL WEAK FORCING,
THERE COULD BE A WEAK EMBEDDED SHORTWAVE WITHIN WEAK
NORTHWESTERLY FLOW ALOFT. THEREFORE, WHILE THE OVERALL THREAT
FOR STRONG TO SEVERE STORMS THIS AFTERNOON AND EARLY EVENING IS
LOW, IT IS STILL GREATER THAN ZERO WITH THE PRIMARY THREATS
BEING 60 MPH WIND GUSTS AND HALF DOLLAR SIZE HAIL.
BEYOND TODAY, THE FORECAST DOESN'T VARY A LOT WITH BELOW
AVERAGE TEMPERATURES AND PERIODIC ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS. THE THREAT FOR SEVERE WEATHER ON ANY GIVEN
DAY IS VERY LOW AT THIS TIME. HOWEVER, THERE WILL PROBABLY BE A
FEW DAYS WHERE A LOW END RISK DEVELOPS SOMEWHERE IN THE CWA.
ESPECIALLY TOWARDS THE END OF THE WEEK WHEN MODELS ARE IN
GENERAL AGREEMENT THAT A LOWLY AMPLIFIED RIDGE MAY APPROACH THE
STATE. IF SO, THIS COULD RESULT IN AT LEAST A SLIGHT WARMING
TREND AND THE POTENTIAL FOR RIDGE RIDING SEVERE WEATHER.
ALL IN ALL, FORECAST HIGHS FOR THE REMAINDER OF THE WORKWEEK
ARE MOSTLY IN THE 70S WITH SOME LOW 80 DEGREE READINGS. LOWS
ARE FORECAST TO DROP DOWN MOSTLY INTO THE 50S. TOWARDS THE END
OF THE WEEK WITH AFOREMENTIONED RIDGING POSSIBLE, HIGHS MAY
REBOUND BACK INTO THE UPPER 70S TO MID 80S, WITH LOWS INCREASING
TO THE LOW 60S IN SOME LOCATIONS.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1245 PM CDT TUE JUL 29 2025
OVERALL VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD, ALTHOUGH
THERE ARE SOME SCT MVFR CEILINGS ACROSS MUCH OF WESTERN AND
CENTRAL NORTH DAKOTA. MAIN FORECAST FOCUS IS ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS, PRIMARILY ACROSS WESTERN
NORTH DAKOTA, THIS AFTERNOON AND INTO THE EVENING. MAIN HAZARDS
WILL BE GUSTY ERRATIC WINDS AND LARGE HAIL. DID INCLUDE TEMPO
AND PROB30 GROUPS AT TERMINALS MOST LIKELY TO SEE IMPACTS.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...JONES
DISCUSSION...TELKEN
AVIATION...JONES
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