314
FXUS63 KBIS 131949
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
249 PM CDT THU AUG 13 2026
KEY MESSAGES
- SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TODAY WEST AND
NORTH CENTRAL, MAINLY DRY ELSEWHERE.
- WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS LATER THIS
EVENING THROUGH FRIDAY MORNING WEST THROUGH NORTH CENTRAL
WITH LOCALLY HEAVY RAIN POSSIBLE.
- SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS SOUTHWEST AND
CENTRAL FRIDAY AND FRIDAY EVENING, THEN MAINLY DRY LATE
FRIDAY AND THROUGH THE WEEKEND.
- TEMPERATURES NEAR TO SLIGHTLY BELOW NORMAL THROUGH THE WEEKEND
WITH HIGHS GENERALLY IN THE 70S. THE EXCEPTION BEING SOME 60S
NORTHWEST AND SOME LOWER 80S SOUTHEAST.
DISCUSSION
ISSUED AT 245 PM CDT THU AUG 13 2026
CURRENTLY, BROAD UPPER LEVEL RIDGING ACROSS THE CENTRAL CONUS
WITH MUCH OF THE NORTHERN PLAINS IN THE RIGHT ENTRANCE REGION OF
A STRONG UPPER JET STREAK LOCATED NORTH OF THE GREAT LAKES
REGION AND OVER THE NEW ENGLAND AREA. OVERRUNNING FLOW ACROSS
WESTERN NORTH DAKOTA COUPLED WITH EMBEDDED MID LEVEL IMPULSES
RIDING OVER THE AFOREMENTIONED RIDGE CONTRIBUTING TO SCATTERED
SHOWERS THIS AFTERNOON WEST INTO NORTH CENTRAL. ONLY WEAK MUCAPE
ABOUT, ROUGHLY A FEW HUNDRED J/KG, BUT ENOUGH FOR A FEW
ISOLATED SHOWERS NOW POPPING UP OVER CENTRAL ND WHERE CLOUD
COVER DECREASED EARLIER ALLOWING FOR SOME SFC HEATING.
INSTABILITY AND SHEAR REMAIN WEAK THROUGH THE DAY, SO WHILE A
FEW THUNDERSTORMS ARE FORECAST, THE THREAT FOR SEVERE WEATHER IS
VERY LOW IF NOT ZERO.
WE REMAIN ON TRACK FOR NUMEROUS SHOWERS AND A FEW THUNDERSTORMS
DEVELOPING TONIGHT INTO TOMORROW OVER WESTERN INTO NORTH CENTRAL
NORTH DAKOTA, WITH THE GREATEST PROBABILITY FOR HEAVIER RAINFALL
OVER THE FAR NORTHWEST. THIS MATERIALIZES AS A SURFACE TROUGH,
NOW DEVELOPING OVER SOUTHEASTERN MONTANA, DEVELOPS OVER EASTERN
MT INTO WESTERN ND LATE TONIGHT/FRIDAY AM, COUPLED WITH A WELL-
DEFINED EMBEDDED S/WV LIFTING NORTHEAST ACROSS EASTERN MT TO
ACROSS NORTHWEST NORTH DAKOTA 06Z TONIGHT THROUGH FRIDAY MORNING
12-18Z. ANY HEAVIER SHOWER/THUNDERSTORM WILL BE CAPABLE OF HEAVY
RAINFALL GIVEN ELEVATED PW VALUES, THOUGH MODELS IN PRETTY GOOD
AGREEMENT THAT THE BEST COMBINED FORCING WILL BE OVER NORTHWEST
NORTH DAKOTA, SO MAYBE POCKETS OF HEAVIER PRECIP OUTSIDE OF THIS
AREA. EFI VALUES REMAIN FOCUSED NORTHWEST AS WELL, NOW AT 90
PERCENT WITH SHIFT OF TAILS STILL AT A VALUE OF 2 (ALL POINTING
TO AN EXTREME QPF EVENT). WE OPTED TO MAINTAIN NO HYDRO
HEADLINES FOR THIS POTENTIAL EVENT, AS A BEST PRACTICE IS TO
TREAT THESE AS SHORT-FUSED PRODUCTS ONCE IT BECOMES MORE EVIDENT
THAT ELEVATED MESSAGING IS NEEDED. WILL CONTINUE TO HIGHLIGHT
IN THE HWO.
AFOREMENTIONED SFC TROUGH ADVANCES EAST ACROSS WESTERN AND
CENTRAL NORTH DAKOTA DURING THE DAY FRIDAY ALONG WITH A
CONTINUED UNSETTLED SOUTHWEST FLOW ALOFT WITH MULTIPLE EMBEDDED
IMPULSES PUSHING THROUGH. THIS WILL BRING DECENT CHANCES FOR
SHOWERS AND A FEW THUNDERSTORMS TO MOST AREAS FRIDAY MORNING AND
AFTERNOON, ENDING GRADUALLY FRIDAY NIGHT AS FORCING DECREASES
AND HIGH PRESSURE BUILDS IN FROM THE WEST. LOCALLY HEAVY PRECIP
REMAINS POSSIBLE WITH PW VALUES REMAINING ELEVATED UNTIL LATE
FRIDAY NIGHT.
THE REMAINDER OF THE WEEKEND WILL BE MAINLY DRY AND COOLER,
WITH SURFACE HIGH PRESSURE OVER THE REGION ALONG WITH ZONAL FLOW
ALOFT. EMBEDDED WAVES RIDING OVER A BROAD UPPER RIDGE BUILDING
OVER THE ROCKIES LOOK TO BRING SOME CHANCES FOR
SHOWERS/THUNDERSTORMS TO THE LOCAL REGION DURING THE DAY SUNDAY
INTO SUNDAY NIGHT.
A QUASI-ZONAL FLOW ALOFT IS ADVERTISED FOR THE FIRST HALF OF
NEXT WEEK, AND WILL RESULT IN TEMPERATURES TRENDING WARMER/MORE
SEASONAL, ALONG WITH DAILY CHANCES FOR SHOWERS AND
THUNDERSTORMS.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1240 PM CDT THU AUG 13 2026
CLOUDY WEST AND NORTH CENTRAL, TO MOSTLY SUNNY SOUTH AND EAST
THIS AFTERNOON, WITH INCREASING CLOUDS SOUTHWEST INTO SOUTH
CENTRAL LATER TODAY. MVFR CEILINGS REMAIN POSSIBLE FOR A FEW
MORE HOURS WEST EARLY THIS AFT, BUT OVERALL VFR CIGS EXPECTED
TODAY. ISOLATED TO SCATTERED SHOWERS AND A FEW THUNDERSTORMS
TODAY WEST WITH AN INCREASING EASTERLY WIND. SHOWERS AND
SCATTERED THUNDERSTORMS BECOME MORE WIDESPREAD ACROSS WESTERN ND
TONIGHT AND MAY SPREAD INTO PORTIONS OF THE NORTH CENTRAL
TOWARDS 12Z FRIDAY. LOOK FOR LOW VFR TO AREAS OF MVFR CEILINGS
IN SHOWER AND THUNDERSTORM ACTIVITY LATE TONIGHT, REMAINING VFR
ELSEWHERE.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...NH
AVIATION...NH
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