833
FXUS63 KBIS 121929
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
226 PM CDT WED AUG 12 2026
KEY MESSAGES
- SCATTERED SHOWERS AND THUNDERSTORMS TODAY AND TONIGHT.
ISOLATED SEVERE STORMS ARE POSSIBLE ALONG AND SOUTH OF THE
HIGHWAY 200 CORRIDOR THIS AFTERNOON INTO THIS EVENING, THOUGH
THE HIGHEST CHANCE IS NEAR THE SOUTH DAKOTA BORDER.
- NEAR DAILY CHANCES FOR SHOWERS AND MAYBE THUNDERSTORMS THROUGH
FRIDAY NIGHT.
- A COOLING TREND IS EXPECTED THROUGH FRIDAY, FOLLOWED BY A
WARMING TREND THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK.
DISCUSSION
ISSUED AT 225 PM CDT WED AUG 12 2026
CURRENTLY NEAR ZONAL FLOW EXIST OVER THE NORTHERN PLAINS WITH A
SLIGHT SOUTHWEST TILT OVER MONTANA. A TROUGH AND UPPER LOW DIGS
THROUGH WASHINGTON STATE AT THIS TIME. AT THE SURFACE A LOW
SITS IN EASTERN WYOMING WITH AN INVERTED TROUGH THROUGH EASTERN
MONTANA WITH SHOWERS AND THUNDERSTORMS AROUND THE LOW.
TODAY WE ARE IN ANOTHER SEVERE RISK, THIS TIME JUST A LEVEL 1
ACROSS THE SOUTHERN HALF OF THE STATE. GLOBAL MODELS HAVE 1000
TO 2000 J/KG OF MUCAPE WITH 45 TO 50KTS OF SHEAR. THE ACTUAL 18Z
SOUNDING FROM BISMARCK SHOWS 1900 J/KG OF CAPE FROM THE SURFACE WITH
VERY LITTLE CIN AND 53 KTS OF SHEAR. HAZARDS TODAY COULD BE GOLF
BALL SIZE HAIL WITH ALL THAT SHEAR AND 60 MPH WINDS. SO FAR VERY
LIGHT RAIN FROM THE LOW PRESSURE IS IN THE SOUTHWEST WITH
THUNDERSTORMS IN SOUTHEAST MONTANA. A FEW FAILING STORMS ARE TRYING
IN SOUTH CENTRAL NORTH DAKOTA. THE FORCING AND INDICATOR FOR WHERE
THE SEVERE STORMS WILL BE IS THE RIGHT ENTRANCE REGION OF THE JET
STREAK. CURRENTLY THAT AREA IS OVER SOUTHEASTERN MONTANA, ENTERING
INTO SOUTHWEST NORTH DAKOTA. LOOKING AT RADAR NEW STORMS ARE QUICKLY
GROWING IN SOUTHEAST MONTANA. THAT JET STREAK IS FORECAST TO MOVE
EAST WITH THE RIGHT ENTRANCE REGION STAYING ALONG THE SOUTH DAKOTA
BORDER. AFTER 00Z, MODELS WANT TO PULL MOST OF THE CAPE OUT OF THE
STATE AND INTO EASTERN SOUTH DAKOTA AS THE SURFACE LOW MOVES EAST.
AFTER THIS EVENING SHOWERS AND MAYBE A THUNDERSTORM ARE POSSIBLE
THROUGH THE NIGHT.
THE REST OF THIS WEEK THE FLOW WILL TURN SOUTHWEST AND THE
TROUGH CONTINUING TO DIG INTO THE WEST CONUS. THIS, IN TURN,
WILL PRODUCE DAILY CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH
FRIDAY NIGHT, WITH THE HIGHEST CHANCES ACROSS THE WEST EVERYDAY.
TEMPERATURES WILL CONTINUE TO REMAIN AT OR BELOW NORMAL IN THE
70S AND LOWER 80S THROUGH SATURDAY. SLIGHT NORTHWEST FLOW
RETURNS THIS WEEKEND WITH A SLIGHT RIDGE TO START NEXT WEEK.
THEREFORE NORMAL TEMPERATURES IN THE 80S WILL RETURN.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1238 PM CDT WED AUG 12 2026
VFR CONDITIONS WILL GIVE WAY TO SOME MVFR CONDITIONS LATER TODAY
INTO TONIGHT AS CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN TO
MUCH OF THE AREA. AN ISOLATED SEVERE THUNDERSTORM IS POSSIBLE AS
WELL THROUGH THIS EVENING, MAINLY IN THE SOUTHERN HALF OF THE
STATE. LATER TONIGHT INTO THURSDAY MORNING, SHOWER ACTIVITY
BECOMES MORE ISOLATED ALTHOUGH CEILINGS COULD LINGER AT MVFR
HEIGHTS. SOME IFR CEILINGS ARE ALSO POSSIBLE, ALTHOUGH
CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE IN THIS TAF SET. AN
EAST WIND LOOKS TO CONTINUE THROUGH THE FORECAST PERIOD.
KDIK COMMUNICATION PROBLEMS CONTINUE. INCLUDED AMD NOT SKED.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...SMITH
AVIATION...ANGLIN
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