611
FXUS63 KBIS 161148
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
648 AM CDT WED SEP 16 2026
KEY MESSAGES
- SEASONABLE TEMPERATURES THROUGH THE END OF WEEK, WITH HIGHS
MOSTLY IN THE 60S AND 70S. LOWS TONIGHT COULD FALL INTO THE
UPPER 30S IN NORTHERN AND WESTERN PARTS OF THE STATE.
- LOW CHANCES FOR SHOWERS TODAY, THEN MEDIUM TO HIGH CHANCES FOR
RAIN LATE IN THE WORK WEEK INTO THE WEEKEND.
UPDATE
ISSUED AT 636 AM CDT WED SEP 16 2026
WE ADDED SOME FOG IN THE JAMES RIVER VALLEY AS A FEW SITES HERE
HAVE BEEN BOUNCING AROUND BETWEEN 1-3SM. OTHERWISE ONLY SOME
MINOR ADJUSTMENTS TO SCALE BACK SKY COVER THIS MORNING. CLOUDS
AND ISOLATED SHOWER ACTIVITY IS CURRENTLY FROM NORTHWEST INTO
NORTH CENTRAL SOUTH DAKOTA TRACKING NORTHEAST. UPDATED TEXT
PRODUCTS WILL BE TRANSMITTED SHORTLY.
DISCUSSION
ISSUED AT 405 AM CDT WED SEP 16 2026
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE INTO THE NORTHERN
HIGH PLAINS THIS WEEKEND AND THEN LINGER OVER THE AREA INTO
EARLY NEXT WEEK. A LOT OF UNCERTAINTY REMAINS IN THE EVOLUTION
OF THIS SYSTEM BUT CURRENTLY IT LOOKS LIKE WESTERN AND SOUTHERN
PORTIONS OF THE FORECAST AREA WILL BE FAVORED FOR PRECIPITATION.
UNTIL IT ARRIVES WE WILL SEE A COUPLE OF PRECIPITATION CHANCES.
THE FIRST BEING DURING THE DAY TODAY IN AN AREA OF STRONG WARM
ADVECTION AHEAD OF AN INVERTED TROUGH OVER SOUTHERN PORTIONS OF
THE AREA, AND WITH A NORTHERN STREAM SHORTWAVE TRACKING ACROSS
SOUTHERN CANADA.
CURRENTLY, SHOWER ACTIVITY IS NOTED OVER NORTH CENTRAL MONTANA
AND INTO SOUTHERN SASKATCHEWAN, ASSOCIATED WITH THE NORTHERN
STREAM WAVE. TO OUR SOUTH, MID AND HIGH LEVEL CLOUDS ARE
INCREASING OVER EASTERN WYOMING INTO WESTERN SOUTH DAKOTA AHEAD
OF AN APPROACHING WAVE. A SURFACE LOW PRESENTLY OVER CENTRAL
WYOMING WILL LIFT INTO NORTHEAST WYOMING BY AROUND 18 UTC WITH
AN INVERTED TROUGH NORTHWARD ALONG THE MT/ND BORDER. STRONG WARM
ADVECTION WITH AN INCREASING SOUTHEAST FLOW WILL RESULT IN
STRONG MOISTURE TRANSPORT INTO THE FORECAST AREA, WITH SHOWERS
DEVELOPING OVER SOUTH CENTRAL ND LATE MORNING TO EARLY
AFTERNOON AND SPREADING NORTH AND EAST THROUGH THE DAY. THIS
ACTIVITY LOOKS TO BE ISOLATED TO SCATTERED IN NATURE, ESPECIALLY
EARLY ON. LATER THIS AFTERNOON, AS THE STRONG MOISTURE
TRANSPORT LIFTS WELL INTO NORTHERN ND, THERE MAY BE SOME
ENHANCEMENT IN SHOWER ACTIVITY AS THE INCREASING MOISTURE
INTERACTS WITH THE AFOREMENTIONED CANADIAN SHORTWAVE. NBM
DEPICTS INCREASING PRECIPITATION CHANCES THROUGH THE AFTERNOON
AS ACTIVITY LIFTS NORTH AND EAST, WITH AN AREA OF LIKELY POPS
NEAR THE TURTLE MOUNTAINS BY MID TO LATE AFTERNOON.
PRECIPITATION WITH THIS SYSTEM TODAY IS EXPECTED TO BE LIGHT,
MAINLY TRACE AMOUNTS TO A TENTH OF AN INCH OR SO, ESPECIALLY
EARLY ON. THE POTENTIAL FOR HIGHER AMOUNTS, TO MAYBE A QUARTER
INCH, INCREASE LATER TODAY FROM THE JAMES RIVER VALLEY INTO THE
TURTLE MOUNTAINS AREA. AND FINALLY, THE POTENTIAL FOR THUNDER IS
LOW, BUT THERE IS A DECENT AMOUNT OF ELEVATED INSTABILITY
SITUATED AROUND THE JRV. IF THERE'S AN AREA WHERE THE WARM
ADVECTION IS STRONG ENOUGH, SOME ELEVATED CONVECTION WOULD BE
POSSIBLE. THIS COULD YIELD SOME LOCALLY HIGHER PRECIPITATION
AMOUNTS. THERE IS ALSO ENOUGH DRY AIR AROUND THAT IF WE DON'T
SEE STRONG ENOUGH WARM ADVECTION TO PRODUCE ELEVATED CONVECTION,
WE MAY JUST END UP WITH OUR LOWER AMOUNTS OF A TRACE TO MAYBE A
TENTH OF AN INCH.
PRECIPITATION LIFTS NORTH AND EAST OF THE FORECAST AREA EARLY
THIS EVENING AND HIGH PRESSURE BUILDS OVER SOUTHERN CANADA AND
INTO NORTHERN NORTH DAKOTA. THERE ARE A COUPLE OF SCENARIOS FOR
TONIGHT INTO THURSDAY MORNING. THE FIRST BEING A POTENTIAL FOR
FROST ACROSS NORTHERN NORTH DAKOTA. CURRENTLY THE NORTHWEST AND
FAR NORTH CENTRAL LOOK TO BE THE FAVORED AREAS. ANOTHER SCENARIO
WOULD BE LOW STRATUS AND FOG OVER THE AREA, LIMITING THE
POTENTIAL FOR FROST. THERE IS A SIGNAL FOR LOW STRATUS AND FOG
IN BOTH THE RAP AND HRRR. BUFKIT RAP/HRRR/NAM SOUNDINGS INDICATE
THE POTENTIAL FOR STRATUS/FOG TONIGHT, BUT NOT SO MUCH FROM THE
GFS. THE LATEST NBM IS DEPICTING AROUND A 15-30 PERCENT
PROBABILITY FOR MVFR CEILINGS THURSDAY MORNING, WITH EVEN LOWER
PROBABILITIES FOR IFR CONDITIONS. I WOULD SUSPECT WE MAY SEE BY
LATE THIS AFTERNOON OR EARLY EVENING IF THIS WOULD OCCUR BY
NOTING THE AMOUNT OF LOWER CLOUDS OVER SOUTHERN CANADA WITHIN
THE CONVERGENCE ZONE NORTH OF THE FORECAST AREA. TONIGHT AS THE
AFOREMENTIONED INVERTED TROUGH TRACKS EAST, NORTHERNLY SURFACE
FLOW WILL SPREAD SOUTH ALLOWING THE LOWER STRATUS TO DROP SOUTH
ACROSS THE FORECAST AREA. FARTHER SOUTH, OVER SOUTHERN PORTIONS
OF THE FORECAST AREA, WE COULD SEE A LITTLE BETTER CHANCE OF
FOG, WITH LESS CLOUDS INITIALLY AND BETTER RADIATIONAL COOLING.
AS HIGH PRESSURE BUILDS OVER THE AREA BY THURSDAY MORNING, THE
FAR NORTH MAY CLEAR OUT ANYWAY, WITH STRATUS EARLY, THEN A FEW
HOURS OF COLD TEMPERATURES EARLY THURSDAY MORNING. WILL NEED TO
MONITOR FOR THE POTENTIAL OF A FROST ADVISORY, BUT AT THIS TIME
THERE IT TOO MUCH UNCERTAINTY.
THE NEXT WAVE TRACKS ACROSS SOUTHERN PORTIONS OF THE AREA
THURSDAY EVENING INTO FRIDAY MORNING. THE GENERAL CONSENSUS IS
THAT THE MAJORITY OF THE HEAVIER RAIN WILL REMAIN SOUTH OF THE
STATE. HOWEVER, THERE HAS BEEN A BIT OF A NORTHWARD SHIFT IN
QPF. CURRENTLY THE NBM INDICATES GENERALLY A QUARTER TO THREE
QUARTERS OF AN INCH OF QPF FROM 06Z-18Z FRIDAY, SO LATE THURSDAY
NIGHT THROUGH FRIDAY MORNING OVER FAR SOUTH CENTRAL ND INTO THE
SOUTHERN JRV. THIS TAPERS TO AROUND 0.05" TO 0.15" FROM
BISMARCK TO JAMESTOWN. THUS, HIGHER AMOUNTS ARE FAVORED ALONG
THE FAR SOUTHERN TIER COUNTIES, FROM EASTERN SIOUX AND EMMONS
INTO DICKEY AND LAMOURE COUNTIES. LITTLE IF ANY PRECIP IS
EXPECTED FROM SOUTHWEST INTO NORTH CENTRAL ND. THERE IS ANOTHER
AREA OF LIGHT QPF (UNDER A TENTH OF AN INCH) NOTED FROM WEST
CENTRAL INTO NORTHWEST ND. THIS IS ASSOCIATED WITH AN AREA OF
MOISTURE CONVERGENCE AND INSTABILITY AHEAD OF THE APPROACHING
UPPER LEVEL LOW AND SHORTWAVE ENERGY AND A WEAK FRONTAL BOUNDARY
OVER SOUTHERN CANADA.
FRIDAY AFTERNOON THROUGH SATURDAY AND INTO EARLY SUNDAY THE
FOCUS SHIFTS TO WESTERN NORTH DAKOTA AS THE UPPER LEVEL LOW
LIFTS ACROSS THE NORTHERN ROCKIES, INTO THE NORTHERN HIGH
PLAINS. WESTERN ND WILL BE THE FOCUS FOR ANY PRECIPITATION OVER
NORTH DAKOTA, WITH COOL AND DRY SURFACE HIGH PRESSURE KEEPING
EASTERN PORTIONS OF THE FORECAST AREA MAINLY DRY. BY LATE IN THE
WEEKEND INTO EARLY NEXT WEEK THE UPPER LOW TRACKS ACROSS THE
NORTHERN PLAINS. AT THIS TIME THE FAVORED SYSTEM TRACK REMAINS
UP IN THE AIR AS THE EC/GFS ENSEMBLES BOTH DEPICT A WIDE SPREAD
IN TRACK OF ANY SURFACE LOW. THE UPPER LEVEL TRACK CURRENTLY
MOVES ALONG THE ND/SD BORDER, SO FAVORED AREAS FOR PRECIPITATION
SHIFT FROM WESTERN ND EARLY IN THE WEEKEND, TO SOUTHERN
PORTIONS OF THE STATE LATE WEEKEND INTO EARLY NEXT WEEK.
THERE MAY BE A DAY OR TWO (TODAY AND FRIDAY) WHERE THE SOUTHWEST
SEES TEMPERATURES IN THE UPPER 70S, BUT OVERALL MOST OF THE
FORECAST AREA WILL SEE HIGH TEMPERATURES IN THE MID 60S TO MID
70S THROUGHOUT THE FORECAST PERIOD. THERE'S A FEW COLD SPOTS
OUT THERE THIS MORNING, AND WE WILL NEED TO MONITOR FOR ANOTHER
POTENTIAL FOR FROST ON THURSDAY MORNING, BUT BEYOND THIS,
MORNING LOWS LOOK TO REMAIN IN THE LOWER 40S TO LOWER 50S.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 636 AM CDT WED SEP 16 2026
VFR CONDITIONS AT ALL TAF SITES EXCEPT KJMS TO BEGIN THE 12Z TAF
PERIOD. PATCHY FOG IN THE JAMES RIVER VALLEY WITH KJMS BOUNCING
FROM AROUND 1 SM TO 6 SM, AND KEPT SOME FOG THROUGH 14 UTC.
ELSEWHERE ONLY SOME SCATTERED HIGH LEVEL CLOUDS. LOOK FOR
INCREASING CLOUDS THROUGH THE DAY WITH ISOLATED TO SCATTERED
SHOWERS LIFTING FROM CENTRAL ND, NORTH AND EAST INTO NORTH
CENTRAL AND EASTERN ND. AN ISOLATED THUNDERSTORM CAN'T BE RULED
OUT EITHER. STRONG SOUTHEAST FLOW THIS MORNING IN SOUTHWEST ND.
DIMINISHING THIS AFTERNOON. LIGHTER SOUTHEAST TO EAST SURFACE
ELSEWHERE. THIS EVENING INTO THE OVERNIGHT THE EAST TO SOUTHEAST
SURFACE FLOW TURNS NORTHERLY AND THERE IS THE POTENTIAL FOR LOW
STRATUS AND FOG DEVELOPING AND/OR DROPPING SOUTH FROM CANADA.
CONFLICTING SIGNALS BUT DO THINK THERE WILL BE SOME POTENTIAL.
FOR NOW INTRODUCED A SCATTERED LAYER AROUND 1000KFT AT ALL TAF
SITES AROUND 06 UTC.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...TWH
DISCUSSION...TWH
AVIATION...TWH
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