406
FXUS63 KBIS 171342
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
842 AM CDT THU SEP 17 2026
KEY MESSAGES
- AREAS OF DENSE FOG ACROSS WESTERN AND CENTRAL NORTH DAKOTA
THIS MORNING.
- SEASONABLE TEMPERATURES THROUGH EARLY NEXT WEEK, WITH HIGHS
MOSTLY IN THE 60S AND 70S.
- MEDIUM TO HIGH CHANCES FOR RAIN ACROSS WESTERN AND FAR
SOUTHERN NORTH DAKOTA TONIGHT THROUGH FRIDAY, CONTINUING IN
THE WEST THROUGH MUCH OF THE WEEKEND.
UPDATE
ISSUED AT 842 AM CDT THU SEP 17 2026
DENSE FOG PERSISTS ACROSS MOST OF THE FORECAST AREA, THOUGH
COVERAGE ACROSS NORTHERN NORTH DAKOTA ISN'T QUITE AS
WIDESPREAD. NEVERTHELESS, WILL LEAVE THE DENSE FOG ADVISORY IN
EFFECT ACROSS THE ENTIRE CWA FOR NOW. CONDITIONS SHOULD IMPROVE
FOR MUCH OF THE AREA THROUGH THE MORNING, THOUGH PATCHY DENSE
FOG COULD LINGER OVER PARTS OF THE AREA INTO THE EARLY
AFTERNOON.
UPDATE
ISSUED AT 609 AM CDT THU SEP 17 2026
DENSE FOG ADVISORY CONTINUES ACROSS MUCH OF WESTERN AND CENTRAL
NORTH DAKOTA. WEBCAMS IN THE WEST CENTRAL PORTION OF THE STATE
ARE SHOWING LOW VISIBILITIES ALONG PORTIONS OF I-94 AND HWY 85
SO WILL ADD MCKENZIE, BILLINGS AND GOLDEN VALLEY TO THE DENSE
FOG ADVISORY. OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING
FORECAST.
UPDATE ISSUED AT 422 AM CDT THU SEP 17 2026
WE ISSUED A DENSE FOG ADVISORY FOR MOST OF WESTERN AND CENTRAL
NORTH DAKOTA. FOG CONTINUES TO EXPAND ACROSS THE FORECAST AREA
WITH MANY LOCATIONS AT OR BELOW A QUARTER MILE. INCLUDED ALL
BUT A PORTION OF THE WEST CENTRAL. THERE ARE SOME AREAS WITHIN
THE ADVISORY WHERE VISIBILITIES ARE OKAY, BUT NEEDED TO CONNECT
AREAS AND WE DO EXPECT CONDITIONS TO DETERIORATE AS WE HEAD
TOWARDS SUNRISE.
DISCUSSION
ISSUED AT 343 AM CDT THU SEP 17 2026
CURRENTLY, SURFACE HIGH PRESSURE IS SITUATED OVER SOUTHERN
SASKATCHEWAN AND MANITIBA, AND INTO NORTHEAST NORTH DAKOTA.
CLEAR TO PARTLY CLOUDY SKIES WERE NOTED ACROSS WESTERN AND
CENTRAL ND, BUT PATCHY FOG WAS INDICATED ON SATELLITE AND LOOKS
TO BE INCREASING IN AREAL COVERAGE. THE EXTENT OF FOG AND
POSSIBLE HAZARDS WILL BE THE MAIN FORECAST ISSUE IN THE SHORT
TERM PERIOD.
AFTER TODAY, THE FOCUS SHIFTS TO AN IMPULSE THAT TRACKS ACROSS
SOUTH DAKOTA TONIGHT INTO FRIDAY MORNING, BRINGING
PRECIPITATION TO FAR SOUTHERN ND, THEN TO WESTERN ND THIS
WEEKEND AS AN UPPER LEVEL LOW APPROACHES THE AREA.
THE IMPULSE TONIGHT SHOULD BRING SOME BENEFICIAL LIGHT RAINS TO
FAR SOUTHERN PORTIONS OF THE FORECAST AREA. YESTERDAY AT THIS
TIME THERE WAS A NORTHWARD TREND IN THE QPF. IF ANYTHING, TODAY
THE TREND IS BACK SOUTH, WITH ONLY THE FAR SOUTHERN TIER
COUNTIES SEEING MORE THAN A TENTH OF AN INCH. THE PROBABILITY
FOR AT LEAST A QUARTER INCH OF RAIN FROM 1 AM FRIDAY TO 1 AM
SATURDAY, IS AROUND 50 PERCENT OVER THE FAR SOUTHERN JAMES RIVER
VALLEY, AND QUICKLY TAPERS AS YOU GO NORTH.
THERE IS ANOTHER AREA OF SHOWERS, AND POSSIBLY A THUNDERSTORM
THAT MODELS CONTINUE TO FOCUS ON, THE NORTHWEST PORTION OF THE
STATE, AND POSSIBLY INTO THE FAR NORTH CENTRAL. AN AREA OF
ELEVATED INSTABILITY IS SITUATED FROM NORTHEAST MT/NORTHWEST ND
AND INTO SOUTHERN MANITOBA, AHEAD OF AN APPROACHING NORTHERN
STREAM WAVE AND ASSOCIATED COLD FRONT. THIS IS ALSO WITHIN AN
AREA OF STRONG WARM ADVECTION AND INCREASING MOISTURE TRANSPORT
AHEAD OF THE CANADIAN COLD FRONT. UNLESS YOU GET A THUNDERSTORM,
DON'T THINK THE QPF AMOUNTS WILL AMOUNT TO MUCH UP HERE, WITH
THE HIGHER TOTALS REMAINING IN SOUTHERN CANADA. THE LATEST NBM
IS SHOWING LOW TO MEDIUM PROBABILITIES (20 TO 60%) FOR AT LEAST
A QUARTER INCH OVER NORTHWEST ND IN THE 24 HOUR PERIOD ENDING 7
PM FRIDAY. THAT INSTABILITY AXIS LINGERS THROUGH SATURDAY ALONG
THE INTERNATIONAL BORDER, BUT QPF AMOUNTS HERE REMAIN LIGHT WITH
HIGH PRESSURE SITUATED OVER SOUTHERN MANITOBA.
THE UPPER LEVEL LOW WILL BE TRACKING THROUGH THE NORTHERN
ROCKIES AND INTO THE NORTHERN HIGH PLAINS SATURDAY THROUGH
SATURDAY NIGHT, THEN INTO THE NORTHERN PLAINS SUNDAY THROUGH
SUNDAY NIGHT. OVERALL, THE TREND HAS BEEN DRIER WITH THIS
SYSTEM. THE TRACK OF THE UPPER LEVEL LOW LOOKS TO BE FARTHER
SOUTH. WE SEE SORT OF A HIGH OVER LOW BLOCKING PATTERN DEVELOP
WITH AN UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE SITUATED
OVER SOUTHERN CANADA, KEEPING THE TRACK OF THE LOW TO OUR SOUTH
AND LIMITING THE NORTHWARD EXTENT OF MOISTURE. QPF TOTALS
CONTINUE TO DIMINISH OVER WESTERN ND. QPF TOTALS IN WESTERN ND
FROM FRIDAY EVENING THROUGH SUNDAY EVENING RANGE FROM A QUARTER
TO A HALF INCH, AND ARE MOSTLY LIMITED TO THE FAR NORTHWEST AND
FAR SOUTHWEST, WITH LESS THAN A COUPLE TENTHS MOST AREAS. ON
MONDAY, THE UPPER LOW EXITS THE AREA AND ANY LOW PRECIPITATION
CHANCES WILL BE LIMITED TO SOUTHERN PORTIONS OF THE FORECAST
AREA. BEYOND MONDAY, THERE MAY BE ANOTHER WAVE BRINGING SOME
LOW PRECIPITATION CHANCES MID-WEEK, BUT UNCERTAINTY IN THIS
REMAINS HIGH.
TEMPERATURE WISE WE REMAIN SEASONABLE WITH HIGH TEMPERATURES
REMAINING MAINLY IN THE 60S AND 70S AND LOW TEMPERATURES IN THE
40S TO LOWER 50S. THERE IS A SIGNAL FOR A GRADUAL WARMING TREND
AS WE HEAD THROUGH THE WORK WEEK, WITH DETERMINISTIC AND
ENSEMBLE MODELS SHOWING AN UPPER LEVEL RIDGE OVER THE CENTRAL
PORTION OF THE U.S. BY THE END OF THE WORK WEEK. HOWEVER THERE
IS UNCERTAINTY AS TO WHETHER OR NOT THIS IS A STRONG RIDGE
YIELDING WARMER TEMPERATURES, OR A FLATTER RIDGE IN OUR NECK OF
THE WOODS, KEEPING TEMPERATURES CLOSER TO NORMAL. ALTHOUGH NBM
ENSEMBLE TEMPERATURES DO INCREASE GRADUALLY THROUGH THE WEEK,
NBM ENSEMBLE TEMPERATURE SPREADS ALSO INCREASE THROUGH THE WEEK.
CONFIDENCE IN A GRADUAL WARMING TREND IN MEDIUM TO HIGH, BUT
CONFIDENCE IN A SIGNIFICANT WARM-UP, ALTHOUGH POSSIBLE, REMAINS
LOW AT THIS TIME.
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 609 AM CDT THU SEP 17 2026
LOW CEILINGS AND FOG ARE FORECAST THROUGH MUCH OF THIS MORNING
ACROSS MOST OF WESTERN AND CENTRAL NORTH DAKOTA. CONDITIONS
SHOULD IMPROVE TO VFR BY THIS AFTERNOON. CONDITIONS ARE THEN
FORECAST TO DETERIORATE TONIGHT WITH MVFR TO POSSIBLY IFR
CONDITIONS DEVELOPING AFTER MIDNIGHT. SCATTERED SHOWERS TONIGHT
IN THE FAR NORTHWEST AND NORTH CENTRAL, AND FAR SOUTH CENTRAL
INTO THE SOUTHERN JAMES RIVER VALLEY SHOULD REMAIN AWAY FROM THE
TAF SITES. AREAS OF FOG ARE ALSO POSSIBLE AGAIN LATE TONIGHT
INTO FRIDAY MORNING. EXPECT AN EASTERLY SURFACE FLOW THROUGH THE
TAF PERIOD. WINDS WILL BE A LITTLE GUSTY OVER WESTERN ND THIS
AFTERNOON.
BIS WATCHES/WARNINGS/ADVISORIES
DENSE FOG ADVISORY UNTIL 11 AM CDT /10 AM MDT/ THIS MORNING
FOR NDZ001>005-009-010-012-013-017>020-022-023-025-031>033-
035>037-040>044-046>048-050-051-055>062.
UPDATE...TELKEN
DISCUSSION...TWH
AVIATION...TWH
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page