167
FXUS63 KBIS 281448
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
848 AM CST SUN DEC 28 2025
KEY MESSAGES
- SNOW AND BLOWING SNOW WITH SIGNIFICANTLY REDUCED VISIBILITY
TODAY INTO EARLY THIS EVENING IN THE JAMES RIVER VALLEY.
- WINDY AND COLD TODAY, WITH WIND CHILLS FROM 20 BELOW TO 35
BELOW ZERO.
- DECREASING WINDS TONIGHT, BUT STILL COLD WITH LOWS 5 BELOW
ZERO TO 15 BELOW ZERO.
UPDATE
ISSUED AT 838 AM CST SUN DEC 28 2025
SNOW CONTINUES OVER THE JAMES RIVER VALLEY AND INTO EASTERN ND.
LINGERING VERY LIGHT SNOW CONTINUES OVER THE REST OF CENTRAL ND.
IN THE WEST, THERE IS A BREAK IN THE CLOUDS OVER THE SOUTHWEST
BUT THAT SHOULDN'T LAST MUCH LONGER AS CLOUDS AND LIGHT SNOW
ASSOCIATED WITH THE MID-UPPER LEVEL LOW DROP CONTINUE TO DROP
SOUTHEAST. CURRENT FORECAST REMAINS ON TRACK. THE ONLY CHANGE
WITH THE MORNING UPDATE WAS TO SWITCH EMMONS COUNTY FROM A
WINTER WX ADVISORY TO A WIND ADVISORY. ACCUMULATING SNOW HAS
ENDED HERE. WE DO EXPECT SOME BLOWING/DRIFTING SNOW BUT WITH
LITTLE IMPACTS. WE COVERED THE MINOR IMPACTS IN THE WIND
ADVISORY. WIND CHILLS IN WESTERN ND REMAIN AROUND 30 BELOW.
WILL MONITOR BUT WILL KEEP IT GOING FOR NOW.
UPDATE
ISSUED AT 645 AM CST SUN DEC 28 2025
BASED ON OBSERVATIONS SHOWING WIND CHILLS AROUND -30 F AS OF 12
UTC IN PARTS OF SOUTH CENTRAL ND, WE EXPANDED THE COLD WEATHER
ADVISORY FOR THIS MORNING EAST ANOTHER ROW OF COUNTIES. OTHER-
WISE, THE REST OF THE FORECAST IS ON TRACK, WITH THE INITIAL
BAND OF SNOW CONTINUING SLOWLY EASTWARD THROUGH THE JAMES RIVER
VALLEY. GUIDANCE CONTINUES TO SUPPORT THE GOING WINTER WEATHER
ADVISORY IN THAT AREA TODAY INTO THIS EVENING. UPSTREAM, THE
UPPER-LEVEL LOW IS APPROACHING SOUTHWESTERN ND, WITH SEVERAL
OBSERVATIONS OF FLURRIES OR LIGHT SNOW IN ITS VICINITY, WHICH
SUPPORTS OUR LOW SNOW CHANCES IN WESTERN ND.
DISCUSSION
ISSUED AT 402 AM CST SUN DEC 28 2025
WINDY AND COLD WEATHER IS EXPECTED TODAY, WITH SNOW AND BLOWING
SNOW IMPACTS IN PARTS OF SOUTH CENTRAL ND INTO THE JAMES RIVER
VALLEY. CONTINUED COLD TEMPERATURES ARE EXPECTED TONIGHT, BUT
WINDS WILL DIMINISH. THE EARLY-WEEK FORECAST WILL BE RELATIVELY
QUIET WITH NO IMPACTS EXPECTED, THOUGH BY MIDWEEK, MEDIUM
CHANCES OF SNOW RETURN TO THE FORECAST.
EARLY THIS MORNING A BAND OF MODERATE SNOW CONTINUES TO SLOWLY
PROGRESS THROUGH CENTRAL ND, WITH VISIBILITIES OCCASIONALLY AS
LOW AS 1/2SM, BUT MORE COMMONLY IN THE 1-2SM RANGE, WITH SNOW
ACCUMULATIONS ON THE ORDER OF 1-2 INCHES BEING OBSERVED SO FAR.
THIS SNOW BAND DOES APPEAR TO BE MOVING A BIT MORE SLOWLY EAST
THAN EXPECTED EARLIER, WHICH MAY BE THE RESULT OF THE MIDDLE-
AND UPPER-LEVEL FLOW BEING MORE SOUTHERLY AHEAD OF THE UPPER-
LEVEL LOW WHICH IS LOCATED IN NORTHEAST MT AT THIS HOUR. WATER
VAPOR IMAGERY SUGGESTS THAT LOW MAY BE A TOUCH FURTHER SOUTH
THAN MANY MODEL SIMULATIONS HAD SUGGESTED PREVIOUSLY. THAT IN
TURN MAY BE RESULTING IN THE MORE MERIDIONAL (SOUTHERLY) FLOW
ALOFT DOWNSTREAM AND A SLIGHTLY SLOWER EASTWARD PROGRESSION OF
THE SNOW BAND, WHICH IS BEING DRIVEN BY AN AREA OF STRONG
MIDLEVEL FRONTOGENESIS. THE GUIDANCE THAT APPEARS TO HAVE THE
BEST HANDLE ON THE PLACEMENT OF THE UPPER-LEVEL LOW SUPPORTS
OBSERVATIONAL TRENDS IN SUGGESTING THE BAND OF MODERATE SNOW
WILL MOVE THROUGH THE JAMES RIVER VALLEY THROUGH MID MORNING,
WITH REDUCED VISIBILITIES IN FALLING AND BLOWING SNOW EVEN IF
TOTAL ACCUMULATIONS REMAIN ON THE ORDER OF 1 TO 3 INCHES. AS THE
UPPER-LEVEL LOW CONTINUES TO MOVE SOUTHEAST, REACHING SOUTHEAST
SD BY THIS AFTERNOON, AN AREA OF MIDLEVEL WARM AIR ADVECTION
AND FORCING ON ISENTROPIC SURFACES TO ITS NORTH SUGGESTS LIGHT
SNOW WILL CONTINUE AND/OR "WRAP-AROUND" ACROSS THE JAMES RIVER
VALLEY THROUGH THE DAY, EVEN AFTER THE INITIAL, FRONTOGENESIS-
DRIVEN BAND OF SNOW MOVES OUT OF THE AREA DURING THE MORNING.
NBM PROBABILITIES OF 1 INCH OF SNOWFALL IN THE JAMES RIVER
VALLEY ARE HIGH (70+ PERCENT), AND OF REACHING 2 INCHES ARE
MEDIUM TO HIGH (ON THE ORDER OF 50 TO 70 PERCENT). AS WILL BE
DISCUSSED FURTHER BELOW, WHERE FALLING SNOW OVERLAPS WITH
STRONG WINDS IN THE JAMES RIVER VALLEY AND PARTS OF SOUTH
CENTRAL ND, SIGNIFICANT BLOWING SNOW IS EXPECTED TODAY AND INTO
THIS EVENING.
WE ALSO INCLUDED LOW CHANCES OF SNOWFALL IN CENTRAL ND TODAY IN
RESPECT TO UNCERTAINTY WITH HOW FAR WEST THE "WRAP-AROUND"
LIGHT SNOWFALL WILL EXTEND, AND IN PARTS OF WESTERN ND THIS
MORNING AS THE UPPER-LEVEL LOW ITSELF CROSSES THAT PART OF THE
STATE.
A STRONG SURFACE PRESSURE GRADIENT IS FORECAST ACROSS THE STATE
TODAY AS AN ARCTIC HIGH PRESSURE SYSTEM ON THE ORDER OF 1040 MB
APPROACHES FROM SOUTHWESTERN CANADA, AND AS A STRONG SURFACE LOW
PRESSURE SYSTEM RAPIDLY DEEPENS WHILE MOVING ACROSS THE MIDWEST
AND INTO THE GREAT LAKES. THE RESULT WILL BE A WINDY DAY, WITH
FORECAST SOUNDINGS SUGGESTING MIXING OF 30 TO 40 KT WINDS AT THE
TOP OF THE BOUNDARY LAYER. BLOWING SNOW MODEL OUTPUT SUGGESTS
SIGNIFICANT BLOWING SNOW IN PARTS OF SOUTH CENTRAL ND AND THE
JAMES RIVER VALLEY, WITH VISIBILITIES OF 1/2SM OR OCCASIONALLY
AS LOW AS 1/4SM EXPECTED WHERE FALLING SNOW COMBINES WITH STRONG
WINDS. WITHOUT SIGNIFICANT PRE-EXISTING SNOWPACK, THE BLOWING
SNOW IMPACTS WILL BE HIGHLY SENSITIVE TO FALLING SNOW, AND HOW
MUCH SNOW FALLS GIVEN THE RELATIVELY LOW ACCUMULATIONS THAT WE
ARE EXPECTING. THIS DOES RAISE SOME UNCERTAINTY IN THE FORECAST,
BUT WE HAVE HIGH CONFIDENCE IN ADVISORY-LEVEL BLOWING SNOW
IMPACTS WHERE THE WINTER WEATHER ADVISORY HAS BEEN ISSUED. A LOW
PROBABILITY DOES EXIST FOR BLIZZARD CONDITIONS TO DEVELOP IN
PARTS OF THE ADVISORY AREA, IF SNOWFALL RATES BECOME HIGH ENOUGH.
WHILE THAT'S A LOW-PREDICTABILITY OUTCOME, IT'S A SCENARIO WE
WILL BE MONITORING FOR CLOSELY IN OBSERVATIONAL TRENDS.
WE DID OPT TO EXTEND THE WIND ADVISORY IN FAR SOUTHWEST AND FAR
SOUTH CENTRAL ND THROUGH THE DAY, WHERE THE SURFACE PRESSURE
GRADIENT REMAINS STRONG ENOUGH FOR MARGINAL ADVISORY-LEVEL WINDS
TODAY. FORECAST SOUNDINGS ARE MARGINAL FOR ADVISORY-LEVEL GUSTS,
AND WE DID CONSIDER ALLOWING THE ADVISORY TO EXPIRE AS SCHEDULED
EARLY THIS MORNING, BUT OPTED TO EXTEND IT GIVEN RECENT TRENDS
IN OBSERVED WINDS.
WE ALSO EXPANDED THE COLD WEATHER ADVISORY SOUTH TO INCLUDE ALL
OF WESTERN ND THROUGH THE MORNING, WITH OBSERVED WIND CHILLS ON
THE ORDER OF -30 F BECOMING WIDESPREAD AS OF 09 UTC. WIND CHILLS
ARE FORECAST TO SLOWLY RISE OUT OF ADVISORY RANGE BY AFTERNOON,
BUT IT'S POSSIBLE SOME PART OF THAT ADVISORY WILL NEED TO BE
EXTENDED LATER PENDING OBSERVED TRENDS.
HIGHS TODAY ARE FORECAST TO ONLY RANGE FROM ZERO TO 10 ABOVE
ZERO. WE EXPECT LOWS TONIGHT TO RANGE FROM 5 BELOW TO 15 BELOW
ZERO, LOWEST IN WESTERN AND NORTH CENTRAL ND CLOSEST TO THE
SURFACE RIDGE AXIS THAT IS FORECAST TO MOVE FROM WESTERN AND
INTO CENTRAL ND OVERNIGHT. THE AIR MASS WILL MODIFY SOMEWHAT
BY TONIGHT AS THE UPPER-LEVEL LOW EXISTS THE AREA, BUT WE DID
LEAN ON THE COLDER EDGE (NEAR THE 25TH PERCENTILE) OF ENSEMBLE
MEMBERSHIP FOR FORECAST LOWS TONIGHT. THAT'S BASED ON THE
POSITION OF THE SURFACE RIDGE AXIS, EXPECTED EFFICIENT
RADIATIONAL COOLING, AND OBSERVED TEMPERATURES UNDERNEATH THE
RIDGE AXIS UPSTREAM IN ALBERTA AND SASKATCHEWAN THAT ARE IN THE
-10 TO -20 F RANGE. IT IS POSSIBLE THAT SOME AREAS OF WESTERN
AND CENTRAL ND MAY BE EVEN COLDER THAN FORECAST TONIGHT BASED ON
THOSE UPSTREAM OBSERVATIONS. WHILE WINDS WILL BE DIMINISHING
TONIGHT, AND WILL BECOME LIGHT IN WESTERN ND, WE MAY NEED TO
EXTEND OR RE-ISSUE ANOTHER COLD WEATHER ADVISORY SINCE EVEN
LIGHT WINDS MAY CAUSE WIND CHILLS IN THE -30 F RANGE WHERE
ACTUAL AIR TEMPERATURES ARE COLDEST.
NORTHWEST FLOW ALOFT IS EXPECTED TO PREVAIL FOR MUCH OF THE
UPCOMING WEEK ACROSS THE NORTHERN PLAINS IN BETWEEN A STRONG
HUDSON BAY LOW AND RIDGING IN THE WESTERN UNITED STATES. THE
SYNOPTIC-SCALE PATTERN HAS STRONG CONFIDENCE FROM ENSEMBLE
GUIDANCE THROUGH MIDWEEK, BUT THE REGIME IS EXPECTED TO YIELD A
STRONG BAROCLINIC ZONE AND RELATED TEMPERATURE CONTRAST ACROSS
THE REGION. THE EXACT PLACEMENT OF THAT FRONTAL ZONE CARRIES
LOWER PREDICTABILITY, AND WILL BE INFLUENCED BY WEAK IMPULSES
EMBEDDED IN THE NORTHWEST FLOW. NBM GUIDANCE HAS RELATIVELY LOW
SPREAD MONDAY AND ESPECIALLY TUESDAY, WHEN A GENERAL WARMING
TREND IS FORECAST. HIGHS BY TUESDAY ARE BROADLY FORECAST TO BE
IN THE 30S F ACROSS MUCH OF THE AREA, AGAIN, WITH LOW SPREAD IN
ENSEMBLE MEMBERSHIP, RESULTING IN HIGH CONFIDENCE IN THAT PART
OF THE FORECAST. HOWEVER, BEGINNING WEDNESDAY THE SPREAD IN NBM
GUIDANCE REMAINS LARGE, ON THE ORDER OF 20 DEGREES OR MORE. AS
AN EXAMPLE, AT BISMARCK, THE REASONABLE RANGE OUTCOMES FOR HIGH
TEMPERATURES ON WEDNESDAY (NEW YEARS EVE) IS FROM 8 F TO 31 F.
SIMILAR SPREADS IN TEMPERATURE FORECASTS THEN CONTINUE THROUGH
THE LATTER PART OF THE WEEK, BOTH DUE TO UNCERTAINTY IN EXACT
LOCATION OF THE FRONTAL ZONE, AND DUE TO UNCERTAINTY IN HOW
AMPLIFIED THE NORTHWEST FLOW ALOFT WILL BE. THAT'S RELATED TO
THE PROGRESSION OF AN UPSTREAM TROUGH IN THE PACIFIC OCEAN. THE
BOTTOM LINE IS THAT THE TEMPERATURE FORECAST IS MORE UNCERTAIN
THAN NORMAL FROM WEDNESDAY ONWARD, AND SHOULD BE EXPECTED TO
CHANGE FOR SOME DAYS AND LOCATIONS WITH LATER FORECASTS.
PRECIPITATION-WISE, ENSEMBLE GUIDANCE CONTINUES TO HIGHLIGHT THE
TUESDAY NIGHT AND WEDNESDAY TIMEFRAME FOR MEDIUM PROBABILITIES
OF SNOWFALL AS AN IMPULSE CROSSES THE REGION IN NORTHWEST FLOW.
WE WOULD EXPECT AN AXIS OF SNOWFALL ALONG AND TO THE COOL
(NORTH) SIDE OF THE BAROCLINIC ZONE, WHEREVER IT ENDS UP EXACTLY
BY THAT TIMEFRAME. NBM PROBABILITIES OF 1 INCH OF SNOWFALL ARE
HIGH IN NORTH CENTRAL ND AND THE JAMES RIVER VALLEY IN THE TIME
PERIOD CENTERED ON WEDNESDAY, WITH MEDIUM PROBABILITIES OF 2
INCHES OR MORE OF SNOWFALL. THOSE PROBABILITIES DIMINISH FURTHER
TO THE SOUTHWEST PART OF THE STATE. OTHERWISE, LOW CHANCES OF
SNOW ARE ALSO INCLUDED IN THE FORECAST NEXT WEEKEND BASED ON A
CONSENSUS OF ENSEMBLE GUIDANCE, TOO.
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
ISSUED AT 645 AM CST SUN DEC 28 2025
NORTHWEST WINDS GUSTING UP TO 30-40 KT WILL PREVAIL TODAY AS STRONG
LOW PRESSURE DEVELOPS IN THE MIDWEST AND GREAT LAKES. IN THE JAMES
RIVER VALLEY AND ADJOINING AREAS OF CENTRAL ND, INCLUDING KJMS, WE
EXPECT IFR CONDITIONS IN SNOW AND BLOWING SNOW TO GENERALLY PREVAIL
TODAY INTO THIS EVENING, WITH MEDIUM CHANCES FOR LIFR VISIBILITY IN
BLOWING SNOW THIS AFTERNOON AND EARLY EVENING. CONDITIONS WILL
SLOWLY BEGIN TO IMPROVE IN THAT AREA TONIGHT. IN WESTERN AND THE
REST OF CENTRAL ND, INCLUDING THE KXWA, KDIK, KMOT, AND KBIS
TERMINALS, A MIX OF VFR TO MVFR CEILINGS ARE EXPECTED TODAY, WITH
OCCASIONAL BLOWING SNOW, POTENTIALLY BRIEF AND LIGHT FALLING SNOW.
FOR KXWA, KDIK, KMOT, KBIS, AND SURROUNDING AREAS, WE EXPECT
DECREASING WINDS AND CLOUDS AFTER 00Z WITH VFR CONDITIONS
PREVAILING IN WESTERN AND MUCH OF CENTRAL ND TONIGHT.
BIS WATCHES/WARNINGS/ADVISORIES
COLD WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NDZ001-002-009-010-017>021-031>034-040>045.
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR NDZ023-
025-036-037-047-048-050-051.
WIND ADVISORY UNTIL 5 PM CST /4 PM MST/ THIS AFTERNOON FOR
NDZ040>046.
UPDATE...TWH
DISCUSSION...CJS
AVIATION...TWH
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