009
FXUS63 KBIS 212030
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
230 PM CST SUN DEC 21 2025
KEY MESSAGES
- PATCHY FOG IS POSSIBLE IN NORTH CENTRAL NORTH DAKOTA INTO THE
NORTHERN JAMES RIVER VALLEY THIS EVENING THROUGH MONDAY
MORNING.
- TEMPERATURES THROUGH THE UPCOMING WEEK ARE FAVORED TO RANGE
FROM NEAR TO BELOW AVERAGE NORTH AND EAST (HIGHS IN THE TEENS
AND 20S) TO ABOVE AVERAGE SOUTHWEST (HIGHS IN THE 30S AND
40S).
- LOW TO MEDIUM CHANCES FOR LIGHT FREEZING RAIN (NORTH OF
INTERSTATE 94) AND LIGHT SNOW (ALONG AND NORTH OF HIGHWAY 2)
ON MONDAY. OTHERWISE, DRY WEATHER IS EXPECTED THROUGH
CHRISTMAS EVE.
- THE TEMPERATURE FORECAST FOR CHRISTMAS EVE AND CHRISTMAS DAY
IS TRENDING COOLER, AND THERE ARE NOW LOW CHANCES FOR LIGHT
MIXED PRECIPITATION (MOSTLY SNOW) CHRISTMAS MORNING.
DISCUSSION
ISSUED AT 230 PM CST SUN DEC 21 2025
NORTHWESTERLY TO NEAR ZONAL FLOW IS FOUND OVER THE NORTHERN
PLAINS THIS AFTERNOON. WITH A TRANSIENT UPPER LEVEL RIDGE
DEVELOPING OVER THE FORECAST AREA, WARMER HIGH TEMPERATURES FROM
THE LOWER TEENS NORTH CENTRAL TO THE LOWER 40S SOUTHWEST ARE
EXPECTED THIS AFTERNOON. A WEAK 700MB RIDGE RIDER IS THEN
ANTICIPATED TO MOVE ACROSS THE SOUTH LATE THIS EVENING. DESPITE
THE WEAK FORCING AND A FAIRLY DRY COLUMN ACROSS MANY OF OUR
SOUTHERN COUNTIES, BRIEF PERIODS OF VERY LIGHT PRECIPITATION
CANNOT BE RULED OUT. WITH A WARM 850MB NOSE ALOFT AND WITH NEAR
TO SUBFREEZING SURFACE TEMPERATURES, THIS PRECPITATION WOULD
FALL AS LIGHT RAIN OR FREEZING RAIN. WITH DRY CONDITIONS RULING,
HOWEVER, OVERALL QPF AMOUNTS ARE EXPECTED TO BE VERY LIMITED,
AND THUS VERY LITTLE TO NO ICE ACCUMULATION IS CURRENTLY
EXPECTED. WITH THIS IN MIND, WE HAVE OPTED TO ADD VERY LOW (LESS
THAN 10%) POPS THIS EVENING THROUGH EARLY MONDAY MORNING TO
ACCOUNT FOR THIS POTENTIAL LIGHT PRECPITATION. OTHERWISE, WITH
VERY LIGHT WINDS AND LINGERING SNOW PACK OVER NORTH CENTRAL
NORTH DAKOTA INTO THE JAMES RIVER VALLEY, PATCHY FOG IS POSSIBLE
THIS EVENING THROUGH MID MONDAY MORNING. LOW TEMPERATURES
TONIGHT ARE FORECAST FROM AROUND 0 IN THE TURTLE MOUNTAIN AREA,
UP TO THE MID 20S IN THE SOUTHWEST.
A WEAK MID TO UPPER LEVEL SHORTWAVE IS THEN ON THE DOCKET
MONDAY MORNING THROUGH EARLY MONDAY NIGHT, REPRESENTING OUR NEXT
OPPORTUNITY FOR MEASURABLE PRECIPITATION ACROSS THE FORECAST
AREA. MODEL GUIDANCE REMAINS FAIRLY DISCORDANT ON POTENTIAL
SCENARIOS, WITH OPERATIONAL NBM REMAINING FAIRLY NONPLUSSED
ABOUT IMPACTFUL WINTER WEATHER THROUGH THIS PERIOD, WHILE THE
CALIBRATE NBM 5.0 AND HREF MODEL MEMBERS A LITTLE MORE
ENTHUSIASTIC ABOUT BOTH POPS AND POSSIBLY FREEZING RAIN. THE
WRINKLE SEEMS TO DERIVE FROM HOW CAMS ARE HANDLING COLUMN
SATURATION THROUGHOUT THIS PERIOD, WITH SOME ADVERTISING DRY
NEAR SURFACE CONDITIONS AND THUS MORE LIMITED PRECIPITATION
POTENTIAL. CONSIDERING THE SLIGHTLY BETTER FORCING AVAILABLE
THIS TIME AROUND, AND CONSIDERING THE EARLIER WAVE THE NIGHT
BEFORE, OUR EXPECTATION REMAINS THAT THERE IS AT LEAST A LOW TO
MEDIUM CHANCE FOR PRECPITATION ACROSS WESTERN AND CENTRAL NORTH
DAKOTA MONDAY MORNING THROUGH MONDAY NIGHT, WITH THE HIGHEST
POTENTIAL ACROSS THE NORTH. THAT BEING SAID, OVERALL QPF SHOULD
REMAIN FAIRLY LIMITED, WITH A VERY LOW POTENTIAL (LESS THAN 10
PERCENT) TO EXCEED A FEW HUNDRETHS OF AN INCH LIQUID EQUIVALENT
OVERALL. WITH A WARM 850-700MB LAYER UP TO +5C EVIDENT, SOME
LIGHT FREEZING RAIN IS POSSIBLE NORTH OF THE THE I-94 CORRIDOR.
WITH THIS, THERE IS A LOW TO MEDIUM CHANCE (20 TO 40 PERCENT)
FOR A GLAZE OF ICE ACCUMULATION ACROSS THIS AREA, WHICH COULD
LEAD TO MINOR TO MODERATE TRAVEL IMPACTS ON MONDAY. AS YOU HEAD
FURTHER NORTH, A GENERAL TRANSITION TO A FREEZING RAIN/SNOW MIX
IS ANTICIPATED, THEN A FULL TRANSITION TO ALL LIGHTLY
ACCUMULATING SNOW BY THE TIME YOU HIT HIT THE INTERNATIONAL
BORDER. OVERALL SNOW ACCUMULATIONS ARE EXPECTED TO BE QUITE
LIMITED, WITH A HIGH CHANCE (80 PERCENT AS PER CALIBRATED NBM
5.0) FOR LESS THAN 1 INCH OVERALL.
OTHERWISE, FOR MONDAY, BREEZY NORTHWEST WINDS ARE EXPECTED ON
THE BACKSIDE OF THE COLD FRONT ASSOCIATED WITH THE
AFOREMENTIONED SHORTWAVE. A MODEST 45-50KNOT JET IS EXPECTED TO
DEVELOP OVER WESTERN AND CENTRAL NORTH DAKOTA MONDAY AFTERNOON
AND EVENING, THOUGH THE STRONGEST WINDS MAY STRUGGLE TO MIX DOWN
DUE TO POOR LOW LEVEL LAPSE RATES OVER THE AREA. THUS, HAVE
OPTED FOR A 1:1 NBM50/NBM90TH BLEND FOR WINDS TO BUMP UP GUSTS
JUST TO AROUND 30 MPH WITH THIS UPDATE. WE WILL CONTINUE TO
MONITOR FORECAST TRENDS TO SEE DETERMINE IF THESE NEED TO BE
BUMPED UP EVEN FURTHER, THOUGH NOTABLY NOT STRONG EFI SIGNAL FOR
WINDS ARE PRESENT MONDAY.
LOOKING AHEAD TO THE REMAINDER OF THE WORKWEEK, NEAR ZONAL FLOW
IS EXPECTED OVER THE NORTHERN PLAINS AS A SHALLOW RIDGING
PATTERN DEVELOPS. WITH THIS, WARMING WEATHER AND GENERALLY DRY
CONDITIONS ARE EXPECTED THROUGH CHRISTMAS. WITH THIS PATTERN, A
STRONG TEMPERATURE GRADIENTS IS EXPECTED ACROSS THE FORECAST
AREA, WITH HIGHS IN THE SINGLE DIGITS TO LOWER TEENS NORTHEAST
TO THE UPPER 30S TO LOWER 40S SOUTHWEST, THUS EVEN SMALL
PERTURBATIONS IN THE FORECAST RESULTS IN WILDLY DIFFERENT
TEMPERATURES. THIS UNCERTAINTY IS CAPTURED IN THE ENSEMBLE, WITH
NEARLY A 20 DEGREE SPREAD IN TEMPERATURES BY CHRISTMAS DAY.
THAT BEING SAID, EVENING THE LOWER END OF THIS SPECTRUM IS NEAR
TO SLIGHTLY ABOVE NORMAL FOR THIS TIME OF YEAR, ESPECIALLY IN
THE SOUTHWEST. STARTING CHRISTMAS DAY ITSELF. THE ENSEMBLE
STRUGGLES TO RESOLVE THE BREAKDOWN OF THE RIDGING PATTERN AS A
POTENTIAL NORTHERN STREAM WAVE PASSES THROUGH THE CANADIAN
PRAIRIES THIS WEEKEND. THIS WAVE WOULD REPRESENT OUR NEXT
OPPORTUNITY FOR PRECPITATION ACROSS THE FORECAST AREA, WITH THE
ENSEMBLE ADVERTISING LOW TO MEDIUM POPS THURSDAY THROUGH
SATURDAY. OVERALL THERE IS NO STRONG SIGNAL FOR QPF DURING THIS
PERIOD, WITH THE CALIBRATED NBM 5.0 ADVERTISING ONLY A LOW TO
MEDIUM CHANCE (20 TO 50 PERCENT) TO EXCEED 0.10" OF TOTAL
PRECPITATION OVER A 72 HOUR PERIOD. DUE TO THE DISCORD WITHIN
THE ENSEMBLE ITSELF, IT IS HARD TO SAY WHAT FORM THIS
PRECPITATION WOULD TAKE, THOUGH A WINTRY MIX SOUTH TO SNOW NORTH
IS PROBABLY A GOOD BET CONSIDERING THE ABOVE NORMAL
TEMPERATURES EXPECTED THROUGH THIS WEEKEND.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 230 PM CST SUN DEC 21 2025
VFR CEILINGS AND VISIBILITY IS FOUND AT ALL TERMINALS
THROUGHOUT THE 18Z TAF PERIOD. PATCHY FOG IS POSSIBLE THIS
EVENING THROUGH MONDAY MORNING ACROSS PORTIONS OF NORTH CENTRAL
NORTH DAKOTA INTO THE NORTHERN JAMES RIVER VALLEY, WITH MVFR TO
IFR CEILINGS AND VISIBILITIES EXPECTED WHEREVER IT DEVELOPS.
HAVE OPTED TO INCLUDE 3SM BR AT KMOT WITH THIS UPDATE, WITH
CONFIDENCE TOO LOW TO INCLUDE AT KJMS AT THIS TIME. OTHERWISE,
LIGHT SOUTHERLY WINDS THIS AFTERNOON WILL BECOME VARIABLE IN
NORTH CENTRAL NORTH DAKOTA OVERNIGHT, WITH WINDS BROADLY
REORGANIZING OUT OF THE SOUTH SOUTHEAST AND STRENGTHENING MONDAY
MORNING THROUGH THE END OF THE TAF PERIOD.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...ADAM
AVIATION...ADAM
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