626
FXUS63 KBIS 270630
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
130 AM CDT MON OCT 27 2025
KEY MESSAGES
- WIDESPREAD PRECIPITATION CHANCES (60 TO 90 PERCENT) DEVELOP
TONIGHT AND CONTINUE MONDAY, BEFORE DIMINISHING FROM WEST TO
EAST MONDAY NIGHT.
- THERE IS A 60 PERCENT PROBABILITY OF HALF AN INCH OR MORE OF
RAIN ACROSS CENTRAL NORTH DAKOTA AND ACROSS THE JAMES RIVER
VALLEY.
UPDATE
ISSUED AT 118 AM CDT MON OCT 27 2025
SHOWERS ACROSS SOUTHWEST NORTH DAKOTA CONTINUE TO EXPAND IN
COVERAGE NORTH TO NORTHEAST AS MID LEVEL ENERGY INTERACTS WITH A
FRONTAL BOUNDARY DRAPED SOUTHWEST TO NORTHEAST ACROSS WESTERN
SOUTH DAKOTA INTO CENTRAL NORTH DAKOTA. UPDATED POPS BASED ON
LATEST RADAR IMAGERY AND CAM GUIDANCE. WITH PRECIPITATION
STARTING A FEW HOURS EARLIER THAN MODELS HAD ADVERTISED, IT
APPEARS THEY WILL ALSO END EARLIER MONDAY NIGHT/TUES MORNING, SO
ADJUSTED THIS ACCORDINGLY. WILL MAINTAIN THUNDER IN THE FORECAST
DESPITE SPC SHRINKING THE GENERAL T-STORM OUTLOOK FOR MONDAY, AS
MODELS STILL SHOW SOME ELEVATED INSTABILITY COUPLED WITH
INCREASING MID LEVEL DYNAMICS.
UPDATE
ISSUED AT 1008 PM CDT SUN OCT 26 2025
RADAR STARTING TO SHOW SHOWER ACTIVITY PUSHING INTO THE
SOUTHWEST. THIS MIGHT BE SLIGHTLY EARLIER THAN PREVIOUSLY
ANTICIPATED, ALTHOUGH THIS INITIAL RAIN WILL HAVE QUITE THE DRY
AIR TO OVERCOME BEFORE BECOMING MORE OF A STEADY RAIN THAT IS
EXPECTED TO DEVELOP LATER TONIGHT. OVERALL MADE SOME SLIGHT POP
ADJUSTMENTS BASED ON LATEST RADAR TRENDS. SOME RECENT HI-RES
MODELS SHOWING PERHAPS EMBEDDED THUNDERSTORMS POSSIBLE OVERNIGHT
TONIGHT, WITH MORE ISOLATED THUNDERSTORMS POSSIBLE ON MONDAY.
KEPT WITH SPC'S GUIDANCE OF GENERAL RISK FOR DAY 2 IN THE SOUTH,
THUS LEFT OUT THUNDER MENTION FOR TONIGHT AND PLACED IN THUNDER
MENTION ON MONDAY. THE THREAT FOR SEVERE WEATHER IS VERY LOW.
UPDATE
ISSUED AT 652 PM CDT SUN OCT 26 2025
LIMITED UPDATES NEEDED AT THIS TIME. SOME BREEZY WINDS REMAIN IN
THE EAST, ALTHOUGH CONTINUE TO GO ON A DIMINISHING TREND. MID TO
HIGH LEVEL CLOUDS REMAIN ACROSS MUCH OF THE AREA, WITH MORE
CLOUD COVER AND CHANCES FOR SHOWERS EXPECTED TO MOVE IN LATER
THIS EVENING. OVERALL THE FORECAST REMAINS ON TRACK.
UPDATE
ISSUED AT 457 PM CDT SUN OCT 26 2025
QUICK UPDATE TO REVIEW THE WIND ADVISORY. MOST WINDS HAVE COME
DOWN IN THIS ADVISORY, ALTHOUGH THERE ARE SOME NEAR ADVISORY
SUSTAINED WINDS LINGERING IN THE SOUTHEAST. THESE WINDS ARE
EXPECTED TO GO ON A DIMINISHING TREND LATE THIS AFTERNOON
THROUGH THE EARLY EVENING HOURS. WITH THE STRONG WIND THREAT
DIMINISHING, WILL LET THE CURRENT WIND ADVISORY EXPIRE ON TIME
AT 5 PM CDT.
DISCUSSION
ISSUED AT 235 PM CDT SUN OCT 26 2025
SOUTHWESTERLY TO NEAR MERIDIONAL FLOW IS FOUND OVER THE
NORTHERN PLAINS THIS AFTERNOON AS HIGH AMPLITUDE RIDGING IS
DISPLACED TO THE EAST BY AN INCOMING LONG-WAVE TROUGH. WITH THIS
PATTERN, A STRONG NEAR SURFACE PRESSURE GRADIENT IS DRAPED
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON, STUCK
BETWEEN HIGH PRESSURE ASSOCIATED WITH THE RIDGE TO OUR SOUTHEAST
AND A LOW PRESSURE SYSTEM ASSOCIATED WITH THE TROUGH TO THE
NORTHWEST. STRONG SOUTHERLY WINDS ARE THUS FOUND ACROSS CENTRAL
NORTH DAKOTA THIS AFTERNOON, WITH SUSTAINED SPEEDS UP TO 30 MPH
AND GUSTS FROM 45 TO 50 MPH POSSIBLE. THE PRESSURE GRADIENT IS
ANTICIPATED TO RELAX THROUGH THE LATE AFTERNOON, RESULTING IN
RAPID DIMINISHMENT IN WIND SPEEDS BY THE EARLY EVENING. A WIND
ADVISORY IS IN EFFECT THROUGH 5 PM CDT THIS AFTERNOON ACROSS
SOUTH CENTRAL NORTH DAKOTA INTO THE JAMES RIVER VALLEY.
OTHERWISE FOR TODAY, SLIGHTLY COOLER HIGHS IN THE UPPER 50S TO
MID 60S ARE ANTICIPATED AS A COLD FRONT IS SLOWLY DRAGGED FROM
WEST TO EAST BY THE SURFACE LOW. SIMILARLY, LOW TEMPERATURES
FROM NEAR FREEZING IN THE NORTHWEST TO THE UPPER 40S IN THE
SOUTHERN JAMES RIVER VALLEY ARE FORECAST FOR TONIGHT.
LATER THIS AFTERNOON AND EVENING, CHANCES FOR PRECIPITATION ARE
EXPECTED TO INCREASE AS ANOTHER LOW PRESSURE SYSTEMS DEVELOPS
OVER THE COLORADO/WYOMING AREA. THE STALLING OF THIS LOW OVER
THE DAKOTAS WILL INDUCE A PERIOD OF PERSISTENT RAINFALL ACROSS
WESTERN AND CENTRAL MONDAY THROUGH EARLY TUESDAY. MODERATE TO
STRONG QG FORCING MIDLEVEL FG IS PROGGED ACROSS CENTRAL NORTH
DAKOTA LATE TONIGHT THROUGH EARLY MONDAY, AND IS ANTICIPATED TO
HERALD SOME DECENT RAINFALL RATES ACROSS THIS AREA. A FEW
RUMBLES OF THUNDER ARE NOT OUT OF THE QUESTION ACROSS OUR
SOUTHERN COUNTIES MONDAY AFTERNOON AS MODEL MUCAPE VALUES TICKLE
THE 100-150 J/KG RANGE, THOUGH THESE SHOULD BE FAIRLY LIMITED.
THE HIGHEST CHANCES FOR RAIN (60 TO 90 PERCENT) ARE EXPECTED TO
MOVE EASTWARD THROUGH LATE MONDAY AFTERNOON THROUGH EARLY
TUESDAY MORNING AS THE COLORADO/WYOMING LOW IS SLOWLY EJECTED
INTO THE SOUTHEASTERN CONUS. NOTABLY, SOME LIGHT SNOW MAY BECOME
MIXED INTO THE RAIN DURING THE COOLEST PERIOD OF TUESDAY
MORNING AS THE RAIN MOVES OFF TO THE EAST, THOUGH NO
ACCUMULATION IS EXPECTED. WHEN IT'S ALL SAID AND DONE, NBM
PROBABILITIES TO EXCEED 0.5 INCHES OF RAINFALL ARE HIGHEST
ACROSS SOUTH CENTRAL NORTH DAKOTA, BROADLY FROM 40 TO 60
PERCENT, WHERE THERE'S A 30 PERCENT CHANCE FOR PORTIONS OF THAT
SAME AREA TO BREAK 1 INCH OVERALL. NOTABLY, A MARKED
NORTHWESTERN SHIFT IN THE AXIS OF PRECIPITATION HAS BEEN
APPARENT OVER THE PAST FEW FORECAST CYCLES, MAINLY AS SHORT-
TERM CAMS ARE INGESTED INTO THE ENSEMBLE. BEFORE, THE AREA OF
HIGHEST PRECIPITATION HAD BEEN FOUND OVER THE SOUTHERN JRV,
WHILE NOW IT IS MUCH MORE BROADLY ACROSS CENTRAL NORTH DAKOTA.
THIS SHIFT ALSO HIGHLIGHTS AN INCREASE IN CONFIDENCE IN
NORTHWESTERN NORTH DAKOTA GETTING AT LEAST 0.1 INCH OF RAINFALL
THROUGH TUESDAY MORNING TO AROUND 30 PERCENT. OTHERWISE, FOR
MONDAY, THE COOLING TREND CONTINUES WITH HIGHS DROPPING DOWN
INTO THE MID 40S TO MID 50S.
BEHIND THIS PRECIPITATION, MAINLY DRY CONDITIONS ARE EXPECTED
ACROSS WESTERN AND CENTRAL NORTH DAKOTA AS A SOMEWHAT CONVOLUTED
UPPER LEVEL SCHEME SETS OVER THE NORTHERN PLAINS. TUESDAY IS
ANTICIPATED TO BE THE COOLEST DAY OF THE WEEK, WITH MORNING LOWS
BROADLY IN THE UPPER 20S TO UPPER 30S AND AFTERNOONS HIGHS
BROADLY IN THE 40S. BREEZY NORTHWEST WINDS, WITH GUSTS UP TO 30
MPH, ARE EXPECTED THROUGH THE AFTERNOON AS A MODERATE PRESSURE
GRADIENT DEVELOPS BETWEEN THE RETREATING LOW SYSTEM AND SURFACE
HIGH PRESSURE MOVING INTO THE WEST. THEN SPLIT- FLOW OVER THE
NORTHERN PLAINS TURNS INCREASINGLY NORTHWESTERLY AS A LOW CENTER
CLOSES OFF OVER THE NORTHERN CANADIAN PRAIRIES, WITH HIGHS
WARMING SLIGHTLY BACK INTO THE MID 40S TO MID 50S THROUGH
FRIDAY. MODEST CHANCES FOR PRECIPITATION (10 TO 30 PERCENT) THEN
DEVELOPED ACROSS NORTHERN AND EASTERN NORTH DAKOTA AS A CLIPPER
SYSTEM ASSOCIATED WITH THE AFOREMENTIONED UPPER LEVEL LOW SINKS
OUT OF THE CANADIAN PRAIRIES DOWN TOWARD THE GREAT LAKES REGION.
THESE LOW POPS ARE MAINLY DUE TO THE HIGH AMOUNT OF UNCERTAINTY
IN THE ENSEMBLE DURING THIS PERIOD, EXEMPLIFIED BY NEAR A 10 TO
15 DEGREE SPREAD IN HIGH TEMPERATURES THIS WEEKEND. AN
INTERROGATION OF ENSEMBLE CLUSTERS REVEALS TWO BROAD SCENARIOS
FOR THIS WEEKEND. A PLURALITY CLUSTER (45 PERCENT) IS THE WETTER
OF THE TWO, AND ADVERTISES THE PATTERN EXPLAINED ABOVE, WITH
THE CLIPPER SYSTEM PASSING THROUGH NORTHERN MINNESOTA AND THUS
PROMOTING RAIN DEVELOPMENT ACROSS EASTERN NORTH DAKOTA. THIS
SCENARIO WOULD BE THE COOLER OF THE TWO, WITH HIGHS BROADLY IN
THE 50S TO LOWER 60S. A MINORITY CLUSTER (35 PERCENT) ALSO
EXISTS, AND INSTEAD CHAMPIONS A TRANSIENT UPPER LEVEL RIDGE
MOVING OVER WESTERN ND SATURDAY THROUGH SUNDAY , DEFLECTING THE
CLIPPER SYSTEM FURTHER TO THE EAST AND KEEPING CONDITIONS ACROSS
THE FORECAST AREA DRY. THIS SCENARIO WOULD ALSO BE SLIGHTLY
WARMER, WITH HIGHS IN THE MID 50S TO MID 60S. THOUGH THE
ENSEMBLE BECOMES INCREASINGLY DISCORDANT BEYOND THIS WEEKEND,
MOST MODEL MEMBERS ADVERTISE DRY CONDITIONS AND ANOTHER PERIOD
OF COOLING TEMPERATURES SUNDAY THROUGH EARLY NEXT WEEK BEHIND
THE CLIPPER SYSTEM.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 118 AM CDT MON OCT 27 2025
CONTINUED OVERCAST CONDITIONS WITH CEILINGS LOWERING AT ALL
TERMINALS THIS MORNING AS SHOWERS INCREASE IN COVERAGE OVER
WESTERN AND CENTRAL NORTH DAKOTA. MVFR TO PERIODS OF IFR
CONDITIONS WILL ACCOMPANY THE SHOWERS THIS MORNING AND INTO MON
EVENING. THIS WILL BE TRUE FOR ALL BUT KXWA WHICH LOOKS TO
REMAIN VFR THROUGH THE PERIOD. IMPROVING CONDITIONS ARE EXPECTED
FROM WEST TO EAST LATER IN THE DAY MONDAY AND THROUGH MONDAY
NIGHT.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...NH
DISCUSSION...ADAM
AVIATION...NH
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