999
FXUS63 KBIS 081501
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1001 AM CDT FRI MAY 8 2026
KEY MESSAGES
- CRITICAL FIRE WEATHER CONDITIONS IN FAR WESTERN AND PARTS OF
SOUTH CENTRAL NORTH DAKOTA INCLUDING THE JAMES RIVER VALLEY
TODAY, WITH NEAR-CRITICAL CONDITIONS ELSEWHERE.
- WARMER AND WINDY TODAY WITH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS IN THE AFTERNOON AND EVENING. THEN SEASONABLY
COOL TEMPERATURES RETURN FOR THE WEEKEND.
- SUB-FREEZING LOW TEMPERATURES ARE POSSIBLE ACROSS NORTHERN
NORTH DAKOTA TONIGHT AND MOST OF THE STATE SATURDAY NIGHT.
- WARM AND WINDY WEATHER NEXT WEEK COULD LEAD TO DAILY CRITICAL
FIRE WEATHER CONDITIONS, ESPECIALLY IN WESTERN NORTH DAKOTA.
UPDATE
ISSUED AT 953 AM CDT FRI MAY 8 2026
STAY SHOWERS OVER SOUTH CENTRAL NORTH DAKOTA HAVE EXITED THE
AREA WITH QUIET WEATHER CONTINUING. OTHERWISE, MAIN CHANGE WAS
TO EXPAND THE RED FLAG WARNING OVER FAR WESTERN NORTH DAKOTA
SOUTHWARD ALONG THE MONTANA BORDER THROUGH BOWMAN COUNTY.
UPDATE ISSUED AT 649 AM CDT FRI MAY 8 2026
RADAR SHOWS A FEW STRAY SHOWERS MOVING SOUTHEAST THROUGH SOUTH
CENTRAL NORTH DAKOTA EARLY THIS MORNING, BUT NOTHING MORE THAN
SPRINKLES ARE LIKELY REACHING THE GROUND DUE TO A VERY DRY LAYER
OF AIR SAMPLED BY THE 12Z BIS RAOB. THE FORECAST FOR TODAY
REMAINS ON TRACK. CURRENT CONDITIONS AND TRENDS WERE BLENDED IN
FOR THIS UPDATE.
DISCUSSION
ISSUED AT 522 AM CDT FRI MAY 8 2026
PERSISTENT NORTHWEST CYCLONIC FLOW PATTERN PROGGED TO REMAIN
OVER THE NORTHERN PLAINS TODAY INTO SUNDAY. TODAY WILL BE WARMER
BUT WINDIER AHEAD OF A COLD FRONT BEING DRIVEN DOWN FROM CANADA
BY A SHORTWAVE DIGGING INTO THE RED RIVER VALLEY THIS EVENING.
HIGH TEMPERATURES IN THE MID 60S TO TO MID 70S YIELDING
AFTERNOON RH AROUND 20 PERCENT COMBINED WITH NORTHWEST WINDS
AROUND 25 TO 30 MPH AND GUSTING TO NEAR 40 MPH ARE EXPECTED TO
RESULT IN CRITICAL FIRE WEATHER CONDITIONS IN FAR NORTHWEST AND
PARTS OF SOUTH CENTRAL NORTH DAKOTA, INCLUDING THE JAMES RIVER
VALLEY. RED FLAG WARNINGS HAVE BEEN ISSUED, WITH MORE DETAILED
INFORMATION IN THE FIRE WEATHER SECTION BELOW. MOST CAMS ARE
SIMULATING ISOLATED TO SCATTERED HIGH- BASED SHOWERS DEVELOPING
AHEAD OF THE FRONT IN THE MID TO LATE AFTERNOON, BECOMING
SCATTERED TO WIDESPREAD WITH THE FRONTAL PASSAGE AND STRONGER
DCVA THIS EVENING. THERE MAY BE ENOUGH CAPE TO SUPPORT A FEW
THUNDERSTORMS THIS AFTERNOON AND EVENING AS WELL, BUT THE
ENSEMBLE RANGE OF OUTCOMES IS FROM ZERO CAPE TO AS MUCH AS 500
J/KG, WITH THESE DIFFERENCES APPARENTLY BEING DRIVEN BY SURFACE
DEWPOINT UNCERTAINTY. AN EXAMPLE OF THE WORST-CASE SCENARIO,
WHICH MAY BE BORDERLINE UNREASONABLE, IS THE 06Z NAMNEST THAT
BRINGS A MATURE BOWING SEGMENT AS PART OF AN MCS THROUGH THE
TURTLE MOUNTAINS AND DEVILS LAKE BASIN AREAS THIS EVENING. UP TO
500 J/KG OF CAPE WOULD SUPPORT MARGINALLY SEVERE CONVECTION IN
THE HIGH-SHEAR ENVIRONMENT THAT IS FORECAST, BUT WE ARE QUITE
SKEPTICAL OF THE MID 40S DEWPOINTS IN THE NAMNEST. HREF MEAN
DEWPOINTS ARE CLOSER TO 40, AND THE HRRR IS IN THE MID 30S.
MEANWHILE, THE RAP ACTUALLY HAS LOWER 40S DEWPOINTS PAIRED WITH
ZERO CAPE. NEVERTHELESS, IN THE ABSENCE OF THE AFOREMENTIONED
WORST-CASE SCENARIO, DEEP INVERTED-V THERMODYNAMIC PROFILES
COULD SUPPORT WIND GUSTS STRONGER THAN THE BACKGROUND BL
MOMENTUM TRANSFER GUSTS WITH ANY SHOWER OR STORM.
THE COLD FRONT WILL USHER IN YET ANOTHER SEASONABLY COOL AND
DRY AIR MASS THAT IS FORECAST TO PERSIST THROUGH THE FIRST HALF
OF THE WEEKEND. TEMPERATURES ACROSS THE NORTHERN HALF OF THE
STATE COULD FALL TO NEAR FREEZING TONIGHT, FOLLOWED BY NEAR TO
BELOW FREEZING TEMPERATURES STATEWIDE SATURDAY NIGHT AS SURFACE
HIGH PRESSURE BUILDS OVER THE CANADIAN PRAIRIE PROVINCES. THE
GROWING SEASON OFFICIALLY BEGINS TODAY, SO FROST/FREEZE
HEADLINES MAY BE NECESSARY BOTH TONIGHT AND ON A MUCH WIDER
BASIS SATURDAY NIGHT. DESPITE THE COOL DOWN TO HIGHS IN THE MID
50S TO MID 60S ON SATURDAY, AFTERNOON HUMIDITY PERCENTAGES IN
THE 20S AND NORTHWEST WINDS STILL BREEZY AT AROUND 15 TO 20 MPH
COULD LEAD TO NEAR-CRITICAL FIRE WEATHER CONDITIONS. A SHORTWAVE
MOVING DOWN THE FOOTHILLS OF THE NORTHERN ROCKIES ON SATURDAY
COULD BRING SOME LIGHT RAIN INTO THE SOUTHWEST CORNER OF THE
STATE, BUT IT MORE LIKELY TO REMAIN DRY. SUNDAY SEES A SLIGHT
WARMUP WITH MUCH LIGHTER WINDS AS AN AMPLIFIED TRANSIENT UPPER
RIDGE PUSHES OFF THE ROCKIES.
ENSEMBLE GUIDANCE CONTINUES TO ADVERTISE A POTENT SHORTWAVE/
CLIPPER TYPE SYSTEM EJECTING OFF THE SOUTHERN CANADIAN ROCKIES
ON MONDAY AND DIGGING INTO THE UPPER MISSISSIPPI RIVER VALLEY
MONDAY NIGHT. ALL ENSEMBLE CLUSTERS SHOW THE 850 MB THERMAL
RIDGE OVER WESTERN NORTH DAKOTA MONDAY AFTERNOON, WHICH COULD
ALLOW TEMPERATURES TO CLIMB ABOVE 80. THERE IS ALSO INCREASING
ENSEMBLE CONSISTENCY WITH THIS SYSTEM NOW BRINGING MEDIUM
CHANCES FOR SHOWERS (AND THUNDERSTORMS) TO AREAS NORTH AND EAST
OF THE MISSOURI RIVER. SOMETHING TO KEEP AN EYE ON IS THAT EVERY
CLUSTER CONTAINS A NARROW RIBBON OF CAPE ON THE ORDER OF A FEW
HUNDRED J/KG SOMEWHERE OVER CENTRAL NORTH DAKOTA MONDAY
AFTERNOON/EVENING WITH NO LOWER THAN 50 KTS OF DEEP LAYER SHEAR.
WINDY CONDITIONS ARE A GIVEN WITH THIS SYSTEM, BUT THERE IS
STILL HIGHER ENSEMBLE UNCERTAINTY ON THE MAGNITUDE OF 850 MB
WINDS FOR MIXING POTENTIAL. A BRIEF, SLIGHT COOL DOWN IN THE
POST FRONTAL AIR MASS ON TUESDAY COULD BE FOLLOWED BY
TEMPERATURES MORE PERSISTENTLY ABOVE NORMAL FOR THE REST OF NEXT
WEEK, WITH ENSEMBLE CLUSTERS CONTINUING TO SHOW NEAR-EQUAL
PROBABILITIES FOR EITHER A PROGRESSIVE, HIGH-AMPLITUDE WAVE
PATTERN OR STAGNANT WESTERN CONUS RIDGING. FOR EITHER SYNOPTIC
PATTERN OUTCOME, CHANCES FOR RAIN AT THIS FORECAST TIME RANGE
REMAIN LOW. THE BIGGEST CONCERN FOR NEXT WEEK IS THE POTENTIAL
FOR DAILY CRITICAL FIRE WEATHER CONDITIONS, WHICH IS FURTHER
DISCUSSED IN THE FIRE WEATHER SECTION BELOW.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 649 AM CDT FRI MAY 8 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. A FEW
STRAY SHOWERS OR SPRINKLES ARE POSSIBLE IN SOUTH CENTRAL NORTH
DAKOTA EARLY THIS MORNING. THEN HIGHER CHANCES FOR SHOWERS AND
ISOLATED THUNDERSTORMS MOVE FROM NORTHWEST TO SOUTHEAST ACROSS
THE STATE THIS AFTERNOON AND EVENING. HEAVIER SHOWERS AND STORMS
COULD PRODUCE STRONG, ERRATIC WIND GUSTS AND BRIEF DOWNPOURS
REDUCING VISIBILITY. NORTHWEST WINDS WILL BECOME STRONG THIS
AFTERNOON AT AROUND 15-25 KTS AND GUSTING TO AROUND 25-35 KTS,
THEN SHIFTING NORTHERLY AROUND 10 KTS TONIGHT.
FIRE WEATHER
ISSUED AT 955 AM CDT FRI MAY 8 2026
FOR MORNING UPDATE, MAIN CHANGE WAS THAT THE FAR WESTERN RED
FLAG WARNING WAS EXPANDED ALONG THE MONTANA BORDER SOUTHWARD
THROUGH BOWMAN COUNTY WITH LATEST GUIDANCE SUGGESTING DEEP
MIXING OF SOME STRONGER WINDS TO THE SURFACE.
TWO SEPARATE PARTS OF THE STATE ARE EXPECTED TO SEE CRITICAL
FIRE WEATHER CONDITIONS TODAY, WITH NEAR-CRITICAL CONDITIONS
ELSEWHERE. THE MINIMUM HUMIDITY FORECAST FOR THIS AFTERNOON
RANGES FROM AS LOW AS 15 PERCENT IN SOUTHWEST NORTH DAKOTA TO
NEAR 35 PERCENT IN THE TURTLE MOUNTAINS. NORTHWEST WINDS WITH
SUSTAINED SPEEDS OF 20 TO 30 MPH AND GUSTS TO NEAR 40 MPH ARE
ALSO EXPECTED THIS AFTERNOON. THE STRONGEST SURFACE WINDS AND
GUSTS ARE FORECAST TO BE ASSOCIATED WITH TWO SEPARATE MAXIMA OF
850 MB WIND SPEEDS:
ONE OVER THE JAMES RIVER VALLEY AND ADJACENT AREAS TO THE WEST
THIS AFTERNOON, AND ANOTHER MOVING OVER FAR NORTHWEST NORTH
DAKOTA LATER IN THE AFTERNOON AND EVENING. BECAUSE LOCAL
RESEARCH SHOWS OUR LARGEST WILDFIRES TEND TO BE ASSOCIATED WITH
STRONGER POCKETS OF 850 MB WINDS, THESE TWO AREAS WERE PLACED IN
A RED FLAG WARNING FOR TODAY, WITH THE JAMES RIVER VALLEY
SEGMENT LASTING FROM LATE MORNING TO EARLY EVENING AND THE FAR
WESTERN ND SEGMENT LASTING FROM EARLY AFTERNOON TO LATE
EVENING.
A COLD FRONT MOVING DOWN FROM CANADA THIS EVENING THROUGH
TONIGHT COULD CAUSE A PERIOD OF SHIFTING GUSTY WINDS, FROM
NORTHWEST TO NORTHEAST AND BACK TO NORTHWEST. BUT ANY GUSTS WITH
THE FRONTAL PASSAGE ARE NOT EXPECTED TO BE AS STRONG AS THOSE
THAT OCCUR DURING THE DAY AHEAD OF THE FRONT. OF NOTE THOUGH,
THE WIND SHIFT COULD MOVE THROUGH THE FAR NORTHWEST SEGMENT OF
THE RED FLAG WARNING PRIOR TO RH RECOVERY. ALSO, AS MENTIONED IN
THE FULL DISCUSSION ABOVE, AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS COULD PRODUCE ERRATIC AND STRONG WIND GUSTS.
LOWER DEWPOINTS (THAN STRAIGHT NBM) WERE BLENDED INTO THE
FORECAST ON SATURDAY, RESULTING IN MINIMUM HUMIDITY AROUND 20 TO
30 PERCENT, LOWEST IN THE NORTHWEST QUADRANT OF THE STATE. THE
WIND FORECAST FOR SATURDAY AFTERNOON HAS SLIGHTLY DIMINISHED
FROM PREVIOUS ITERATIONS, BUT STILL HAS NORTHWEST WINDS AROUND
15 TO 25 MPH, STRONGEST IN THE JAMES RIVER VALLEY AREA. BECAUSE
THE STRONGEST WINDS AND LOWEST RH ARE NOT FORECAST TO GREATLY
OVERLAP, ONLY NEAR-CRITICAL FIRE WEATHER CONDITIONS ARE BEING
MESSAGED FOR SATURDAY AT THIS TIME.
AFTER ONE DAY OF MUCH LIGHTER WINDS ON SUNDAY, A LONG STRETCH
OF ENHANCED FIRE WEATHER CONCERNS ENTERS THE FORECAST NEXT WEEK
AS TEMPERATURES ARE FAVORED TO BE WELL ABOVE NORMAL. CONFIDENCE
IS INCREASING THAT MUCH OF WESTERN NORTH DAKOTA WILL EXPERIENCE
CRITICAL FIRE WEATHER CONDITIONS ON MONDAY, WITH GUSTY SOUTHERLY
WINDS EARLY IN THE DAY SHIFTING TO THE NORTHWEST AND BECOMING
STRONG IN THE AFTERNOON AS HUMIDITY FALLS TO NEAR 20 PERCENT.
THE RISK FOR CRITICAL FIRE WEATHER CONDITIONS MORE OR LESS
CONTINUES IN WESTERN NORTH DAKOTA THROUGH THE WORK WEEK, WITH
DAILY GUSTY WINDS AND MINIMUM RH AROUND 20 PERCENT. TUESDAY
LOOKS TO BE THE LEAST WINDY DAY IN THE WEST, BUT PERHAPS THE
WINDIEST DAY FOR THE EASTERN HALF OF THE STATE. A SECONDARY AREA
THAT SHOWS UP REPEATEDLY IN NBM GUIDANCE FOR CRITICAL FIRE
WEATHER NEXT WEEK IS A PORTION OF SOUTH CENTRAL NORTH DAKOTA
BOUNDED BY INTERSTATE 94, THE JAMES RIVER, SOUTH DAKOTA, AND
LAKE OAHE. DAILY DETAILS FOR FIRE WEATHER BEYOND THE MONDAY/
TUESDAY TIME FRAME REMAIN UNCERTAIN, BUT THERE IS UNDOUBTEDLY
INCREASING POTENTIAL FOR A LONGER DURATION OF HIGH- IMPACT FIRE
WEATHER, AT LEAST UNTIL FUELS START TO GREEN UP.
BIS WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 10
PM CDT /9 PM MDT/ THIS EVENING FOR NDZ001-009-017-031-032-040-
043.
RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR NDZ023-025-
036-037-047-048-050-051.
UPDATE...JJS
DISCUSSION...HOLLAN
AVIATION...HOLLAN
FIRE WEATHER...HOLLAN/JJS
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