581
FXUS63 KBIS 021742
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1242 PM CDT SUN AUG 2 2026
KEY MESSAGES
- HOT AND WINDY TODAY, WITH CRITICAL FIRE WEATHER CONDITIONS IN
WESTERN NORTH DAKOTA AND HIGH TEMPERATURES AND HEAT INDEX
VALUES AROUND 100 IN SOUTH CENTRAL NORTH DAKOTA.
- SMOKE FROM DISTANT WILDFIRES COULD REDUCE VISIBILITY TODAY
THROUGH MONDAY.
- LOW TO MEDIUM CHANCES FOR SHOWERS AND THUNDERSTORMS TONIGHT
THROUGH MONDAY. A FEW STORMS COULD BE STRONG TO SEVERE IN
CENTRAL AND EASTERN PARTS OF THE STATE.
- MUCH COOLER BUT STILL WINDY ON MONDAY, WITH NEAR-CRITICAL TO
CRITICAL FIRE WEATHER CONDITIONS SOUTH AND WEST OF THE
MISSOURI RIVER.
- HIGHS ONLY IN THE 70S ON TUESDAY, THEN WARMING BACK UP TO THE
80S AND 90S THROUGH THE END OF THE WORK WEEK.
UPDATE
ISSUED AT 1242 PM CDT SUN AUG 2 2026
LIMITED UPDATES NEEDED EARLY THIS AFTERNOON. SURFACE FRONT IS
PROGRESSING ACROSS WESTERN ND BRINGING AREAS OF SMOKE AND A
SHIFT TO WEST NORTHWEST WINDS BREEZY AT TIMES. THIS FRONT IS
ALSO BRINGING DRY AIR, FURTHER CONTRIBUTING TO NEAR CRITICAL TO
CRITICAL FIRE WEATHER CONDITIONS TODAY. MEANWHILE AHEAD OF THIS
FRONT WARM DRY AND BREEZY CONDITIONS ARE FOUND IN CENTRAL AND
EASTERN AREAS WITH SLIGHTLY HIGHER DEWPOINTS BRINGING INCREASED
HEAT INDEX VALUES. OVERALL THE FORECAST IS REMAINING ON TRACK,
ALTHOUGH THE MENTIONED FRONT MAY HAVE SLIGHTLY HIGHER WINDS THAN
PREVIOUS FORECAST. LIMITED CHANGES WERE NEEDED THIS UPDATE.
UPDATE
ISSUED AT 955 AM CDT SUN AUG 2 2026
NO MAJOR UPDATES NEEDED AT THIS TIME. SOME WILDFIRE SMOKE IS
STARTING TO ENTER INTO NORTHWESTERN ND, WITH MORE ABUNDANT
SMOKE FURTHER UPSTREAM SHOWING UP ON THE GEOCOLOR RGB SATELLITE
PRODUCT. OTHERWISE TEMPERATURES ARE STARTING TO WARM UP, WITH
THE HIGHEST HEAT INDEX VALUES STILL EXPECTED IN THE ONGOING HEAT
ADVISORY AREA. CRITICAL FIRE WEATHER CONDITIONS ARE ALSO
EXPECTED IN THE WEST TODAY, WHERE THE CURRENT RED FLAG WARNING
IS. OVERALL THE FORECAST REMAINS ON TRACK WITH LITTLE UPDATES
NEEDED AT THIS TIME.
DISCUSSION
ISSUED AT 539 AM CDT SUN AUG 2 2026
POSITIVELY-TILTED UPPER LEVEL RIDGE EXTENDS FROM THE DESERT
SOUTHWEST THROUGH THE NORTHERN PLAINS EARLY THIS MORNING. A
"COLD" FRONT/SURFACE TROUGH IS MOVING FROM CENTRAL INTO EASTERN
MONTANA, ATTENDANT TO A CANADIAN SURFACE CYCLONE WHOSE PARENT
UPPER LOW IS CROSSING THE CANADIAN ROCKIES. LOW LEVEL JET
INDUCED WARM AIR ADVECTION HAS GENERATED SOME ISOLATED SPRINKLES
OR LIGHT RAIN SHOWERS IN NORTHERN PARTS OF THE STATE EARLY THIS
MORNING, AND THIS ACTIVITY MAY CONTINUE INTO THE EARLY
AFTERNOON WHILE SLIDING EASTWARD. THE FRONT WILL ENTER WESTERN
NORTH DAKOTA LATER THIS MORNING AND REACH CENTRAL NORTH DAKOTA
THIS AFTERNOON BEFORE IT BEGINS TO STALL AS THE CANADIAN LOW
OCCLUDES. THE THERMAL RIDGE AXIS SHOULD MOSTLY ALIGN WITH THE
FRONTAL INTERFACE, WHICH GIVES HIGH CONFIDENCE IN THE HOTTEST
TEMPERATURES AT OR SLIGHTLY ABOVE 100 DEGREES IN SOUTH CENTRAL
NORTH DAKOTA THIS AFTERNOON. HEAT INDICES SHOULD BE SIMILAR TO
AIR TEMPERATURES IN THIS PART OF THE STATE AS DEWPOINTS FALL
INTO THE 50S OR PERHAPS 40S. A HEAT ADVISORY HAS BEEN ISSUED
FOR MORTON, GRANT, SIOUX, BURLEIGH, AND EMMONS COUNTIES FROM
NOON TO 8 PM CDT. HIGH TEMPERATURES WILL BE COOLER WITH
INCREASING DISTANCE FROM THE HEAT ADVISORY, MOSTLY IN THE 90S
BUT WITH MID TO UPPER 80S FAR NORTHWEST. WINDY CONDITIONS ARE
ANTICIPATED BOTH AHEAD OF AND BEHIND THE FRONT, BUT MAY
ACTUALLY BE LIGHTER ALONG THE FRONTAL INTERFACE. ALREADY SEEING
BREEZY SOUTHERLY WINDS EARLY THIS MORNING, WHICH SHOULD
INCREASE TO 20-30 MPH WITH GUSTS NEAR 40 MPH IN CENTRAL NORTH
DAKOTA THIS AFTERNOON. BEHIND THE COLD FRONT, NORTHWEST WINDS
ARE EXPECTED TO INCREASE TO AROUND 20 MPH WITH GUSTS TO 30 MPH
THROUGH EARLY AFTERNOON, BUT THEN DECREASE LATER IN THE
AFTERNOON AS MEAN BOUNDARY LAYER WINDS BECOME LIGHTER. THE
COMBINATION OF WINDY CONDITIONS AND VERY LOW HUMIDITY WILL
PRODUCE NEAR-CRITICAL TO CRITICAL FIRE WEATHER CONDITIONS IN
THE WESTERN HALF OF THE STATE TODAY. SEE THE FIRE SECTION BELOW
FOR DETAILS.
THE OCCLUDED CANADIAN LOW WILL SPIN ACROSS SASKATCHEWAN LATE
TONIGHT, PUSHING MID LEVEL HEIGHT FALLS INTO THE NORTHERN
PLAINS AND TURNING FLOW ALOFT SOUTHWESTERLY. UNDERNEATH, THE
SURFACE FRONT IS FORECAST TO STALL FROM NORTHEAST TO SOUTH
CENTRAL NORTH DAKOTA. THE INCREASE IN SYNOPTIC SCALE FORCING,
INCLUDING AN INCREASING LOW LEVEL JET ON THE LEEWARD SIDE OF
THE SURFACE TROUGH, COULD INITIATE SCATTERED SHOWERS AND
THUNDERSTORMS OVER PARTS OF THE STATE LATE TONIGHT INTO MONDAY
MORNING. WHILE MUCAPE COULD INCREASE ABOVE 1000 J/KG AND
EFFECTIVE BULK SHEAR FOR THE MOST-UNSTABLE ELEVATED PARCELS
COULD INCREASE ABOVE 40 KTS, MOST CAM GUIDANCE IS PESSIMISTIC
THAT THE MAXIMUM CAPE/SHEAR PARAMETER SPACE WILL BE REALIZED. A
FEW UH TRACKS DO BEGIN TO SHOW UP IN THE DEVILS LAKE BASIN AND
JAMES RIVER VALLEY BY AROUND 6 AM CDT MONDAY MORNING, BUT THIS
IS NOT UNIVERSAL AMONG ALL CAMS. WE WILL CONTINUE TO ADVERTISE
A STRONG TO MARGINAL SEVERE STORM RISK TONIGHT INTO MONDAY
MORNING, WITH BASELINE SEVERE HAZARDS OF QUARTER SIZE HAIL AND
WIND GUSTS NEAR 60 MPH.
DURING THE DAY MONDAY, A SEPARATE SHORTWAVE EJECTING FROM THE
AMERICAN SIDE OF THE NORTHERN ROCKIES WILL JOIN FORCES WITH THE
CANADIAN OCCLUDED LOW AND PUSH A SECONDARY BUT MUCH STRONGER
COLD FRONT INTO THE NORTHERN PLAINS. HIGH TEMPERATURES COULD
STILL REACH THE 80S IN SOUTH CENTRAL AND EASTERN NORTH DAKOTA,
BUT THE NORTHWEST CORNER OF THE STATE MAY STRUGGLE TO RISE
ABOVE 70! WINDY CONDITIONS WILL ALSO CONTINUE ON MONDAY, OUT OF
THE NORTH TO NORTHWEST AROUND 25 TO 30 MPH WITH GUSTS TO NEAR
40 MPH. DESPITE THE COOLER TEMPERATURES, HUMIDITY WILL STILL
FALL LOW ENOUGH TO PROLONG FIRE WEATHER CONCERNS SOUTH AND WEST
OF THE MISSOURI RIVER. PLEASE REFER TO THE FIRE SECTION BELOW
FOR FURTHER DETAILS. THE OTHER CONCERN FOR MONDAY IS THE
EASTWARD PROGRESSION OF THE LEAD SURFACE TROUGH AND TRAILING
SHORTWAVE, WHICH WILL DETERMINE WHETHER MID TO LATE-DAY
THUNDERSTORMS DEVELOP IN OUR FORECAST AREA. CAMS SHOW A MIXTURE
OF POTENTIAL OUTCOMES, RANGING FROM NO STORMS AFTER THE MORNING
(E.G., THE 06Z HRRR) TO SCATTERED STRONG TO SEVERE STORMS IN THE
EASTERN HALF OF THE STATE LATE MONDAY AFTERNOON AND EVENING
(E.G., THE 06Z NAMNEST). IT IS DIFFICULT TO PUT TOO MUCH WEIGHT
INTO ANY SPECIFIC OUTCOME GIVEN THE POTENTIAL FOR THE MIDDAY
ENVIRONMENT TO BE MODIFIED BY MORNING CONVECTION. WE WILL
THEREFORE TIE THE SEVERE RISK ON MONDAY IN WITH THAT OF
TONIGHT/MONDAY MORNING FOR MESSAGING PURPOSES.
FORECAST CONFIDENCE IS HIGH THAT SURFACE HIGH PRESSURE WILL
BUILD INTO THE REGION ON TUESDAY UNDER AN UPPER LEVEL LONGWAVE
TROUGH. THIS SHOULD BRING BELOW NORMAL TEMPERATURES TO ALL,
WITH HIGHS ON TUESDAY IN THE 70S AND LOWS AROUND 45 TO 50 BOTH
MONDAY AND TUESDAY NIGHTS. A QUICK WARM UP REMAINS FAVORED
THEREAFTER, WITH NEAR NORMAL HIGHS IN THE 80S ON WEDNESDAY
INCREASING TO ABOVE NORMAL IN THE 90S ALONG AND SOUTH AND WEST
OF THE MISSOURI RIVER BY FRIDAY. BUT THERE IS STILL UNCERTAINTY
IN THE EVOLUTION OF THE SYNOPTIC PATTERN AND HOW MUCH THE
HUDSON BAY LOW MAY KEEP THE WESTERN CONUS UPPER RIDGE FROM
BUILDING EASTWARD. THIS UNCERTAINTY IS REFLECTED IN LARGER
TEMPERATURE SPREADS BY THE END OF THE WORK WEEK, AND ALSO KEEPS
PRECIPITATION CHANCES AFTER MONDAY VERY LOW FOR THE TIME BEING.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1242 PM CDT SUN AUG 2 2026
VFR CONDITIONS ARE GENERALLY EXPECTED FOR THE FORECAST PERIOD.
COLD FRONT WILL MOVE FROM WEST TO EAST TODAY, CHANGING A BREEZY
SOUTH WIND TO A BREEZY WEST NORTH WEST WIND. BEHIND THIS FRONT
WILL BE AREAS OF SMOKE, WITH VISIBILITIES MAINLY VFR TO PERHAPS
BRIEFLY MVFR AT TIMES. THIS SMOKE COULD CONTINUE TONIGHT THROUGH
MUCH OF MONDAY MORNING. SMOKE IS THEN EXPECTED TO DIMINISH FROM
NORTHWEST TO SOUTHEAST MONDAY AFTERNOON AND EVENING. MAINLY DRY
CONDITIONS ARE EXPECTED TODAY. TONIGHT INTO MONDAY COULD SEE
SOME SHOWERS AND THUNDERSTORMS, ALTHOUGH CONFIDENCE WAS NOT HIGH
ENOUGH TO INCLUDE IN THE TAFS AT THIS TIME. ALTHOUGH CONFIDENCE
WAS NOT HIGH ENOUGH TO INCLUDE AT THIS TIME, LOW LEVEL WIND
SHEAR MAY RETURN TO EASTERN PORTIONS OF THE STATE TONIGHT INTO
MONDAY MORNING, INCLUDING IN THE KJMS AREA.
FIRE WEATHER
ISSUED AT 539 AM CDT SUN AUG 2 2026
AHEAD OF A COLD FRONT MOVING INTO WESTERN NORTH DAKOTA LATER
THIS MORNING, SOUTHERLY WINDS SHOULD STEADILY INCREASE THROUGH
THE DAY, REACHING SUSTAINED SPEEDS AROUND 20 TO 30 MPH WITH
GUSTS NEAR 40 MPH IN CENTRAL NORTH DAKOTA THIS AFTERNOON. WIND
SPEEDS ALONG THE FRONTAL BOUNDARY ARE NOT PROJECTED TO BE QUITE
AS STRONG, BUT THERE COULD BE A RAPID SHIFT IN DIRECTION FROM
SOUTH TO NORTHWEST. GUSTY WINDS ARE EXPECTED BEHIND THE FRONT
IN WESTERN NORTH DAKOTA LATE THIS MORNING INTO THE AFTERNOON.
BUT BY LATE AFTERNOON, WIND SPEEDS ALONG AND BEHIND THE FRONT
ARE FORECAST TO WEAKEN, FOLLOWING THOSE ABOVE THE SURFACE. THIS
WIND FORECAST ADDS COMPLEXITY TO THE FIRE WEATHER FORECAST FOR
TODAY. THE RH FORECAST IS MORE STRAIGHTFORWARD, WITH MINIMUM
FORECAST VALUES AROUND 10-15 PERCENT IN WESTERN NORTH DAKOTA
SOUTH OF THE MISSOURI RIVER, INCREASING TO ONLY 20-25 PERCENT
ALONG THE EASTERN PERIPHERIES OF THE MISSOURI RIVER VALLEY. A
RED FLAG WARNING HAS BEEN ISSUED FOR THE AFOREMENTIONED 10-15
PERCENT RH AREA, AS WELL AS WILLIAMS COUNTY. NEAR-CRITICAL FIRE
WEATHER CONDITIONS ARE EXPECTED ACROSS THE REST OF THE WESTERN
HALF OF THE STATE. OUTSIDE OF THE WARNING, THE AREA THAT HAS
THE HIGHEST CHANCE FOR APPROACHING CRITICAL FIRE WEATHER
CONDITIONS IS IN BURLEIGH AND EMMONS COUNTIES WHERE THERE COULD
BE JUST ENOUGH OVERLAP OF STRONGER SOUTHERLY WINDS WITH LOWER
RH. THE AREA BETWEEN THE RED FLAG WARNING AND BURLEIGH/EMMONS
COUNTIES IS NOT EXPECTED TO HAVE STRONG ENOUGH WINDS FOR LONG
ENOUGH OF A DURATION. BUT THERE WILL STILL BE THE SHIFT IN
DIRECTION THERE, AND HIGH TEMPERATURES ARE EXPECTED TO REACH
AROUND 100 DEGREES.
TEMPERATURES WILL BE MUCH COOLER ON MONDAY COMPARED TO TODAY.
BUT WITH DEWPOINTS FALLING AS LOW AS THE MID 30S, RH COULD
STILL FALL AS LOW AS 20 PERCENT IN SOUTHWEST NORTH DAKOTA. IT
WILL ALSO BE WINDIER ON MONDAY, WITH NORTH TO NORTHWEST WINDS
AROUND 25 TO 30 MPH AND GUSTS UP TO 40 MPH. THE NBM HAS BEEN
VERY CONSISTENT OVER THE PAST SEVERAL DAYS IN BRINGING 6-8
HOURS OF CRITICAL FIRE WEATHER CONDITIONS TO SLOPE AND BOWMAN
COUNTIES ON MONDAY. GIVEN THAT INFORMATION PAIRED WITH HUMIDITY
TONIGHT ONLY RISING TO AROUND 45 PERCENT AND NORTHERLY WINDS
NOT FALLING UNDER 10 MPH, THE DECISION WAS MADE TO EXTEND THE
RED FLAG WARNING INTO MONDAY EVENING FOR JUST SLOPE AND BOWMAN
COUNTIES. FIRE WEATHER CONDITIONS WILL BE AT LEAST NEAR-CRITICAL
FOR OTHER AREAS SOUTH AND WEST OF THE MISSOURI RIVER ON MONDAY.
THE MOST RECENT NBM GUIDANCE TOOK A SIGNIFICANT JUMP IN A MORE
CONCERNING DIRECTION, PAINTING +3 HOURS OF CRITICAL CONDITIONS
AS FAR NORTH AS LAKE SAKAKAWEA AND AS FAR EAST AS LAKE OAHE.
BUT GIVEN THIS IS THE FIRST OCCURRENCE OF CRITICAL CONDITIONS
FORECAST TO BE THIS WIDESPREAD ON MONDAY, WOULD LIKE TO SEE
BETTER CONSISTENCY BEFORE PIVOTING THE FORECAST AND MESSAGING
(ALTHOUGH TIME IS RUNNING SHORT). THIS WAS THE MAIN FACTOR IN
DECIDING NOT TO ISSUE A FIRE WEATHER WATCH FOR A LARGER AREA ON
MONDAY AT THIS TIME, AND INSTEAD OPTING FOR THE HIGHER
CONFIDENCE RED FLAG WARNING IN THE FAR SOUTHWEST.
BIS WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING UNTIL 8 PM CDT /7 PM MDT/ THIS EVENING FOR
NDZ009-017-018-031>033-041-044.
HEAT ADVISORY UNTIL 8 PM CDT /7 PM MDT/ THIS EVENING FOR
NDZ035-042-046-059>062.
RED FLAG WARNING UNTIL 8 PM MDT MONDAY FOR NDZ040-043.
UPDATE...ANGLIN
DISCUSSION...HOLLAN
AVIATION...ANGLIN
FIRE WEATHER...HOLLAN
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