827
FXUS63 KBIS 252341
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
641 PM CDT MON MAY 25 2026
KEY MESSAGES
- WELL ABOVE AVERAGE TEMPERATURES THIS WEEK, WITH NEAR-RECORD
HIGHS AROUND 90 TO 95 TODAY AND TUESDAY. WINDY CONDITIONS
EXPECTED TUESDAY THROUGH THE END OF THE WEEK.
- LOW TO MEDIUM CHANCES FOR SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS TUESDAY EVENING INTO WEDNESDAY MORNING.
OTHERWISE, MOSTLY DRY UNTIL NEAR THE END OF THE WEEK.
- THE COMBINATION OF HOT, DRY, AND WINDY CONDITIONS COULD
PRODUCE NEAR-CRITICAL TO CRITICAL FIRE WEATHER CONDITIONS
TUESDAY THROUGH FRIDAY, ESPECIALLY IN FAR WESTERN NORTH
DAKOTA.
UPDATE
ISSUED AT 639 PM CDT MON MAY 25 2026
NO MAJOR CHANGES ARE NEEDED FOR THIS UPDATE. CURRENT CONDITIONS
AND TRENDS WERE BLENDED INTO THE FORECAST. QUIET WEATHER SHOULD
PREVAIL THROUGH TONIGHT.
DISCUSSION
ISSUED AT 227 PM CDT MON MAY 25 2026
RIDGE OF HIGH PRESSURE ALOFT WILL REMAIN ACROSS THE STATE
THROUGH TONIGHT BRINGING DRY AND WELL ABOVE NORMAL CONDITIONS.
WINDS WILL ALSO TREND ON THE LIGHT SIDE THROUGH THIS EVENING,
THEN BECOME A STEADY SOUTHEAST WIND TONIGHT AS A SURFACE LOW
BEGINS TO FORM LEE OF THE NORTHERN ROCKIES. VERY LOW RH VALUES
WILL BE FOUND THROUGH THIS EVENING, ALTHOUGH LIGHT WINDS WILL
LIMIT THE FIRE WEATHER THREAT. LOWS TONIGHT WILL BE IN THE 50S
WITH PERHAPS SOME LOWER 60S. CAMS HAVE BACKED OFF ON CONVECTION
THROUGH TONIGHT, AS INSTABILITY SEEMS LIMITED. TUESDAY, UPPER
LEVEL RIDGE GETS COMPACTED BETWEEN TWO UPPER LEVEL LOWS.
MEANWHILE THE MENTIONED SURFACE LOW IN THE NORTHERN ROCKIES
STARTS DEVELOPING MORE. THE RESULT WILL BE HOT TEMPERATURES IN
THE 90S ACROSS MOST AREAS, PERHAPS BREAK SOME RECORD HIGHS. A
BREEZY TO WINDY SOUTHEAST FLOW MAY ALSO BE FOUND TUESDAY. THESE
INCREASED WINDS COMBINED WITH DRY CONDITIONS COULD BRING SOME
NEAR CRITICAL TO CRITICAL FIRE WEATHER CONDITIONS, ESPECIALLY IN
FAR WESTERN NORTH DAKOTA. HERE A FIRE WEATHER WATCH HAS BEEN
ISSUED. FOR MORE DETAILS ON THESE POTENTIAL CRITICAL FIRE
WEATHER CONDITIONS SEE THE FIRE WEATHER DISCUSSION BELOW. SOME
NEAR ADVISORY WINDS ARE ALSO POSSIBLE IN THE WEST TUESDAY,
ALTHOUGH THE PRESSURE GRADIENT DRIVEN SOUTHEAST FLOW MAY BE
TOUGH TO MAKE STRONG WINDS THUS WILL HOLD OFF ON ANY WIND
PRODUCTS. THERE COULD ALSO BE A MODERATE TO VERY ISOLATED AREAS
OF HIGH HEAT RISK TUESDAY AFTERNOON. WITH DRY AIR IN PLACE, THE
HEAT INDEX WILL REMAIN NEAR TO EVEN BELOW AIR TEMPERATURES. THUS
WILL HOLD OFF ON ANY HEAT PRODUCTS. LATER TUESDAY THROUGH
TUESDAY NIGHT, HIGHER AMOUNTS OF INSTABILITY LOOK TO BE FOUND
ALONG A WEAK SURFACE FRONT ASSOCIATED WITH THE DEVELOPING
SURFACE LOW. THIS COMBINED WITH INFLUENCES FROM THE LOW LEVEL
JET COULD BRING SOME ISOLATED TO SCATTERED THUNDERSTORMS,
ESPECIALLY IN THE NORTH AND EAST. ALTHOUGH INSTABILITY IS HIGH,
SHEAR IS MODEST AT BEST. THIS COMBINED WITH LACK OF A STRONGER
LIFT MECHANISM SHOULD LIMIT THE SEVERE WEATHER POTENTIAL. STEADY
EAST TO SOUTHEAST WIND MAY LINGER THROUGH TUESDAY NIGHT WITH
LOWS IN THE 50S TO LOWER 60S.
WEDNESDAY THROUGH FRIDAY, NEAR CRITICAL TO CRITICAL FIRE WEATHER
CONDITIONS COULD BE FOUND EACH DAY AS HOT, DRY, AND WINDY
CONDITIONS PERSIST THROUGH THE WEEK. HEAT RISK WILL ALSO REMAIN
MODERATE TO ISOLATED HIGH WEDNESDAY AND THURSDAY WITH FORECAST
HIGHS IN THE 90S. HEAT INDEX VALUES SHOULD STILL REMAIN BELOW
ADVISORY CRITERIA. SURFACE LOW LOOKS TO LINGER IN MONTANA
THROUGH MUCH OF THE WEEK, WHICH WILL CONTINUE NEAR WIND ADVISORY
SOUTHEAST WINDS. UPPER LEVEL RIDGE TRIES TO REESTABLISH MID
WEEK, WHICH COULD LIMIT CHANCES FOR SHOWERS AND THUNDERSTORMS.
NBM CURRENTLY KEEPS A MAINLY DRY FORECAST ALTHOUGH PERHAPS AN
ISOLATED AFTERNOON OR EVENING THUNDERSTORM IS POSSIBLE. LATER IN
THE WEEK INTO THE UPCOMING WEEKEND THE MENTIONED UPPER LEVEL
RIDGE MAY SHIFT SLIGHTLY ENOUGH EAST TO ALLOW A BROAD WESTERN
TROUGH TO INFLUENCE THE REGION MORE. THIS COULD SLIGHTLY COOL
TEMPERATURES, BRING DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS,
AND CONTINUED BREEZY TO WINDY CONDITIONS. RH VALUES MAY IMPROVE
SLIGHTLY IF THIS RIDGE SHIFTS EASTWARD, WHICH COULD PROVIDE SOME
RELIEF TO THE FIRE WEATHER THREAT IN THE WEST. THIS LATE WEEK
PATTERN DOES GREATLY DEPEND ON THE INFLUENCE OF THE MENTIONED
RIDGE. SOME CLUSTERS HAVE IT STAYING PUT INSTEAD OF SHIFTING.
WHICH COULD CONTINUE MAINLY DRY AND WARM CONDITIONS. SOMETHING
TO MONITOR THROUGHOUT THE UPCOMING WEEK.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 639 PM CDT MON MAY 25 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. WINDS
WILL BECOME SOUTHEASTERLY AROUND 5-10 KTS OVERNIGHT, INCREASING
TO 15-25 KTS WITH GUSTS UP TO 35 KTS ON TUESDAY.
FIRE WEATHER
ISSUED AT 227 PM CDT MON MAY 25 2026
REST OF TODAY WILL SEE VERY WARM TEMPERATURES IN THE MID 80S TO
MID 90S ACROSS THE AREA ALONG WITH VERY DRY CONDITIONS. EXPECT
AFTERNOON AND EVENING HUMIDITY VALUES IN THE TEENS AND 20S. LIGHT
WINDS ARE GENERALLY EXPECTED. TONIGHT, MAINLY DRY CONDITIONS WILL
PERSIST WITH WINDS BECOMING A STEADY SOUTHEAST WIND. HUMIDITY
RECOVERIES WILL GENERALLY BE ABOVE 50 PERCENT.
TUESDAY, HOT TEMPERATURES IN THE 90S WILL CONTINUE. THIS WILL
BRING LOW HUMIDITY VALUES IN THE 20S WEST TO THE 30S EAST. A
BREEZY TO WINDY SOUTHEAST WIND IS ALSO EXPECTED TO DEVELOP FOR
TUESDAY. THIS WIND COMBINED WITH LOW HUMIDITY VALUES COULD BRING
NEAR CRITICAL TO CRITICAL FIRE WEATHER CONDITIONS, ESPECIALLY
TO THE FAR WEST. THE MAIN UNCERTAINTY WITH FIRE WEATHER
CONDITIONS THIS WEEK ARE THE STATUS OF FUELS, ESPECIALLY AFTER
RECENT RAINFALLS. CURRENT MODELED LIVE HERBACEOUS FUEL MOISTURE
SHOWING VALUES BELOW 100 IN THE WEST, NEAR 100 NORTH, AND
GENERALLY ABOVE 120 ELSEWHERE. THIS COULD INDICATE FAR WESTERN
FUELS ARE NOT FULLY GREEN, WITH THE NORTH TRENDING IN THE GREEN
DIRECTION, AND GREENUP STARTING ELSEWHERE. ANOTHER INDICATOR CAN
BE (CALENDAR) DAYS SINCE 0.5" OF RAINFALL. FAR WESTERN AREAS
REMAIN ABOVE 200 DAYS ESPECIALLY IN THE NORTHWEST. SOME NORTH
CENTRAL AREAS ARE ALSO ABOVE 200 DAYS, ALTHOUGH HAVE HIGHER
HERBACEOUS FUEL MOISTURE VALUES. REMAINING AREAS HAVE RECEIVED
A DECENT AMOUNT OF RAINFALL IN THE PAST WEEK. ALL THINGS
CONSIDERED, DECIDED TO ISSUE A FIRE WEATHER WATCH IN THE FAR
WESTERN AREAS WHERE CONFIDENCE IN GREENUP IS LOWER. THE OTHER
WESTERN AND NORTHERN AREAS MENTIONED NOW HAVE NEAR CRITICAL
WORDING IN THEIR HWO SEGMENTS, AND WILL NEED TO BE MONITORED
CLOSELY.
WELL ABOVE AVERAGE TEMPERATURES LOOK TO CONTINUE THROUGH THE WEEK,
ALONG WITH A BREEZY TO WINDY SOUTHEASTERLY WIND. AFTERNOON
HUMIDITY VALUES COULD BE IN THE 20S TO 30S EACH DAY, IMPROVING
ONLY SLIGHTLY TO END THE WEEK. DEPENDING ON AREA FUELS, NEAR
CRITICAL TO CRITICAL FIRE WEATHER CONDITIONS MAY BE FOUND EACH DAY
MID TO LATE WEEK, ESPECIALLY IN FAR WESTERN AREAS. LATER IN THE
DAY TUESDAY THOUGH TUESDAY NIGHT COULD SEE SOME ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS ESPECIALLY IN NORTHERN AND
EASTERN AREAS. SOME INCREASED CHANCES FOR SHOWERS AND
THUNDERSTORMS MAY RETURN LATER IN THE WEEK, WITH MAINLY DRY
CONDITIONS TO PERHAPS A FEW ISOLATED THUNDERSTORMS EXPECTED IN
BETWEEN.
BIS WATCHES/WARNINGS/ADVISORIES
FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY
EVENING FOR NDZ001-009-017-031-032-040-043.
UPDATE...HOLLAN
DISCUSSION...ANGLIN
AVIATION...HOLLAN
FIRE WEATHER...ANGLIN
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