699
FXUS63 KBIS 091458
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
958 AM CDT FRI MAY 9 2025
KEY MESSAGES
- NEAR-CRITICAL TO CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE
AT TIMES SATURDAY THROUGH MONDAY.
- MAINLY DRY WITH WELL ABOVE AVERAGE TEMPERATURES AND PERIODIC
BREEZY CONDITIONS THIS WEEKEND. WIDESPREAD HIGHS IN THE 90S
ARE LIKELY ON SUNDAY AND MONDAY.
- TEMPERATURES TREND COOLER AFTER MONDAY, WITH MORE FREQUENT
CHANCES FOR SHOWERS AND THUNDERSTORMS.
UPDATE
ISSUED AT 942 AM CDT FRI MAY 9 2025
OVERALL THE FORECAST REMAINS IN GOOD SHAPE. SMOKE FROM CANADIAN
WILDFIRES HAS MOVED SOUTH INTO NORTH CENTRAL AND NORTHEAST ND,
AND IS CREATING SOME VISIBILITY REDUCTIONS. THUS, WILL ADD IN A
MENTION OF SMOKE FOR A FEW HOURS. ONCE WE BETTER MIX, CONDITIONS
SHOULD IMPROVE.
UPDATE
ISSUED AT 627 AM CDT FRI MAY 9 2025
NO MAJOR CHANGES WERE NEEDED FOR THIS UPDATE. JUST BLENDED IN
THE LATEST OBSERVATIONS TO THE GOING FORECAST.
DISCUSSION
ISSUED AT 345 AM CDT FRI MAY 9 2025
WE WILL GRADUALLY SHIFT FROM NEAR ZONAL FLOW ALOFT TO NORTHWEST
FLOW ALOFT THROUGH THE DAY AS THE NEXT RIDGE STARTS TO POP UP TO
OUR WEST. AT THE SURFACE, THERE IS A COLD FRONT THAT IS
CURRENTLY DRAPED FROM AROUND THE NORTHEAST CORNER OF THE STATE
TO THE SOUTHWEST CORNER. EARLY SHOWERS THAT WERE ONGOING ALONG
THIS BOUNDARY HAVE NOW ALL BUT DIMINISHED.
FOR TODAY, IT WILL BE JUST A TOUCH COOLER BEHIND THE COLD FRONT
WITH HIGHS FORECAST TO RANGE FROM THE UPPER 60S TO THE UPPER
70S. WHILE MOST AREAS WILL SEE A BREAK IN THE HIGHER WINDS, THE
JAMES RIVER VALLEY AND VICINITY WILL CONTINUE TO SEE SOME
BREEZY NORTH NORTHEAST WINDS THROUGH THIS AFTERNOON. DRY
CONDITIONS WILL ALSO CONTINUE THROUGH THE AFTERNOON WITH
DEWPOINTS MIXING OUT INTO THE LOWER 30S TO LOWER 40S. THUS,
AFTERNOON HUMIDITY WILL LIKELY BOTTOM OUT INTO THE 20 TO 30
PERCENT RANGE FOR ALL OF WESTERN AND CENTRAL NORTH DAKOTA. SOME
NEAR-CRITICAL FIRE WEATHER CONDITIONS COULD BE POSSIBLE IN THE
AFTERNOON ACROSS THE JAMES RIVER VALLEY WHERE THE WINDS ARE
FORECAST TO BE STRONGER, BUT FUELS ARE FAIRLY GREEN HERE.
THE UPPER LEVEL RIDGE AXIS STARTS TO MOVE INTO WESTERN NORTH
DAKOTA ON SATURDAY, WITH THE THERMAL RIDGE ALSO NUDGING CLOSER.
HIGHS WILL BE QUITE WARM ON SATURDAY, FORECAST TO RANGE FROM THE
LOWER 80S EAST TO THE UPPER 80S AND LOWER 90S WEST. A TIGHTENING
PRESSURE GRADIENT WILL LEAD TO ANOTHER DAY OF BREEZY TO WINDY
CONDITIONS (WINDS OUT OF THE SOUTH). ADDITIONALLY, THE WARMER
TEMPERATURES WILL MEAN AFTERNOON HUMIDITY DIPPING EVEN LOWER
WITH MOST OF WESTERN AND CENTRAL NORTH DAKOTA FORECAST TO BOTTOM
OUT IN THE 15 TO 25 PERCENT RANGE. THERE IS SOME FAVORABLE
OVERLAP HERE IN THE WEATHER FIELDS THAT COULD LEAD TO SOME
CRITICAL FIRE WEATHER CONDITIONS ON SATURDAY AFTERNOON BUT
CONSIDERABLE UNCERTAINTY REMAINS REGARDING SOME DETAILS. FOR
ONE, CRITICAL CONDITIONS MAY ONLY BE IN PLACE FOR AN HOUR OR TWO
IN THE FAVORABLE AREAS. SECONDLY, ONE OF THE MORE FAVORABLE
AREAS THAT SHOW A NICE OVERLAP IN PARAMETERS IS FOCUSED ON THE
JAMES RIVER VALLEY AND VICINITY WHERE FUELS ARE FAIRLY GREEN.
THUS, WE WILL CONTINUE TO HIGHLIGHT THE POTENTIAL FOR NEAR-
CRITICAL TO CRITICAL FIRE WEATHER CONDITIONS IN THE HAZARDOUS
WEATHER OUTLOOK AND HOLD OFF ON ANY PRODUCT ISSUANCE FOR NOW.
WE START TO GRADUALLY TRANSITION TO SOUTHWEST FLOW ALOFT ON
SUNDAY AS AN UPPER LEVEL TROUGH STARTS TO COME ON SHORE IN THE
PACIFIC NORTHWEST. THE CORE OF THE THERMAL RIDGE WILL ALSO MOVE
INTO WESTERN AND CENTRAL NORTH DAKOTA ON SUNDAY, LEADING TO
WIDESPREAD HIGHS IN THE 90S. THE TIGHTER PRESSURE GRADIENT WILL
MOVE INTO THE EASTERN HALF OF THE STATE ON SUNDAY, SO THE
BREEZIER CONDITIONS WILL MAINLY BE ALONG AND EAST OF THE HIGHWAY
83 CORRIDOR (STRONGEST WINDS IN THE JAMES RIVER VALLEY). SUNDAY
WILL ALSO BE VERY DRY WITH ALL OF WESTERN AND CENTRAL NORTH
DAKOTA FALLING INTO THE 15 TO 20 PERCENT RANGE FOR MINIMUM
HUMIDITIES IN THE AFTERNOON. THUS MORE NEAR-CRITICAL TO CRITICAL
FIRE WEATHER CONDITIONS ARE POSSIBLE ON SUNDAY WITH MANY OF THE
SAME UNCERTAINTIES AS SATURDAY.
AN INITIAL IMPULSE MAY LEAD TO A FEW SHOWERS AND THUNDERSTORMS
SUNDAY EVENING, WITH THE BEST CHANCES (30 PERCENT) WEST.
INSTABILITY IS FORECAST TO BE WEAK BUT SOME MODEST SHEAR COULD
LEAD TO A STRONGER STORM OR TWO. COVERAGE WILL LIKELY BE OF THE
HIT OR MISS VARIETY.
HIGHS ON MONDAY WILL NOT BE MUCH (IF ANY) COOLER AS TEMPERATURES
CONTINUE TO TREND UP, NOW FORECAST TO RANGE FROM THE UPPER 80S
TO MID 90S. THE EXTREME FORECAST INDEX (EFI) CONTINUES TO
PRODUCE WIDESPREAD VALUES OF 1.0 ACROSS MUCH OF WESTERN AND
CENTRAL NORTH DAKOTA FOR HIGH TEMPERATURES ON SUNDAY AND MONDAY
WITH A SHIFT OF TAILS OF 1 FOR MUCH OF THE SAME AREA. THIS
SUGGESTS A HIGHLY ANOMALOUS TEMPERATURES ACROSS WESTERN AND
CENTRAL NORTH DAKOTA FOR THIS TIME OF YEAR. IF THE NBM 90TH
PERCENTILE WERE TO VERIFY, A FEW SITES COULD SEE HIGHS IN THE
TRIPLE DIGITS ON SUNDAY AND MONDAY. MONDAY WILL HAVE SIMILAR
FIRE WEATHER CONCERNS AS SATURDAY AND SUNDAY.
A COLD FRONT APPROACHES MONDAY NIGHT AND WE COULD SEE A FEW MORE
ISOLATED TO SCATTERED SHOWERS AND STORMS (HIGHEST CHANCES
NORTHWEST AROUND 30 PERCENT) IN THE EVENING. COOLER TEMPERATURES
ARE THEN FORECAST TO MOVE FROM NORTHWEST TO SOUTHEAST BEHIND THE
FRONT. HIGHS ON TUESDAY WILL RANGE FROM THE MID TO UPPER 70S
NORTHWEST, TO THE UPPER 80S AND LOWER 90S SOUTHEAST. A COUPLE OF
WAVES WILL THEN APPROACH LATE ON TUESDAY, BRINGING MULTIPLE
CHANCES OF SHOWERS AND STORMS TO WESTERN AND CENTRAL NORTH
DAKOTA TUESDAY EVENING THROUGH THURSDAY. WHILE IT IS TOO FAR
OUT FOR DETAILS, THE MONDAY EVENING THROUGH WEDNESDAY TIMEFRAME
MAY END UP BEING A PERIOD TO WATCH FOR A FEW STRONG TO SEVERE
STORMS DEPENDING ON HOW THE PATTERN UNFOLDS. CSU MACHINE
LEARNING GUIDANCE HAS BEEN HIGHLIGHTING THIS PERIOD IN RECENT
DAYS AND CONTINUES TO DO SO. CIPS ANALOGS HAVE ALSO BEEN SHOWING
A SIGNAL FOR SEVERAL RUNS. TUESDAY EVENING THROUGH THURSDAY WILL
ALSO BE OUR NEXT CHANCE FOR SOME WIDESPREAD BENEFICIAL RAINS.
WEDNESDAY'S HIGHS ARE FORECAST TO RANGE FROM THE MID 60S
NORTHWEST, TO THE MID 80S SOUTHEAST. HIGHS ON THURSDAY WILL BE
COOLER ALL AROUND, FORECAST TO RANGE FROM THE UPPER 50S
NORTHWEST, TO THE LOWER 70S SOUTHEAST. THAT BEING SAID, NBM
TEMPERATURE SPREADS BECOME RATHER LARGE ON WEDNESDAY AND
THURSDAY.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 627 AM CDT FRI MAY 9 2025
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SHIFTING WINDS
WILL BE THE MAIN FORECAST CHALLENGE FOR EACH TERMINAL, BUT WINDS
WILL GENERALLY BE LIGHT. THE ONE EXCEPTION WILL AT KJMS AND
VICINITY WHERE WINDS WILL BECOME FAIRLY BREEZY THIS AFTERNOON
OUT OF THE NORTH.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...NH
DISCUSSION...ZH
AVIATION...ZH
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