932
FXUS63 KBIS 110257
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
957 PM CDT SAT MAY 10 2025
KEY MESSAGES
- UNSEASONABLY HOT THIS WEEKEND INTO EARLY NEXT WEEK, WITH
WIDESPREAD HIGHS IN THE 90S. SEVERAL MAXIMUM TEMPERATURE
RECORDS COULD BE BROKEN.
- CRITICAL FIRE WEATHER CONDITIONS ACROSS MUCH OF CENTRAL NORTH
DAKOTA INCLUDING THE JAMES RIVER VALLEY SUNDAY.
- STRONG WINDS ARE EXPECTED ACROSS CENTRAL AND EASTERN NORTH
DAKOTA SUNDAY AND MONDAY. NEAR-CRITICAL TO CRITICAL FIRE
WEATHER CONDITIONS ARE POSSIBLE AGAIN ON MONDAY.
- THERE IS A 20 PERCENT CHANCE OF THUNDERSTORMS ACROSS WESTERN
AND PORTIONS OF NORTH CENTRAL NORTH DAKOTA SUNDAY EVENING. A
FEW STORMS COULD BECOME STRONG TO MARGINALLY SEVERE.
- HIGHER CHANCES FOR RAIN AND MUCH COOLER TEMPERATURES RETURN
FOR THE SECOND HALF OF NEXT WEEK.
UPDATE
ISSUED AT 947 PM CDT SAT MAY 10 2025
WINDS CONTINUE TO GRADUALLY DIMINISH AS THIS EVENING GOES ON,
WHILE SHOWERS/STORMS HAVE COME TO AN END OVER OUR AREA. WITH
THAT SAID, SOME WEAKENING SHOWERS CONTINUE TO MOVE THROUGH
NORTHEAST MONTANA, AND MAY PUSH INTO NORTHERN PORTIONS OF OUR
AREA LATER TONIGHT. THEREFORE, HAVE ADDED A 20 PERCENT CHANCE OF
SHOWERS SPREADING THROUGH OVERNIGHT.
UPDATE
ISSUED AT 653 PM CDT SAT MAY 10 2025
ISOLATED SHOWERS WITH A COUPLE OF THUNDERSTORMS HAVE DEVELOPED
OVER PARTS OF CENTRAL NORTH DAKOTA, AND CONTINUE TO SLIDE
EASTERLY. THIS SHOULD CONTINUE FOR A COUPLE MORE HOURS BEFORE
DIMINISHING AND DEPARTING THE AREA. OTHERWISE, DRY AND WINDY
CONDITIONS WILL CONTINUE FOR THE NEXT HOUR OR TWO, SO WILL KEEP
ONGOING RED FLAG WARNING IN PLACE.
DISCUSSION
ISSUED AT 302 PM CDT SAT MAY 10 2025
THE MAIN FORECAST FOCUS OF THE NEXT FEW DAYS IS FIRE WEATHER
CONCERNS ACROSS WESTERN AND CENTRAL NORTH DAKOTA. FOR MORE
SPECIFIC INFORMATION ON FIRE WEATHER, SEE THE FIRE WEATHER
DISCUSSION BELOW.
THIS AFTERNOON, THE SYNOPTIC FLOW WAS DOMINATED BY A BROAD RIDGE
EXTENDING OVER MUCH OF THE CONUS, WITH A DOWNSTREAM TROUGH OVER
THE NORTHEAST AND A DEEPENING UPSTREAM TROUGH OFF THE COAST OF
BRITISH COLUMBIA. AT THE SURFACE, AN ELONGATED LOW STRETCHED
FROM CENTRAL SASKATCHEWAN BACK THROUGH NORTH CENTRAL MONTANA,
WITH A WARM FRONT ORIENTED NORTH-SOUTH THROUGH NORTH DAKOTA.
STRONG WINDS CONTINUE ACROSS THE FORECAST AREA, SOUTHERLY AHEAD
OF THE FRONT AND SOUTHWESTERLY ON THE WEST SIDE OF THE FRONT.
TODAY IS THE FIRST OF 3 HOT DAYS ACROSS THE AREA, WITH AFTERNOON
HIGHS IN THE MID 80S TO LOWER 90S. A RED FLAG WARNING IS IN
EFFECT THROUGH THE EVENING FOR WESTERN AND MUCH OF CENTRAL NORTH
DAKOTA.
WE ARE SEEING A FEW SCATTERED, LIGHT RADAR RETURNS NORTH OF THE
INTERNATIONAL BORDER, WHICH VARIOUS CAMS HAVE BEEN ADVERTISING
THROUGH THE DAY, WITH SCATTERED SHOWERS AND A FEW RUMBLES OF
THUNDER POSSIBLE ACROSS THE NORTH LATER THIS AFTERNOON AND INTO
THE EVENING. WE ARE CARRYING A 20 PERCENT CHANCE FOR
PRECIPITATION, WITH LOW CONFIDENCE IN TIMING AND LOCATION,
ALTHOUGH WE ARE STARTING TO SEE A CU FIELD DEVELOPING IN
SOUTHWEST NORTH DAKOTA JUST BEHIND THE WARM FRONT. WINDS WILL
STAY BREEZY OVERNIGHT, ESPECIALLY CENTRAL AND EAST, WITH
SEASONABLY MILD LOWS IN THE MID 50S TO LOWER 60S.
RECORD-SETTING HEAT IS FORECAST ON SUNDAY AND MONDAY AS THE
UPPER RIDGE AND A LOWER LEVEL THERMAL RIDGE MOVES OVERHEAD,
WITH WIDESPREAD HIGHS IN THE 90S BOTH DAYS. ECMWF EFI AND NAEFS
GUIDANCE BOTH HIGHLIGHT HOW CLIMATOLOGICALLY SIGNIFICANT THE
FORECAST HOT TEMPERATURES ARE. WE DID BLEND UP JUST A BIT FROM
THE DETERMINISTIC NBM SINCE IT WAS SKEWING ON THE COOL SIDE OF
ITS SPREAD. THE NORTH CENTRAL PART OF THE STATE, SPECIFICALLY
THE MINOT AREA, IS THE FOCUS OF THE EXTREME HEAT IN THE NBM
OUTPUT, WITH A 40 TO 60 PERCENT CHANCE OF REACHING 100 F ON BOTH
SUNDAY AND MONDAY, MULTIPLE DEGREES ABOVE CURRENT MAX
TEMPERATURE RECORDS. EVEN WITH LOWER APPARENT TEMPERATURES DUE
TO THE EXTREMELY DRY AIR MASS, MAKE SURE TO TAKE PRECAUTIONS
FROM HEAT RELATED ILLNESSES, ESPECIALLY WITH HOW EARLY IN THE
SEASON IT IS. WE HAVE ISSUED A RED FLAG WARNING ON SUNDAY FOR
PARTS OF CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY DUE TO
THE COMBINATION OF STRONG WINDS AND LOW RELATIVE HUMIDITY. ALSO
OF CONCERN ON SUNDAY IS A LEVEL 1 OUT OF 5 RISK (ISOLATED) FOR
SEVERE THUNDERSTORMS AS AN EMBEDDED WAVE MOVES THROUGH THE AREA.
LATEST CAMS ADVERTISE WIDELY SCATTERED CONVECTION DEVELOPING
LATE TOMORROW AFTERNOON THROUGH THE EVENING ACROSS EASTERN
MONTANA AND INTO WESTERN NORTH DAKOTA. INSTABILITY IS QUITE
MARGINAL BUT FORECAST SOUNDINGS ARE THE TYPICAL INVERTED V THAT
OCCURS WITH A VERY DRY LOWER ATMOSPHERE, SO MAIN THREAT WE ARE
ADVERTISING IS DAMAGING WIND GUSTS UP TO 60 MPH, WITH SMALL HAIL
POSSIBLE AS WELL.
HOT AND DRY WEATHER AGAIN ON MONDAY, WITH NEAR-CRITICAL TO
CRITICAL FIRE WEATHER CONDITIONS POSSIBLE FOR ANOTHER DAY.
BLENDED GUIDANCE HAS A LOW CHANCE FOR SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS THE NORTHWEST MONDAY EVENING, AS FLOW ALOFT
CONTINUES TO TURN SOUTHWESTERLY IN RESPONSE TO A DEEPENING LOW
OFF THE COAST OF THE WESTERN CONUS. THE OTHER WEATHER CONCERN ON
SUNDAY AND MONDAY IS THAT WINDS WILL LIKELY BE STRONG ENOUGH,
PRIMARILY IN THE JAMES RIVER VALLEY AREA, TO WARRANT A WIND
ADVISORY, BUT WILL LEAVE THAT TO NEXT SHIFT.
TUESDAY BEGINS THE PATTERN SWITCH AS THE UPPER LOW DEEPENS
FURTHER AND THE FIRST OF MULTIPLE FRONTS BEGINS TO MOVE THROUGH
THE STATE. HIGHS ON TUESDAY WILL LIKELY VARY SIGNIFICANTLY
ACROSS THE FORECAST AREA DEPENDING ON THE TIMING OF THINGS, WITH
THE CURRENT NBM ADVERTISING HIGHS FROM THE MID TO UPPER 70S WEST
TO THE LOWER 90S SOUTHEAST. THESE ARE A BIT WARMER THAN PREVIOUS
RUNS AS UPPER FEATURES HAVE BEEN TRENDING A BIT SLOWER. A
LEADING IMPULSE AHEAD OF THE TROUGH BASE WILL LEAD TO MODEST
MID-LEVEL HEIGHT FALLS AND MARGINAL INSTABILITY AND SHEAR, WITH
BLENDED POPS ADVERTISING A 30 TO 50 PERCENT CHANCE FOR SHOWERS
AND THUNDERSTORMS TUESDAY NIGHT. CSU AND NSSL MACHINE LEARNING
HIGHLIGHT POTENTIAL FOR SEVERE THUNDERSTORMS CENTRAL AND EAST
FOR THIS PERIOD.
WEDNESDAY THROUGH THURSDAY IS WHEN ENSEMBLE CLUSTER ANALYSIS IS IN
AGREEMENT ON A DEEP TROUGH CLOSING OFF SOMEWHERE OVER THE NORTHERN
PLAINS AND BRINGING WIDESPREAD, HIGH PRECIPITATION CHANCES TO NORTH
DAKOTA. LUCKILY THE ODDS FOR BENEFICIAL RAINS IS MODEST, WITH MEDIUM
CHANCES FOR AT LEAST ONE INCH OF RAIN ACROSS THE ENTIRE FORECAST
AREA, AND A 20 TO 30 PERCENT CHANCE FOR EXCEEDING 2 INCHES ACROSS
WESTERN AND PARTS OF CENTRAL ND. THE GENERAL AXIS OF HEAVIEST
PRECIPITATION IS CONSISTENT AMONG CLUSTERS, FAVORING WESTERN INTO
NORTH CENTRAL NORTH DAKOTA. THE ECMWF EFI DOESN'T HAVE TOO STRONG OF
A SIGNAL FOR HEAVY RAIN BUT IT DOES HAVE A SHIFT OF TAILS BOTH
WEDNESDAY AND THURSDAY, INDICATING THAT THERE ARE A ENSEMBLE MEMBERS
PRODUCING QPF EXTREMES. WEDNESDAY ALSO HAS THE STRONGEST SIGNAL FOR
POTENTIAL SEVERE THUNDERSTORMS IN BOTH NSSL AND CSU MACHINE LEARNING
GUIDANCE, PRIMARILY OVER THE CENTRAL AND EASTERN DAKOTAS RIGHT
AHEAD OF THE APPROACHING TROUGH BASE / CLOSED LOW. BREEZY WINDS
ARE ALSO LIKELY AS THE LOW MOVES THROUGH AND IN THE POST-
FRONTAL REGIME, ALTHOUGH WITH THE RAIN AND COOLER TEMPERATURES,
FIRE WEATHER CONCERNS WILL BE MUCH LOWER COMPARED TO RECENT
DAYS.
WITH THE RAIN COMES HIGH CONFIDENCE IN COOLING TEMPERATURES THROUGH
THE MIDDLE AND END OF NEXT WEEK. THE LATEST NBM HAS TEMPERATURES
BOTTOMING OUT ON FRIDAY, WITH WIDESPREAD HIGHS IN THE 50S TO
LOWER 60S, AND LOWS FRIDAY NIGHT INTO SATURDAY MORNING IN THE
MID TO UPPER 30S. THE LOCAL GROWING SEASON STARTED YESTERDAY SO
FROST/FREEZE HEADLINES WILL BE ISSUED AS NEEDED. NEXT WEEKEND
WILL CERTAINLY BE COOLER THAN THIS WEEKEND, WITH NBM TEMPERATURE
PERCENTILES NOT SIGNALING ANY SIGNIFICANT WARM UP THROUGH THE
START OF THE THIRD WEEK OF MAY, AND CPC OUTLOOKS ALSO SLIGHTLY
FAVORING COOLER THAN NORMAL CONDITIONS.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 653 PM CDT SAT MAY 10 2025
VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. LLWS
MAY DEVELOP LATE THIS EVENING AND CONTINUE OVERNIGHT AFFECTING
THE KBIS, KMOT, AND KDIK TERMINALS.
FIRE WEATHER
ISSUED AT 940 PM CDT SAT MAY 10 2025
THERE CONTINUES TO BE MULTIPLE DAYS OF FIRE WEATHER CONCERNS
ACROSS THE STATE AS ANOMALOUS HEAT, A VERY DRY ATMOSPHERE, AND
STRONG WINDS WILL PRODUCE NEAR CRITICAL TO CRITICAL FIRE WEATHER
CONDITIONS TODAY THROUGH MONDAY.
A RED FLAG WARNING REMAINS IN EFFECT FOR MUCH OF CENTRAL NORTH
DAKOTA INCLUDING THE JAMES RIVER VALLEY FROM LATE SUNDAY
MORNING THROUGH SUNDAY EVENING. MINIMUM RELATIVE HUMIDITY IN THE
WARNING AREA WILL DROP INTO THE LOWER TO MID TEENS RANGE, AND
SOUTH- SOUTHWEST WINDS WILL BE STRONGER THAN TODAY, ESPECIALLY
IN THE JAMES RIVER VALLEY WHERE SUSTAINED WINDS ARE EXPECTED TO
BE AROUND 35 MPH WITH GUSTS UP TO 50 MPH. THERE IS SOME CONCERN
WITH GREENING FUELS, BUT THE COMBINATION OF THE WIND SPEEDS,
VERY DRY AIR, AND HIGHS IN THE LOWER TO MID 90S TIPPED THE
SCALES ENOUGH TO WARRANT A WARNING. FARTHER TO THE WEST, EVEN
THOUGH RELATIVE HUMIDITY WILL BE THE LOWEST IN THIS AREA, WINDS
WILL BE LIGHT ENOUGH TO LIMIT CRITICAL FIRE WEATHER CONCERNS,
ALTHOUGH WILL STILL MENTION NEAR-CRITICAL FOR THIS AREA.
MONDAY LOOKS SIMILAR TO SUNDAY IN THAT THE LOWEST RELATIVE
HUMIDITY VALUES, IN THE LOWER TO MID TEENS, ARE ACROSS WESTERN AND
INTO NORTH CENTRAL NORTH DAKOTA WHERE WINDS ARE FORECAST TO BE
LIGHT ENOUGH TO FEND OFF ANY CRITICAL FIRE WEATHER CONDITIONS. IN
PARTS OF THE JAMES RIVER VALLEY, SOUTHERLY WINDS AROUND 25 MPH AND
MINIMUM RELATIVE HUMIDITY IN THE UPPER TEENS TO LOWER 20 PERCENT
RANGE COULD COMBINE FOR CRITICAL FIRE WEATHER CONDITIONS.
A COLD FRONT MOVES THROUGH ON TUESDAY PROVIDING SOME RELIEF TO
THE WEST BUT WE COULD SEE ONE MORE ROUND OF AT LEAST NEAR-
CRITICAL CONDITIONS ACROSS THE SOUTHEAST DURING THE AFTERNOON.
WIDESPREAD WETTING RAINS ARE THEN HIGHLY LIKELY ACROSS ALL OF
WESTERN AND CENTRAL NORTH DAKOTA LATE TUESDAY EVENING THROUGH AT
LEAST THURSDAY NIGHT.
BIS WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING FROM 11 AM CDT /10 AM MDT/ TO 10 PM CDT /9 PM
MDT/ SUNDAY FOR NDZ005-012-013-021>023-025-034>037-042-045>048-
050-051.
UPDATE...JJS
DISCUSSION...JONES
AVIATION...JJS
FIRE WEATHER...JJS/JONES
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