089
FXUS63 KBIS 102002
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
302 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 CONTINUE ACROSS WESTERN AND
MOST OF CENTRAL NORTH DAKOTA THROUGH THIS EVENING. ANOTHER
DAY OF CRITICAL FIRE WEATHER CONDITIONS IS EXPECTED ACROSS
PARTS OF CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY ON
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.
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 /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1226 PM CDT SAT MAY 10 2025
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. STRONG SOUTH TO
SOUTHWESTERLY WINDS WILL CONTINUE ACROSS THE AREA INTO THE
EVENING BEFORE DIMINISHING SOME OVERNIGHT. LLWS WAS INCLUDED AT
KBIS WITH THIS UPDATE OVERNIGHT. WINDS TONIGHT WILL TURN MORE
SOUTHERLY BEFORE BECOMING SOUTHWESTERLY DURING THE DAY SUNDAY,
AND STRONGEST IN THE JAMES RIVER VALLEY WHERE SUSTAINED WINDS
AROUND 25 KNOTS ARE EXPECTED. SOME SCATTERED MID TO HIGH CLOUDS
WILL BE PASSING THROUGH DURING THE TAF PERIOD.
FIRE WEATHER
ISSUED AT 302 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 THROUGH THIS EVENING FOR
WESTERN AND MUCH OF CENTRAL NORTH DAKOTA. STRONG SOUTHERLY WINDS
WILL CONTINUE THE REST OF THE DAY, WITH WINDS BECOMING MORE
SOUTHWESTERLY ACROSS WESTERN NORTH DAKOTA BEHIND A WARM FRONT
MOVING THROUGH THE STATE. RELATIVE HUMIDITY HAS ALREADY DROPPED
INTO THE 20 PERCENT RANGE ACROSS THE FORECAST AREA, WITH SOME
STATIONS REPORTING HUMIDITY VALUES IN THE TEENS IN SOUTHWEST NORTH
DAKOTA. EXPECT HUMIDITY TO BOTTOM OUT IN THE LOWER TO MID TEENS
RANGE ACROSS WESTERN AND PARTS OF CENTRAL NORTH DAKOTA. OUTSIDE OF
THE RED FLAG WARNING, WE CONTINUE TO ADVERTISE NEAR-CRITICAL FIRE
WEATHER CONDITIONS IN THE JAMES RIVER VALLEY, WHERE HUMIDITY IS
JUST A TOUCH HIGHER AND FUELS ARE GREENING UP A BIT MORE.
WE HAVE ISSUED A RED FLAG WARNING FOR PARTS OF CENTRAL NORTH
DAKOTA AND 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 UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR
NDZ001>005-009>013-017>023-025-031>034-040>045.
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.
DISCUSSION...JONES
AVIATION...JONES
FIRE WEATHER...JONES
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