371
FXUS63 KBIS 051809
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
109 PM CDT MON MAY 5 2025
KEY MESSAGES
- NEAR-CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY
ACROSS MUCH OF CENTRAL NORTH DAKOTA, INCLUDING THE JAMES RIVER
VALLEY.
- WIND ADVISORY IN THE NORTHWEST FOR GUSTS UP TO 50 MPH AND
BLOWING DUST.
- INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS IN WESTERN
AND CENTRAL ND THIS AFTERNOON AND EVENING. ISOLATED SEVERE
THUNDERSTORMS SOUTHWEST INTO CENTAL, MAINLY FOR 60 MPH WINDS.
- COOLER ON TUESDAY, WITH A FEW LINGERING SHOWERS MAINLY IN THE
SOUTHWEST. THEN MOSTLY DRY WITH ABOVE AVERAGE TEMPERATURES
AND BREEZY CONDITIONS AT TIMES THROUGH THE END OF THE WEEK.
UPDATE
ISSUED AT 105 PM CDT MON MAY 5 2025
THE ISOLATED RISK OF SEVERE STORMS WAS EXPANDED NORTHEAST A
LITTLE, AND THE TIMING OF THE STORMS NOW DELAYED TO AROUND 7PM
CT. THE RISKS ARE THE SAME. THE BLOWING DUST PLUME CONTINUES TO
EXPAND SOUTH, NOW INTO BILLINGS AND GOLDEN VALLEY COUNTIES. THE
FORECAST WAS UPDATED WITH THE LATEST NBM DATA.
UPDATE
ISSUED AT 1025 AM CDT MON MAY 5 2025
SPC UPGRADED US TO A LEVEL 1 RISK FOR SEVERE STORMS THIS
EVENING. THIS AREA COVERS PORTIONS OF THE SOUTHWEST AND SOUTH
CENTRAL. WITH DRIER AIR PRESENT, THE MAIN THREAT WILL BE WINDS
AROUND 60 MPH. CAPE IS LOW, AROUND 1000 J/KG OR LESS AND WIND
SHEAR 15 TO 30 KTS. THIS DOES INCLUDE THE BISMARCK/MANDAN AREA
AROUND 6PM.
BLOWING DUST ALONG WITH 40 TO 50 MPH WINDS HAVE STARTED IN THE
NORTHWEST. WE ISSUED A WIND ADVISORY THROUGH THIS AFTERNOON FOR
THOSE HAZARDS. THERE WILL BE ISOLATED SHOWERS IN THE NORTHWEST,
WHICH WILL HELP SUPPRESS THE DUST.
UPDATE
ISSUED AT 642 AM CDT MON MAY 5 2025
A FEW SHOWERS ARE PRESENT ALONG A COLD FRONTAL BOUNDARY IN
NORTHWESTERN NORTH DAKOTA. AN OCCASIONAL RUMBLE OF THUNDER HAS
BEEN OBSERVED OVER THE PAST COUPLE HOURS. WITH GRADUAL INCREASES
IN INSTABILITY THROUGH THE DAY, OCCASIONAL RUMBLES WILL
PROBABLY PERSIST THROUGH THE MORNING BEFORE MORE ORGANIZED
THUNDERSTORMS DEVELOP THIS AFTERNOON.
DISCUSSION
ISSUED AT 419 AM CDT MON MAY 5 2025
ELONGATED SURFACE LOW AND ASSOCIATED COLD FRONTAL BOUNDARY
PRESENTLY SIT FROM MANITOBA THROUGH WESTERN ND AND INTO WYOMING,
AND WILL GRADUALLY SLIDE EASTWARD TODAY THROUGH TONIGHT. AHEAD
OF THE ELONGATED LOW, A TIGHTER PRESSURE GRADIENT WILL PERSIST
THROUGH THIS MORNING AND EARLY AFTERNOON OVER THE EASTERN HALF
OF ND. THIS WILL RESULT IN BREEZY SOUTHERLY FLOW AND WARM
TEMPERATURES APPROACHING 80. MINIMUM RELATIVE HUMIDITY VALUES
WILL DROP INTO THE 20S TO AROUND 30 PERCENT FOR MOST OF CENTRAL
ND, INCLUDING THE JAMES RIVER VALLEY, RESULTING IN NEAR-CRITICAL
FIRE WEATHER CONDITIONS.
BEHIND THE FRONTAL BOUNDARY, COOLER HIGHS IN THE 60S TO LOW 70S
ARE EXPECTED FOR TODAY IN FAR WESTERN ND, ALONG WITH GUSTY
NORTHERLY WINDS. PERIODIC SHOWERS ARE ALSO POSSIBLE MAINLY IN
THE WEST THIS MORNING AND EARLY AFTERNOON. VERY LITTLE
INSTABILITY IS PRESENT, BUT AS OBSERVED WITHIN THE PAST FEW
HOURS, EMBEDDED POCKETS OF UNANALYZED INSTABILITY ARE ALLOWING
THE OCCASIONAL RUMBLE OF THUNDER AS WELL. AS THE FRONT SLOWLY
MOVES EASTWARD TODAY, SHOWER AND THUNDERSTORM CHANCES ARE
EXPECTED TO INCREASE LATER THIS AFTERNOON AND ESPECIALLY
EVENING. CAMS ARE VERY CONSISTENT IN A FAIRLY NARROW
(APPROXIMATELY 50 MILES WIDE) LINE OF THUNDERSTORMS DEVELOPING
WITH A SOUTHWEST TO NORTHEAST ORIENTATION ALONG THE FRONTAL
BOUNDARY, WITH THE BEST CHANCES FROM SOUTHWESTERN THROUGH NORTH
CENTRAL ND. CURRENTLY, THE BEST INSTABILITY IS PROGGED TO REMAIN
AHEAD OF THE STRONGEST SHEAR, SO SEVERE WEATHER SEEMS UNLIKELY,
THOUGH A STRONG STORM OR TWO WOULD NOT BE IMPOSSIBLE.
SHOWERS MAY LINGER MAINLY IN THE SOUTHWEST THROUGH THE DAY
TUESDAY, BUT ONCE THEY CLEAR OUT, EXPECT MOSTLY DRY CONDITIONS
TO FINISH OUT THE WEEK. ALTHOUGH A WEAK WAVE COULD BRING A FEW
SHOWERS TO FINISH OUT THE WORKWEEK. HIGHS TUESDAY WILL BE COOLER
WITH MOST LOCATIONS REMAINING IN THE 60S WITH SOME 70S POSSIBLE
NEAR THE ND/SD BORDER. WEDNESDAY WILL SEE HIGHS MOSTLY IN THE
UPPER 60S TO LOW 70S. ABOVE AVERAGE TEMPERATURES ARE THEN
EXPECTED TO RETURN TO FINISH OUT THE WEEK AND CONTINUE INTO
EARLY NEXT WEEK WITH HIGHS MAINLY FROM THE MID 70S TO LOW 80S.
FOR REFERENCE, BY THE END OF THE WEEK, AVERAGE HIGHS FOR THIS
TIME OF YEAR ARE MOSTLY IN THE MID 60S.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 105 PM CDT MON MAY 5 2025
VFR CIGS AND VIS, EXCEPT IN BLOWING DUST IN THE FAR WEST
CURRENTLY. CIGS WILL INCREASE WEST TO EAST THROUGH THE PERIOD
WITH MVFR IN THE WEST AND SOUTH CENTRAL. THUNDERSTORMS ARE
LIKELY IN THE SOUTH CENTRAL AND CENTRAL THIS EVENING AND
OVERNIGHT, WINDS COULD GUST UP TO 50KTS IN THE STORMS. WINDS
WILL CONTINUE TO GUST AROUND 35KTS THROUGH THIS EVENING,
ESPECIALLY WEST.
BIS WATCHES/WARNINGS/ADVISORIES
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR
NDZ001-002-009-010-017.
UPDATE...SMITH
DISCUSSION...TELKEN
AVIATION...SMITH
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