060
FXUS63 KBIS 052339
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
639 PM CDT MON MAY 5 2025
KEY MESSAGES
- NEAR-CRITICAL FIRE WEATHER CONDITIONS CONTINUE ACROSS THE
JAMES RIVER VALLEY THIS EVENING.
- 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 EVENING. ISOLATED SEVERE THUNDERSTORMS
SOUTHWEST INTO CENTRAL, MAINLY FOR 60 MPH WINDS.
- MOSTLY DRY WITH ABOVE AVERAGE TEMPERATURES AND BREEZY
CONDITIONS AT TIMES THROUGH THE END OF THE WEEK.
UPDATE
ISSUED AT 639 PM CDT MON MAY 5 2025
COLD FRONT EXTENDS FROM THE TURTLE MOUNTAINS AREA, THROUGH
WASHBURN, TO GRANT COUNTY, WITH SHOWERS AND THUNDERSTORMS
DEVELOPING ALONG THE FRONT. THERE IS A SECONDARY BOUNDARY,
ORIENTED NORTH-SOUTH, CONNECTED TO THE FRONT IN PIERCE COUNTY
AND EXTENDING SOUTH THROUGH KIDDER AND EMMONS COUNTIES. THE MOST
WELL DEVELOPED, ALTHOUGH STILL SUBSEVERE, STORMS HAVE BEEN IN
THE SHERIDAN AND WELLS COUNTY AREAS. AHEAD OF THE FRONT, AS
PREVIOUSLY THOUGHT, SHEAR IS QUITE LOW, WITH THE SPC
MESOANALYSIS PAGE ADVERTISING LESS THAN 25 KNOTS OF 0-6 KM
SHEAR. BECAUSE OF THIS, EVEN THOUGH WE HAVE MODERATE INSTABILITY
AND LAPSE RATES, EXPECTING STORMS TO BE MOSTLY PULSE / POPCORN
THUNDERSTORMS. CAN'T RULE OUT SMALL TO POTENTIALLY EVEN
BORDERLINE SEVERE HAIL, BUT WOULD NOT EXPECT STORMS TO BE LONG-
LIVED SEVERE DUE TO THE LACK OF SHEAR LEADING TO UPDRAFTS BEING
CUT OFF RELATIVELY QUICKLY. FURTHER TO THE WEST, A FEW STORMS
HAVE TRIED TO DEVELOP IN THE WESTERN MORTON AND GRANT COUNTY
AREA, BUT INCREASING SHEAR AND DECREASING INSTABILITY BEHIND THE
FRONT HAS LED TO CONVECTION DYING OFF SOON AFTER IT DEVELOPS.
THE WIND ADVISORY FOR NORTHWEST NORTH DAKOTA IS STILL IN EFFECT
FOR THE NEXT HALF HOUR. THINKING WE WILL BE ABLE TO DROP IT,
WITH WINDS BELOW CRITERIA, BUT WINDS WILL LIKELY STAY STRONG
THROUGH THE NEXT FEW HOURS BEFORE DIMINISHING FURTHER OVERNIGHT.
MEANWHILE, WE DID ISSUE TWO DUST ADVISORIES FOR PARTS OF WESTERN
NORTH DAKOTA, DOWNSTREAM OF THE RAY AND EPPING AREAS.
VISIBILITIES HAVE BEEN ON AND OFF REDUCED IN THE WATFORD CITY
AREA AND SOUTH, AND WE DID JUST GET A REPORT OF SOME DUST IN THE
HAZEN AREA, INDICATING DUST IS BEING CARRIED PRETTY FAR
DOWNSTREAM. AS THE WINDS RELAX, GUESSING THAT THE DUST WILL
BEGIN TO SETTLE. FRESHENED UP POPS WITH THIS UPDATE, AND WILL BE
KEEPING AN EYE ON CONVECTION AND DUST THROUGH THE EVENING.
DISCUSSION
ISSUED AT 230 PM CDT MON MAY 5 2025
CURRENTLY A COLD FRONT IS ACROSS THE STATE SOUTHWEST TO
NORTHEAST. SHOWERS IN THE FAR NORTHWEST HAVE BEEN MIXING DOWN 50
TO 60 MPH WINDS. THE LOWER LEVELS ARE ALSO DRY SO THIS AIDS IN
THE DOWNWARD MOMENTUM. BLOWING DUST PLUMES FROM THE BURN SCARS
IN RAY AND TIOGA HAVE MADE THEIR WAY TO SLOPE COUNTY! WE HAVE AN
SPS OUT FOR THAT AND A WIND ADVISORY OUT FOR WINDS IN THE
NORTHWEST.
CUMULUS HAVE STARTED TO POP ALONG THE EASTERN EDGE OF
THE FRONT IN WESTERN MORTON THROUGH HETTINGER COUNTY. THERE IS
CURRENTLY AROUND 500 J/KG ACROSS THE SOUTH CENTRAL BUT CAPPED.
SO IT SHOULD BE AT LEAST AN HOUR OR TWO FOR ATTEMPTS TO BREAK
IT. THE RAP FORECAST HAS THE CAP BREAKING AT 3PM CT. MIXED LAYER
CAPE IS ALMOST NOTHING. LAPSE RATES ARE CONVECTIVELY OKAY AT
7.5 AND FORECAST TO STAY THE SAME. WIND SHEAR IS 30KTS ALONG THE
FRONT WHERE THE CUMULUS ARE LOCATED. DCAPE IS CONCERNINGLY HIGH
AT 1200 J/KG CURRENTLY, AND FORECAST TO BE 1400 J/KG LATER.
AGAIN ALL THIS IS BASED OFF THE RAP. SPC HAS A MARGINAL RISK
(ISOLATED) FROM THE SOUTHWEST TO THE CENTRAL PART OF THE STATE,
INCLUDING BIS/MAN. THE MAIN THREATS ARE WINDS AROUND 60 MPH
BASED ON THE DRY LOWER LEVELS OF THE ATMOSPHERE AND STORM MODE.
MODEL SOUNDINGS HAVE AN INVERTED V HINTING AT DRY AIR DOWN LOW
THAT WILL ACCELERATE THE DOWNDRAFTS OF THE STORMS. STORM MODE
WILL BE LINEAR AS THE WIND SHEAR VECTOR IS NEAR PARALLEL WITH
THE FRONT. QUARTER SIZE HAIL IS POSSIBLE AS STORMS DEVELOP BUT
THEN IT WILL MAINLY BE A WIND THREAT. THE CAMS HAVE SLOWED THE
TIMING DOWN TO AROUND 23Z, BUT WILL KEEP A VERY CLOSE EYE ON THE
CUMULUS THAT ALREADY STARTED. THE SEVERE THREAT SHOULD END
AROUND 10PM CT, BUT SHOWERS AND THUNDERSTORMS WILL CONTINUE IN
THE SOUTH AND EAST THROUGH 5AM CT WITH WRAP AROUND MOISTURE WITH
THE SURFACE LOW. ALL THIS IS IN SOUTHWEST FLOW, WHICH WILL
CHANGE TO A RIDGE UNTIL FRIDAY. TUESDAY WILL BE SLIGHTLY COOLER
BEHIND THE FRONT IN THE 60S AND 70S. THEN THE WARMER AIR WITH
THE RIDGE MOVES IN. FRIDAY THE FLOW CHANGES TO ZONAL, ALLOWING
SOME SHORTWAVES OFF THE MONTANA MOUNTAINS TO GIVE A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS AGAIN. THIS WEEKEND ANOTHER
RIDGE MOVES OVER, ALLOWING TEMPERATURES TO POSSIBLE CLIMB INTO
THE UPPER 80S! SUNDAY NIGHT INTO MONDAY WHERE THE ACTIVE
SOUTHWEST FLOW SETS BACK UP. TEMPERATURES COULD ALSO BE IN THE
UPPER 80S, ALLOWING THUNDERSTORMS TO FORM.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 639 PM CDT MON MAY 5 2025
SCATTERED SHOWERS AND THUNDERSTORMS ARE LIKELY ACROSS CENTRAL
NORTH DAKOTA THROUGH THE FIRST HALF OF THE TAF PERIOD, WITH
MVFR VISIBILITIES POSSIBLE IN ANY AREAS OF PRECIPITATION. A
COLD FRONT MOVING THROUGH WILL CONTINUE SHIFTING STRONG WINDS
FROM THE SOUTH TO THE NORTH. MVFR CEILINGS WILL MOVE IN TO
SOUTHWEST NORTH DAKOTA LATE TONIGHT INTO TUESDAY MORNING,
POTENTIALLY IMPACTING KDIK. WINDS WILL SHIFT TO BECOME
NORTHEASTERLY DURING THE DAY TUESDAY, SUSTAINED AROUND 15 KNOTS.
ISOLATED SHOWERS ARE POSSIBLE THROUGH THE DAY TUESDAY, BUT TOO
LOW OF CONFIDENCE IN TIMING AND LOCATION TO INCLUDE AT ANY
TERMINAL WITH THIS UPDATE.
BIS WATCHES/WARNINGS/ADVISORIES
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR
NDZ001-002-009-010-017.
UPDATE...JONES
DISCUSSION...SMITH
AVIATION...JONES
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