969
FXUS63 KBIS 290259
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
959 PM CDT MON JUL 28 2025
KEY MESSAGES
- THERE IS A LOW CHANCE (LESS THAN 20 PERCENT) FOR STRONG TO
POSSIBLY SEVERE STORMS AFTER MIDNIGHT IN FAR WESTERN NORTH
DAKOTA.
- ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS NORTHERN
NORTH DAKOTA TUESDAY AFTERNOON. EXPECTED HAZARDS INCLUDE HAIL
AS LARGE AS HALF DOLLARS AND WIND GUSTS UP TO 60 MPH.
- BELOW AVERAGE TEMPERATURES ARE EXPECTED THIS WEEK, WITH HIGHS
MAINLY IN THE 70S AND LOWS MAINLY IN THE 50S.
UPDATE
ISSUED AT 946 PM CDT MON JUL 28 2025
CONVECTION CONTINUES TO TRACK EASTWARD THROUGH EASTERN MONTANA.
LEADING EDGE OF THE CONVECTION REMAINS WEST OF A LINE FROM GGW
TO MLS. UPDATED POPS BASED ON A BLEND OF 00Z SHORT TERM GUIDANCE
AND THIS BRINGS DYING CONVECTION INTO WESTERN ND IN THE 05-06Z
TIMEFRAME. A COUPLE OF THE CAMS HOLD ON TO THE CONVECTION AS IT
MOVES INTO SOUTHWEST ND, MOST DO NOT. WILL MAINTAIN THE SMALL
(LESS THAN 20%) CHANCE OF AN ISOLATED STRONG TO POSSIBLY SEVERE
THUNDERSTORM. POTENTIAL FOR PATCHY FOG REMAINS, BUT IS NOT
OVERLY BULLISH. GIVEN THE HIGH HUMIDITY AND IF CENTRAL ND CAN
MAINTAIN IT'S CLEAR TO PARTLY CLOUDY CONDITIONS, CAN'T RULE OUT
SOME PATCHY FOG. MORE MID-HIGH LEVEL CLOUDS IN THE WEST MAY
LIMIT FOG POTENTIAL. PREVIOUS SHIFT HAD ALREADY ADDED SOME
PATCHY FOG. NO CHANGES NEEDED AT THIS TIME.
UPDATE
ISSUED AT 609 PM CDT MON JUL 28 2025
THE THREAT FOR SEVERE STORMS HAS ALL BUT ENDED OVER THE
SOUTHERN JAMES RIVER VALLEY. THUS THE ONLY REMAINING THREAT FOR
TONIGHT WILL BE A LOW CHANCE (LESS THAN 20 PERCENT) IN THE FAR
WEST, AND MOSTLY AFTER MIDNIGHT. WE ADJUSTED POPS BASED ON
LATEST RADAR AND SHORT TERM GUIDANCE.
UPDATE
ISSUED AT 348 PM CDT MON JUL 28 2025
QUICK UPDATE TO CLEAN UP PRODUCTS AFTER THE CANCELLATION OF THE
SEVERE THUNDERSTORM WATCH. ALSO UPDATED POPS THROUGH THIS
EVENING. THE MORNING CONVECTION HAS REALLY PUT A DAMPER ON THE
POTENTIAL CONVECTION FOR THE REST OF THE AFTERNOON. SATELLITE
AND SURFACE OBSERVATIONS SHOW THAT ALTHOUGH IT HAS CLEARED OUT
ACROSS A GOOD PORTION OF THE SOUTHWEST AND SOUTH CENTRAL, A
STRONG NORTHEAST SURFACE FLOW BEHIND THE EXITING CONVECTION
INDICATES A RATHER STABLE BOUNDARY LAYER. THERE IS STILL ON THE
ORDER OF 1000-2000J/KG ALONG THE SD BORDER IN THE JAMES RIVER
VALLEY BUT ANY CONVECTION IN SD WILL LIKELY HAVE A HARD TIME
MAKING IT INTO ND. WILL HOWEVER KEEP A MENTION OF A SMALL CHANCE
FOR SEVERE IN THE SOUTHERN JRV THROUGH THE AFTERNOON OR POSSIBLY
INTO THE EARLY EVENING. CONVECTION IN MONTANA MAY APPROACH THE
ND BORDER LATE THIS EVENING OR OVERNIGHT, BUT AT THIS TIME THE
THREAT FOR SEVERE STORMS AT THIS TIME SHOULD BE MINIMAL.
DISCUSSION
ISSUED AT 241 PM CDT MON JUL 28 2025
THE SEVERE WEATHER THREAT CONTINUES TO DIMINISH ACROSS THE
SOUTH CENTRAL AND SOUTHWEST THIS AFTERNOON AS SUBSIDENCE MOVES
INTO THE REGION. THE SEVERE STORMS THAT MOVED THROUGH THE
REGION THIS MORNING HAVE WORKED OVER MUCH OF THE INSTABILITY
DIMINISHING THE AFTERNOON SEVERE WEATHER THREAT. HOWEVER,
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO PROGRESS EASTWARD
ACROSS THE SOUTHERN HALF OF THE STATE TODAY WITH SOME POSSIBLE
STORMS MOVING INTO THE WEST LATE TONIGHT FROM MONTANA. THESE
STORMS MAY STILL PRODUCE HAIL AND GUSTY WINDS. HIGH
TEMPERATURES TODAY ARE FORECAST TO WARM INTO THE UPPER 70S NORTH
TO THE LOWER 80S SOUTH. OVERNIGHT LOWS ARE FORECAST TO DROP
DOWN INTO THE 50S TO LOWER 60S AS A WEAK COLD FRONT PUSHES
THROUGH THE REGION.
TOMORROW THERE IS A CHANCE FOR ISOLATED SEVERE THUNDERSTORMS AS
THE CAMS ARE BRINGING IN SOME STRONG TO SEVERE THUNDERSTORMS
INTO THE NORTH CENTRAL BY TOMORROW AFTERNOON. THE MAIN THREAT
IS 60 MPH WINDS AND HALF DOLLAR SIZE HAIL. THE INSTABILITY
TOMORROW IS AROUND 500 TO 1000 J/KG OF SBCAPE AND AROUND 50 KTS
OF SHEAR. I WOULD NOT BE SURPRISED IF THE HAIL SIZE INCREASES.
TEMPERATURES WILL COOL A FEW DEGREES ACROSS THE STATE INTO THE
LOWER 70S TO LOWER 80S.
THE MIDDLE OF THIS WEEK A DEEP UPPER LEVEL TROUGH WILL STALL
AND DEEPEN OVER THE HUDSON BAY WHILE AN UPPER LEVEL RIDGE WILL
AMPLIFY OVER THE CANADIAN ROCKIES. THIS WILL PLACE NORTH DAKOTA
ON THE EQUATORWARD SIDE OF THE JET STREAM WITH WEAK UPPER LEVEL
FLOW. THIS WILL LEAD TO SLIGHTLY COOLER TEMPERATURES ACROSS THE
STATE. THE UPPER LEVEL RIDGE WILL BEGIN TO TREK EASTWARD
LEADING TO WARMING TEMPERATURES BY THE WEEKEND. THE CURRENT
MACHINE LEARNING PROGRAMS ARE NOT HIGHLIGHTING NORTH DAKOTA
LATER THIS WEEK FOR SEVERE WEATHER CHANCES. HOWEVER THIS COULD
CHANGE IF THE UPPER LOW DIGS FURTHER SOUTH OR THE RIDGE DAMPENS.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 609 PM CDT MON JUL 28 2025
VFR CONDITIONS ARE FORECAST THROUGH THE 00Z TAF PERIOD. SOME
GUIDANCE DOES INDICATE THE POTENTIAL FOR SOME PATCHY FOG LATE
TONIGHT INTO TUESDAY MORNING. AT THIS TIME WITH SHORT TERM
GUIDANCE NOT IN GREAT AGREEMENT AND NBM PROBABILITIES OF MVFR
CEILINGS 15 PERCENT OR LESS AT ALL TAF SITES, WILL HOLD OFF ON
INTRODUCING FOG AT THIS TIME. THERE COULD ALSO BE A BRIEF PERIOD
OF MVFR CEILINGS AS CUMULUS FIELD DEVELOPS TUESDAY MORNING.
VARIABLE WINDS THROUGH THE PERIOD WITH WIND SPEEDS AOB 12 KNOTS.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...TWH
DISCUSSION...JOHNSON
AVIATION...TWH
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