046
FXUS63 KBIS 151145
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
645 AM CDT SAT AUG 15 2026
KEY MESSAGES
- MAINLY DRY TODAY THROUGH SUNDAY, ALTHOUGH LOW CHANCES (20-30%)
FOR THUNDERSTORMS RETURN TO THE SOUTHWEST SUNDAY AFTERNOON.
- LOW TO MEDIUM CHANCES (20-60%) FOR SHOWERS AND ISOLATED
THUNDERSTORMS SUNDAY NIGHT.
- NEAR DAILY LOW TO MEDIUM CHANCES (20-60%) CHANCES FOR RAIN
EXPECTED THROUGH THE WORK WEEK.
- BELOW AVERAGE TEMPERATURES THIS WEEKEND, FOLLOWED BY A BRIEF
WARM UP ON MONDAY. COOLER TUESDAY AN WEDNESDAY, THEN WARMING
LATER IN THE WEEK.
UPDATE
ISSUED AT 626 AM CDT SAT AUG 15 2026
SHOWERS HAVE EXITED THE FORECAST AREA TO THE EAST. WILL BEGIN
THE DAY WITH A DRY FORECAST. AS MENTIONED EARLIER WILL MAINTAIN
A DRY FORECAST THROUGH THE DAY, BUT A SPRINKLE OR BRIEF SHOWER
CAN NOT BE RULED OUT IN THE WEST. AREAS OF FOG REMAIN, MAINLY
IN THE NORTH AND THE SOUTHWEST. LOWEST VISIBILITIES GENERALLY
HOLDING IN THE 1-3SM RANGE SO NO SPS OR ADVISORY IS
ANTICIPATED AT THIS TIME. UPDATED POPS AND SKY COVER, OTHERWISE
NO CHANGES TO THE GOING FORECAST.
DISCUSSION
ISSUED AT 210 AM CDT SAT AUG 15 2026
SHOWERS CONTINUE TO TRACK EAST ACROSS CENTRAL ND EARLY THIS
MORNING. SURFACE LOW PRESSURE WAS SITUATED AROUND THE TURTLE
MOUNTAINS WITH A SOUTHERLY SURFACE FLOW INTO THE JAMES RIVER
VALLEY. BACK TO THE WEST, A NORTHERLY SURFACE FLOW WAS BRINGING
LOW STRATUS INTO WESTERN ND.
FOR TODAY, SHOWERS ARE EXPECTED TO EXIT THE TURTLE MOUNTAINS
AREA INTO THE JAMES RIVER VALLEY BY MID MORNING, IF NOT SOONER.
THE MAJORITY OF THE DAY IS EXPECTED TO BE RAIN FREE. HOWEVER A
SPRINKLE OR BRIEF SHOWER CAN NOT BE RULED OUT IN THE FAR WEST
THIS AFTERNOON. LOOK FOR HIGHS MOSTLY IN THE 70S TODAY WITH SOME
LOWER 80S POSSIBLE IN THE SOUTHERN JAMES RIVER VALLEY. EXPECT
CLOUDY SKIES THIS MORNING, WITH PATCHY FOG, ESPECIALLY NORTH.
SKIES ARE EXPECTED TO SLOWLY CLEAR FROM WEST TO EAST THIS
AFTERNOON. THE NORTH CENTRAL INTO THE NORTHERN JAMES RIVER
VALLEY MAY NOT SEE MUCH OF THE SUN UNTIL LATE AFTERNOON. IT WILL
ALSO BE BREEZY LATE THIS MORNING AND THIS AFTERNOON, ESPECIALLY
OVER CENTRAL ND WITH NORTHWEST WINDS OF 15 TO 20 MPH AND SOME
GUSTS TO AROUND 30 MPH.
SKIES WILL CLEAR TONIGHT AS HIGH PRESSURE BUILDS OVER THE STATE.
LOW TEMPERATURES SUNDAY MORNING WILL RANGE FROM THE MID 40S TO
MID 50S.
A NORTHWEST UPPER LEVEL FLOW BECOME ESTABLISHED ON SUNDAY. AS
SURFACE HIGH PRESSURE TRACKS EAST DURING THE DAY, WE SEE RETURN
FLOW INTO WESTERN ND SUNDAY AFTERNOON. THE ATMOSPHERE BECOMES
SLIGHTLY UNSTABLE IN THE SOUTHWEST SUNDAY AFTERNOON AND
SHORTWAVE ENERGY BEGINS TO IMPEDE UPON THE STATE AS IT WORKS ITS
WAY THROUGH A MEAN WESTERN UPPER RIDGE. BULK SHEAR IS INITIALLY
MODEST SUNDAY BUT INCREASES SUNDAY AFTERNOON TO 30 TO 40 KNOTS
OR SO, IT'S POSSIBLE WE COULD SEE AN AFTERNOON THUNDERSTORM IN
THE FAR SOUTHWEST SUNDAY WITH POSSIBLY SOME SMALL HAIL OR
LOCALLY GUSTY WINDS. CURRENTLY THE SPC HAS A MARGINAL RISK FOR
SEVERE STORMS (LEVEL 2 OUT OF 5) JUST TO THE SOUTH, IN WESTERN
SOUTH DAKOTA. THE CSU MACHINE LEARNING MODEL DOES BRING A LOW
RISK FOR SEVERE HAIL A BIT FARTHER NORTH, INTO SOUTHWEST ND.
LATER SUNDAY NIGHT ANOTHER SHORTWAVE TRACKS SOUTHEAST ACROSS THE
FORECAST AREA, BRINGING A CHANCE OF SHOWERS AND ISOLATED
THUNDERSTORMS TO THE AREA. SHEAR WILL REMAIN MODERATE TO STRONG
BUT INSTABILITY IS MODEST AT BEST. CURRENT THINKING IS THAT THE
THREAT FOR STRONGER STORMS WILL BE LOW.
WE SEE A BRIEF WARM-UP MONDAY, ESPECIALLY IN THE SOUTHWEST WHERE
HIGH COULD REACH THE MID 80S. A NORTHERN STREAM SHORTWAVE AND
ATTENDANT COLD FRONT, ROTATING AROUND A HUDSON BAY LOW WILL
BRING A COLD FRONT THROUGH THE AREA WITH A CHANCE OF SHOWERS
AND THUNDERSTORMS MONDAY INTO TUESDAY, WITH COOLER TEMPERATURES
TUESDAY AND WEDNESDAY. A NORTHWEST UPPER FLOW REMAINS OVER THE
AREA THROUGH THE REST OF THE WORK WEEK. AFTER WEDNESDAY, THE
HUDSON BAY LOW MOVES OFF TO THE EAST AND A WESTERN UPPER LEVEL
RIDGE BECOME BETTER ESTABLISHED JUST TO OUR WEST. THIS SHOULD
BRING A WARMING TREND AS WE GO THROUGH THE END OF THE WORK WEEK
AND INTO NEXT WEEKEND. WITH A NORTHWEST UPPER FLOW CONTINUING, A
LOW THREAT FOR SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE
FORECAST.
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 626 AM CDT SAT AUG 15 2026
LOW STRATUS, AND AREAS OF FOG ACROSS MUCH OF WESTERN AND NORTH
CENTRAL ND TO BEGIN THE 12Z TAF PERIOD. THERE ARE A FEW BREAKS
IN THE FAR SOUTH, BUT THESE MAY FILL IN YET THIS MORNING.
CURRENTLY IFR CEILINGS ALONG THE NORTHERN TAF SITES AND MVFR
CEILINGS ACROSS THE SOUTHERN TAF SITES. EXPECT THE MVFR TO IFR
CEILINGS TO CONTINUE THROUGH AT LEAST LATE MORNING SOUTH AND
EARLY AFTERNOON NORTH. CEILINGS DO LIFT/DISSIPATE FROM SOUTHWEST
TO NORTHEAST LATE THIS MORNING THROUGH THIS AFTERNOON. CURRENT
THINKING IS VFR CEILINGS BY 18Z AT KXWA AND KDIK, 19Z AT KBIS
AND 21Z AT KMOT AND KJMS. VFR CEILINGS CONTINUE TO DISSIPATE
WITH MOSTLY CLEAR SKIES BY THIS EVENING. THERE IS THE POTENTIAL
FOR SOME PATCHY FOG LATE IN THE FORECAST PERIOD UNDER CLEAR
SKIES AND LIGHT WINDS. DID NOT ADD ANY RESTRICTIONS TO
VISIBILITY AT THIS TIME BUT WILL CONTINUE TO MONITOR. NORTHWEST
SURFACE FLOW CONTINUES THROUGH THE DAY TODAY, GENERALLY 10-15
KTS WEST AND 15-25KTS CENTRAL.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...TWH
DISCUSSION...TWH
AVIATION...TWH
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