416
FXUS63 KBIS 150040
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
740 PM CDT FRI AUG 14 2026
KEY MESSAGES
- RAIN OVER WESTERN AND CENTRAL NORTH DAKOTA WILL CONTINUE TO
GRADUALLY MOVE TO THE EAST-NORTHEAST THIS EVENING INTO
TONIGHT.
- MAINLY DRY SATURDAY INTO EARLY SUNDAY, WITH RAIN CHANCES
RETURNING WEST TO EAST LATE SUNDAY. NEAR DAILY LOW TO MEDIUM
(20 TO 60 PERCENT) CHANCES FOR RAIN ARE THEN EXPECTED FOR THE
WORK WEEK.
- BELOW AVERAGE TEMPERATURES THIS WEEKEND, FOLLOWED BY A BRIEF
WARM UP ON MONDAY, THEN BELOW AVERAGE AGAIN THROUGH MID-
WEEK.
UPDATE
ISSUED AT 739 PM CDT FRI AUG 14 2026
AT 630 PM MDT, A BROKEN LINE OF LOW-TOPPED THUNDERSTORMS
EXTENDED FROM NEAR RICHARDTON TO HETTINGER. SPC MESOANALYSIS
SHOWS THESE STORMS TO BE IN AN ENVIRONMENT WITH 1000-1500 J/KG
CAPE AND 30 KTS OF EFFECTIVE BULK SHEAR. BUT THEY ARE ALSO NOW
MOVING INTO AN AREA OF INCREASED CIN, AND MID LEVEL LAPSE RATES
ARE MOSTLY ANCHORED TO THE MOIST ADIABATIC LAPSE RATE. IT
THEREFORE SEEMS UNLIKELY THAT THE INTENSITY OF CONVECTION WILL
INCREASE BEYOND WHAT HAS ALREADY BEEN OBSERVED. FORECAST
ADJUSTMENTS FOR THIS UPDATE WERE DRIVEN BY CURRENT OBSERVATIONS
AND TRENDS, BUT NO MAJOR CHANGES WERE MADE. SHOWERS AND
THUNDERSTORMS SHOULD DIMINISH FROM WEST TO EAST THROUGH TONIGHT.
DID ADD A PATCHY FOG MENTION TO WESTERN PARTS OF THE STATE
TONIGHT INTO SATURDAY MORNING. THIS WOULD MAINLY IMPACT HIGHER
TERRAIN AREAS WHERE CLOUDS COULD LOWER TO THE SURFACE.
DISCUSSION
ISSUED AT 218 PM CDT FRI AUG 14 2026
CURRENT SURFACE ANALYSIS PLACES INVERTED TROUGH OVER THE
WESTERN DAKOTAS, WITH HIGH OVER EASTERN MANITOBA INTO ONTARIO.
UPPER LEVEL ANALYSIS PLACES HIGH OVER THE SOUTHERN MISSISSIPPI
VALLEY WITH RIDGE THROUGH THE MIDWEST. TO THE WEST, TROUGH
NOTED OVER THE WEST COAST RESULTING IN SOUTHWEST FLOW OVER THE
NORTHERN PLAINS. OVER OUR AREA, BROAD AREA OF RAINFALL CONTINUES
OVER MUCH OF CENTRAL AND WESTERN NORTH DAKOTA.
FOR THE REST OF THIS AFTERNOON INTO THIS EVENING, BROAD AREA OF
RAIN PREVIOUSLY MENTIONED WILL CONTINUE TO GRADUALLY TRACK
TOWARDS THE EAST-NORTHEAST. TOWARDS THE BACKSIDE WHERE RAIN HAD
TAPERED OFF OVER SOUTHWEST NORTH DAKOTA, CAMS HAVE BEEN
CONSISTENTLY SHOWING SOME CONVECTION DEVELOPING, SOME OF WHICH
IS SHOWING UP ON RADAR OVER WESTERN SOUTH DAKOTA. OVER OUR
AREA, THIS IS RIGHT IN LINE WITH A NARROW INSTABILITY CORRIDOR
ADVERTISED ON THE RAP OF CAPE VALUES PUSHING AROUND 1500 J/KG.
SO, CANT RULE OUT A STRONGER CELL PRODUCING SOME SMALL HAIL OVER
THIS AREA, BUT BELIEVE THE SEVERE THREAT SHOULD REMAIN LIMITED.
AS WE GO THROUGH THE NIGHT PRECIPITATION WILL GRADUALLY EXIT
THE AREA. WITH THE LOW LEVEL MOISTURE IN PLACE THERE WAS SOME
CONCERN FOR FOG DEVELOPING OVER THE WEST, BUT BELIEVE THIS
SHOULD BE LIMITED BY THE EXPECTED NORTH-NORTHWESTERLY WINDS, BUT
DO EXPECT LOW CEILINGS TO DEVELOP AND POSSIBLY A FEW PATCHES OF
FOG PARTICULARLY IN HIGHER TERRAIN.
QUIETER WEATHER EXPECTED OVER THE AREA ON SATURDAY AS RIDGE
STARTS TO REBUILD OVER THE ROCKIES, THOUGH TEMPERATURES WILL
REMAIN ON THE COOLER SIDE OF AVERAGE. FLOW REMAINS
WEST/NORTHWESTERLY ON SUNDAY, BUT A WAVE MOVING THROUGH THE FLOW
MAY PRODUCE SOME SHOWERS/STORMS LATE SUNDAY INTO THE OVERNIGHT
HOURS.
TEMPERATURES WARM TO NEAR AVERAGE FOR MONDAY BEFORE A STRONG
SHORT WAVE AND AFFILIATED COLD FRONT PUSH INTO THE AREA, WHICH
WILL BRING COOLER TEMPERATURES AND MEDIUM CHANCES (ABOUT 40 TO
60 PERCENT) FOR PRECIPITATION ON TUESDAY. REMAINDER OF THE
WORK WEEK LOOKS TO REMAIN A BIT ACTIVE WITH OCCASIONAL LOW
CHANCES FOR PRECIPITATION.
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
ISSUED AT 739 PM CDT FRI AUG 14 2026
SHOWERS CONTINUE ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA TO START THE 00Z FORECAST PERIOD, WITH A FEW
THUNDERSTORMS MOVING FROM SOUTHWEST INTO SOUTH CENTRAL NORTH
DAKOTA. THE THUNDERSTORMS SHOULD MOVE EAST OF KDIK AFTER 01Z
AND MAY APPROACH KBIS LATER IN THE EVENING, BUT CONFIDENCE WAS
NOT HIGH ENOUGH TO INCLUDE A TS MENTION AT KBIS. DOWNPOURS WITH
THUNDERSTORMS COULD BRIEFLY REDUCE VISIBILITY AS LOW AS LIFR.
MEANWHILE, MVFR TO IFR VISIBILITY WILL BE MORE COMMONLY
ASSOCIATED WITH LIGHTER RAIN SHOWERS. RAIN SHOULD DIMINISH FROM
WEST TO EAST THROUGH TONIGHT.
LOW CEILINGS ARE FORECAST TO SPREAD ACROSS MUCH OF WESTERN AND
CENTRAL NORTH DAKOTA TONIGHT INTO SATURDAY MORNING, WITH LIFR
ALREADY OVER KXWA. CLOUDS SHOULD LIFT AND/OR SCATTER AROUND LATE
MORNING/EARLY AFTERNOON SATURDAY. THERE COULD ALSO BE SOME FOG
ACROSS PARTS OF WESTERN NORTH DAKOTA LATER TONIGHT INTO SATURDAY
MORNING. WINDS WILL BECOME NORTHWESTERLY AROUND 10-15 KTS ON
SATURDAY, WITH SOME HIGHER GUSTS IN THE AFTERNOON.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...HOLLAN
DISCUSSION...JJS
AVIATION...HOLLAN
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