069
FXUS63 KBIS 012014
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
314 PM CDT TUE SEP 1 2026
KEY MESSAGES
- ISOLATED SHOWERS ARE POSSIBLE ACROSS THE SOUTH TONIGHT.
- LOW TO MEDIUM CHANCES FOR SHOWERS AND THUNDERSTORMS MAINLY
WEST AND NORTH CENTRAL WEDNESDAY EVENING THROUGH THURSDAY
MORNING. PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
BE POSSIBLE FRIDAY THROUGH SUNDAY.
- MEDIUM TO HIGH CHANCES FOR SHOWERS AND THUNDERSTORMS SUNDAY
NIGHT THROUGH THE EARLY PORTIONS OF NEXT WEEK.
- EXPECT A WARMING TREND THROUGH THE END OF THE WEEK, THEN
COOLING SOMEWHAT LATE THIS WEEKEND INTO EARLY NEXT WEEK.
DISCUSSION
ISSUED AT 1245 PM CDT TUE SEP 1 2026
WE ARE CURRENTLY SITUATED UNDER WEAK HIGH PRESSURE ALOFT AS WELL
AS AT THE SURFACE, BETWEEN OUR EXITING CYCLONE THAT BROUGHT US
THE WINDY CONDITIONS YESTERDAY AND ANOTHER UPPER LEVEL LOW OVER
THE EASTERN PACIFIC. A SHORTWAVE TO OUR SOUTH WILL SPARK SHOWERS
AND THUNDERSTORMS FROM SOUTH CENTRAL SD INTO SOUTHERN MINNESOTA
LATER THIS AFTERNOON THROUGH TONIGHT. THIS ACTIVITY IS FORECAST
TO REMAIN WELL SOUTH OF THE STATE. HOWEVER, ISOLATED TO
SCATTERED SHOWERS COULD SLIP INTO FAR SOUTHERN ND TONIGHT.
AS THE EASTERN PACIFIC UPPER LOW DROPS SOUTH ALONG THE BRITISH
COLUMBIA AND PACIFIC NORTHWEST COAST TONIGHT THROUGH WEDNESDAY,
THE UPPER LEVEL FLOW TRANSITIONS TO A SOUTHWEST FLOW AND WAVE
WILL EJECT NORTHEASTWARD THROUGH THE ROCKIES AND INTO OUR NECK
OF THE WOODS LATE WEDNESDAY. THIS WILL BRING OUR NEXT CHANCE OF
SHOWERS AND THUNDERSTORMS. THE MAIN WAVE IS FORECAST TO LIFT
THROUGH CENTRAL/EASTERN MONTANA INTO SOUTHERN SASKATCHEWAN, BUT
THERE SHOULD BE AN AXIS OF INSTABILITY FROM THE CENTRAL PLAINS,
INTO NORTHEAST MONTANA. MODERATE WARM ADVECTION AND A
STRENGTHENING LOW LEVEL JET, COMBINED WITH THE SHORTWAVE LIFTING
NORTHEAST THROUGH THE AREA, SHOULD PROVIDE THE FORCING TO
DEVELOP ISOLATED TO SCATTERED THUNDERSTORMS WEDNESDAY NIGHT INTO
THURSDAY. AT THIS TIME THE COVERAGE LOOKS TO BE PRETTY SPARSE
WITH BETTER CHANCES WEST CENTRAL INTO NORTHWEST AND NORTH
CENTRAL ND, BUT AS THE LLJ STRENGTHENS, ISOLATED TO SCATTERED
CONVECTION MAY SPREAD NORTH AND EAST ACROSS THE FORECAST AREA.
TIMING WISE, FOR THE MOST PART IT LOOKS TO BE A WEDNESDAY NIGHT
EVENT, SO WEDNESDAY CURRENTLY LOOKS TO BE MOSTLY DRY. IF THIS
TIMING HOLDS AND IT'S MAINLY AN EVENING AND OVERNIGHT EVENT WITH
A STRENGTHENING LLJ, THE MAIN HAZARD WOULD LIKELY BE QUARTER
SIZED HAIL. CONVECTION MAY LINGER INTO THURSDAY OVER EASTERN
PORTIONS OF THE FORECAST AREA. WITH INSTABILITY REMAINING STRONG
OVER EASTERN ND AND DEPENDING ON THE TIMING, THERE MAY BE
ANOTHER SHOT OF STRONG TO POSSIBLY SEVERE CONVECTION INTO
THURSDAY AFTERNOON. THINK THE BETTER INGREDIENTS WILL BE SETTING
UP TO THE EAST OF THE FORECAST AREA, BUT A STRONG TO SEVERE
THUNDERSTORM CAN'T BE RULED OUT FROM THE TURTLE MOUNTAINS INTO
THE JAMES RIVER VALLEY THURSDAY AFTERNOON.
FRIDAY AND THROUGH THE WEEKEND THE UPPER LEVEL LOW CONTINUES TO
SPIN OVER THE PACIFIC NORTHWEST, WHILE UPPER LEVEL RIDGING
BUILDS STRONGLY NORTHWARD THROUGH THE CENTRAL AND SOUTHERN
PLAINS AND WELL INTO THE NORTHERN PLAINS. THIS WILL ALLOW
TEMPERATURES TO REALLY WARM-UP ON FRIDAY WITH HIGHS IN THE MID
AND POSSIBLY EVEN UPPER 90S IN THE SOUTHWEST AND SOUTH CENTRAL.
WITH THE WARM TEMPERATURES AND
NBM ENSEMBLE TEMPERATURE SPREADS ARE PRETTY LOW THROUGH FRIDAY,
ESPECIALLY WEST, BUT INCREASE THEREAFTER, THUS CONFIDENCE IS
RATHER HIGH IN A STEADY WARMING TREND, ESPECIALLY WEST AND SOUTH
CENTRAL THROUGH FRIDAY, BUT CONFIDENCE IN TEMPERATURES LOWERS
THEREAFTER AS THERE IS A LOT OF UNCERTAINTY IN THE EVOLUTION OF
THE WESTERN U.S. TROUGH AND CENTRAL U.S. RIDGE PATTERN LATE IN
THE WEEKEND AND ESPECIALLY INTO EARLY NEXT WEEK. WITH THE
SOUTHWEST UPPER LEVEL FLOW, AT LEAST A PERIODIC CHANCE OF
SHOWERS AND THUNDERSTORMS SEEMS REASONABLE FRIDAY THROUGH SUNDAY.
THE WESTERN TROUGH DOES LOOK TO LIFT INTO THE CENTRAL U.S. BUT
THE TIMING IS HIGHLY UNCERTAIN AT THIS TIME. THERE MAY ALSO BE A
NORTHERN STREAM WAVE THAT MAY HELP FLATTEN THE CENTRAL U.S.
RIDGE AS WELL. THE NBM IS DEPICTING WIDESPREAD MODERATE
PRECIPITATION CHANCES SUNDAY NIGHT THROUGH MONDAY EVENING.
WHETHER THIS OCCURS OR NOT, WHEN THE WESTERN LOW EVENTUALLY DOES
BREAK DOWN THE UPPER RIDGE AND EJECTS INTO THE CENTRAL U.S. WE
SHOULD SEE A PERIOD OF SHOWERS AND THUNDERSTORMS WITH DECENT
CHANCES FOR SOME SOAKING RAINS. THE NBM IS CURRENTLY DEPICTING
ABOUT A 30% (SOUTH) TO 50% (NORTH) PROBABILITY OF AT LEAST A
HALF INCH OF RAIN IN THE 24 HOUR PERIOD ENDING AT 12Z TUESDAY.
AFTER TEMPERATURES TOP OUT ON FRIDAY, AND REMAIN WARM SATURDAY,
WE SHOULD DROP BACK DOWN TO NEAR NORMAL TEMPERATURES LATE IN THE
WEEKEND INTO EARLY NEXT WEEK.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1150 AM CDT TUE SEP 1 2026
VFR CONDITIONS ARE EXPECTED ACROSS THE FORECAST AREA, INCLUDING
ALL TAF SITES THROUGH THE 18Z TAF PERIOD. THE EXCEPTION COULD BE
AREAS OF LOW STRATUS/FOG IN THE SOUTHWEST WEDNESDAY MORNING.
HOWEVER, CONFIDENCE IS TOO LOW TO MENTION AT THE KDIK AIRPORT AT
THIS TIME. OTHERWISE MAINLY HIGH CLOUDS NORTH AND MID-LEVEL AND
HIGH CLOUDS SOUTH, THERE MAY BE A SPRINKLE OR SHOWER ALONG THE
SOUTH DAKOTA BORDER TONIGHT INTO EARLY WEDNESDAY MORNING.
NORTHWEST SURFACE FLOW OVER CENTRAL ND WILL DIMINISH AND SHIFT
SOUTHEAST LATER TODAY. SOUTHEAST SURFACE FLOW WILL CONTINUE
THROUGH THE FORECAST PERIOD OVER WESTERN ND. IT MAY BE BREEZY AT
TIMES THIS AFTERNOON SOUTHWEST.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...TWH
AVIATION...TWH
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