361
FXUS63 KBIS 211951
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
251 PM CDT MON SEP 21 2026
KEY MESSAGES
- A GRADUAL WARMING TREND IS FORECAST THROUGH THE WEEK, WITH
HIGHS IN THE 60S TODAY INCREASING TO THE 70S AND LOWER 80S
BY THURSDAY AND FRIDAY.
- BEST CHANCE (60-90%) FOR SHOWERS AND THUNDERSTORMS WILL BE
LATE TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. OUTSIDE OF THIS
PERIOD WILL BE MAINLY DRY TILL LATE NEXT WEEKEND.
DISCUSSION
ISSUED AT 250 PM CDT MON SEP 21 2026
CURRENTLY, SLOW MOVING MID LEVEL LOW OVER THE UPPER MISSISSIPPI
VALLEY CONTINUES TO PUSH EAST, WITH WEAK UPPER LEVEL RIDGING
OVER THE ROCKIES AND SOUTH CENTRAL CANADA. LINGERING BOUNDARY
LAYER MOISTURE CONTINUES TO RESULT IN DIURNALLY DRIVEN CU OVER
SOME AREAS OF THE LOCAL REGION, WHICH HAS BEEN ON THE DECREASE
THE PAST FEW HOURS. COMFORTABLE TEMPERATURES IN THE 60S THIS
AFTERNOON WITH LIGHT WINDS.
WILL SEE INCREASING SOUTHERLY RETURN FLOW FOR TOMORROW AS A LEE
SIDE SFC LOW DEVELOPS ACROSS THE NORTHERN HIGH PLAINS IN
RESPONSE TO A DECENT MID LEVEL S/WV MOVING NORTHEAST OUT OF THE
DESERT SOUTHWEST INTO THE WYOMING ROCKIES. THE INCREASED
PRESSURE GRADIENT WILL SEE BREEZY SOUTH/SOUTHEASTERLY WINDS
DURING THE DAY TUESDAY, THOUGH LACK OF WAA RESULTS IN SIMILAR
TEMPERATURES AS TODAY (60'S).
THIS WAVE CONTINUES NORTHEAST AND MOVES OVER THE NORTHERN PLAINS
FROM LATE TUESDAY NIGHT BEFORE EXITING WEDNESDAY NIGHT. THIS
FEATURE BRINGS THE BEST CHANCES FOR PRECIPITATION THIS WEEK, AND
ALSO MAY RESULT IN A FEW THUNDERSTORMS.
S/WV RIDGING ON THURSDAY BRINGS THE BETTER WAA INTO THE REGION
FOR THE WEEK, WITH FORECAST HIGH TEMPERATURES CLOSER TO NORMAL
IF NOT ABOVE, WELL INTO THE 70S TO MID 80S. THEREAFTER, A
QUASI-SOUTHWESTERLY FLOW DEVELOPS SUPPORTING NEAR NORMAL HIGHS
AND LOWS, AND MAINLY DRY WEATHER. NBM AND ENSEMBLES THEN SUGGEST
ANOTHER INCREASE IN POPS LATER NEXT WEEKEND/EARLY NEXT WEEK,
WHEN THE BASE OF A WESTERN CONUS TROUGH IS PROJECTED TO MOVE
THROUGH.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1228 PM CDT MON SEP 21 2026
MAINLY VFR CONDITIONS EXPECTED THROUGH THE 18Z TAF PERIOD. AREAS
OF LOW VFR TO MVFR CEILINGS THIS AFTERNOON, LIFTING TO MAINLY
VFR THROUGH THE DAY. SOUTHERN AREAS OF ND MAY SEE LOW STRATUS
RETURN LATE TONIGHT IN THE 06-12Z TIMEFRAME, POSSIBLY EXPANDING
FARTHER TO THE NORTH AFTER 12Z. EAST TO SOUTHEAST SURFACE FLOW
5 TO 15 KTS THROUGH THE 18Z TAF PERIOD.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...NH
AVIATION...NH
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