883
FXUS63 KBIS 231928
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
228 PM CDT WED SEP 23 2026
KEY MESSAGES
- SHOWERS WILL PUSH ACROSS THE STATE THROUGH TONIGHT, WITH
ISOLATED TO SCATTERED THUNDERSTORMS EVENING. A FEW STORMS MAY
BECOME STRONG TO SEVERE WEST AND SOUTH OF THE MISSOURI RIVER.
- PATCHY TO AREAS OF FOG MAY RETURN LATER TONIGHT INTO THURSDAY
MORNING.
- HIGHS MOSTLY IN THE 60S AND 70S AND LOWS AROUND 40 TO 55
THROUGH EARLY NEXT WEEK. BREEZY CONDITIONS EXPECTED TODAY,
FRIDAY, AND SATURDAY.
- MEDIUM TO HIGH CHANCES FOR RAIN IN CENTRAL AND EASTERN NORTH
DAKOTA FRIDAY AFTERNOON THROUGH FRIDAY NIGHT, THEN STATEWIDE
EARLY NEXT WEEK.
DISCUSSION
ISSUED AT 228 PM CDT WED SEP 23 2026
UPPER LEVEL WAVE WILL CONTINUE TO PUSH EASTWARD ACROSS THE AREA
THIS EVENING. THIS WILL LIFT THE ONGOING RAIN NORTH AND EAST.
BEHIND THIS WAVE WILL BE A TRAILING SURFACE LOW THAT COULD BRING
A SECOND ROUND OF SHOWERS AND PERHAPS A FEW STRONG TO SEVERE
THUNDERSTORMS. MODEST CAPE AT THE SURFACE AND MIX LAYER MAY
BRIEFLY BECOME UNCAPPED LATER THIS AFTERNOON THROUGH THE EARLY
EVENING. SHEAR ALSO LOOKS TO BE MODEST, WITH THE HIGHER SHEAR
PUSHING EAST FOLLOWING THE UPPER LEVEL WAVE. IN ADDITION,
LINGERING LOW CLOUDS COULD ALSO LIMIT HEATING THIS AFTERNOON,
AND THE TOTAL AMOUNTS OF INSTABILITY. THUS SEVERE STORMS REMAIN
QUITE CONDITIONAL THROUGH THIS EVENING. IF A STRONGER STORM CAN
DEVELOP, NEARLY STRAIGHT HODOGRAPHS WOULD INDICATE HAIL BEING
THE MAIN THREAT. GIVEN THE LIMITED INSTABILITY, HAIL SIZE WOULD
LIKELY BE AROUND AN INCH IN DIAMETER TODAY. WINDS TO 60 MPH ARE
ALSO POSSIBLE, ALTHOUGH DCAPE LOOKS TO BE LOW. THE TORNADO
THREAT IS ALSO LOW TODAY, DESPITE SOME INCREASED SRH. IF
STRONGER SURFACE HEATING CAN BE FOUND TODAY, THEN PERHAPS A
NON-SUPERCELL TORNADO IS POSSIBLE YET STILL PRETTY LOW CHANCE.
FOR THE MOST PART SHOWERS AND THUNDERSTORMS WILL PUSH EAST AND
OUT OF THE CWA OVERNIGHT TONIGHT. LIGHT WINDS AND LINGERING LOW
LEVEL MOISTURE COULD THEN BRING SOME FOG TONIGHT INTO THURSDAY
MORNING. LOOK FOR LOWS IN THE UPPER 40S TO MID 50S. THE REST OF
THURSDAY THEN SEES CLEARING SKIES UNDER A RIDGE OF HIGH
PRESSURE. THIS WILL ALSO PROVIDE FOR LIGHT WINDS AND SOME
WARMING TEMPERATURES, WITH HIGHS IN THE 70S. DRY CONDITIONS LOOK
TO CONTINUE THURSDAY NIGHT, WITH SIMILAR LOWS IN THE UPPER 40S
TO MID 50S. A SWITCH TO SOUTHERLY FLOW OVERNIGHT COULD AGAIN
PROVIDE SOME INCREASED MOISTURE, AND PERHAPS SOME PATCHY TO
AREAS OF FOG. A DEVELOPING SURFACE LOW TO THE WEST WILL BRING A
BREEZY SOUTHERLY FLOW ON FRIDAY, AND MAINTAINING TEMPERATURES
NEAR NORMAL. AS THE UPPER LEVEL RIDGE MOVES EASTWARD SOUTHWEST
FLOW LOOKS TO TAKE OVER ALOFT, WHICH COULD BRING SOME CHANCES
FOR SHOWERS, MAINLY SOUTH, CENTRAL, AND EAST. LIMITED
INSTABILITY SHOULD LIMIT THE THUNDERSTORM THREAT.
THIS WEEKEND, SOUTHWEST FLOW ALOFT LOOKS TO REMAIN ACROSS THE
AREA, ALTHOUGH THE BROADER TROUGH CAUSING THIS LOOKS TO LIFT
MORE INTO WESTERN CANADA. THUS TEMPERATURES LOOK TO BE NEAR 70
DEGREES EACH DAY, WITH LOWS IN THE MID 40S TO MID 50S. CHANCES
FOR PRECIPITATION LOOKS TO BE LIMITED THROUGH THE MAJORITY OF
THE WEEKEND. SATURDAY COULD SEE A WEAK COLD FRONT MOVE THROUGH.
THIS MAY PROVIDE SOME LOW CHANCES FOR SHOWERS AND THUNDERSTORMS IN
THE NORTH AND EAST. THIS FRONT COULD ALSO TURN A BREEZY
SOUTHERLY WIND INTO A BREEZY WESTERLY WIND. ZONAL FLOW ALOFT
BECOMING SOUTHWESTERLY COULD BRING MAINLY DRY CONDITIONS DURING
THE DAY SUNDAY, ALTHOUGH INCREASING MOISTURE WILL BRING
INCREASED CLOUD COVER THROUGH THE DAY.
THE MAIN FEATURE OF INTEREST HEADING INTO EARLY NEXT WEEK
REMAINS A DEEP BUT PROGRESSIVE TROUGH MOVING FROM THE PACIFIC
COAST LATE SUNDAY INTO THE PLAINS BY MID WEEK. ENSEMBLES REMAIN
SIMILAR TO THE PREVIOUS SHIFT, AND ARE IN GOOD AGREEMENT ON THE
EXISTENCE OF THE TROUGH, BUT UNCERTAINTY IN TIMING AND
PLACEMENT OF ITS STRONGEST ENERGY IS EVIDENT. CLUSTER ANALYSIS
REVEALS TWO DISTINCT AND NEARLY- EQUAL OUTCOMES IN THE EVOLUTION
OF THE TROUGH: ONE KEEPS THE BASE OF THE TROUGH OVER THE DESERT
SOUTHWEST FOR A LONGER PERIOD OF TIME, ALLOWING A NORTHERN
STREAM WAVE TO DEEPEN; THE OTHER IS MORE PROGRESSIVE AND KEEPS
THE BASE OF THE TROUGH MORE NORTH WITH SOME SPLIT FLOW LIKE
FEATURES. THEN THERE ARE SUBSETS WITHIN EACH OF THOSE OUTCOMES
THAT INCLUDE A SOUTHERN CUTOFF LOW IN THE FORMER (VERY LOW
PROBABILITY) AND SPLIT FLOW IN THE LATTER (NEARLY EQUAL
PROBABILITY AS NO SPLIT FLOW). REGARDLESS OF THESE DIFFERENCES,
ALL ENSEMBLE CLUSTERS SHOW THE HIGHEST PROBABILITIES FOR RAIN IN
SOUTHEAST NORTH DAKOTA EARLY NEXT WEEK, AND THE LOWEST TO THE
NORTHWEST. NBM POPS BEGIN TO INCREASE SUNDAY EVENING AND ARE
HIGHEST DURING THE DAY MONDAY WHEN SOME GUIDANCE, INCLUDING CSU
MACHINE LEARNING, INDICATES A CONDITIONAL RISK FOR STRONG TO
SEVERE THUNDERSTORMS IN A LOW CAPE/HIGH SHEAR ENVIRONMENT. THE
ARRIVAL AND PASSAGE OF THE DEEPER TROUGH SHOULD TREND
TEMPERATURES COOLER EARLY NEXT WEEK, BUT STILL REMAINING NEAR
AVERAGE AS AVERAGE VALUES THEMSELVES (HIGHS IN THE 60S AND LOWS
AROUND 40 BY THE END OF THE MONTH) ARE BEGINNING TO COOL MORE
STEADILY.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1234 PM CDT WED SEP 23 2026
PERIODS OF MVFR TO IFR CONDITIONS WILL BE FOUND THROUGHOUT THE
FORECAST PERIOD. SHOWERS WILL CONTINUE TO PUSH EASTWARD ACROSS
THE STATE THIS AFTERNOON, BRINGING SOME MVFR TO IFR CEILINGS.
BEHIND THESE SHOWERS COULD SEE SOME VFR CONDITIONS, ALTHOUGH LOW
CLOUDS HAVE LINGERED SO FAR LEAVING MVFR TO IFR CEILINGS. LATER
THIS AFTERNOON THROUGH THIS EVENING, LOW CEILINGS LOOK TO
CONTINUE ALONG WITH CHANCES FOR ANOTHER ROUND OF SHOWERS AND
PERHAPS SOME THUNDERSTORMS. TONIGHT INTO THURSDAY MORNING, LOW
CLOUDS AND PATCHY TO AREAS OF FOG REMAIN POSSIBLE BRINING IFR TO
PERHAPS LIFR CONDITIONS. CONFIDENCE IN FOG STILL REMAINS
SOMEWHAT LOW, ALTHOUGH DID ADD IN SOME LOWER CEILINGS AND BR TO
MOST TAF SITES. CONDITIONS SHOULD GRADUALLY IMPROVE LATER
THURSDAY MORNING. BREEZY SOUTHERLY WINDS TODAY WILL BECOME LIGHT
AND VARIABLE TONIGHT INTO THURSDAY.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...ANGLIN/MH
AVIATION...ANGLIN
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