890
FXUS63 KBIS 201947
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
247 PM CDT MON APR 20 2026
KEY MESSAGES
- HIGHS TODAY WARM TO ABOVE NORMAL, WITH HIGHS IN THE MID 60S
TO MID 70S.
- TEMPERATURES WILL CONTINUE TO AVERAGE WELL ABOVE NORMAL BOTH
TUESDAY AND WEDNESDAY, ALONG WITH MAINLY DRY WEATHER
CONDITIONS.
- ACTIVE WEATHER PATTERN IS FAVORED WEDNESDAY NIGHT THROUGH THE
END OF THE WEEK, WITH MEDIUM TO HIGH PRECIPITATION CHANCES
ALONG WITH A STRONG COOLING TREND.
- STRONG NORTHWEST WINDS ARE POSSIBLE THURSDAY AND FRIDAY.
DISCUSSION
ISSUED AT 247 PM CDT MON APR 20 2026
THIS AFTERNOON, THE SYNOPTIC PATTERN WAS CHARACTERIZED BY
TROUGHING OVER THE EASTERN CONUS, WITH A STRONGER CLOSED LOW AND
ATTENDANT TROUGHING OFF THE COAST OF CALIFORNIA. FLOW OVER THE
NORTHERN PLAINS WAS WEAKLY CYCLONIC, WITH A WEAK FRONTAL
BOUNDARY MOVING THROUGH NORTH DAKOTA, EXTENDING FROM A SURFACE
LOW WELL TO OUR NORTHEAST IN MANITOBA. BEHIND THE BOUNDARY,
WINDS WERE TURNING MORE NORTHWESTERLY, WITH A FEW HIGH CLOUDS
PASSING THROUGH BUT LOTS OF SUNSHINE AND HIGHS IN THE UPPER 60S
NORTH TO LOWER 80S SOUTHWEST THIS AFTERNOON. NEAR CRITICAL FIRE
WEATHER CONDITIONS ARE EXPECTED IN BOTH THE SOUTHWEST AND THE
SOUTHERN JAMES RIVER VALLEY THIS AFTERNOON, OTHERWISE NO BIG
WEATHER CONCERNS IN THE NEAR TERM.
QUIET AND WARM WEATHER CONTINUES ON TUESDAY, WITH HIGHS SIMILAR
TO TODAY, AND BREEZY SOUTHERLY WINDS. WE START TO SEE MORE
CHANGES MIDWEEK AS THE AFOREMENTIONED CLOSED LOW MOVES ONSHORE
AND AMPLIFIES HEIGHTS OVER THE REGION ON WEDNESDAY, WITH
TEMPERATURES PEAKING THIS DAY IN THE MID 70S NORTH CENTRAL TO
AROUND 90 SOUTHWEST. AS THE TROUGH BASE MOVES OVER THE NORTHERN
ROCKIES, SURFACE LOW PRESSURE WILL BEGIN DEEPENING IN CENTRAL
MONTANA, WITH STRONG SOUTHERLY LOW-LEVEL FLOW OUT AHEAD OF THE
SYSTEM. WEDNESDAY WILL BE QUITE WINDY AND WARM ACROSS THE
FORECAST AREA, WITH SOME QUESTION ON HOW HIGH DEW POINTS END UP
DUE TO MOISTURE ADVECTION. GENERALLY LOOKS LIKE 500-1000 J/KG OF
INSTABILITY AVAILABLE PER DETERMINISTIC GUIDANCE, WITH VERY
MARGINAL SHEAR BUT FALLING HEIGHTS TO SUPPORT SHOWERS AND
THUNDERSTORMS WEDNESDAY EVENING AS THE LARGER SYSTEM APPROACHES
THE AREA. ALTHOUGH WE ARE NOT CURRENTLY OUTLOOKED BY SPC IN
ANYTHING BEYOND GENERAL THUNDER, WORTH NOTHING THAT BOTH NSSL
AND CSU MACHINE LEARNING GUIDANCE HAS LOW PROBABILITIES FOR
SEVERE WEATHER FOCUSED ACROSS CENTRAL AND EASTERN NORTH DAKOTA.
AS THE LOW BECOMES STACKED ON THURSDAY, PRECIPITATION CHANCES
INCREASE AND BECOME WIDESPREAD, WITH THE HIGHEST CHANCES OF RAIN
AROUND 80 PERCENT IN WESTERN NORTH DAKOTA. THERE COULD BE SOME
ISOLATED THUNDERSTORMS DURING THE DAY THURSDAY AS WELL, BUT THAT
WINDOW ENDS QUICKLY AS TEMPERATURES FALL THROUGH THE DAY ON THE
BACKSIDE OF THE SYSTEM. WITH COOLER AIR SURGING IN,
PRECIPITATION IS FAVORED TO TRANSITION FROM RAIN TO SNOW
THURSDAY NIGHT, WITH LOW TO MEDIUM POPS CONTINUING THROUGH
FRIDAY AS THE UPPER LOW ABSORBS ANOTHER LOBE MOVING SOUTH FROM
THE CANADIAN PRAIRIES. ALTHOUGH SNOW ACCUMULATIONS WILL BE
HIGHLY DEPENDENT ON HOW THE LOW TRACKS AND WHEN PROFILES TURN
COLD ENOUGH FOR SNOW, LATEST NBM 5.0 DATA HAS A MEDIUM TO HIGH
CHANCE FOR MEASURABLE SNOW ACROSS WESTERN AND NORTHERN NORTH
DAKOTA, WITH A 20 TO 40 PERCENT CHANCE FOR AT LEAST 4 INCHES OF
SNOW ACROSS THE FAR NORTHWEST.
THE OTHER CONCERN WITH THIS SYSTEM IS WINDS, ESPECIALLY WITH THE
LOW PROJECTED TO BECOME STACKED. BACKGROUND SYNOPTIC WINDS WITH
THESE SYSTEMS GET TO BE QUITE STRONG, WITH THE CURRENT
EXPECTATION FOR WIDESPREAD ADVISORY CRITERIA, IF NOT APPROACHING
WARNING CRITERIA. ECMWF EFI CONTINUES TO ADVERTISE THE WIND
POTENTIAL, ALTHOUGH PERHAPS NOT AS STRONG AS ONE WOULD THINK
BASED ON THE GENERAL PATTERN. CURRENT FORECAST LOOKS STRONGEST
ON THURSDAY, ALTHOUGH STILL STRONG ON FRIDAY AND BREEZY ON
SATURDAY.
THE OTHER DISCUSSION POINT WITH THIS SYSTEM IS TEMPERATURES.
QUITE A GRADIENT ON THURSDAY AS THE ATTENDANT FRONT MOVES
THROUGH, WITH HIGHS IN THE LOWER 50S WEST TO LOWER 70S EAST, AND
MANY LOCATIONS SEEING THEIR HIGH TEMPERATURES EARLY IN THE DAY.
THERE IS THEN HIGH CONFIDENCE IN WELL BELOW NORMAL TEMPERATURES
THROUGH THE WEEKEND, GENERALLY FROM THE 30S NORTH TO 40S SOUTH.
ALTHOUGH BLENDED POPS TAPER OFF ON SATURDAY, WOULD NOT BE
SURPRISED TO SEE WRAP-AROUND LIGHT PRECIPITATION (EITHER RAIN
OR SNOW) LINGER THROUGH SATURDAY AND POTENTIALLY INTO SUNDAY.
ENSEMBLE GUIDANCE SEEMS FAIRLY SET ON THE LOW VERY SLOWLY
LIFTING NORTH THROUGH THE WEEKEND, WHICH WILL KEEP US UNDER ITS
INFLUENCE FOR LONGER. THERE ARE ALSO SIGNS OF ANOTHER SYSTEM
TRACKING TO OUR SOUTH LATE IN THE WEEKEND, WITH BROADLY CYCLONIC
FLOW CONTINUING INTO NEXT WEEK. BELOW NORMAL TEMPERATURES ARE
FAVORED THROUGH THE END OF THE MONTH.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1249 PM CDT MON APR 20 2026
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. WINDS WILL SHIFT
FROM SOUTHWESTERLY TO NORTHWESTERLY THIS AFTERNOON AS A WEAK
FRONT MOVES THROUGH THE AREA, WITH LIGHT AND VARIABLE WINDS
OVERNIGHT TONIGHT. WINDS THEN BECOME MORE SOUTHERLY AND BREEZY
ON TUESDAY.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...JONES
AVIATION...JONES
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