091
FXUS63 KBIS 200602
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
102 AM CDT MON APR 20 2026
KEY MESSAGES
- TEMPERATURES WILL AVERAGE ABOVE NORMAL MONDAY THROUGH
WEDNESDAY, ALONG WITH MAINLY DRY WEATHER CONDITIONS.
- ACTIVE WEATHER PATTERN IS THEN FAVORED WEDNESDAY NIGHT THROUGH
THE END OF THE WEEK, WITH MEDIUM TO HIGH PRECIPITATION
CHANCES ALONG WITH A COOLING TREND INTO NEXT WEEKEND.
UPDATE
ISSUED AT 1254 AM CDT MON APR 20 2026
TWEAKED SKY COVER A BIT, OTHERWISE THE INHERITED FORECAST
REMAINS ON TRACK.
UPDATE
ISSUED AT 957 PM CDT SUN APR 19 2026
DRY CONDITIONS REMAIN WITH WINDS STARTING TO BECOME SOUTHERLY.
HIGH CLOUDS ARE ALSO STARTING TO FILTER IN AND MAY LINGER
THROUGH THE NIGHT. OVERALL THE FORECAST REMAINS ON TRACK WITH
LITTLE UPDATES NEEDED LATE THIS EVENING.
UPDATE
ISSUED AT 700 PM CDT SUN APR 19 2026
LITTLE UPDATES NEEDED EARLY THIS EVENING AS SKIES REMAIN MAINLY
CLEAR. HUMIDITY VALUES ARE QUITE LOW IN SOME AREAS, ALTHOUGH
WINDS REMAIN LIGHT, LIMITING THE FIRE WEATHER THREAT THIS
EVENING. WINDS MAY INCREASE OUT OF THE SOUTH TONIGHT, WITH LOW
HUMIDITY RECOVERIES. OVERALL THE FORECAST REMAINS ON TRACK.
DISCUSSION
ISSUED AT 244 PM CDT SUN APR 19 2026
THIS AFTERNOON, THE NORTHERN PLAINS WERE PLACED BETWEEN A HUDSON
BAY LOW AND A SECONDARY LOW OFF THE COAST OF BRITISH COLUMBIA,
WITH UPPER RIDGING BEGINNING TO BUILD OVER THE NORTHERN ROCKIES
AND SUBSEQUENT DOWNSTREAM CYCLONIC FLOW OVER THE REGION. AT THE
SURFACE, BROAD HIGH PRESSURE WAS ANALYZED OVER EASTERN NORTH
DAKOTA, WITH SOME FAIR WEATHER CU AROUND THE CENTER OF THE LOW.
SUNSHINE INCREASES TO THE WEST, WITH A BIT OF A BREEZE
DEVELOPING THIS AFTERNOON FROM MIXING AND A TIGHTENING SURFACE
PRESSURE GRADIENT. SEASONABLY COOL TEMPERATURES CONTINUE, WITH
HIGHS IN THE 40S NORTH AND EAST TO THE UPPER 50S FAR WEST.
LOW LEVEL WARM AIR ADVECTION STRENGTHENS TONIGHT AND WE BEGIN TO
WARM UP IN EARNEST TO START THE WORK WEEK, WITH BREEZY TO
STRONG SOUTHWEST WINDS TONIGHT THROUGH MONDAY. MAIN WEATHER
CONCERN ON MONDAY IS NEAR CRITICAL FIRE WEATHER CONDITIONS IN
THE SOUTHERN JAMES RIVER VALLEY, WHERE THERE IS THE MOST
FAVORABLE OVERLAP OF THE STRONG SOUTHWEST WINDS AND MINIMUM
RELATIVE HUMIDITY FROM 25 TO 35 PERCENT. LOWER HUMIDITY EXISTS
IN THE SOUTHWEST, BUT LIGHTER WINDS WILL LIMIT FIRE WEATHER
CONCERNS IN THIS AREA. HIGHS ON MONDAY WILL BE IN THE MID 60S TO
MID 70S, WITH SOME PASSING CLOUDS FROM AN IMPULSE TO OUR
NORTHEAST.
TEMPERATURES WARM UP FURTHER ON TUESDAY AND WEDNESDAY, WITH
INCREASING SOUTHERLY LOW-LEVEL FLOW AS THE DEEP LOW MOVES
ONSHORE TO THE WESTERN CONUS. HIGHS PEAK ON WEDNESDAY IN THE
LOWER 70S NORTH TO MID 80S FAR SOUTH, ALTHOUGH THE DETERMINISTIC
NBM IS BELOW THE 25TH PERCENTILE, SO WOULDN'T BE SURPRISED IF
THE FORECAST HIGHS KEEP INCREASING IN FUTURE RUNS.
ENSEMBLE GUIDANCE IS IN GOOD AGREEMENT ON THE AFOREMENTIONED DEEP
TROUGH EJECTING OVER THE ROCKIES MIDWEEK, WITH PRECIPITATION CHANCES
QUICKLY INCREASING FOR THE BACK HALF OF THE WORK WEEK. WEDNESDAY
EVENING WILL BE THE MAIN WINDOW FOR THUNDERSTORMS, WITH
DETERMINISTIC GUIDANCE ADVERTISING SUFFICIENT INSTABILITY AND
SHEAR FOR POTENTIALLY A FEW STRONGER STORMS. CSU AND NSSL
MACHINE LEARNING GUIDANCE BOTH HIGHLIGHT A NORTH-SOUTH AXIS OF
INCREASED PROBABILITIES ACROSS SOUTH CENTRAL NORTH DAKOTA AND
THE JAMES RIVER VALLEY.
AS THE UPPER LOW CLOSES OFF AND TRACKS THROUGH THE DAKOTAS ON
THURSDAY, BLENDED POPS ARE ALREADY SHOWING WIDESPREAD 60 TO 80
PERCENT CHANCES FOR SHOWERS AND THUNDERSTORMS, WITH A MEDIUM CHANCE
FOR AT LEAST HALF AN INCH OF QPF ACROSS WESTERN AND NORTHERN NORTH
DAKOTA. TEMPERATURES WILL RANGE ACROSS THE AREA AS THE
ASSOCIATED COLD FRONT MOVES THROUGH THE STATE, WITH HIGHS
OCCURRING EARLY IN THE DAY IN THE NORTHWEST WHERE THE FRONT GETS
TO FIRST. FORECAST HIGHS ARE IN THE MID 40S NORTHWEST TO UPPER
60S SOUTHEAST.
WITH THE OVERALL SETUP AND THE STRENGTH OF THE LOW, IT IS NO
SURPRISE THAT THE ECMWF EFI IS ALREADY ADVERTISING POTENTIAL FOR
STRONG WINDS, WITH A SHIFT OF TAILS ACROSS THE MAJORITY OF NORTH
DAKOTA THURSDAY AND FRIDAY.
PRECIPITATION CHANCES LESSON LATE THURSDAY INTO FRIDAY, ALTHOUGH THE
GENERAL EXPECTATION IS FOR ANOTHER CLOSED LOW TO DROP SOUTH FROM THE
SOUTHERN CANADIAN PRAIRIES AND BE ABSORBED INTO THE BROADER TROUGH.
MUCH COLDER AIR IS EXPECTED BEHIND THE SYSTEM, WITH LOWS IN THE MID
20S TO LOWER 30S FRIDAY MORNING, AND HIGHS ON FRIDAY MAINLY IN THE
MID 30S TO MID 40S. EXPECT SIMILAR TEMPERATURES ON SATURDAY, AND
WITH LOW POPS CONTINUING THROUGH THIS PERIOD, SNOW BECOMES THE
DOMINANT P-TYPE. THE LIKELIHOOD OF MEASURABLE SNOW IS BROADLY
40 TO 60 PERCENT NORTH AND WEST WHERE TEMPERATURES STAY COLDER,
WITH A LOW CHANCE OF EXCEEDING AN INCH OF NEW ACCUMULATION.
WINDS STAY ELEVATED ON SATURDAY BUT DIMINISH FURTHER ON SUNDAY,
ALTHOUGH TEMPERATURES STILL LOOK SEASONABLY COOL IN THE 40S. BELOW
NORMAL TEMPERATURES ARE FAVORED THROUGH THE END OF THE MONTH.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 1254 AM CDT MON APR 20 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE 06Z FORECAST PERIOD.
SOME HIGH LEVEL CLOUDS WILL STREAM ALOFT AT TIMES, ALONG WITH
SKC CONDITIONS AS WELL. SOUTH-SOUTHEASTERLY WINDS AREA WIDE
THIS MORNING, GUSTY ACROSS EASTERN NORTH DAKOTA THROUGH THE DAY
AND BECOMING MORE SOUTHWESTERLY THERE IN THE AFTERNOON. WINDS
BECOME MORE WEST FOLLOWED BY NORTHWEST FROM WESTERN INTO
CENTRAL AREAS OF THE STATE THROUGH THE AFTERNOON BEHIND A
FRONTAL PASSAGE, NORTHWESTERLY ACROSS THE EAST IN THE EVENING.
LOW LEVEL WIND SHEAR IS POSSIBLE AT MOST CENTRAL AND EASTERN
SITES THROUGH MONDAY MORNING.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...NH
DISCUSSION...JONES
AVIATION...NH
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