589
FXUS63 KBIS 270544
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
1244 AM CDT WED MAY 27 2026
KEY MESSAGES
- HIGH TEMPERATURES IN THE 90S WILL CONTINUE THROUGH THE WEEK.
- LOW SHOWER/THUNDERSTORM CHANCES OVERNIGHT, OTHERWISE MAINLY
DRY CONDITIONS THROUGH FRIDAY.
- CRITICAL FIRE WEATHER CONDITIONS ACROSS FAR WESTERN NORTH
DAKOTA AGAIN WEDNESDAY, AND POSSIBLY THROUGH THE REST OF THE
WEEK.
UPDATE
ISSUED AT 1240 AM CDT WED MAY 27 2026
A WEAK THUNDERSTORM EARLIER MOVED OUT OF FOSTER COUNTY, BUT
ADDITIONAL ECHOS ARE NOW SHOWING UP ON RADAR OVER VARIOUS PARTS
OF SOUTH CENTRAL NORTH DAKOTA INTO THE JAMES RIVER VALLEY, WITH
A WEAK THUNDERSTORM NEAR THE LOGAN/LAMOURE COUNTY LINE.
THEREFORE, FOR LATE NIGHT UPDATE HAVE EXPANDED LOW SHOWER/STORM
CHANCES FATHER WEST.
UPDATE ISSUED AT 1005 PM CDT TUE MAY 26 2026
THUNDERSTORMS HAVE BEEN, SO FAR, RETICENT TO DEVELOP OVER
WESTERN AND CENTRAL NORTH DAKOTA SO FAR THIS EVENING. A HANDFUL
OF ATTEMPTS WERE MADE IN SOUTH CENTRAL NORTH DAKOTA AND INTO THE
NORTHERN JAMES RIVER VALLEY, THOUGH THESE HAVE BEEN QUICK TO
FALL APART WITH A DECENT CAP ALREADY FOUND OVER THIS AREA. CAMS
CONTINUE TO PUSH INITIATION LATER INTO THE EARLY OVERNIGHT
PERIOD, MAINLY WHEN THEY ADVERTISE INCREASED FORCING DUE TO FGEN
IN THE MID LEVELS. HOWEVER, BY THIS TIME, DIMINISHING CAPE AND
SHEAR IS ALSO ANTICIPATED ACROSS THE REGION. WILL HAVE TO
CONTINUE TO MONITOR DEVELOPMENT OVER THE NEXT FEW HOURS. WITH
THIS UPDATE, HAVE TWEAKED SKY AND POP GRIDS BASED OFF THE MOST
RECENT MODEL TRENDS.
UPDATE
ISSUED AT 630 PM CDT TUE MAY 26 2026
ISOLATED POCKETS OF CUMULUS CLOUDS HAVE DEVELOPED OVER PORTIONS
OF THE NORTHWEST AND CENTRAL NORTH DAKOTA OVER THE PAST FEW
HOURS. IN THE NORTHWEST, WHERE THIS CUMULUS WAS OVER RUN BY HIGH
BASED CLOUDS, A BRIEF POP-UP SHOWER AND AN ISOLATED RUMBLE OF
THUNDER DEVELOPED. WHILE THIS SHOWER HAS LONG SINCE DISSIPATED,
WE WILL CONTINUE TO MONITOR FOR ADDITIONAL DEVELOPMENT THROUGH
THIS EVENING. WITH THIS UPDATE, HAVE TWEAKED THE SKY COVER AND
POP GRIDS TO ACCOUNT FOR THE LATEST SATELLITE AND MODEL TRENDS.
DISCUSSION
ISSUED AT 225 PM CDT TUE MAY 26 2026
CURRENTLY A LARGE UPPER LOW PRESSURE SYSTEM SITS IN NORTHERN
CALIFORNIA, CREATING A LARGE RIDGE PATTERN ACROSS THE CENTRAL
AND NORTHERN PORTIONS OF THE CONUS. AT THE SURFACE A WEAK LOW
PRESSURE SITS IN EASTERN MONTANA, WITH A STATIONARY FRONT
ACROSS NORTH DAKOTA.
WITH TEMPERATURES WELL ABOVE NORMAL IN THE 90S TODAY, ALONG WITH
DIRECTIONAL SHEAR BETWEEN THE SURFACE AND UPPER ATMOSPHERE,
STORMS ARE POSSIBLE. MOST MODELS HAVE AROUND 1500 J/KG OF CAPE
WITH AROUND 15 TO 25 KNOTS OF SHEAR. THIS CAPE EXISTS IN AN
EAST/WEST CORRIDOR LAID ACROSS THE MIDDLE OF THE STATE. THE
CAPE DOES DECREASE AS THE SUN ANGLE GETS LOWER, HOWEVER MOST
CAMS DONT HAVE STORMS FIRING UNTIL CLOSE TO SUNSET WHEN THE LOW
LEVEL JET KICKS IN. THE MAJORITY OF THE STORMS LOOK TO BE EAST
OF JAMESTOWN INITIALLY, BEFORE ALSO DEVELOPING IN THE NORTHERN JAMES
RIVER VALLEY TONIGHT. SEVERE STORMS ARE POSSIBLE IN THE JAMES RIVER
VALLEY, PROBABLY ONLY ONE INCH HAIL FOR HAZARDS. SPC HAS OUR EAST IN
A LEVEL 1 OF 5 RISK.
THE REST OF THIS WEEK WILL BE MUCH OF THE SAME. VERY WARM HIGH
TEMPERATURES IN THE 90S, WITH BREEZY SOUTHERLY WINDS AS THE
RIDGE CONTINUES TO HOLD ACROSS THE REGION. THIS WILL IN TURN
CREATE THE ALL TOO WELL FAMILIAR CRITICAL FIRE WEATHER
CONDITIONS IN THE FAR WEST. ANOTHER RED FLAG WARNING WAS ISSUED
FOR THE SAME FAR WESTERN COUNTIES FOR WEDNESDAY. THIS COMING
WEEKEND LOOKS TO SEE A PATTERN SHIFT AS THE LOW PRESSURE IN
NORTHERN CALIFORNIA FINALLY MOVES EAST. THIS COULD CREATE DAILY
CHANCES FOR SHOWERS AND THUNDERSTORMS, ALONG WITH SLIGHTLY
COOLER TEMPERATURES BUT STILL ABOVE NORMAL.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 1240 AM CDT WED MAY 27 2026
ISOLATED THUNDERSTORMS WILL BE POSSIBLE OVERNIGHT OVER CENTRAL
NORTH DAKOTA INCLUDING THE JAMES RIVER VALLEY. OTHERWISE, VFR
CONDITIONS ARE EXPECTED. SOUTHEAST WINDS WILL BE ON THE INCREASE
TODAY, STRONGEST OVER WESTERN NORTH DAKOTA.
BIS WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING FROM 11 AM CDT /10 AM MDT/ THIS MORNING TO 10
PM CDT /9 PM MDT/ THIS EVENING FOR NDZ001-009-017-031-032-040-
043.
UPDATE...JJS
DISCUSSION...SMITH
AVIATION...JJS
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