776
FXUS63 KBIS 301151
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
651 AM CDT THU JUL 30 2026
KEY MESSAGES
- MEDIUM TO HIGH CHANCES (40 TO 70 PERCENT) FOR SHOWERS AND
THUNDERSTORMS ACROSS THE SOUTHERN TWO THIRDS OF NORTH DAKOTA
TODAY. A FEW STORMS COULD BE SEVERE AND PRODUCE LOCALLY HEAVY
RAINFALL.
- COOLER BUT HUMID TODAY, THEN BECOMING VERY HOT AGAIN OVER THE
WEEKEND.
- HOT, DRY, AND WINDY CONDITIONS ON SUNDAY COULD RESULT IN AT
LEAST NEAR-CRITICAL FIRE WEATHER CONDITIONS ACROSS MUCH OF
THE WESTERN HALF OF THE STATE.
UPDATE
ISSUED AT 651 AM CDT THU JUL 30 2026
BETWEEN 5 AND 6 AM CDT, SHOWERS AND THUNDERSTORMS BLOSSOMED
OVER SOUTH CENTRAL NORTH DAKOTA. THE STRONGEST STORMS MAY BE
PRODUCING PEA SIZE HAIL, AND GUSTS UP TO 35 MPH HAVE BEEN
OBSERVED IN NORTHEAST BURLEIGH COUNTY. THE MOST RECENT SUITE OF
CAMS DID A POOR JOB IN PREDICTING THIS DEVELOPMENT, BUT CAN
RECALL A FEW EARLIER RUNS THAT DID HINT AT THIS POTENTIAL. SPC
MESOANALYSIS SUGGESTS THIS ACTIVITY IS TIED TO DEEP MOISTURE
AND 850 MB WIND CONVERGENCE. CONVECTION MAY CONTINUE AND SLOWLY
SPREAD NORTHEASTWARD THROUGH THE MORNING.
DISCUSSION
ISSUED AT 529 AM CDT THU JUL 30 2026
A SERIES OF SHORTWAVE TROUGHS IS LOCATED AT THE TOP OF A
CENTRAL CONUS RIDGE EARLY THIS MORNING. OCCASIONAL SHOWERS AND
THUNDERSTORMS HAVE BEEN OBSERVED IN NORTH DAKOTA OVERNIGHT,
MAINLY IN HETTINGER AND GRANT COUNTIES AND ALONG THE CANADIAN
BORDER. A DEEPER SHORTWAVE EJECTING OFF THE NORTHERN ROCKIES
EARLY THIS MORNING IS FORECAST TO TO REACH THE NORTHERN PLAINS
THIS AFTERNOON. THE BROAD SYNOPTIC SCALE LIFT IS EXPECTED TO
RESULT IN PERIODS OF SHOWERS AND THUNDERSTORMS THROUGHOUT THE
DAY, MAINLY ACROSS THE SOUTHERN TWO THIRDS OF THE STATE AND WITH
PROBABILITIES PEAKING IN THE AFTERNOON. BUT CAMS CONTINUE TO BE
HIGHLY INCONSISTENT WITH TIMING AND COVERAGE OF CONVECTION.
MORE RECENT MODEL INITIALIZATIONS (AFTER 00Z) HAVE TRENDED
TOWARD A MUCH DRIER OUTCOME UNTIL LATER THIS AFTERNOON, BUT THIS
DOESN'T SEEM TO FIT THE CONCEPTUAL MODEL OF MODEST DIFFERENTIAL
CYCLONIC VORTICITY ADVECTION THROUGH A DEEPLY MOIST AIR MASS.
IT DOES APPEAR THERE COULD BE FORCING ASSISTANCE FROM WEAK UPPER
LEVEL JET DYNAMICS LATER THIS AFTERNOON, WHICH MAY BE WHAT 06Z
AND LATER GUIDANCE IS HONING IN ON. WHETHER CONVECTION LATER
TODAY REMAINS ELEVATED OR BECOMES ROOTED IN THE NEAR-SURFACE OR
MIXED LAYER COULD BE STRONGLY DEPENDENT ON HOW CLOUD COVER
INFLUENCES DIURNAL HEATING. BUT EVEN IF THERE IS MORE SUNSHINE
THAN EXPECTED, UPDRAFTS MAY STILL NEED TO OVERCOME A CAPPING
LAYER ALOFT. CAPE IS FORECAST TO INCREASE INTO THE 1000-2000
J/KG RANGE THIS AFTERNOON, BUT COULD BE HIGHER IF THE RAP/NBM
ADVERTISED DEWPOINTS OF UPPER 60S TO MID 70S COME TO FRUITION.
SHEAR AT ALL LAYERS IS FORECAST TO REMAIN WEAK THOUGH, WITH
EFFECTIVE BULK SHEAR UNDER 30 KTS. THE WEAKER SHEAR WITH A LACK
OF A WELL-DEFINED SURFACE BOUNDARY GIVES HIGH CONFIDENCE IN A
CLUSTER STORM MODE WITH PULSE INTENSITY. A FEW STRONGER TO
MARGINALLY SEVERE STORMS CAN STILL NOT BE RULED OUT, BUT THE
THREAT CEILING SHOULD REMAIN CLOSER TO BASELINE SEVERE HAZARDS
OF QUARTER SIZE HAIL AND WIND GUSTS NEAR 60 MPH. IT DOES APPEAR
THERE MAY BE A CONDITIONAL THREAT FOR NON-SUPERCELL TORNADOES,
ESPECIALLY IF THE BOUNDARY LAYER IS ABLE TO BECOME UNSTABLE. THE
CONDITIONAL ASPECT OF THIS THREAT IS THAT IT WOULD LIKELY
REQUIRE OUTFLOW BOUNDARY COLLISIONS TO GENERATE THE REQUISITE
SURFACE VORTICITY NEEDED FOR LANDSPOUTS. THIS POTENTIAL WILL NOT
BE MESSAGED IN ANY OF OUR OTHER PRODUCTS, BUT IS SOMETHING TO
KEEP IN MIND HEADING INTO THE AFTERNOON. FINALLY, THERE IS STILL
A RISK FOR LOCALLY EXCESSIVE RAINFALL FROM STORMS TODAY, WITH
ANOMALOUSLY HIGH PRECIPITABLE WATER, HIGH DEEP-LAYER RH, AND THE
POTENTIAL FOR BOTH TRAINING CONVECTION AND SLOW STORM MOTIONS.
HREF GUIDANCE WOULD INDICATE THAT A MAXIMUM RAIN AMOUNT OF 2 TO
4 INCHES IS A REASONABLE HIGH-END OUTCOME, BUT THE SPATIAL
COVERAGE OF EVEN JUST +1" IS LIKELY TO BE VERY LIMITED.
THE SHORTWAVE RESPONSIBLE FOR TODAY'S CONVECTION IS FORECAST TO
DIG INTO THE UPPER MISSISSIPPI RIVER VALLEY ON FRIDAY. A
TRAILING, MUCH LOWER-AMPLITUDE SHORTWAVE COULD BRING A FEW
SHOWERS OR THUNDERSTORMS TO WESTERN PARTS OF THE STATE
THROUGHOUT THE DAY FRIDAY, SHIFTING INTO NORTHERN NORTH DAKOTA
FRIDAY NIGHT WHEN A LOW LEVEL JET COULD INCREASE COVERAGE.
HIGHER CIN AND LOWER CAPE SHOULD PREVENT SEVERE STORMS ON
FRIDAY, BUT IF A STORM CAN BECOME ROOTED IN THE NEAR- SURFACE
LAYER IT WOULD HAVE ACCESS TO AS MUCH AS 40 KTS OF EFFECTIVE
BULK SHEAR. FORECAST UNCERTAINTY PAIRED WITH CAM REFLECTIVITY
OUTPUT PRECLUDES MESSAGING OF STRONGER CONVECTION AT THIS TIME.
TODAY WILL BE MUCH COOLER THAN YESTERDAY, AND LIKELY THE
COOLEST DAY OF THE WEEK FOR MOST WITH FORECAST HIGHS GENERALLY
IN THE 80S. THERE CONTINUES TO BE HIGH CONFIDENCE IN THE
UPSTREAM UPPER LEVEL RIDGE RE-AMPLIFYING AND TILTING BACK OVER
THE NORTHERN PLAINS THROUGH THE WEEKEND. MOST LOCATIONS SOUTH OF
HIGHWAY 2 AND WEST OF HIGHWAY 83 ARE LIKELY TO SEE AT LEAST ONE
DAY THIS WEEKEND WITH A HIGH TEMPERATURE OF AT LEAST 100
DEGREES. THE TRIPLE-DIGIT HEAT SHOULD REMAIN CONFINED TO WESTERN
PARTS OF THE STATE ON SATURDAY, WITH SPATIAL EXTENT LESS
CERTAIN ON SUNDAY BECAUSE OF THE TIMING OF A COLD FRONT. AREAS
WHERE THE FRONT PASSES THROUGH PRIOR TO PEAK HEATING (MOST
LIKELY FAR NORTHWEST NORTH DAKOTA) COULD SEE HIGHS CLOSER TO 90
ON SUNDAY. BUT AREAS ALONG AND AHEAD OF THE COLD SUNDAY
AFTERNOON (MOST LIKELY SOUTHWEST/CENTRAL NORTH DAKOTA) COULD
EASILY REACH OR EVEN EXCEED 105 DEGREES WITH THE ASSISTANCE OF
COMPRESSIONAL HEATING. NOT ONLY COULD HEAT BE AN IMPACT THIS
WEEKEND, BUT STRONGER WINDS ON SUNDAY COULD COMBINE WITH THE HOT
TEMPERATURES AND RH AS LOW AS 10-15 PERCENT TO PRODUCE AT LEAST
NEAR- CRITICAL FIRE WEATHER CONDITIONS.
THERE IS A LOW CHANCE THAT SHOWERS AND THUNDERSTORMS COULD
DEVELOP ALONG THE COLD FRONT AS IT MOVES INTO CENTRAL AND
EASTERN NORTH DAKOTA LATER IN THE DAY SUNDAY INTO SUNDAY NIGHT,
BUT STRONGER FORCING ALOFT FROM A POTENT SHORTWAVE/UPPER LOW IS
PROJECTED TO LAG BEHIND IN SASKATCHEWAN. A SECONDARY SURGE OF
NOTABLY COOLER AIR SHOULD BEGIN PUSHING INTO THE REGION ON
MONDAY AS A SEPARATE SHORTWAVE SWINGS FROM THE PACIFIC NORTHWEST
TOWARD THE NORTHERN PLAINS. FORECAST HIGH TEMPERATURES FALL
INTO THE MID 70S NORTHWEST TO MID AND UPPER 80S SOUTH ON MONDAY
(WHICH COULD BE ANOTHER WINDY DAY WITH FIRE WEATHER CONCERNS IN
THE SOUTHWEST), THEN TO AROUND 75 TO 80 DEGREES FOR ALL OF
WESTERN AND CENTRAL NORTH DAKOTA ON TUESDAY. ENSEMBLE SPREAD IN
SYNOPTIC SCALE FEATURES GROWS MID TO LATE NEXT WEEK. SOME
CLUSTERS FAVOR THE WESTERN CONUS RIDGE REBUILDING AND SHIFTING
BACK EASTWARD, WHILE OTHERS TRANSITION TO MORE OF A ZONAL FLOW
PATTERN OVER THE NORTHERN PLAINS.
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 651 AM CDT THU JUL 30 2026
ON AND OFF PERIODS OF SHOWERS AND THUNDERSTORMS ARE LIKELY
ACROSS THE SOUTHERN HALF OF THE STATE THROUGH THIS EVENING. THE
HIGHEST PROBABILITIES ARE ACROSS SOUTHERN NORTH DAKOTA THIS
AFTERNOON AND EARLY EVENING, BUT STORMS HAVE ALREADY DEVELOPED
NEAR KBIS TO START THE FORECAST PERIOD. MVFR TO IFR VISIBILITY
AND GUSTY WINDS CAN BE EXPECTED WITH HEAVIER SHOWERS AND STORMS.
VFR CONDITIONS ARE OTHERWISE LIKELY TO PREVAIL, EXCEPT FOR SOME
BRIEF PATCHY FOG/LOW CEILINGS IN THE NORTHWEST EARLY THIS
MORNING. VARIABLE WIND DIRECTION THIS MORNING, BECOMING
PREDOMINANTLY NORTHEASTERLY BY THIS EVENING, WITH SPEEDS AROUND
10 KTS OR LESS THROUGH THE FORECAST PERIOD (OUTSIDE OF SHOWERS
AND STORMS).
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...HOLLAN
DISCUSSION...HOLLAN
AVIATION...HOLLAN
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