203
FXUS63 KBIS 040608
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
108 AM CDT SAT JUL 4 2026
KEY MESSAGES
- ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MOVE WEST TO
EAST OVERNIGHT. THERE REMAINS A MARGINAL SEVERE RISK.
- LOW SHOWER AND THUNDERSTORM CHANCES (10-20 PERCENT MAINLY
CENTRAL AND EAST) DURING THE DAY ON INDEPENDENCE DAY. ACTIVE
WEATHER CONTINUES THROUGH EARLY NEXT WEEK.
- HIGH TEMPERATURES CLIMB INTO THE UPPER 80S TO MID 90S ON
SUNDAY.
UPDATE
ISSUED AT 1258 AM CDT SAT JUL 4 2026
TWO AREAS OF SHOWERS AND THUNDERSTORMS REMAIN OVER OUR AREA,
WITH THE FIRST ONE OVER THE FAR NORTHWEST AND THE OTHER OVER THE
FAR SOUTHWEST. THE SOUTHERN ONES HAVE BEEN REMAINING TAME, AND
THE NORTHERN ONES HAVE WEAKENED OVER THE PAST HALF HOUR. STILL,
WOULD NOT BE SURPRISED TO SEE ONE QUICKLY PULSE UP AND DOWN
GIVEN ONGOING INSTABILITY, ESPECIALLY OVER THE NORTH.
UPDATE
ISSUED AT 906 PM CDT FRI JUL 3 2026
WE CONTINUE TO MONITOR A LINEAR COMPLEX OF STRONG TO SEVERE
THUNDERSTORMS APPROACHING FROM EASTERN MONTANA, WITH ADDITIONAL
CONVECTION NOW DIVING SOUTHEASTWARD FROM SOUTHERN SASKATCHEWAN.
LATEST SPC MESOANALYSIS SHOWS AROUND 2000-3000 J/KG CAPE IN
NORTHWEST NORTH DAKOTA WITH LITTLE TO NO SURFACE-BASED OR MIXED
LAYER INHIBITION. CIN SHOULD BEGIN AN INCREASING TREND VERY SOON
WITH DIMINISHING SOLAR INSOLATION AND INCREASED ANVIL SHADING,
BUT SURFACE DEWPOINTS THERE HAVE RISEN TO AROUND 65-70 F, AND
SURFACE WIND VECTORS ARE GENERALLY POINTED TOWARD THE
APPROACHING STORMS. DEEP LAYER AND EFFECTIVE BULK SHEAR REMAIN
ON THE WEAKER SIDE AT AROUND 20-25 KTS, AND 0-3 KM SHEAR IS
ANALYZED TO BE EVEN LOWER. BUT DCAPE ACROSS THE WESTERN TIER OF
COUNTIES IS STILL AROUND 1100-1200 J/KG. OUR EXPECTATION IS THAT
THESE STORMS WILL CROSS INTO NORTH DAKOTA AROUND 10-11 PM CDT
AT A SLIGHTLY LOWER INTENSITY THAN WHAT IS CURRENTLY BEING
OBSERVED. MAXIMUM WIND GUSTS IN THE 40-50 MPH COULD BE COMMON,
WITH ISOLATED INSTANCES OF 50 TO 60 MPH IN THE NORTHWEST. RECENT
CAMS CONTINUE TO INDICATE THAT THE CONVECTION HAS BETTER
CHANCES OF PERSISTING AND REMAINING STRONGER IN THE NORTHWEST
COMPARED TO THE SOUTHWEST, AND MESOANALYSIS TRENDS SUPPORT THIS
OUTCOME.
UPDATE
ISSUED AT 712 PM CDT FRI JUL 3 2026
DURING THE MID TO LATE AFTERNOON HOURS, THUNDERSTORMS INITIATED
ALONG AN OUTFLOW BOUNDARY PROGRESSING EASTWARD THROUGH SOUTH
CENTRAL NORTH DAKOTA, INCLUDING A BRIEF SEVERE STORM OVER FORT
YATES. THE INTENSITY OF THUNDERSTORMS HAS DRAMATICALLY DECREASED
OVER THE LAST HOUR OR SO, AND THE LIGHTNING OBSERVATION NETWORK
SHOWS NO THUNDERSTORMS AT THE TIME OF THIS WRITING. SCATTERED
SHOWERS CONTINUE TO PERCOLATE OVER SOUTH CENTRAL NORTH DAKOTA
EARLY THIS EVENING, BUT IT IS CLEAR THAT OUTFLOW FROM THE MID TO
LATE AFTERNOON CONVECTION HAS STABILIZED THE BOUNDARY LAYER.
ATTENTION NOW TURNS TO UPSTREAM CONVECTION IN NORTHEAST
MONTANA. EMBEDDED CELLS WITHIN A BROADER NORTH-SOUTH LINEAR
COMPLEX HAVE BEEN SEVERE AT TIMES AND PRODUCED LOCALLY EXCESSIVE
RAINFALL. BY THE TIME THESE STORMS REACH THE ND/MT AROUND 10-11
PM CDT, THE BOUNDARY LAYER SHOULD BE DECOUPLING, AND THE STORMS
SHOULD BE ENTERING A WEAKER DEEP LAYER SHEAR ENVIRONMENT.
CURRENT ANALYSIS OF DCAPE REMAINS ABOVE 1000 J/KG IN NORTHWEST
NORTH DAKOTA THOUGH, SO WOULD NOT BE SURPRISED TO SEE SOME
HIGHER WIND GUSTS (AROUND 50 TO 60 MPH) WITH THIS CONVECTION.
CAMS THAT ARE ASSIMILATING THIS CONVECTION MODEL IT TO BE
DECAYING AS IT ENTERS FARTHER INTO WESTERN NORTH DAKOTA LATE
TONIGHT.
DISCUSSION
ISSUED AT 147 PM CDT FRI JUL 3 2026
SOUTHWEST FLOW ALOFT CONTINUES TODAY AS THE NORTHERN PLAINS SIT
UPSTREAM OF A BROAD UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST AND NORTHERN ROCKIES. THE SPEED OF THIS FLOW IN THE
MID TO UPPER LEVELS IS NOT PARTICULARLY STRONG WHICH IS BRINGING
SOME FORECAST CHALLENGES IN REGARDS TO THUNDERSTORM LOCATION,
TIMING, AND STRENGTH THROUGH TONIGHT. THE CONVECTIVE SETUP IS
CHARACTERIZED BY ADEQUATE LOW LEVEL MOISTURE WITH WIDESPREAD
SURFACE DEW POINTS IN THE UPPER 50S TO LOWER 60S. COMBINED WITH
MODEST MID-LEVEL LAPSE RATES, AN MLCAPE FIELD OF 1000-2000 J/KG
IS LIKELY, WITH THE MAJOR CAVEAT THAT IT WILL REQUIRE ADEQUATE
SURFACE HEATING. A BATCH OF THUNDERSTORMS MOVED INTO THE FAR
SOUTHWEST PORTIONS OF THE STATE EARLIER THIS MORNING WHILE A
BROAD STRATUS DECK REMAINS EARLY THIS AFTERNOON ACROSS THE NORTH
CENTRAL PORTIONS. THIS UNCERTAINTY IN INSTABILITY TODAY HAS
BROUGHT STRONG INCONSISTENCY BETWEEN SHORT TERM MODELS AND MODEL
RUNS TODAY. IF CONVECTION DOES FORM THIS AFTERNOON/EVENING
UNDER POCKETS OF STRONGER SURFACE HEATING, A MARGINAL SEVERE
WEATHER THREAT WITH THE POSSIBILITY OF 60 MPH WINDS AND QUARTER
SIZE HAIL SHOULD MATERIALIZE. THE WEAK FLOW ALOFT KEEPS SHEAR ON
THE LOWER END BUT NOT INADEQUATE FOR SEVERE WEATHER. AGAIN THIS
SEVERE POSSIBILITY REMAINS HIGHLY CONDITIONAL WITH UNCERTAINTY
IN CONVECTIVE DEVELOPMENT THIS AFTERNOON/EVENING. THERE REMAINS
A REAL POSSIBILITY THAT THE INTRODUCTION OF ADDITIONAL
THUNDERSTORMS MAY HOLD OFF UNTIL ACTIVITY MOVES IN FROM MONTANA
LATE THIS EVENING.
ON SATURDAY FLOW ALOFT BECOMES MORE WESTERLY BEFORE RIDGING
STARTS TO SET IN. THIS WILL TREND THUNDERSTORM CHANCES DOWNWARD,
ESPECIALLY IN WESTERN PORTIONS OF THE STATE WHERE DRY AIR WILL
MOVE IN. LINGERING MOISTURE AND CYCLONIC FLOW IN THE CENTRAL TO
EAST WILL COME WITH A LOW BUT NON-ZERO CHANCE OF AN AFTERNOON OR
EVENING THUNDERSTORM.
THE AFOREMENTIONED RIDGING TREND WILL BRING HOTTER TEMPERATURES
ON SUNDAY WITH FORECAST HIGHS IN THE UPPER 80S TO MID 90S. THIS
RIDGE WILL BE FLATTENED SUNDAY AFTERNOON AND NIGHT BY A CROSSING
SHORTWAVE TO THE NORTH, BRINGING THE POTENTIAL FOR SHOWERS AND
THUNDERSTORMS ALONG AN ASSOCIATED LOW LEVEL FRONT. WITH THE
CURRENTLY MODELED MOISTURE AND SHEAR FIELDS AS WELL AS 00Z
MACHINE LEARNING GUIDANCE, A SEVERE THUNDERSTORM THREAT MAY
ARISE, ESPECIALLY IN NORTHERN AREAS OF THE STATE.
THE COMING WEEK WILL CONTINUE TO SEE ACTIVE FLOW WITH PERIODS OF
THUNDERSTORM ACTIVITY, WITH SOME SHIFTING IN MODEL TO MODEL
RUNS IN REGARDS TO LOCATION AND TIMING.
AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
ISSUED AT 1258 AM CDT SAT JUL 4 2026
AMPLE LOW LEVEL MOISTURE OVER THE AREA WILL BRING AREAS OF MVFR
TO LOCALIZED IFR CEILINGS EARLY THIS MORNING TO PARTS OF CENTRAL
AND NORTHWEST NORTH DAKOTA. THERE ALSO WILL BE SOME PATCHY FOG
REDUCING VISIBILITY. CONDITIONS IMPROVE TO VFR THROUGH THE
MORNING INTO SATURDAY AFTERNOON.
SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE
OVERNIGHT, WITH A BREAK BY LATE SATURDAY MORNING. THEN ISOLATED
SHOWERS AND THUNDERSTORMS WILL AGAIN BE POSSIBLE SATURDAY
AFTERNOON OVER CENTRAL AND PARTS OF WESTERN NORTH DAKOTA.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...JJS
DISCUSSION...EDWARDS
AVIATION...HOLLAN
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