123
FXUS63 KFGF 031747
AFDFGF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
1247 PM CDT THU SEP 3 2026
KEY MESSAGES
- THERE IS A LEVEL 2 OUT OF 5 RISK FOR SEVERE STORMS TODAY.
- ADDITIONAL CHANCES FOR STRONG THUNDERSTORMS EXIST SATURDAY AND
SUNDAY.
UPDATE
ISSUED AT 1247 PM CDT THU SEP 3 2026
STORMS HAVE DEVELOPED OVER CENTRAL ND AND MOVED INTO THE DEVILS
LAKE BASIN, STARTING TO FORM A MORE LINEAR COMPLEX PRODUCING
WIND GUSTS UP TO 70 MPH. THIS COMPLEX IS EXPECTED TO FOLLOW
ALONG THE THETA-E GRADIENT NEAR THE HIGHWAY 2 CORRIDOR, AND WITH
PLENTY OF INSTABILITY AND DEEP LAYER SHEAR, WILL CONTINUE TO
PRODUCE SEVERE WINDS AND A SEVERE THUNDERSTORM WATCH HAS BEEN
ISSUED. WINDS AND HAIL LOOK TO BE THE MAIN THREAT, BUT CAN'T
COMPLETELY RULE OUT A BRIEF TORNADO SPIN UP IF THE STORMS BECOME
MORE ROOTED IN THE BOUNDARY LATER, PARTICULARLY ALONG THE WARM
FRONT ACROSS THE CENTRAL RED RIVER VALLEY INTO WEST CENTRAL MN.
WILL CONTINUE TO MONITOR.
UPDATE
ISSUED AT 557 AM CDT THU SEP 3 2026
MACHINE LEARNING CONVECTIVE OUTLOOKS AND NADOCAST ALL CONTINUE
TO PINPOINT THE MID RED RIVER VALLEY REGION AS AN AREA WHERE
TORNADOES WILL BE POSSIBLE LATER THIS AFTERNOON OR EARLY
EVENING. MUCH DEPENDS ON WHERE THE WEAK SURFACE LOW AND FRONT
IS LOCATED. AND THIS WILL DEPEND ON HOW FAR NORTH THE SURFACE
WARM FRONT REACHES, WHICH APPEARS TO BE AT LEAST TO I-94 IN ND,
MAYBE A BIT FARTHER NORTH. SOUTH WINDS SOUTH OF THIS FRONT WITH
MORE EAST-SOUTHEAST NORTH OF IT. UPPER WAVE MOVING NORTHEAST
WILL BE OVER THE NORTHERN AND CENTRAL RRV AT 00Z SO TIMING WISE,
IT WILL COME THROUGH AT PEAK HEATING. ONE THING THAT MAY OCCUR
TO REDUCE SEVERE CHANCES AND THIS IS IF MORNING STORMS INCREASE
IN COVERAGE AND CONTINUE THRU MIDDAY AND CLOUDS REDUCE SURFACE
HEATING. THOSE DETAILS ARE NOT YET KNOWN.
UPDATE
ISSUED AT 1005 PM CDT WED SEP 2 2026
LATEST 00Z HIGH RESOLUTION GUIDANCE STILL REVEALS MULTIPLE
POTENTIAL SCENARIOS REGARDING CONVECTION EVOLUTION TOMORROW.
WHILE CONFIDENCE HAS GROWN IN THERE BEING SEVERE STORMS WITHIN
OUR AREA TOMORROW, THE EVOLUTION OF WHICH AS WELL AS LOCATION
REMAIN IN QUESTION.
MOST IMPACTFUL SCENARIO INCLUDES SEVERE STORMS IN NORTHEAST ND
MID TO LATE AFTERNOON MIGRATING EAST AND SOUTHEAST, INCLUDING
DISCRETE TO SEMI-DISCRETE SUPERCELLS. THIS WOULD ALLOW ALL
HAZARDS TO BE POSSIBLE, WITH PERHAPS VERY LARGE HAIL POSSIBLE
(IN EXCESS OF 2 INCHES) ALONG WITH A TORNADO THREAT. SHOULD
STORMS EVOLVE INTO MORE OF A LINE OF STORMS, GUSTY WINDS TO 70
MPH AND HAIL NOT EXCEEDING 2 INCHES WOULD BE THE MAIN THREATS -
WITH SOME LOWERED CHANCE FOR LINE-EMBEDDED TORNADOES.
THERE IS ALSO A POTENTIAL SCENARIO THAT INCLUDES EARLY MORNING
ISOLATED SEVERE STORMS NEAR THE TRI-STATE AREA INTO WEST-CENTRAL
MN - OF WHICH COULD BE ELEVATED SUPERCELLS CAPABLE OF LARGE
HAIL. DESPITE FORCING ALOFT BEING WEAK, THERE IS SOME PRESENT
(MAINLY VIA WEAK WARM AIR ADVECTION NEAR 700 MB). THIS IS THE
MAIN QUESTION - WHETHER OR NOT STRONG ENOUGH FORCING WILL BE
PRESENT TO SUSTAIN ROBUST CONVECTION IN AMID VERY FAVORABLE
HAIL-PRODUCING ENVIRONMENT COMPRISED OF MODERATE INSTABILITY
AND MODERATE TO STRONG SHEAR.
DISCUSSION
ISSUED AT 155 PM CDT WED SEP 2 2026
..SYNOPSIS
A FEW ISOLATED SPRINKLES NEAR THE SOUTH DAKOTA BORDER THIS
MORNING AS A WEAK EMBEDDED SHORTWAVE MOVED THOUGH, BUT FAIRLY
TRANQUIL NOW WITH SURFACE HIGH PRESSURE AND THE INSTABILITY
PUSHED SOUTH OF OUR AREA. INSTABILITY WILL RETURN TONIGHT INTO
TOMORROW AS SURFACE WINDS SHIFT TO THE EAST SOUTHEAST, AND A
LEAD SHORTWAVE COMING OUT FROM THE WESTERN PLAINS INTO MANITOBA
WILL PROVIDE THE FOCUS FOR SOME CONVECTION TOMORROW. BLOCKY
UPPER RIDGING WILL BUILD INTO THE REGION FOR FRIDAY AND CONTINUE
INTO THE WEEKEND, WITH SOME RIDGE RIDING SHORTWAVES COMING
THROUGH. THE FAIRLY ACTIVE PATTERN WILL CONTINUE INTO MONDAY AND
TUESDAY AS THE UPPER RIDGE SHIFTS SLIGHTLY EAST AND
SOUTHWESTERLY FLOW ALOFT SETS UP OVER OUR AREA. SOME OF THE
DETERMINISTIC SOLUTIONS TRY TO BREAK DOWN THE RIDGE JUST TO OUR
EAST AND SHIFT FLOW TO A MORE WEST TO NORTHWESTERLY DIRECTION,
WITH CLUSTER ANALYSIS SHOWING ABOUT 30 PERCENT OF MEMBERS
AGREEING WHILE THE MAJORITY OF THE ENSEMBLE KEEPS US IN RIDGING
OR SOUTHWESTERLY FLOW.
..SEVERE CHANCES THURSDAY
BOTH THE HIGH RESOLUTION AND SYNOPTIC MODELS ARE ALL OVER THE
PLACE AS TO HOW FAR NORTH THE HIGHEST INSTABILITY GETS TOMORROW
AND WHERE AND WHEN THEY BREAK OUT CONVECTION. A FEW LIKE THE NAM
KEEP MOST OF THE SURFACE BASED CAPE SOUTH OF THE SD BORDER,
WHILE THE GFS BRINGS A NARROW BAND OF INSTABILITY ALL THE WAY UP
TO HIGHWAY 200. MUCH WILL DEPEND ON WHAT HAPPENS TONIGHT, AS
SEVERAL OF THE CAMS BRING OUT SOME STORMS INTO THE SOUTHERN RED
RIVER VALLEY TOMORROW MORNING WITH A WEAK LEAD SHORTWAVE. SOME
OF THE CAMS INTENSIFY THE EARLY ACTIVITY FAIRLY QUICKLY
TOMORROW, WITH UPDRAFT HELICITY TRACKS STARTING TO SHOW UP
BEFORE 18Z, WHILE OTHER MODELS DON'T HAVE ANYTHING UNTIL THE
MAIN SHORTWAVE COMES OUT LATER IN THE AFTERNOON AND EVENING.
EVEN WITH THE MORNING CONVECTION, SEVERAL SOLUTIONS SHOW ENOUGH
RECOVERY TIME TO GET OVER 2000 J/KG ML CAPE AGAIN IN THE
AFTERNOON, AND WITH 40 KTS OF DEEP LAYER SHEAR, SEVERE WEATHER
IS POSSIBLE AND THE SLIGHT RISK HAS BEEN EXPANDED NORTHWARD.
STORM MODE IS ALSO NOT WELL RESOLVED, WITH SEVERAL CAMS SHOWING
LINEAR STORMS ALONG THE SURFACE BOUNDARY WHILE OTHERS LIKE THE
HRRR HAVE A MUCH MORE CURVED HODOGRAPH AND SUPERCELLS. AT THIS
POINT, ALL SEVERE IMPACTS ARE ON THE TABLE, AND WILL SEE HOW
THINGS DEVELOP DURING THE DAY TOMORROW.
..HEAT FRIDAY AND INTO THE WEEKEND
WITH RISING HEIGHTS AS THE UPPER RIDGE BUILDS FRIDAY AND INTO
THE WEEKEND, TEMPERATURES WILL BE WELL ABOVE AVERAGE INTO THE
WEEKEND. THE ECMWF EFI SHOWS A STRONG SIGNAL FOR WARM TEMPS,
PARTICULARLY IN THE SOUTHERN RED RIVER VALLEY. APPARENT TEMPS DO
NOT GET ABOVE ADVISORY CRITERIA UNLESS LOOKING AT THE MAX
PERCENTILE MEMBERS, BUT THE WET BULB GLOBE GETS INTO THE 80S AND
HEAT RISK IS UP INTO THE MAJOR CATEGORY FOR PORTIONS OF THE
SOUTHERN RED RIVER VALLEY AND WEST CENTRAL MN BOTH FRIDAY AND
SATURDAY. MAY NOT NEED HEADLINES ESPECIALLY THIS FAR IN ADVANCE,
BUT WILL CONTINUE TO MESSAGE SUMMER TEMPS HEADING INTO THE
WEEKEND.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1247 PM CDT THU SEP 3 2026
THUNDERSTORMS MOVING THROUGH THE KDVL AND KGFK AREAS, WITH THE
STRONGEST CONVECTION CURRENTLY BETWEEN THOSE TWO AIRPORTS. THESE
STORMS WILL CONTINUE TO PUSH EAST THROUGH THE AFTERNOON,
AFFECTING KTVF IN THE NEXT FEW HOURS. A LITTLE MORE UNCERTAINTY
AT KBJI AND KFAR, SO KEPT MENTION OF THUNDERSTORMS AS PROB30 FOR
NOW. MOST OF THE CONVECTIVE ACTIVITY SHOULD MOVE EAST OF OUR TAF
SITES BY LATE EVENING. MVFR TO IFR CEILINGS WILL MOVE IN BEHIND
THE CONVECTION, STARTING JUST BEFORE 06Z AT KDVL AND PUSHING EASTWARD
TO KGFK AND THE MN AIRPORTS LATER IN THE EARLY MORNING HOURS.
KEPT KFAR AT VFR FOR NOW, BUT WILL KEEP AN EYE ON HOW FAR SOUTH
THE STRATUS GOES. WINDS WILL BE ALL OVER THE PLACE DUE TO
THUNDERSTORMS, WITH MOSTLY EAST TO SOUTHEAST AT 10 TO 20 KTS
OUTSIDE OF THAT ACTIVITY. WINDS WILL EVENTUALLY BECOME MORE
NORTHEASTERLY OR LIGHT AND VARIABLE TOWARDS TOMORROW MORNING AS
THE SURFACE LOW MOVES THROUGH.
FGF WATCHES/WARNINGS/ADVISORIES
ND...NONE.
MN...NONE.
UPDATE...CJ/RIDDLE/JR
DISCUSSION...JR
AVIATION...JR
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