037
FXUS63 KFGF 240919
AFDFGF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
419 AM CDT MON AUG 24 2026
KEY MESSAGES
- THERE IS A LEVEL 2 OUT OF 5 RISK FOR SEVERE THUNDERSTORMS THIS
AFTERNOON INTO THE OVERNIGHT. HAIL TO THE SIZE OF GOLF BALLS
AND WIND GUSTING TO 70 MPH WILL BE THE MAIN THREATS.
UPDATE
ISSUED AT 419 AM CDT MON AUG 24 2026
A LINE OF SLOW MOVING THUNDERSTORMS DEVELOPED WITHIN THE REGION
OF 925-850MB WAA AND A 25-30KT LOW LEVEL JET WHERE THERE WAS AN
AXIS OF ELEVATED MID LEVEL CONVERGENCE. A WEAKER FRONTAL
ZONE/OUTFLOW IS MOVING IN FROM THE WEST (NEAR MINOT) WITH THE
MAIN UPPER WAVE STILL WELL OVER TO THE NORTHWEST ALONG WITH
IT'S ASSOCIATED FRONT. THERE WAS TRAINING WITH HIGH RAIN RATES
WITHIN THIS LINE THAT MAY HAVE BEEN ENOUGH TO SUPPORT FLOODING
OF LOW LYING/POOR DRAINAGE AREAS WITHING PARTS OF NORTHWEST
BENSON COUNTY. THIS MORNINGS ACTIVITY IS ALREADY SHOWING SIGNS
OF WEAKENING AS IT MOVES OFF THE AXIS OF BETTER INSTABILITY TO
OUR WEST, AND AS THE LLJ IS CONTINUING TO WEAKEN. THIS TREND
SHOULD CONTINUE, THOUGH SOME REMNANT SHOWERS/WEAK THUNDERSTORMS
MAY CONTINUE TO MOVE EAST INTO THE NORTHERN RRV DURING THE
MORNING HOURS.
THE MAIN FOCUS FOR SEVERE CHANCES TODAY WILL CONTINUE TO BE THE
COLD FRONT EXPECTED TO ARRIVE THIS AFTERNOON AND PUSH EAST
THROUGH THE EVENING/OVERNIGHT HOURS AS THE MAIN MID/UPPER WAVES
PASSES TO THE NORTH. MORNING CONVECTIVE ACTIVITY/CLOUD COVER
COULD INITIALLY PLAY A COMPLICATING ROLE IN EARLIER INITIATION
AND IF THERE ISN'T ENOUGH CLEARING ACTIVITY MAY TEND TO BE MORE
ELEVATED (LOWERING THE CEILING ON SEVERE IMPACTS). CONSIDERING
THE ADVERTISED EFFECTIVE SHEAR WITH GENERALLY STRAIGHT
HODOGRAPHS ORIENTATED W-E WITH THE FRONTAL ZONE. THIS WOULD
SUPPORT THE POTENTIAL FOR SPLITTING SUPERCELLS AT LEAST EARLY
ON DURING THE EVENING (LATE AFTERNOON/EVENING) BEFORE ANY
ACTIVITY CLUSTERS UP AND POTENTIALLY TURNS INTO ONE OR SEVERAL
MCS'S. 0-3KM SHEAR DOES INCREASE TO 30KT BEHIND THE FRONT LATER
THIS EVENING AS A NW ORIENTATED LLJ DEVELOPS, BUT AHEAD OF AND
ALONG THE FRONT LOW LEVEL SHEAR IS WEAKER (25KT OR LESS), SO THE
WIND THREAT MAY REMAIN DEPENDENT ON RFD SURGES OR COLD POOL
DEVELOPMENT. THE MORE ELEVATED THE ACTIVITY BECOMES THOUGH THE
LESS LIKELY WIND WILL BE A FACTOR, AND THE MORE HAIL WOULD
BECOME THE MAIN THREAT.
THERE MAY BE JUST ENOUGH EFFECTIVE SRH NEAR THE
FRONTAL ZONE TO SUPPORT A LOW TORNADO RISK EARLY IN THE EVENING,
WITH RIGHT SPLIT SUPERCELLS (VERY SUBTLE RIGHT CURVATURE ON
SOME HODOGRAPHS), AND SOME AI SYSTEMS ARE HIGHLIGHTING THIS
RISK. JUST LIKE WITH THE WIND THREAT TODAY, ANY TORNADO RISK
WILL BE HIGHLY DEPENDENT ON THE NATURE OF THE STORMS AND IF
THEY REMAIN SURFACE BASED (HARD TO SAY AT THIS POINT).
UPDATE
ISSUED AT 1146 PM CDT SUN AUG 23 2026
NORTHERN END OF SOME CONVECTION HAS BEEN TRACKING THROUGH THE
DEVILS LAKE BASIN FOR THE LAST COUPLE OF HOURS, WITH THE MAIN
IMPACTS BEING SOME RAIN UP TO 4 TENTHS OF AN INCH SO FAR AND
SOME LIGHTNING. HEAVIER CELLS TRACKING SOUTHEASTWARD THROUGH
WELLS AND FOSTER COUNTIES, BUT ON A WEAKENING TREND AS THEY MOVE
INTO LESS UNSTABLE AIR. MOST OF THE CAMS HAVE THE COMPLEX
WEAKENING AS IT MOVES TOWARDS THE RED RIVER LATER TONIGHT,
ALTHOUGH A FEW MODELS BREAK OUT SOME STRONGER CONVECTION AGAIN
ON THE NORTHWEST SIDE. GIVEN CELL CURRENTLY TRACKING INTO
NORTHWESTERN ND FROM MT, WILL KEEP A CLOSE EYE ON THE ACTIVITY.
DISCUSSION
ISSUED AT 258 PM CDT SUN AUG 23 2026
..SYNOPSIS
NORTHWEST FLOW PREVAILS THIS AFTERNOON INTO THE EVENING, GRADUALLY
BECOMING ZONAL OVERNIGHT. SHOWERS AND ISOLATED THUNDERSTORMS COULD
WORK INTO PARTS OF EASTERN NORTH DAKOTA OVERNIGHT AS WARM AIR
ADVECTION INCREASES AHEAD OF AN APPROACHING SHORTWAVE. UPPER FLOW
THEN BECOMES SLIGHTLY SOUTHWEST LATE OVERNIGHT INTO MONDAY MORNING.
THIS WILL BE IN RESPONSE TO THE SHORTWAVE AND WEAK UPPER LOW MOVING
ACROSS SOUTHERN MANITOBA LATE MONDAY INTO TUESDAY. SHOWERS AND
THUNDERSTORMS ARE EXPECTED AS THE ASSOCIATED COLD FRONT SWEEPS
ACROSS THE NORTHERN PLAINS INTO THE UPPER MIDWEST, WITH A CHANCE FOR
ISOLATED SEVERE THUNDERSTORMS MONDAY AFTERNOON AND EVENING. WARM AIR
ADVECTION AHEAD OF THE FRONT WILL ALLOW AFTERNOON TEMPERATURES TO
CLIMB WELL INTO THE 80S ACROSS MOST OF THE AREA. SLIGHTLY COOLER
TEMPS RETURN ON TUESDAY AND WEDNESDAY. RAIN CHANCES LATE TUESDAY
THROUGH THURSDAY WILL BE MINIMAL, WITH POPS INCREASING ONCE MORE
LATE FRIDAY INTO THE WEEKEND.
..ISOLATED SEVERE THUNDERSTORMS LATE MONDAY
SEVERE THUNDERSTORM COVERAGE ON MONDAY AFTERNOON AND EVENING WILL
DEPEND HEAVILY ON THE TIMING OF AN APPROACHING COLD FRONT. WARM AIR
ADVECTION WILL BE STRONG THROUGH MUCH OF THE DAY ACROSS EASTERN
NORTH DAKOTA AND WEST CENTRAL MINNESOTA; HOWEVER, WITH REMNANT
SHOWER ACTIVITY ON MONDAY MORNING POTENTIALLY LINGERING, THIS COULD
SHORTEN THE WINDOW OF POTENTIAL SEVERE WEATHER LATE MONDAY. LOOKING
AT CAMS, THERE ARE SEVERAL POTENTIAL SCENARIOS, RANGING FROM
POTENTIAL SPLITTING SUPERCELLS, TO ELEVATED CLUSTERS. MODEL
SOUNDINGS ARE CONSISTENT WITH NEARLY STRAIGHT HODOGRAPHS AS THE
FRONT APPROACHES, WHICH CONTINUE TO SUPPORT SPLITTING SUPERCELLS AND
HYBRID CLUSTERS. AS SUCH, A HIGH END SCENARIO SUPPORTS SUPERCELLS
DEVELOPING WEST OF THE RED RIVER DURING THE LATE AFTERNOON, WITH
HAZARDS INCLUDING WIND GUSTS TO 75 MPH AND LARGE HAIL TO THE SIZE OF
GOLF BALLS. A MORE LIKELY SCENARIO WOULD BE THAT WE HAVE LINGERING
CONVECTIVE INHIBITION LATER INTO THE AFTERNOON, THUS DELAYING
CONVECTION UNTIL LATER IN THE EVENING. THIS WOULD STILL SUPPORT WIND
GUSTS UP TO 70 MPH, BUT WOULD TRANSITION INTO MAINLY AN ELEVATED
HAIL SCENARIO THAT EXTENDS INTO THE EARLY OVERNIGHT HOURS. WITH THIS
LATER SCENARIO, WE COULD SEE ISOLATED SEVERE THUNDERSTORMS LINGERING
INTO TUESDAY MORNING ACROSS PARTS OF NORTHWEST MINNESOTA.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 1146 PM CDT SUN AUG 23 2026
THE MAIN CHALLENGE THROUGHOUT THE TAF PERIOD WILL BE SHOWER AND
THUNDERSTORM ACTIVITY. SHOWERS AND THUNDERSTORMS HAVE MOVED INTO THE
DEVILS LAKE BASIN. THIS ACTIVITY WILL CONTINUE PUSHING EASTWARD
OVERNIGHT, IMPACTING KDVL, KGFK AND KTVF. INSTABILITY IS GREATEST
FURTHER WEST, THEREFORE MAINTAINED A PROB30 FOR -TSRA AT KDVL, WHILE
AT THE OTHER TWO TERMINALS MAINTAINED -SHRA. CLOUDS WILL THIN OUT AS
SHOWERS/STORMS DECREASE IN COVERAGE ON MONDAY MORNING. SOUTHERLY
WINDS OF 10 TO 14 KNOTS ACCOMPANIED BY A FEW GUSTS TO 20 KNOTS
WITHIN THE RED RIVER VALLEY WILL PREVAIL MONDAY AFTERNOON.
ADDITIONAL THUNDERSTORM DEVELOPMENT MAY OCCUR LATE MONDAY AFTERNOON
AND EVENING, PERSISTING INTO THE OVERNIGHT. AT THIS TIME, LOW
PREDICTABILITY IN WHERE STORMS FORM PRECLUDES ANY MENTION OF THEM
WITHIN THE LAST FEW HOURS OF THE TAF. ONCE TIMING AND LOCATION
INFORMATION BECOMES MORE CLEAR, FUTURE ITERATIONS OF THE TAF WILL
LIKELY NEED PROB30S OR TEMPOS FOR AT LEAST A HANDFUL OF TERMINALS.
FGF WATCHES/WARNINGS/ADVISORIES
ND...NONE.
MN...NONE.
UPDATE...JR/DJR
DISCUSSION...LYNCH
AVIATION...RAFFERTY
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