259
FXUS63 KFGF 140439
AFDFGF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
1139 PM CDT SAT SEP 13 2025
KEY MESSAGES
- THERE IS A LEVEL 1 OUT OF 5 (MARGINAL) RISK FOR SEVERE
THUNDERSTORMS SUNDAY INTO MONDAY. THE MAIN HAZARDS WILL BE
QUARTER SIZE HAIL AND WIND GUSTS UP TO 70 MPH. A FEW TORNADOES
ARE ALSO POSSIBLE.
- WELL ABOVE AVERAGE TEMPERATURES CONTINUE INTO NEXT WEEK ALONG
WITH AN ACTIVE PATTERN. THIS INCLUDES CHANCES FOR STRONG TO
SEVERE THUNDERSTORMS.
UPDATE
ISSUED AT 950 PM CDT SAT SEP 13 2025
OTHER THAN SOME SLIGHT TWEAKS TO POPS THROUGH THE NEXT FEW HOURS
ONLY REAL CHANGE TO THE FORECAST HAS BEEN THE ADDITION OF SOME
PATCHY FOG IN THE GRIDS FROM 09Z TO 15Z FOR MUCH OF THE
SOUTHEAST QUARTER OF ND AND WEST CENTRAL MINNESOTA INTO WADENA
COUNTY. ITS POSSIBLE FOG COULD DEVELOP FURTHER NORTH INTO THE
BEMIDJI AREA BUT AS OF NOW LOOKS TO REMAIN SOUTH OF THERE.
UPDATE
ISSUED AT 632 PM CDT SAT SEP 13 2025
STILL HIGH UNCERTAINTY REGARDING EVOLUTION OF SUNDAY'S SEVERE
THREAT. SCATTERED SHOWERS CONTINUE IN THE MEANTIME ACROSS
EASTERN NORTH DAKOTA WITH THIS ACTIVITY WORKING NORTH OF THE
BORDER BY 9PM. POTENTIAL SEEMS TO BE ON THE RISE FOR FOG IN
CENTRAL MN TONIGHT BUT CONFIDENCE IS STILL TOO LOW ON
PLACEMENT.
DISCUSSION
ISSUED AT 124 PM CDT SAT SEP 13 2025
..SYNOPSIS
SURFACE ANALYSIS THIS AFTERNOON SHOWS A WEAK SURFACE LOW OVER
EASTERN SOUTH DAKOTA THAT HASN'T MOVED MUCH OVER THE LAST 6
HOURS. MOVEMENT LOOKS TO REMAIN VERY SLOW WITH LITTLE FORWARD
MOTION, THUS FORCING FOR ASCENT SHOULD REMAIN TO THE WEST OF THE
RED RIVER VALLEY MAINLY THROUGH TOMORROW MORNING. SHOWERS AND A
FEW THUNDERSTORMS WILL LINGER ACROSS SOUTHEAST NORTH DAKOTA AND
AREAS WEST OF THE RED RIVER VALLEY THROUGH THE REMAINDER OF
TODAY.
FORWARD PROPAGATION OF THE SURFACE LOW SHOULD INCREASE TOMORROW
AFTERNOON AS THE MAIN UPPER LOW UNDERGOES LEE CYCLOGENESIS AND
PROGRESSES NORTHWARD TOWARDS OUR AREA. AN ATTENDANT LOW AND MID-
LEVEL JET SHOULD PROVIDE SOLID MOISTURE ADVECTION AND SHEAR FOR
ORGANIZED SHOWERS AND THUNDERSTORMS SUNDAY AFTERNOON THROUGH
MONDAY MORNING, ALTHOUGH THE SPATIAL EXTENT OF THUNDERSTORMS IS
OF LOW CONFIDENCE.
AS THE LOW PROGRESSES AWAY FROM OUR REGION, MOISTURE ADVECTION
IS CUT OFF BUT FORCING FOR ASCENT SHOULD CONTINUE TO LINGER
THROUGH THE WEEK. PREDICTABILITY FOR SEVERE STORMS IS LOW, BUT
PERIODIC SHOWERS AND THUNDERSTORMS CAN CONTINUE TO BE EXPECTED
THROUGH THE WORK WEEK. THE STRONGEST SIGNALS FOR PRECIPITATION
ARE WEDNESDAY AND FRIDAY.
..SEVERE STORM POTENTIAL SUNDAY
A MOSTLY STATIONARY UPPER LOW SHOULD BEGIN TO EJECT OFF THE
ROCKY MOUNTAINS TOMORROW, FORCING CYCLOGENESIS AND AN
INTENSIFYING PRESSURE GRADIENT AT THE BASE OF THE LOW. AS THIS
OCCURS, FORWARD PROPAGATION FOR THE LOW WILL INCREASE AND PUSH
THE SURFACE LOW OVER SOUTH DAKOTA INTO OUR AREA BY EARLY
TOMORROW AFTERNOON. SURFACE THETA-E ADVECTION FROM THE SOUTHEAST
SHOULD PROVIDE FOR SOLID DESTABILIZATION NEAR THE SURFACE. THE
MAIN QUESTION RIGHT NOW IS IF ENOUGH DESTABILIZATION OCCURS FROM
BOTH ADVECTIVE AND DIURNAL HEATING. WEAK WARM AIR ADVECTION
WILL BE ONGOING ACROSS MUCH OF THE REGION IN ADVANCE OF THE LOW,
SO SKY CLEARING MAY BE DIFFICULT TO COME BY. ADVECTIVE
PROCESSES MAY BE ENOUGH TO INDUCE SURFACE-BASED THUNDERSTORM
DEVELOPMENT AS THE LOW PROGRESSES THROUGH THE AREA.
IF THUNDERSTORMS DO FORM, THE MAIN HAZARDS SHOULD BE SEVERE
HAIL AND DAMAGING WIND GUSTS. VERY LARGE HAIL PRODUCTION IS
UNLIKELY AS THE ORIENTATION OF THE UPPER LOW KEEPS THE ELEVATED
MIXED LAYER AWAY FROM OUR AREA, SO WE END UP WITH MUCH SKINNIER
CAPE PROFILES. CLUSTERING OF STORMS APPEARS TO BE THE LESS
LIKELY SOLUTION AS FORCING REMAINS MOSTLY TO THE WEST AND SHEAR
VECTORS ARE MOSTLY PERPENDICULAR TO THE BOUNDARY. IF STORMS
REMAIN ISOLATED, SUPERCELLS CAN BE A POSSIBILITY AS EFFECTIVE
LAYER SHEAR APPROACH 30 KNOTS WITH WEAK VEERING IN THE LOWEST 3
KM. DIRECTIONAL SHEAR COULD FACILITATE A TORNADO THREAT,
PARTICULARLY WHERE THE LOW-LEVEL JET ALIGNS WITH STORMS, WHICH
SHOULD HAVE THE MOST INTENSE VEERING. THIS WILL DEPEND ON TRACK
OF THE LOW AND IF STORMS CAN REMAIN ISOLATED.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 1139 PM CDT SAT SEP 13 2025
MVFR CIGS WILL PERSIST THROUGH THE NIGHT AT DVL WITH A GRADUAL
DROP TO IFR AND POTENTIALLY LIFR BY 12Z BEFORE RECOVERING TO
MVFR FOR THE AFTERNOON. BJI FOLLOWING A SIMILAR OVERNIGHT TREND
WITH IFR LIKELY AND LIFR POSSIBLE THOUGH CONFIDENCE HAS
INCREASED THAT CENTRAL MN WILL REMAIN SOUTH OF BJI AND BE A NON
FACTOR FOR AIRPORT OPERATIONS. VALLEY SITES MAY DROP BRIEFLY TO
MVFR AROUND SUNRISE BUT OTHERWISE NEXT HAZARD IS SHOWERS AND
SCATTERED THUNDERSTORMS THROUGH THE LATE MORNING BEFORE ANOTHER
ROUND IN THE AFTERNOON AND EVENING.
FGF WATCHES/WARNINGS/ADVISORIES
ND...NONE.
MN...NONE.
UPDATE...TT
DISCUSSION...PERROUX
AVIATION...TT
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