802
FXUS63 KFGF 171724
AFDFGF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
1224 PM CDT SUN MAY 17 2026
KEY MESSAGES
- THERE IS A 2 OUT OF 5 RISK FOR A FEW THUNDERSTORMS BRINGING A
THREAT FOR 1.5 INCH HAIL SUNDAY AFTERNOON.
UPDATE
ISSUED AT 650 AM CDT SUN MAY 17 2026
SHOWERS ARE JUST STARTING TO WORK INTO CENTRAL NORTH DAKOTA THIS
MORNING, AND GENERALLY REMAIN ON TRACK TO ENTER THE CWA HEADING
INTO MIDDAY. THE BEST PROBABILITY FOR SEVERE THUNDERSTORMS
REMAINS LARGELY TO OUR SOUTHEAST TODAY; HOWEVER, ISOLATED TO
SCATTERED SEVERE THUNDERSTORMS COULD MOVE INTO THE FAR SOUTHERN
RED RIVER VALLEY LATER THIS AFTERNOON AND EVENING. MODEL
SOUNDINGS REFLECT SUPPORT FOR LARGE HAIL UP TO THE SIZE OF PING
PONG BALLS.
UPDATE
ISSUED AT 909 PM CDT SAT MAY 16 2026
UPDATE TO REMOVE KEY MESSAGE FOR THE EXPIRATION OF RED FLAG
WARNING AT 9PM. RH VALUES ARE 40% OR HIGHER AND WINDS GENERALLY
5-15MPH. A FROST ADVISORY REMAINS IN EFFECT FOR FAR
NORTHWEST/NORTH CENTRAL MN WHERE MOSTLY CLEAR SKIES/LIGHT WINDS
SHOULD SUPPORT GOOD RADIATIONAL COOLING AND 2M TEMPS ARE LIKELY
TO FALL TO 36F OR LOWER.
DISCUSSION
ISSUED AT 132 PM CDT SAT MAY 16 2026
..SYNOPSIS
SURFACE ANALYSIS THIS AFTERNOON SHOWS A COLD FRONT DRAPED ALONG
THE DAKOTA STATE LINE INTO WEST-CENTRAL MINNESOTA. TEMPERATURES
NORTH OF THE FRONT ARE GENERALLY IN THE UPPER 40S TO LOW 50S,
WITH NOT MUCH RECOVERY IN TEMPERATURES EXPECTED THIS AFTERNOON.
WINDS WILL REMAIN ELEVATED BETWEEN 10-20 MPH WITH OCCASIONAL
GUSTS TO 30 MPH, BUT WILL BEGIN TO DIMINISH CLOSE TO SUNSET.
EASTERLY WINDS WILL BEGIN TO INCREASE OVERNIGHT AS A QUICK
MOVING VORTICITY MAXIMA AHEAD OF A BROAD LONGWAVE TROUGH OVER
THE GREAT BASIN FIRES OFF A SURFACE LOW IN LEE OF THE ROCKY
MOUNTAINS. MOISTURE WILL ADVECT FROM SOUTH TEXAS UP TOWARDS THE
NORTHERN GREAT PLAINS TOMORROW AFTERNOON. WITH INCREASED
MOISTURE ADVECTION AND STRONG SYNOPTIC AND MESOSCALE FORCING,
WIDESPREAD RAIN IS EXPECTED TOMORROW THROUGH MONDAY MORNING.
GENERAL RAINFALL AMOUNTS 0.25-0.75" WITH AREAS THAT RECEIVE
THUNDERSTORMS CLOSEST TO THE SURFACE LOW (SUCH AS WEST-CENTRAL
MINNESOTA) APPROACHING 2+ INCHES. THERE IS THE POTENTIAL FOR
ADDITIONAL RAINFALL ACROSS THE REGION ON MONDAY AS THE BROADER
LONGWAVE TROUGH LIFTS NORTHEAST. THERE IS A WAVE INTERACTION
ONGOING WITH THIS, HOWEVER, SO CONFIDENCE IN PRECIPITATION
AMOUNTS IS LOW AND COULD RANGE ANYWHERE FROM A FEW TENTHS TO A
BROAD SWATH OF HALF AN INCH OR GREATER. REGARDLESS, INSTABILITY
WILL BE CUT OFF TO THE SOUTHEAST, SO PRECIPITATION IS MUCH MORE
LIKELY TO BE STRATIFORM RATHER THAN CONVECTIVE.
THE FLOW PATTERN ALOFT BECOMES MUCH WEAKER SO THE PROBABILITY
FOR WIDESPREAD IMPACTS IS LOW AT THIS TIME WITH HARDLY ANY
CHANCES FOR SEVERE THUNDERSTORMS OR CRITICAL FIRE WEATHER.
..RED FLAG TODAY
AS A COLD FRONT CONTINUES TO SAG SOUTHWARD THIS AFTERNOON,
RELATIVE HUMIDITY VALUES SOUTH OF THE FRONT GENERALLY RANGE IN
THE UPPER 20S TO LOW 30S THIS AFTERNOON. FURTHER REDUCTIONS IN
RELATIVE HUMIDITY ARE EXPECTED THIS AFTERNOON AND WITH WINDS
SHIFTING AND REMAINING ELEVATED, THE WEATHER ENVIRONMENT REMAINS
CONDUCIVE FOR RAPID FIRE SPREAD. FUEL INFORMATION ALSO ADDS TO
THIS, WITH ERC VALUES REMAINING HIGH FROM THE PAST WEEK DESPITE
GREEN-UP ONGOING. FOR THIS REASON, A RED FLAG WARNING HAS BEEN
ISSUED ACROSS WEST-CENTRAL MINNESOTA WHERE THERE IS MOST LIKELY
TO BE THE CONFLUENCE OF LOW RH AND HIGHER WINDS. CONDITIONS
IMPROVE AFTER TODAY AS WIDESPREAD PRECIPITATION IS EXPECTED
TOMORROW AND MONDAY.
..SEVERE STORMS SUNDAY
AS THE SHORTWAVE EJECTS TOMORROW AFTERNOON, A DEEPENING SURFACE
LOW IS FORECAST TO DEVELOP IN THE CENTRAL/NORTHERN GREAT PLAINS.
ACCOMPANYING THIS WILL BE A DEVELOPING WARM FRONT THAT WILL PUSH
MOISTURE NORTHWARD TOWARDS OUR AREA. SOUTH OF THIS FRONT,
THETA-E VALUES EXCEEDING 330 K WILL PROVIDE FOR A RISK OF
SURFACE-BASED THUNDERSTORMS, WHILE NORTH OF THE WARM FRONT WILL
CREATE A RISK FOR ELEVATED THUNDERSTORMS. THIS WILL LARGELY
DRIVE THE HAZARDS THAT WE WILL SEE TOMORROW AFTERNOON/EVENING.
AS TIME HAS GONE ON, IT IS APPEARING MORE AND MORE LIKELY THAT
WE WILL BE ON THE NORTHERN END OF THE WARM FRONT, WHERE VERY
STRONG ISENTROPIC ASCENT WILL EXIST, BUT WITH COOLER SURFACE
TEMPERATURES IN THE 60S. THIS MEANS WE WILL MORE LIKELY FALL
TOWARDS ELEVATED SUPERCELLS CAPABLE OF HAIL UP TO 1.5". ON THE
FLIP SIDE, THIS MEANS OUR TORNADO RISK IS ALSO SIGNIFICANTLY
DIMINISHED. WHILE ESRH ALONG THE WARM FRONT IS VERY GOOD WITH
EXCELLENT STREAMWISE VORTICITY, THE OVERWHELMING BULK OF
GUIDANCE KEEPS THIS SOUTH OF AREA. THERE REMAINS THE LOW CHANCE
FOR THIS WARM FRONT TO PROPAGATE NORTHWARD AND SLICE INTO OTTER
TAIL/GRANT/HUBBARD COUNTIES, BUT THIS LOOKS TO BE THE OUTLIER
AND ABSOLUTE NORTHERN MAX WITHIN THE RANGE OF SCENARIOS. THE
TIMEFRAME FOR SEVERE STORMS IS GENERALLY BETWEEN 3 PM AND 11 PM
WITH THE MOST LIKELY ZONE FOR SEVERE IN THE 4 PM TO 9 PM
TIMEFRAME. FOR ANY TORNADO RISK, SHOULD IT ARISE, THIS WOULD BE
CLOSER TO THE LATE AFTERNOON EARLY EVENING TIMEFRAME.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1220 PM CDT SUN MAY 17 2026
CEILINGS WILL LOWER THROUGH THE AFTERNOON AS SHOWERS OVERSPREAD
MUCH OF THE REGION. AT LEAST MVFR CEILINGS ARE EXPECTED TO
DEVELOP THIS AFTERNOON WITH EVENTUAL IFR EXPECTED AROUND SUNSET.
SHOWERS WILL LIKELY REDUCE VISIBILITY IN SOME CAPACITY, BUT
SHOULD GENERALLY REMAIN IN THE 3-8 MILE RANGE. LATER THIS
AFTERNOON, EMBEDDED THUNDERSTORMS MAY IMPACT FAR, BUT THE
PROBABILITY IS DIMINISHING AS WE APPROACH SINCE INSTABILITY
REMAINS WELL SOUTH OF THE TERMINAL. SHOWERS WILL DIMINISH
GENERALLY AFTER 00Z, BUT IFR CEILINGS WILL REMAIN THROUGH THE
END OF THE TAF PERIOD, WITH THE LOW POTENTIAL FOR LIFR. WINDS
TODAY WILL GENERALLY BE EASTERLY, SHIFTING TO NORTHERLY TOWARDS
MIDNIGHT AND PREVAILING NORTHERLY THE REST OF THE WAY THROUGH
THE END OF THE TAF PERIOD.
FGF WATCHES/WARNINGS/ADVISORIES
ND...NONE.
MN...NONE.
UPDATE...DJR
DISCUSSION...PERROUX
AVIATION...PERROUX
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