Grafton, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

539
FXUS63 KFGF 182323
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
623 PM CDT Thu Jun 18 2026

.KEY MESSAGES...

- After a few showers and thunderstorms on Friday, temperatures
  will slowly warm to near 80 by late next week.

&&

.DISCUSSION...
Issued at 202 PM CDT Thu Jun 18 2026

...Synopsis...

Northwest flow remains in place over the Northern High Plains and
Upper Midwest this afternoon. Embedded in northwesterly flow will
be a handful of weak waves. The most prominent shortwave
propagates through Friday. As it tracks through, a few showers
and thunderstorms are forecasted to develop. Several more weak
waves will traverse the region late this weekend into early next
week as northwest to zonal flow continues. This will bring
additional low chances for showers and thunderstorms to start
the work week.

Temperatures will remain cooler then average throughout much of the
forecast period, although by mid to late next week the pattern does
shift as ridging builds in. This will finally help us get
temperatures back to near average by Thursday. While there are some
differences from ensemble member to ensemble member of the ridges
strength, there is surprisingly little spread in temperatures from
the NBM. For example, at KGFK, the 25th and 75 percentiles for next
Thursday are 75 and 80 degrees. Average for the date is 78 degrees.
So, while warmer then the current cool spell we are experiencing,
even ridging will only bring temperatures up to near average.

...Showers and Thunderstorms Friday...

A wave propagating southeastward from Saskatchewan Thursday night
quickly into Minnesota by Friday afternoon will be the trigger for
shower and thunderstorm development beginning tonight. As the low
swings through the FA late Friday morning into the afternoon, an
airmass characterized by up to 1000 J/Kg of MUCAPE and 20 to 30
knots of effective shear will allow for showers and thunderstorms to
blossom. The speed at which the low tracks through the FA will
determine where the strongest thunderstorms initiate. A quicker
low will whisk much of the instability eastward by afternoon,
leaving all but our far southeastern counties with any chance
for a stronger storm. A slower system would allow instability to
remain over more of the region, and storms to develop further
west, probably closer to the MN side of the Red River Valley.
The best overlap in shear and instability in either scenario is
in west central MN (Park Rapids, Detroit Lakes, Wadena, Fergus
Falls areas). If a thunderstorm were to become strong to
marginally severe, it would be in this region during the mid to
late afternoon hours, with just sufficient speed shear for hail
to be the primary threat. Therefore, the Storm Prediction Center
has placed our far southeastern counties in a marginal, level 1
out of 5 risk for severe thunderstorms Friday afternoon.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 619 PM CDT Thu Jun 18 2026

VFR conditions will prevail for the evening with very minimal
impacts. Ceilings will begin to lower later this evening as
showers work their way through the region. This may cause some
visibility reductions, but this carries a low predictability.
Ceiling-wise, guidance has a wide array of potential scenarios
for ceilings, ranging from MVFR to VFR. Reasonably the worst
case scenario ceiling for any TAF site through the end of the
TAF period is around 2000ft, although the majority of guidance
keeps things in the 2500-3500ft range. Additional showers and
thunderstorms are likely to develop tomorrow afternoon, although
they will be very scattered and thus carries a low probability
of terminal site impacts. As we progress through the afternoon,
winds will also shift to northwesterly with increasing
magnitudes towards sustained 10-15 knots with occasional gusts
approaching 20 knots. Ceilings should begin to improve as
showers and storms diminish towards the end of the TAF period,
giving way to VFR conditions tomorrow evening.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.

&&

$$

DISCUSSION...Rafferty
AVIATION...Perroux