Mayville, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

743
FXUS63 KFGF 191956
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
256 PM CDT Sat Jul 19 2025

.KEY MESSAGES...

- Severe storms developing over south central North Dakota will
  push into eastern North Dakota late Sunday. There is a level 1
  out of 5 risk for our counties along and west of the Red
  River.

- Smoke from Canadian wildfires will degrade air quality this
  afternoon through Monday.

- There is a level 1 out of 5 risk for severe storms south of
  the Highway 2 corridor on Monday. Additional severe risk into
  Tuesday.

&&

.DISCUSSION...
Issued at 256 PM CDT Sat Jul 19 2025

...Synopsis...

Water vapor loop and upper air obs show near zonal flow with
weak shortwaves moving through. One such shortwave could bring
some showers and a few thunderstorms into our forecast area late
tonight into tomorrow morning. However, instability so far is
limited and not expecting severe impacts until later on Sunday.
By that point, the surface low deepening over WY should help
boost the southeasterly winds and bring moisture advection into
the Northern Plains. Several shortwaves will be coming through
the zonal flow Monday and again Tuesday, bringing additional
convective chances as we head into the work week. A little bit
of a break indicated by some of the ensemble members into
Thursday as flow briefly becomes northwesterly behind a
shortwave trough moving into Ontario. Next Friday and Saturday
however will see a return to near zonal flow and an active and
warm pattern.

...Mostly marginal severe risk on Sunday...

Most of the CAMs and even a few of the larger scale models bring
some convective remnants from the High Plains into our counties
late tonight and into Sunday morning. Instability will be weak
at this point, so not expecting severe impacts. However, many of
the models, although not all, clear out the morning activity and
destabilize over south central ND. HREF has around a 20 percent
chance for strong updraft helicity tracks to enter our far
southwestern counties later Sunday evening. Model soundings have
some pretty warm temperatures aloft, but there is good elevated
instability and can`t rule out some hail moving into east
central or southeastern ND. The slight risk currently clips our
Sheyenne Valley counties, but think the better chances for early
surface based convection will remain to our west and we will
see mainly elevated hailers Sunday night.

...Smoke tonight and tomorrow...

While current smoke concentrations over eastern ND and
northwestern MN are still mostly in the good to satisfactory
category, Purple Air shows higher concentrations just north of
the Canadian border. The HRRR and Canadian models backdoor this
smoke into northwestern MN later tonight, then have it hang
around through much of tomorrow. While concentrations from the
models vary, it does seem that there will be at least some smoke
for a time tonight or tomorrow, so will continue mention and
AQA.

...Severe risk Monday and Tuesday...

Near zonal to southwesterly flow aloft continues into the first
part of the work week. Southeasterly surface winds will continue
to bring moisture and instability ahead of a weak trough axis,
and some of the ensemble members have CAPE values as high as
2500 J/kg along with 45 to 50 kts of bulk shear. Forcing will be
mainly from very minor shortwaves however, and there will be a
lot of CIN to overcome. Machine learning has greatest severe
probabilities to our southwest for Monday, but still could see
some isolated severe impacts for our area. Additional
thunderstorms could develop on Tuesday with a stronger surface
trough arriving, although much will depend on how tomorrow and
Monday play out.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1249 PM CDT Sat Jul 19 2025

Most of the TAF sites have gone VFR, although there was still
some MVFR clouds hanging around the KBJI area at issuance time.
Mostly VFR conditions for the rest of the period with mainly mid
and high clouds moving in from the west. Some smoke getting near
the surface will be possible this afternoon and into tonight,
but concentrations at this point do not seem too bad so kept vis
6SM and above. Light and variable winds will steady out of the
southeast and then pick up with gusts to around 20 kts by the
end of the period.

&&

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

&&

$$

DISCUSSION...Lynch
AVIATION...JR