457
FXUS63 KFGF 031732
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1232 PM CDT Sun Aug 3 2025

.KEY MESSAGES...

- Air quality impacts continue over parts of the region today due
  to lingering wildfire smoke.

- Scattered showers and thunderstorms are expected through Monday.
  Best chances are across southeast North Dakota and northwest
  Minnesota. Locally heavy rain and lightning are the main
  threats.

- Strong to severe thunderstorm chances return to the region
  Tuesday into the next weekend.

&&

.UPDATE...
Issued at 1232 PM CDT Sun Aug 3 2025

Cloud cover continues to fill into the area from southwest to
northeast, with scattered showers in portions of west central
Minnesota. Slight adjustments were made to PoPs, mainly to
reduce chances in portions of northeast North Dakota as the
system is a bit slower to produce showers through midday.

UPDATE
Issued at 651 AM CDT Sun Aug 3 2025

A slow moving area of rain is starting to spread into southeast
ND while additional shower activity is developing into west
central MN on the northern part of the mid level circulation.
Instability remains low in our south (MU CAPE under 500 J/KG)
and trend is that this will remain limited the farther north
and east through the afternoon/evening. I made adjustments to
PoPs for coverage of rain and lowered thunder probs based on
these trends. Under the area of slow moving rain, NDAWN sites
show a smaller area of 0.5-1.3" rainfall was measured just to
our west, though most locations are lighter (0.05-0.25). These
reports are in line with the expectations for rainfall today
with light to moderate totals where activity tracks, and
localized higher values (1"+) where slower moving showers or
thunderstorms track.

&&

.DISCUSSION...
Issued at 330 AM CDT Sun Aug 3 2025

...Synopsis...

Split flow remains in place through Monday. A monsoonal ridge
strengthens over the southwest CONUS midweek, while troughing
develops into the Pacific NW, resulting in a persistent SW flow
pattern developing into the Northern Plains Tuesday into the
upcoming weekend. This pattern results in increasing return flow
and moisture/instability. Temperatures be warmer (mid to upper
80s) Wednesday into Friday as southerly flow increases, with
increasing Tds supporting a moderate heat risk for parts of the
region. Otherwise, most periods highs will be mild (70s). This
pattern will also keep thunderstorm chances in the forecast
daily/nightly, with details less predictable most periods
regarding coverage/impacts.

...Wildfire smoke impacts today and Monday...

There are still pockets of wildfire smoke impacting the region,
though concentrations have improved, particularly in the south.
Trends should be for southerly flow to continue to push remaining
smoke north and east through the day, with smoke models showing a
marked decrease in near surface smoke by tonight even in our
north. There may still be smoke over parts of northwest MN into
Monday, but as the mid level wave passes the shifting pattern will
tend to keep highest concentrations north.

...Shower and thunderstorms through Monday...

A slow moving mid level wave just south of our CWA is expected to
finally drift northeast into our region, with scattered showers
and a few pockets of more organized rain rotating across
southeast ND and northwest MN today into Monday as this moves
east. Instability initially may not support much in terms of
lightning activity, however it does begin to increase later in the
day night, with scattered thunderstorms or embedded thunderstorms
forecast into Monday. The increase in PWATs as this wave arrives
(1-1.5") and skinny CAPE profiles later tonight would support
efficient rain processes and locally heavy rain rates may occur
with some some activity. General trend on 24hr 1"+ rainfall point
probabilities from HREF shows values in the 20-40% range in SE ND
and northwest MN though PMM signal for higher values are much
smaller/localized which supports the idea of a more localized
heavy rain threat tied to embedded thunderstorm activity.

...Severe thunderstorm risk Tuesday into Sunday...

The development of SW flow will result in pooling BL moisture into
the region with increasing instability locally each day Tuesday
into the upcoming weekend. Initially the timing of weaker mid
level waves and location of frontal zones/mesoscale interactions
play roles in creating more uncertain in coverage/potential for
severe impacts. Late in the week a stronger trough develops then
eventually passes the region. This feature may carry a better for
organized severe convection Thursday and Friday. Machine learning
based systems highlight at least some severe risk in our area
every day, but the later week periods are of particular interest
and carry higher probabilities. It`s hard to have too much
confidence in evolution of thunderstorms in how this pattern
ultimately evolves, but it is worth noting there is support within
some deterministic guidance at this range for a higher impact
scenario (supercell/MCS potential) considering the thermo/shear
profiles depicted later this week. That would still depend on the
right alignment of mesoscale/synoptic features, which at this
range do not have a strong consensus. &&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1131 PM CDT Sat Aug 2 2025

Smoke continues across the area, with visibility down to 5SM in
some locations like GFK. This continues overnight, with other
sites potentially following GFK and dropping in visibility.
There will be a chance for a light shower around 10-12z in FAR
and 14-16z for GFK and TVF. Thunderstorm chances increase for
BJI, GFK, TVF, and FAR around 17-19z and continue through the
end of the TAF period. Ceilings will be MVFR to potential IFR
underneath precipitation as it spreads across the area. DVL will
be on the edge of the precipitation potential. Winds will be out
of the southeast through the day tomorrow and into the end of
the TAF period.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1232 PM CDT Sun Aug 3 2025

MVFR conditions are becoming more widespread as cloud cover
continues to increase across the area. IFR ceilings are possible
later this evening and overnight, especially for KFAR and KDVL.
Scattered showers are still expected today; however, this has
been slow to develop and has less coverage than expected. Rain
chances persist into the overnight hours before diminishing
later Monday morning.

&&

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

&&

$$

UPDATE...Lynch/DJR
DISCUSSION...DJR
AVIATION...Lynch