Casselton, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

414
FXUS63 KFGF 191502
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1002 AM CDT Sat Jul 19 2025

.KEY MESSAGES...

- There is a level 1 out of 5 risk for severe storms for
  portions of eastern North Dakota late Sunday. Additional
  potential for strong to severe storms Monday and Tuesday.

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

&&

.UPDATE...
Issued at 1002 AM CDT Sat Jul 19 2025

Web cams and obs sites show visibility starting to improve
across most of the area, with some spots already completely
clear. Adjusted cloud cover and put in patchy fog mention for
another hour, but no longer dense so will let the advisory
expire. Continued burning off of any lingering stratus and fog
through mid-day.

UPDATE
Issued at 627 AM CDT Sat Jul 19 2025

Dense fog is impacting portions of northeast North Dakota and
northwest Minnesota this morning, with visibility down to 1/4
mile or less in spots. Thus far, winds are just high enough to
inhibit fog formation in the southern Red River Valley and west
central Minnesota, but fog cannot be ruled out as winds continue
to diminish to near calm.

&&

.DISCUSSION...
Issued at 355 AM CDT Sat Jul 19 2025

...Synopsis...

Zonal H5 westerly flow continues this weekend across the Northern
Plains and Upper Midwest. Low to mid level shortwave activity
remains well advertised through at least Tuesday, with thunderstorm
chances in the forecast starting Sunday. Strong to severe storms
become increasingly likely each day Sunday through Tuesday as
moisture return brings PW values into the 75th to 90th percentile.
Heavy rain is expected to accompany stronger thunderstorms during
this period, raising the concerns for localized flash flooding,
especially Monday into Tuesday. Further into next week, another
shortwave passage brings precipitation chances back into the area
Friday into Saturday. This will be followed by a warming trend as
ridging builds into the Northern Plains heading into next weekend.

...Wildfire Smoke Today...

Wildfire smoke is possible today as northwest winds stream into
northwest Minnesota and the northern Red River Valley. The highest
probability for degraded air quality will be in Northwest Minnesota,
with lower chances further south and west. This pattern will
continue through late Sunday before a frontal boundary pushes across
the area heading into Monday.

...Severe Thunderstorms Possible Sun Through Tue...

Instability builds into the area by Sunday afternoon, with about a
40 percent chance of 1000 J/Kg of SBCAPE, mainly for southeastern
North Dakota and the southern Red River Valley. While mid to upper
level shear looks supportive of organization, very warm air in the
850-700mb layer could suppress initiation, thus lowering the overall
coverage potential. If anything is able to form, large hail and
damaging wind gusts would be the primary risk. Heading into Monday
and Tuesday, conditions look more supportive for organized
thunderstorms, possibly supercells as SBCAPE shows a 70 to 80
percent chance of exceeding 2000 J/Kg; however, the warm layer looks
to remain in place on Monday, which could increase inhibition once
more. For Tuesday, lapse rates improve as cooler air works into the
850-700mb layer. Soundings show the potential for discrete clusters
or hybrid supercells, with a risk of large hail, damaging wind
gusts, and possibly tornadoes. Flash flooding will be a concern for
both Monday and Tuesday as well. PW values are expected to reach the
90th percentile, which will combine with a generally slow-moving
boundary to facilitate longer exposure to heavy rain where stronger
storms form.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 627 AM CDT Sat Jul 19 2025

Calm winds prevail this morning along with patchy dense fog.
LIFR conditions prevail at KGFK, KDVL, and KTVF, with IFR
conditions at KBJI and MVFR ceilings at KFAR. Visibility down to
1/4 mile or less remains possible through around 15Z before
temperatures rebound and support the dissipation of fog. Added
TEMPO groups to TAF sites without current fog to allow the
mention of intermittent BR or FG through 15Z. Once fog clears
late this morning, VFR conditions are expected through the
remainder of the TAF period at all sites.

&&

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

&&

$$

UPDATE...Lynch/JR
DISCUSSION...Lynch
AVIATION...Lynch