853 
FXUS63 KFGF 251728
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1228 PM CDT Sat Oct 25 2025

.KEY MESSAGES...

- Warmer then average through the weekend with gusty winds on 
 Sunday.

- High confidence in a wetting rain early next week.

&&

.UPDATE...
Issued at 1227 PM CDT Sat Oct 25 2025

Fog has improved across most of the SPS area, although stratus
continues to stretch towards Devils Lake as well as the Fargo
area and west central MN. Will let the SPS expire as scheduled
at the top of the hour, but bumped up cloud cover across
portions of our forecast area for the rest of the afternoon.

UPDATE
Issued at 730 AM CDT Sat Oct 25 2025

Dense fog continues to slowly work its way northward into
far southeast ND, as driven by moisture advection. Fog will
continue to migrate northward deeper into eastern ND just west
of the Red River Valley.

Uncertainty exists in cloud cover today, with low stratus 
capable of lingering throughout the day. Should this occur, 
cooler daytime temperatures will ensue staying within the 50s.

&&

.DISCUSSION...
Issued at 338 AM CDT Sat Oct 25 2025

...Synopsis...

Upper ridging aloft this weekend will promote above average
temperatures today and Sunday. Tightening pressure gradient and
increased low level winds will bring gusty winds today, tonight,
and Sunday. This weekend's upper ridging will give way to
troughing aloft early next week. Sufficient forcing and moisture
lends high confidence in at least a wetting rainfall within
portions of eastern Dakotas into Minnesota between Monday and
Tuesday.

...Dense fog this morning...

Early this morning, satellite is showing fog and very low
stratus forming/advecting within eastern South Dakota,
with dense fog noted along and near the escarpment west of 
James River Valley. This is due to low level moisture advection
into relatively cool air mass over the Northern Plains. High
resolution guidance like HRRR/RAP/HREF all depict this scenario,
with eventual overspreading of dense fog into eastern ND, mainly
west of the Red River Valley. There is some potential in dense
fog hugging along the western portion of the Red River Valley
itself, however, there is lower confidence in this. Guidance
advects this fog into the region by sunrise, lingering through 
the morning, and perhaps lasting into the afternoon hours. As is
typical for this time of year, fog can linger a bit longer than
what guidance would indicate. One thing that may help cease fog
by the afternoon will be increasing winds, perhaps helping mix
out or at least lift fog into stratus. While there isn't a 
Dense Fog Advisory out yet, there will likely be a need for one 
today.

...Above average temperatures and gusty winds this weekend...

Upper ridging over the region today and Sunday and long southerly
fetch will promote warming temperatures aloft to advect into 
the region. This will bring above average temperatures, although
how much above will depend on cloud cover. Temperatures will
confidently reach into the 50s, with temperatures into the 60s
still possible (more likely if skies remain clear). 

Tightening surface pressure gradient as well as increasing winds
aloft over the Dakotas will promote gusty south to southeast winds
in excess of 30 mph today through Sunday. The south-southeast 
direction of winds tonight as well as low level jet around 45 
mph may promote gusty winds through the overnight hours Saturday
within the Red River Valley.

While pressure gradient alone will help drive windy conditions,
there is some uncertainty in how high wind gusts will reach. 
This is due to uncertainty in mixing potential into the stronger 
wind just above the surface, particularly on Sunday. Increasing 
cloud cover ahead of an approaching trough and associated 
moisture may temper mixing potential. 

There is a 30% chance winds will reach into the 45-55 mph range
Saturday overnight into Sunday within eastern North Dakota and
the Red River Valley.

...Wetting rainfall early next week...

This weekend's upper ridge will continue to build north and east
into Canada, to a point where it cuts itself off as strong
anticyclone near the southern Hudson Bay region. While this 
occurs, upper troughing on the cyclonic side of upper jet 
nosing into the Pacific Northwest will induce upper troughing 
into the central CONUS along with Pacific-sourced moisture. 

The strong upper anticyclone will promote a block-type pattern,
helping split energy associated with the upper trough into 
interior Canada as well as into the Central Mississippi Valley 
by Tuesday. During this transition, sufficient moisture and 
forcing will produce rainfall within the Northern Plains Monday 
and Tuesday. While this splitting of energy will mitigate 
overall strength of synoptic forcing, relatively rich moisture 
content along with mesoscale forcing will drive rainfall in 
excess of 0.25 inches, potentially as high as 1.5 inches.

Strong and persistent convergence within the central and 
eastern Dakotas will help focus precipitation near a surface 
north-to-south oriented surface trough. This convergence 
coupled with divergence aloft will also help promote fgen in the
low and mid levels. Guidance also hints as some
conditional/slantwise instability feeding into these fgen
circulations. These mesoscale forcing mechanisms lower 
confidence in how widespread soaking rainfall amounts in excess 
of 0.5 inches will be. Should this type of mesoscale forcing 
dominate, rainfall may be locally enhanced while also spatially 
smaller near the surface trough. This would also make higher end
amounts in the 1.0-1.5 inch range more likely, but again in a 
spatially smaller area. As of now, ensemble guidance keeps the 
chance for these higher end amounts (30%) within central to 
eastern North Dakota Monday through Tuesday.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1227 PM CDT Sat Oct 25 2025

Stratus moving into the southern and western portions of the
forecast area, with IFR over the Devils Lake basin and MVFR for
the southern Red River Valley into west central MN. KGFK and the
MN airports remain VFR, but think there will be at least some
period of MVFR this afternoon. Some improvement to VFR as some
mid clouds move in, but most locations should drop down to the
2500-3000 ft range by the end of the period as moisture
continues to move north on the stout south winds. Winds will
remain fairly breezy overnight, with 15 to 20 sustained and some
gusts up above 20 kts possible. Winds will pick up further by
tomorrow morning from the south to southeast, with gusts above
30 kts. 

&&

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

&&

$$

UPDATE...CJ/JR
DISCUSSION...CJ
AVIATION...JR