495 
FXUS63 KFGF 092009
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
309 PM CDT Wed Sep 9 2026

.KEY MESSAGES...

- There is a level 2 out of 5 risk for severe storms Friday
  afternoon and evening for portions of west central into north  
  central Minnesota.

- There is a high chance for soaking rainfall Sunday night into
  Monday night across the region which could impact outdoor
  activities.

&&

.DISCUSSION...
Issued at 309 PM CDT Wed Sep 9 2026

...Synopsis...

Northwest flow is in place across our region on the back side of
the upper low now centered over Hudson Bay. Shortwave ridging 
moves over the region Thursday followed by southwest flow ahead 
of deepening troughing over the Northern Rockies and Pacific 
Northwest. After a near seasonable day today, much warmer 
temperatures return Thursday and Friday over much of the region,
though there may be a larger spread in temperatures Friday due 
to the arrival and timing of a strong cold front. This front 
Friday brings the next chance for organized thunderstorms to 
parts of the region (mainly MN). Much more seasonal or even 
below average temperatures return this weekend into next week 
behind that front and lowering heights in response to several 
deepening upper lows in Canada and the Pacific NW that will 
migrate over our region. 

...Severe Risk Friday Afternoon and Evening...

Southerly flow ahead of the cold front Friday brings increased
BL moisture (Tds 62-68F) and a narrow corridor of higher 
instability (MLCAPE 2000-3500 J/KG) in response to steepening 
mid level lapse rates (7.5-8.5 C/km). Increased mid level flow 
will bring effective shear values in excess of 40kt to much of 
our region, and ahead of the cold front there is a window where 
hodographs are supportive of supercells and even some supportive
of dominant right moving supercells and tornadoes. The tornadic
environment may remained more capped before forcing increases 
and shear profiles change in in our area making the threat more 
conditional. Ultimately, the location, coverage, and impacts of 
severe thunderstorm activity will be determined by the cap 
weakening and the frontal timing during the afternoon/evening. 
Ensemble/deterministic guidance have zeroed in at this range on 
a timing favoring mainly our western MN/north central MN 
counties. This is also reflected in AI based systems which show 
strong signals for severe impacts in those regions. The ceiling 
on impacts for this event includes s significant severe impacts 
from hail (2"+), a conditional risk for tornadoes, and damaging 
wind gusts to 70 mph. though there are enough uncertainties that
there are equal or greater chances impacts end up lower due to 
how narrow the window/corridor for the higher end of parameters 
will be. This is certainly a set-up to monitor. 

...Soaking Rainfall Sunday night into Monday night...

There is strong consensus that a strong upper low will bring 
widespread rainfall to our region Sunday night through Monday. 
NBM probabilities are 60-80% for greater than 0.5" rainfall in 
our CWA during that period, and probabilities for greater than 
1" of rain range from 40-60% (highest in the southern RRV). 
While it is an organized synoptic system, the locations that 
receive 1"+ or even 2"+ rainfall (30% chance) will be determined
by deformation zone location and embedded thunderstorm activity
which will be less predictable. As the warmer more unstable air
mass will be cut off to the south of this system there is 
currently not a signal for severe thunderstorm risk after 
Friday. 

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1220 PM CDT Wed Sep 9 2026

CU has developed across eastern ND and northwest MN, with lowest 
bases in the 2500-3000 ft agl range, with prevailing heights 
generally 4000-9000 ft agl. The trend should be for VFR to 
prevail, though brief/localized MVFR cigs can't be ruled out 
early in the TAF period. West-northest winds 12-15kt (gusts 25kt
or less) are expected this afternoon across the region. The CU 
should dissipate and the winds should drop off as we approach 
sunset following the standard diurnal trends and drier air and 
weaker surface gradient persists overnight into Thursday 
morning. Low pressure developing to the west should result in 
south to southwest winds increasing by midday (8-13kt). VFR 
conditions should prevail Thursday.

&&

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

&&

$$

DISCUSSION...DJR
AVIATION...DJR