987
FXUS63 KFGF 011158
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
658 AM CDT Mon Sep 1 2025

.KEY MESSAGES...

- Scattered showers and thunderstorms are forecast late today
  through Tuesday.

- A seasonably strong cold front moves through Tuesday, bringing
  with it below average temperatures mid to late week.

&&

.UPDATE...
Issued at 640 AM CDT Mon Sep 1 2025

Fortunately any fog has remain isolated and centered around
Gwinner/Forman ND. Otherwise have a narrow band of high clouds
moving east ahead of an upper level short wave trough which will
move thru. No precipitation in the area besides a couple
t-storms near Brandon MB.

Will maintain the grids and forecast as is which is dry thru
midday.


&&

.DISCUSSION...
Issued at 346 AM CDT Mon Sep 1 2025

...Synopsis...

An upper level trough, short wave, in southern Saskatchewan is
moving into southwest Manitoba. Isold showers and a t-storm with
this wave in western Manitoba. This short wave trough will move
east and be over the Red River valley at 00z Tue. High temps
today 75 to 80 will be enough with cooler air aloft with short
wave trough to generate 700 to 1200 j/kg MUCAPE and give at
least a low chance for a few showers or t-storms mid afternoon
into the evening. 0-6km bulk shear in the 30 kt range would
support a possibility (10 pct chance) for isold strong storms to
form in eastern ND mid to late aftn with risk of small hail.

Upstream is a cold front that is moving south thru Manitoba, but
this cold front will generally wait til the main 500 mb wave
drops south from northwest Canada Tuesday, with cold front
passing south thru the area Tuesday daytime, reaching far
southeast ND and west central MN at peak heating. MU CAPES 1000
to 1400 j/kg range and bulk shear 35 kts may be enough to
generate strong or severe storm near the MN/ND/SD border area
(20 pct chance severe). Though a tad higher chance does appear
to be just south of our forecast area. Day 2 SPC has far south
fcst area in marginal risk Tues aftn. But this tied to timing of
front southward, and its possible any isold severe threat is
more south.

Cooler airmass moves in in full force Tues night and Wed as
upper level short wave drop south into the northern valley 12z
Wed and then becomes an upper low in MN Arrowhead region
Wednesday afternoon. Significant cooling with highs Wed mid 50s
to low 60s along with a gusty north wind to 30 mph in E ND/RRV and
cloud cover and a chance for showers in NW MN. Clearing works
in Wednesday evening and night and will determine low temps with
fcsts low temps by Thu AM in the mid 30s in NW MN where frost is
possible.

Fast on its heels is another short wave that will drop quickly
southeast Thursday, with ECMWF/GEM/ICON much wetter than the
operational GFS and data used from the NBM (national model
blend). High pressure moves in Friday into Saturday iwth Friday
night and Saturday night seeing lows in mid 30s in areas of NW
MN where frost is possible.

Both periods the NBM shows a 10 pct chance of below 32F Park
Rapids and Langdon.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 640 AM CDT Mon Sep 1 2025

VFR conditions today into tonight. Clouds 8000 ft agl or above.
South winds 10 kts turning gradually northwest tonight.

&&

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

&&

$$

UPDATE...Riddle
DISCUSSION...Riddle
AVIATION...Riddle