394 
FXUS63 KFGF 091211
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
711 AM CDT Tue Sep 9 2025

.KEY MESSAGES...

- Patchy dense fog this early Tuesday morning and possibly 
  again early Wednesday morning. 

- Chance for thunderstorms Thursday and Thursday night, mainly
  northeast ND near the border. Small chances of t-storms this
  weekend.

&&

.UPDATE...
Issued at 653 AM CDT Tue Sep 9 2025

Been watching visibilities and webcams all night with the fog.
Overall seeing improvement in more areas, still patchy coverage,
but where fog was dense it was very dense. May cut out part of
the dense fog advisory prior to 13z, and more may be able to cut
counties out of the advisory before ending time which is 15z.
Otherwise have some mid cloud bands moving east and lingering
stratocu Park Rapids area....but lots of clear sky upstream.  

&&

.DISCUSSION...
Issued at 338 AM CDT Tue Sep 9 2025

...Synopsis...

A true hodgepodge of conditions to start this Tuesday morning
over the area. Overall have been seeing gradual clearing but
there remains mid cloud patches in E ND into NW MN and areas of
lower stratocu in west central into northeast MN. 

...Patchy Dense Fog This Morning...

In between cloud areas
where skies went clear, fog has quickly formed and in the last 
hour the fog has spread and getting a bit more widespread than 
earlier. First fog formed over the grass fields at ASOS and AWOS
stations, but seeing some fog starting to move into towns. With
coverage likely to continue to increase thru 12z went ahead 
with a dense fog advisory for parts of E ND and northwest MN 
thru 15z. This matches time frame from DLH on their NPW. 

Outside of this, once the fog burns off should be a mostly sunny
day. Some lingering high level smoke around but HRRR smoke
forecasts indicate the high level stuff improving from the north
today. Mainly clear tonight but would expect with similar light
winds patchy fog to form again and is shown via NBM wx forecast
grids for 06z-14z period Wed. So did add patchy fog to grids for
eastern ND (not DVL) and into NW MN. Mainly sunny Wednesday.
Highs both days mid to upper 70s, with a few low 80s possible. 
Dry weather is anticipated both today and Wednesday.

...T-storm Chances Thursday and beyond...

500 mb upper ridge builds north Wed-Thu period ahead of a
developing trough in the western US as upper low does form in
southern Oregon by 12z Thu. 500 mb short wave from this system
is forecast to move into SE Saskatchewan by 12z Thu and generate
an area of showers and t-storms in south central and southeast
Saskatchewan and northwest ND or possibly southwest Manitoba by
12z Thu. Track of short wave should be east near the Intl border
with shower and t-storm chances increasing thru the day into Thu
night along ND/MB border. Instablity appears weak with MU CAPES
well under 1000 j/kg so severe wx threat appears low. 

Weekend storm chances appear pretty low at this time as most of
the energy with upper level trough is western ND into
Saskatchewan.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 653 AM CDT Tue Sep 9 2025

Ground fog bringing its typical high variation and changeable
conditions. Overall will see variable conditions but general
improvement thru 14/15z. But as fog is low lying and in many
cases over the grassy fields near the equipment sensors expect
quick changes. Overall though from late morning thru the evening
VFR.  May have patchy fog again after 06z Wed. 

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Dense Fog Advisory until 10 AM CDT this morning for NDZ016-
     026>030-038-039.
MN...Dense Fog Advisory until 10 AM CDT this morning for MNZ001>003-
     005>009-013>017-022>024-027-028.

&&

$$

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