998
FXUS63 KFGF 161752
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1252 PM CDT Thu Oct 16 2025

.KEY MESSAGES...

- Dense fog west of the Red River Valley through early tonight.

- Showers and thunderstorms will move north today. This rain
  may impact harvest. The main impact from any thunderstorm that
  develops will be lightning.

&&

.UPDATE...
Issued at 1252 PM CDT Thu Oct 16 2025

A thunderstorm riding along a gradient of 500 MUCAPE or so
continues to push northeastward, passing through Grand Forks
this hour. Fog continues west of the Red River Valley, with
other much more localized patches occuring just about anywhere
within the FA. No major changes to headlines or the going
forecast.

UPDATE
Issued at 943 AM CDT Thu Oct 16 2025

Biggest change with this update is to issue a dense fog
advisory until 1 AM for areas west of the Red River Valley from
Barnes county northward to the Canadian border. Visibilities are
trending downward within this area as rain ends. With easterly
flow ahead of our approaching center of low pressure and warm
front, fog seems likely to expand in coverage in the advisory
area. Fog will dissipate from south to north as the front pushes
northward, clearing the northern portion of the advisory around
its current end time. Otherwise, blended in observations, with
rain ongoing over northwestern MN.

UPDATE
Issued at 722 AM CDT Thu Oct 16 2025

Area of rain and t-storms on track about as expected, with
scattered showers still moving into the south valley. Overall
things looking pretty good with pops and timing.

&&

.DISCUSSION...
Issued at 344 AM CDT Thu Oct 16 2025

...Synopsis...

The previous idea of how this system will evolve into today is
working out pretty well. 500 mb low near Salt Lake City with
feed of moisture, increasing over time, from the Pacific north
thru New Mexico in a narrow zone then north into the western
Dakotas. As this upper low moves north-northeast and over NW
North Dakota near Williston 03z Fri. Surface low with this
system is farther east and at this time quite weak in northeast
Colorado and western Nebraska. It will strengthen some as it
moves north into area between BIS/JMS and then north thru DVL
area to south central Manitoba south central North Dakota late
by 06z Fri. So a pretty fast moving system. The main deformation
zone rain and band of 1-2 inch rainfall will be found from far
western South Dakota the north along the Montana/North Dakota
state line into far SE Saskatchewan and southwest Manitoba.

850 mb jet of 50 kts in central Nebraska will move north-
northeast thru today and nose of 850 mb jet is into SE ND early
this morning and will spread north thru the morning. This
advance of low level jet and 850 mb moisture/warm advection has
caused an increased development of showers and t-storms in a
band from south central ND into northeast SD and southwest MN
and it is lifting north. This band of warm advection precip,
along the 850 mb warm front will lift north thru the morning. So
for most the majority of the rain will occur now thru early
afternoon. As the low moves into ND late today, do look for the
warm front and surge of temps into the low 70s to reach the
southern RRV mid to late aftn. Instability from NAM which is
warmer than GFS with sfc temps indicates 700-1100 j/kg potential
in this warmer zone over the southern and central RRV and parts
of west central MN. But area will be in a dry slot aloft with
limited moisture available. As low moves north toward DVL early
evening a cold front will move east and there is a chance for a
narrow band of t-storms to develop in the southern RRV into MN.
Severe weather is not anticipated and movement will be quick to
the northeast.

Upper low and surface low lifts into Canada overnight Thu night
and Friday will see breezy/windy west-southwest winds and
slightly cooler air move in and also drier air, esp for southern
regions of ND/west central MN. Far north near Canadian border
will see lingering clouds and a chance for showers in the
wraparound moisture of departing low as it moves north into
northeast Manitoba.

Weekend is looking dry, some clouds around Saturday south of
departing upper low then sunnier late Saturday into Sunday.

Early next week is indicating some potential for a upper wave
Mon-Tues period but model ensembles show wide dispersion with
speed with ECMWF very quick in moving thru Monday and GFS a bit
slower. At this time impacts from this would be minimal as rain
amounts would be light.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1252 PM CDT Thu Oct 16 2025

A very complicated TAF period. To start, showers/rouge
thunderstorms will continue for the next few hours followed by
more shower development this evening. Fog/mist/drizzle west of
the Red River Valley will impact KDVL through the evening hours.
Ceilings today will be LIFR/IFR with ever so slow improvement
into MVFR starting mid afternoon at KFAR. Wind will shift
overnight from the south/southeast to the southwest. These winds
should finally whisk away the lower ceilings, improving all
terminals to MVFR by Friday morning.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Dense Fog Advisory until 1 AM CDT Friday for NDZ006-007-014-
     015-024-026-028-038-054.
MN...None.

&&

$$

UPDATE...Rafferty/Riddle
DISCUSSION...Riddle
AVIATION...Rafferty