782
FXUS63 KFGF 171156
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
656 AM CDT Thu Jul 17 2025

.KEY MESSAGES...

- Rain and storm chances return Thursday night into Friday,
  however the next threat for strong to severe storms is not
  expected until Sunday into Tuesday.

&&

.UPDATE...
Issued at 653 AM CDT Thu Jul 17 2025

Mainly clear and cool to start the day. Lows around 40 to the
mid 40s in most areas. Patchy ground fog and webcams support the
patchy coverage and regulated to grassy fields. It will burn off
fast with full sun to start the day.

&&

.DISCUSSION...
Issued at 316 AM CDT Thu Jul 17 2025

...Synopsis...

Sfc high pressure is over central ND early this morning. Clear
sky and near calm wind allowing temps to drop into the 40s in
many areas. Likely a few upper 30s in colder spots. It will
start off sunny today, with patchy morning ground fog, then
increasing clouds, mostly high, as we go into the afternoon,
then thickening clouds this evening.

500 mb flow remains for the most part west to east along the
International border. An upper low over north Hudson Bay and the
500 mb jet from central British Columbia east-southeast into
North Dakota and northern Minnesota. Next 500 mb short wave is
near Calgary this early morning with thunderstorms in that area.
This wave will follow the 500 mb jet into North Dakota tonight
and into Minnesota Friday. Area of showers and t-storms with
this wave. Location of a weak surface low and 850 mb low tonight
will be in west into central SD with 850 mb 30 kt jet into SE ND
and WC MN late tonight and Friday morning. 850 mb frontogentical
forcing is also present near I-94 in North Dakota overnight. So
it makes sense that heavier rainfall potential is across the
south half of the fcst area with focus near I-94 in ND then east
into west central MN thru noon Friday. Fast moving wave, but
PWATs increase to over 1 inch in southern ND into MN with this
system. So enough moisture present to give spotty rainfall
totals near 1 inch with qpf from NBM/WPC reasonable.
Areas that could use higher rainfall totals include parts of
Devils Lake basin into Grand Forks but rainfall looks lighter in
this area at least as of this morning fcst.

Clearing out Friday overnight into Saturday. Saturday still
looks like a nice day with light winds and highs in the mid to
upper 70s.

...Strong to severe storm chance Sunday into Tuesday...

Getting into next week, attention turns to thunderstorm chances
and potential for strong/severe storms. 500 mb ridge builds a
west and a bit north into the central Plains next week. 500 mb
jet will remain on the north edge of this ridge, but models
diverge on how far north the ridge will get and any potential
trough into the Pacific northwest. Sunday afternoon into Tuesday
and possibly beyond will feature an extended period with sfc
CAPEs 1000-3000 j/kg and potential for storms to form with these
waves moving thru the area in the 500 mb jet. It may be that if
there is a more southwest flow aloft with a trough into
Washington state per 00z ECMWF that higher severe chances shift
a bit more north of the border for Sun-Mon period. Needless to
say the set up favors strong/severe storms but the specifics are
highly uncertain.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 653 AM CDT Thu Jul 17 2025

VFR today into most of tonight. Any patchy ground fog around
AWOS`s is short lived. Otherwise mainly clear to a few mid
clouds this morning into early afternoon then increasing cirrus
and mid clouds later today into this evening and thickening up
overnight with chance of showers E ND sites after midnight. I
put VCSH in E ND sites for later on tonight to give approx
timing. Winds light/variable this morning but eventually turning
south- southeast this aftn into tonight 5-12 kts.

&&

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

&&

$$

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