416
FXUS63 KFGF 071757
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1257 PM CDT Mon Jul 7 2025

.KEY MESSAGES...

- Scattered thunderstorms today, a few may be severe with
  damaging wind gusts or hail to 1.50 inch. The risk of severe
  storms is a 2 out of 5 for parts of the Red Rive valley.

- Isolated severe storms possible Wednesday afternoon or
  evening, risk level 1 out of 5.

- Increasing risk for severe storms into Thursday, late in the
  day and night.

&&

.DISCUSSION...
Issued at 329 AM CDT Mon Jul 7 2025

...Synopsis...
Busy 500 mb pattern with zonal flow more or less and short waves
moving into British Columbia and then often taking a dive
southeast toward our area. This continues this week and likely
beyond. Thus periodic t-storm chances with severe risk dependent
on instability, forcing and 0-6 km bulk shear values.


...Severe Risk Today...

This early Monday morning SPC meso analysis has a broad 850 mb
moisture advection over the area with 25kts 850 mb south winds
focus into Jamestown, Devils Lake area. There has been a slow
increase in mid level showers in this area since 06z. Main upper
wave is in Saskatchewan and giving an area of shower and
t-storms with it southeast of Saskatoon. This wave will will be
near the Manitoba/ND/MN border at 00z Tue. Thus the idea in pops
is to have a lower pop to start today in E ND but increase pops
into categorical range north valley later this aftn/eve.
Considerable cloud cover today in that area may prevent a lot of
sfc heating and MUCAPE in that area remains sub 1000 j/kg. But
with cold pool aloft with 500 mb wave moving over cannot rule
out some hailers with storms in the north valley. Multi-cell
likely as 0-6 km bulk shear may not be strong enough to maintain
supercells.

Farther south there does appear to be a wave at 500 mb that will
move east thru northern SD into northeast SD by late today.
Doesnt seem to be picked up well by models. But with this area
the area east of it will have more surface heating and a bit
higher dew pts with MUCAPES in the 1500 j/kg range. 0-6 km shear
not great, but signals from SPC HREF does indicate higher
intensity and longer track UH tracks along the SD/ND border late
this aftn. SPC did extend slight risk a bit farther north for
this.

Not much support for strong/severe storms once you get past 02z,
with lingering activity likely to exit fcst area around 06z-7z.

Tuesday will see high pressure move in and dry conditions.


...Wednesday Severe Risk...

Wednesday late aftn/eve will see a short wave move ESE across
the area. The airmass advecting north into the area, esp central
ND, is more unstable with MUCAPES over 3500 j/kg and high temps
in central ND fcst to be low 90s. 0-6 km shear is 30kts or less
though. SPC did insert a marginal risk for eastern and central
ND due to instability being quite high and weak wave moving ESE
thru the area.


...Thursday....

Thursday afternoon and night has for the last several days been
highlighted as the most unstable day in the 7 days. MUCAPE
values from ensembles (EC/GEM,GFS) from 00z runs all over 3500
j/kg with likely over 4000 j/kg. But issue is placement of 500
mb system with this and placement of 500 mb jet. Model
continuity has been poor. Thus question is with all the
instability will there be enough forcing and shear aloft to
generate a higher end severe threat. That remains to be seen.
Given the conditions fcst all hazards would be possible, though
wind/hail favored vs tornado as unsure of any surface boundary
location. We also have some sfc CIN to overcome. But highs are
forecast to be low 90s and dew pts low 70s. If either one can
over achieve that will add to instability.

For Friday and Saturday forecast hangs on development of 500 mb
low and placement and track. GFS been all over the place in the
last 24 hours with ECMWF the most consistent in having upper low
in the area Saturday with persistent area of showers and
t-storms near and just east of the wave over much of the area
Friday. Slower ECMWF would keep rain chance longer into Saturday
vs NBM.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1257 PM CDT Mon Jul 7 2025

A few isolated showers/storms around could impact KBJI/KTVF
initially in the period. Otherwise additional development
expected late this afternoon/evening that could impact all TAF
sites from 22-03Z from NW to ESE as storms develop along a cold
front dropping through the forecast area. This will allow winds
to shift from south to southeast to the northwest behind the
front for late tonight into Tuesday. Tried to time the greatest
chance for the storms at each site, with dry conditions expected
mainly after 06Z into Tuesday.


&&

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

&&

$$

DISCUSSION...MJB
AVIATION...MJB