837
FXUS63 KFGF 271149
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
649 AM CDT Fri Jun 27 2025

.KEY MESSAGES...

- There is a 2 out of 5 risk for severe thunderstorms after 4 PM
  this afternoon into the early overnight period.

- Isolated to scattered severe thunderstorms may develop again
  Saturday, with better chances towards far southeast North
  Dakota and west central Minnesota in the late afternoon and
  early evening.

&&

.UPDATE...
Issued at 649 AM CDT Fri Jun 27 2025

Stratus is persisting across much of our area with a clearing
in the northern Red River Valley. This shouldn`t impact
forecast highs as the low clouds are expected to clear this
afternoon with plenty of opportunity for daytime heating with
late seasonal sunset. There are a few clusters of showers and
embedded thunderstorms near northwest ND and another in northwest
SD that have been struggling to hold together as they move east
away from the moist/unstable axis where they developed. There is
a low chance (less than 20%) a few light showers hold together
into our western CWA later this morning, but for now I held off
on adjusting PoPs based on current trends.

&&

.DISCUSSION...
Issued at 344 AM CDT Fri Jun 27 2025

...Synopsis...

Westerly zonal flow across the Northern Plains will be in place
over the next few days. An open mid level trough currently
over the Pacific Northwest and northern Rockies will slowly
progress east, with low amplitude SW flow supporting increasing
moisture/instability and several rounds of potential severe
convection today and Saturday, with lower severe potential
Sunday as drier/stable air arrives. Saturday will be the warmest
day with moderate to locally high heat risk as temperatures
reach the upper 80s ahead of the main cold front and Tds
increase to the upper 60s/near 70 at some locations. Behind this
trough ridging builds to the west and amplifies, while our
region remains predominantly within NW flow until late next
week. This favors near seasonal temperatures and much lower
chances for thunderstorms or severe weather through mid week. By
late week the ridge flattens, with much higher spread in
ensemble clusters on potential waves that could bring low severe
chances back to the region at the end of next week (5% probs
with some machine learning systems).

...Severe risk for this afternoon into tonight...

Initially this afternoon deeper BL moisture is shown to advect
and pool in our west towards central ND. Steep mid level lapse
rates with an EML advecting into the region combines to support
ML CAPE values 2500-4000 J/KG and veering hodographs along our
far western CWA late in the afternoon/early in the evening. This
would support potential for discrete convection/supercells and
some CAMs are showing this along a war frontal zone just to our
west towards the Devils Lake Basin. Capping however and less
certain forcing today lowers confidence in initiation and
eventual evolution. There is no surprise then that CAMs show
high run-run spatial and track evolution. The majority of CAMs
support some form of MCS eventually developing upstream or
locally over our CWA and progressing southeast through the
evening (some slower and lingering into the overnight). MUCAPE
2000-3000 J/kG and effective shear 35-45kt coincide with the LLJ
developing this evening/overnight which would support
organizing and maintenance of an MCS if it does develop from a
merger of upstream convection.

In the scenario where supercells develop in our west large hail,
damaging winds, and some tornado threat would exist (favored
closer to the surface backing along the warm frontal zone in
central ND early in the event). Severe wind to 70 mph and hail
to 1.5" would be the primary threat with the more common
solutions for our area (clusters and MCS propagation west to
southeast).

...Severe risk for Saturday...

There is a low chance for severe hail and wind Saturday morning
in the event there is lingering convection from the overnight
period as elevated instabilty and high effective shear will
remain in place. After any early morning convection ends (if it
is still ongoing) there should be a lull until peak heating.
Capping plays a role in limiting organized severe convection
initially, with it weakening late afternoon after this front is
in our southeast CWA (based on a consensus of guidance). In
proximity and southeast of this frontal zone there will be some
supercell potential once again, though shear profiles/hodographs
would tend to favor left movers in our southeast (hail/wind
primary threats). Farther west and north there is still a low
chance for a severe thunderstorm capable of marginally severe
hail/wind before sunset as elevated instabilty will be in place
as the main trough progresses east and height falls increase.
Coverage as resolved continues to be a question for any
convection, with the best signal in the far southeast part of
our CWA late afternoon/early evening.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 649 AM CDT Fri Jun 27 2025

MVFR stratus is lingering over many locations in eastern ND and
northwest MN, with a region of clearing in far northeast ND and
northwest MN. There may be brief pockets of MVFR even in these
areas of clearing through mid morning before the stratus layer
finally clears out late morning/early afternoon. KFAR and KBJI
have the best chance to see MVFR linger into the afternoon hours
before improving. The next aviation concern will be timing and
coverage of thunderstorm activity later this evening into the
overnight hours, with the best signal in eastern ND and lower
confidence farther east. South to southeast winds increase as
low pressure builds to the west 10-15kt and a few higher gusts
may occur in eastern ND this afternoon.

&&

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

&&

$$

UPDATE...DJR
DISCUSSION...DJR
AVIATION...DJR