504
FXUS63 KFGF 270844
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
344 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.

&&

.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 /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1055 PM CDT Thu Jun 26 2025

With rain/drizzle now completely out of the region attention
turns to dropping ceiling with many already MVFR or near it.
Fog looks to become a late overnight problem for DVL and FAR
with a tempo near sunrise being added for this 06z set of tafs.
Clearing then expected by noon with evening storms rolling west
to east from 00z to 06z with DVL, FAR holding the highest
chance of impacts and a lower but still mention worthy chance in
GFK. TVF and BJI look to have much lower chances of storm
impacts Friday night.

&&

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

&&

$$

DISCUSSION...DJR
AVIATION...TT