563
FXUS63 KFGF 171924
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
224 PM CDT Sun May 17 2026

.KEY MESSAGES...

- There is a 2 out of 5 risk for a few thunderstorms bringing a
  threat for 1.5 inch hail Sunday afternoon.

&&

.DISCUSSION...
Issued at 144 PM CDT Sun May 17 2026

...Synopsis...

Severe convection potential looks to remain mainly in west-
central Minnesota this afternoon/evening as model guidance
continues to prog the main surface-based instability barely
approaching southern Grant County. Elevated instability remains
expected to ascend north of the warm front this afternoon,
bringing the potential for elevated showers and thunderstorms
across southeast North Dakota and west-central Minnesota. Areas
that see storms through the evening will have the potential to
see rainfall exceed 1 inch. Elsewhere, generally expect rainfall
totals between a quarter inch to half inch. For severe
convection potential, see the severe section below.

Rainfall should exit the region late this evening/early tomorrow
morning giving a brief break from precipitation before the main
upper trough ejects over the intermountain west. As this trough
ejects, it looks increasingly likely that a swath of
precipitation will dump a broad swath of at least a quarter of
an inch of precipitation. Unfortunately, there looks like there
will be a region between where rain falls today and where rain
falls tomorrow that could see very limited rainfall amounts,
which may exacerbate ongoing dryness. Instability will be well
cut off tomorrow so severe thunderstorms and thunderstorms are
not expected to develop.

The remainder of the period will be characterized by relatively
cool temperatures through midweek with frost/freeze potential
Wednesday morning. Drier conditions will also return but with
flow aloft being relatively weak, the probability for red flag
conditions is low.

...SEVERE POTENTIAL TODAY...

Surface analysis this afternoon shows the warm front roughly
situated just north of Sioux Falls. This has allowed intense
isentropic ascent over our area, bringing some solid moisture
content to the region. This warm front remains expected to
propagate northward this afternoon and bringing surface moisture
with it. CAM guidance continues to generally prog the surface
instability south of our CWA, barely scraping Grant County. Per
HREF probabilities, there is only a 10% chance to even see 500
J/kg of SCAPE. MUCAPE also is very closely attached to this warm
front and shares similar probabilities as a result. Having said
that, shear associated with the front is rather strong,
approaching 50+ knots. There will be a brief window this evening
(likely at most 1-2 hours) wherein severe convection may impact
our west-central Minnesota counties. Any severe convection will
most likely be hail as storms are likely to be elevated as storm
relative winds in the 0-2km layer are most likely to be due
easterly, so it will be difficult to ingest warmer air to the
south. If surface-based convection arises, tornadoes can`t be
ruled out but again this is very unlikely at this time and would
require very strong propagation northward in the warm front. The
window of severe thunderstorms ends roughly close to midnight at
the lastest, but should generally be out of the area by 8-10 PM
CDT.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1220 PM CDT Sun May 17 2026

Ceilings will lower through the afternoon as showers overspread
much of the region. At least MVFR ceilings are expected to
develop this afternoon with eventual IFR expected around sunset.
Showers will likely reduce visibility in some capacity, but
should generally remain in the 3-8 mile range. Later this
afternoon, embedded thunderstorms may impact FAR, but the
probability is diminishing as we approach since instability
remains well south of the terminal. Showers will diminish
generally after 00z, but IFR ceilings will remain through the
end of the TAF period, with the low potential for LIFR. Winds
today will generally be easterly, shifting to northerly towards
midnight and prevailing northerly the rest of the way through
the end of the TAF period.

&&

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

&&

$$

DISCUSSION...Perroux
AVIATION...Perroux