312
FXUS63 KFGF 041950
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
250 PM CDT Thu Jun 4 2026

.KEY MESSAGES...

- Widely scattered showers and weak thunderstorms are forecast
  today. Storms are not expected to be severe, but some small
  hail could develop with stronger cells near the South Dakota
  border.

- More widespread chances for showers and storms this weekend  into
next week. Some storms could be strong to severe.

- Heat returns for the weekend.

&&

.DISCUSSION...
Issued at 250 PM CDT Thu Jun 4 2026

...Synopsis...

Upper low still spinning over southern Manitoba, and will push
further east into Ontario tonight, leaving near zonal flow over
the Northern Plains with several weak embedded shortwaves. A
stronger trailing shortwave tomorrow. By Saturday, upper ridging
starts to move into the Plains and Upper Midwest, with south to
southeasterly winds and better instability starting to return.
On Sunday, the upper ridge moves east and southwesterly flow
aloft sets up and continues into the upcoming week. Several
shortwaves are likely to come out in this pretty active pattern.
As of now the models are clustering around timing of one decent
shortwave coming through Sunday night and Monday and another
late Tuesday into Wednesday. Predicitbility is low, but it does
look like a warm and relatively stormy period as we head into
next week.

...Shower and thunderstorm chances tonight and tomorrow...

Main front is across our southeastern counties, with another
weak boundary from near Hallock to Valley City. Both boundaries
have some cumulus developing along them, with the more southern
boundary looking a bit more robust on satellite with some hints
of icing at the tops. That area has better instability with over
1000 J/kg of ML CAPE and 30 kts of shear, so will have to keep
and eye on development. Higher instability as well as better
forcing further south into SD and there has already been some
fairly strong convection in that area. Most of the CAMs have
some consolidation into a thunderstorm complex, which then
pushes east through northern SD into MN later tonight. Will
have to keep an eye on the far southern tier of counties, in
case parts of that convection move into ND and west central MN.
Another shortwave will come through tomorrow, but again the
amount of destabilization is uncertain and shear is pretty weak.
For now just think we will be more garden variety showers and
thunderstorms rather than severe potential.

...Severe potential this weekend into early next week...

Instability will be increasing this weekend as we have
temperatures climbing back into the 80s and even low 90s, with
southeasterly winds bringing better moisture. Upper ridging
Saturday should keep most of the activity well to our west, but
by Sunday the ridge starts to move east and many ensemble
members have a decent shortwave coming out Sunday night into
Monday. Timing of all these shortwaves in the southwesterly flow
is very uncertain, but CWASP is up into the 50s by 06Z Monday,
so have at least some chances for severe. Another relatively
higher period of CWASP values Tuesday night into Wednesday, but
spread among the ensembles for CAPE is also very high, around
1000 J/kg differences between some members. Predictability too
low to start any specific messaging at this point, but pattern
definitely looks active.

...Heat over the weekend...

With southerly winds ahead of the surface trough over the
weekend, there is a 60 to 90 percent probability for
temperatures on Sunday to climb above 90 degrees. Dew points
are also on the rise, and although apparent T values are still
below 100, the heat risk and WBGT values on on the rise. Will
continue to monitor for the need for any heat messaging over the
weekend.


&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1230 PM CDT Thu Jun 4 2026

VFR conditions at all TAF sites although some lower ceilings
have been hanging around KBJI and scattered in and out. Will
keep them at 3500 ft for now. Other sites should see increasing
mid and high clouds later in the period. West to southwest
winds mostly under 12 kts will shift around the northwest at
some of the more northern sites this evening. Then become light
and variable everywhere.

&&

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

&&

$$

DISCUSSION...JR
AVIATION...CJ