595
FXUS63 KFGF 291807
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
Issued by National Weather Service Bismarck ND
107 PM CDT Sat Jun 29 2024

.KEY MESSAGES...

- There is a low chance for a strong thunderstorm to move into the
  Devils Lake basin late Sunday night.

- There is a level 2 out of 5 risk for severe thunderstorms Monday
  afternoon and evening.

- A system may bring numerous showers and thunderstorms to parts
  of the Northern Plains on Independence Day Holiday, with a
  low chance for severe thunderstorms.

&&

.UPDATE...
Issued at 105 PM CDT Sat Jun 29 2024

Rain and drizzle has ended across the CWA. Low clouds are
starting to dissipate in coverage, although remain at low
levels. Any sort of clearing today will just promote more fair
weather cumulus clouds to develop as well. Thus look for a
partly cloudy to partly clear day. Temperatures today will be
cooler and generally in the 60s. Breezy northwest winds may also
linger into the afternoon hours, although should start
diminishing by the early evening hours. Overall little changes
we needed early this afternoon.

UPDATE
Issued at 630 AM CDT Sat Jun 29 2024

The main area of rain has transition well east of our area,
however there is still lingering light rain or drizzle mainly in
northwest MN where lower level moisture is pooling closer to
the cold front that is almost out of our CWA. Drier air is
starting to filter into northeast ND and stratus is beginning to
clear a bit faster as a result. Where highest 925MB CAA and max
winds aloft are transitioning through the RRV behind the front
winds have occasionally gusts to around 38 mph, but as expected
we are seeing a downward trends in our northwest. Near term
adjustments were made to reflect these trends, otherwise the
forecast remains on track.

&&

.DISCUSSION...
Issued at 358 AM CDT Sat Jun 29 2024

...Synopsis...

A mid/upper trough is activity transitioning east of our region,
with shortwave ridging expected to build over the Northern Plains
today into Sunday. The larger scale flow/pattern remains progressive
and active with several additional mid/upper level waves bringing
high precipitation chances and at least conditional severe
thunderstorm chances. Ensembles show strong consensus on the mean
500 MB pattern keeping highest mean heights to the south into the
end of next week. There is a signal for a pattern shift later next
weekend, which could result in amplified/strong ridging building
across either the western US or even into the central US (4 ensemble
clusters split between these solutions). Depending on the evolution
of that pattern above average temperatures and less organized
precipitation chances would be expected.

...Strong thunderstorms late Sunday night...

There is a signal for a strong mid/upper level wave to build near
the Pacific NW with SW flow bringing higher moisture into the region
late Sunday night as the shortwave ridge transitions east. The main
axis of instability and forcing will remain well west towards the
Montana and western Dakotas where initial severe thunderstorms
develop. As a LLJ develops Sunday night this has a chance to
organize into either clusters of showers/storms or a possible MCS.
The timing favors a general weakening and elevation of any activity
as it moves towards our area, however there is a low chance as
highlighted by SPC marginal risk for this to hold together into the
Devils Lake Basin. Confidence is low based on the current timing
(after 06Z) and sounding profiles. With the increase in deep layer
shear and potential for modest elevated instability strong storms
can`t be ruled out. Timing and upstream trends will be key.

...Severe thunderstorms Monday...

The main mid/upper level wave will be pushing east along with a weak
cold front/surface trough axis. Stronger surface low pressure
continues to be favored south of the region placing the warm from
with most clusters south (SD/NE). North of the warm front parcels
will tend to be highly elevated, lowering confidence in impacts and
severe coverage despite the dynamics at play. Widespread showers and
lower stratus may be in place due to strong moisture advection
within WAA across our area, however isolated severe threat would
still be expected considering the magnitude of deep layer shear and
decent elevated CAPE, with more robust/higher CAPE the close to the
warm front. More breaks in cloud cover or a farther north surface
low (not currently favored) would increase the potential for
supercells. High PWATs (greater than 1.5") and potential deformation
could create areas of higher rain totals once again (50% probs for
1"+). The signal for flash flooding isn`t as high at this time, but
this could result in localized excessive runoff and additional rises
on rivers.

...Independence Day Rain and Severe Threat...

Yet another mid/upper wave dives into the Northern Plains towards
Wednesday night into Thursday night. This carries another increased
signal for showers and thunderstorms, locally heavy rain, and a low
probably for severe thunderstorms (5% on CSU GEFS machine learning).
Even with increasing consensus on the general pattern,
impacts/details are still uncertain with slight variances in
track/timing between clusters. As this will be a period of interest
and impacts are possible it is worth monitoring despite the
uncertainty at this range.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 105 PM CDT Sat Jun 29 2024

MVFR to low VFR clouds will remain through this afternoon.
Breezy northwest winds may also be found this afternoon. This
evening will see clouds lift and diminish in coverage, while
winds diminish and eventually go light and variable. Look for
mainly clear skies and light winds through Sunday morning. Light
winds could become southerly by early Sunday afternoon, with
a few VFR cumulus clouds also developing at this same time.

&&

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

&&

$$

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