960
FXUS63 KFGF 151245
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
745 AM CDT Sat Jun 15 2024

.KEY MESSAGES...

- Isolated to scattered severe thunderstorms are possible today
  for the Devils Lake area and portions of the northern Red
  River Valley. Impacts could include damaging wind gusts up to
  60 mph and large hail up to the size of quarters.

- Isolated severe thunderstorms are possible Sunday afternoon in
  the southern Red River Valley and west-central Minnesota.
  Impacts are possible and could include strong wind gusts and
  large hail up to the size of quarters.

- There will be another chance for scattered severe
  thunderstorms on Monday, with much of the area seeing the
  potential for large hail and damaging wind gusts. Flash
  flooding is possible as there is support for persistent heavy
  rainfall.

&&

.UPDATE...
Issued at 745 AM CDT Sat Jun 15 2024

Showers and mainly embedded thunderstorms continue to move
slowly off to the east this morning, with southerly to
southeasterly winds increasing. Temperatures are hovering in the
low to mid 60s with dew points in the upper 50s to low 60s.
Minimal adjustments were needed this update as the forecast
remains on track.


&&

.DISCUSSION...
Issued at 411 AM CDT Sat Jun 15 2024

...Synopsis...

A very active weather pattern continues across the Northern Plains
and into the Upper Midwest through the next several days. Upper
ridging builds into the Ohio Valley and the Eastern Seaboard
starting today, which will continue into the early part of next
week. As this happens, H5 troughing digs into the western Conus,
facilitating a favorable pattern for repeated trough passages along
southwesterly flow into the Northern Plains. Moisture will be able
to flow into the area along strong 850 mb transport winds, with long
fetch gulf moisture working into the northern Mississippi Valley
ahead of our H5 troughs. This will set the stage for active weather
to include strong to severe thunderstorms and very heavy rainfall.

...Isolated to Scattered Severe Thunderstorms Today and Sunday...

Theta-e values continue to climb this morning as mixing ratios are
now in the range of 11-13 g/Kg in central North Dakota. This
moisture will continue working eastward into the Devils Lake Basin
by early afternoon, with SBCAPE climbing upwards of 1500 J/Kg by
late afternoon. Shear in the 0-3Km and 0-6Km layers remain
supportive of discrete cells; however, forcing is expected to stay
west of the area, with remnant strong to severe storms working into
the Devils Lake Basin later in the afternoon and into the evening
hours. Environmental support for discrete cells diminishes as this
happens, with clusters and possibly line segments being the primary
mode heading into late evening. Soundings support large hail up to 1
inch, with a more conditional threat of damaging wind gusts due to
storms becoming elevated during the overnight period.

For Sunday, the theta-e gradient along a lifting warm front will be
our primary driver of potentially strong to severe storms. While
shear in the low levels supports a mention of tornadoes, the better
environment looks to stay south of the area. CAPE still looks
supportive of large hail and damaging wind gusts, however, primarily
for portions of the southern Red River Valley and west-central
Minnesota.

...Scattered Severe Thunderstorms Monday...

A stronger trough is set to bring severe thunderstorm chances back
into area on Monday as moisture continues to stream into the area.
Mixing ratios climb upwards of 14 g/Kg in the southern Red River
Valley with values of up to 12 g/Kg for the central and northern Red
River Valley. This will usher in a conditional threat of severe
storms that could expand across a larger portion of the area. How
much coverage we see will depend on the speed of the theta-e
gradient boundary associated with a push of cooler and drier air
working in from the northwest. Guidance shows a range of solutions
that support anything from elevated large hail producing supercells,
to potentially tornadic cells ahead of the boundary. With the slow
forward movement expected with this system, we could also see a
flash flood risk emerge as training storms could move repeatedly
over the same area. The best chances for impacts, resides in the
southern and central Red River Valley and portions of west central
Minnesota; however, the position of the boundary will ultimately
determine the axis of heaviest precipitation and strongest
thunderstorm potential.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 625 AM CDT Sat Jun 15 2024

Scattered showers and thunderstorms are moving across the area
this morning, primarily impacting KGFK and KTVF. Brief MVFR
conditions are possible during thunderstorm activity due to
lower ceilings and visibility. Additional thunderstorm activity
moves into the area later this afternoon and evening, with MVFR
CIGs possible once more. Winds are already increasing this
morning and are expected to remain southerly through much of the
TAF period. Wind gusts of 25 knots are possible through late
this afternoon.

&&

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

&&

$$

UPDATE...Lynch
DISCUSSION...Lynch
AVIATION...Lynch