629
FXUS63 KFGF 182324
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
624 PM CDT Wed Sep 18 2024

.KEY MESSAGES...

- There is a level 1 out of 5 risk for severe storms this
  evening across the area, and a level 2 out of 5 risk for far
  southern portions of the valley. Main impacts would be hail
  up to ping pongs, winds to 60mph, and possible tornadoes.

&&

.UPDATE...
Issued at 622 PM CDT Wed Sep 18 2024

We continue to monitor the latest conditions across the area,
as a few isolated storms have developed in Eddy county and
within Trail county this hour. The chance for a few isolated
strong to severe thunderstorms are possible this evening, but as
we continue on through the evening we start to decrease that
possibility. Otherwise, the main low pressure is still out in
western ND as indicated on satellite, with a boundary
approaching the Devils Lake Basin.

&&

.DISCUSSION...
Issued at 310 PM CDT Wed Sep 18 2024

...Synopsis...

Strong, wrapped up upper low continues near the MT/ND border,
with the center of the surface low still well stacked and out
west. The upper system will push off into Canada tonight, with
the trailing surface boundary moving into the Red River Valley.
Some wrap around into Thursday as the upper system continues to
lift northeast, but then flow transitions more towards a more
split pattern with the northern branch bringing some weak waves
by our CWA. A few of the deterministic models bring the southern
branch cut off into MN near our counties. However, there is not
a lot of ensemble agreement on this solution and there does not
seem to be much of a wet signal in the R or M climate. Temps do
seem like they will be trending more towards seasonal averages
up until Wednesday when ridging builds back in.

...Severe potential this afternoon and tonight...

Clouds and shower activity continue to slowly diminish across
our forecast area. SPC mesoanalysis has 1000-1500 J/kg of ML
CAPE across eastern ND and effective bulk shear of 35 to 40 kts.
There has not been much in the way of forcing, but there is a
boundary/dryline and one of the vort lobes currently over
western ND could skirt our CWA. Can`t completely rule out
severe thunderstorm development, but given weak forcing the
marginal/small slight risk continues to seem reasonable. If
anything does fire, supercells will be possible, with the
possibility of a tornado, along with ping pong ball sized hail
and 60 mph winds. Several of the CAMs runs are not very
impressive with storm development this evening, but do break out
some elevated activity later tonight along the boundary as it
moves through western MN thanks to the low level jet. SSCRAM
guidance isn`t too bullish on severe impacts and HREF just has
a few updraft helicity paintballs above 75 m2/s2. Will continue
to monitor how things evolve this evening.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 622 PM CDT Wed Sep 18 2024

SCT to BKN clouds continue to shift through the region this
evening, with a few isolated thunderstorms developing across
portions of the DVL and GFK area. A few of these storms may be
on the stronger side. Winds continue to be out of the south
through the TAF period, with sustained winds around 10-15kts
through the overnight period. Gusts increase to 25-30kts for
TVF, GFK, FAR, and DVL post 16z through the end of the TAF
period. Another round of showers and storms are possible for DVL
near the end of the TAF period.

&&

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

&&

$$

UPDATE...Spender
DISCUSSION...Godon
AVIATION...Spender