105
FXUS63 KFGF 240640
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
140 AM CDT Mon Jun 24 2024

.KEY MESSAGES...

- Showers and thunderstorms will move into eastern North Dakota,
  especially northeast parts, after midnight tonight. Isolated
  severe storms are possible.

- Monday will see additional severe storm chances for all areas.

- The next storm threat arrives in the Thursday to Friday time
  frame.

&&

.UPDATE...
Issued at 133 AM CDT Mon Jun 24 2024

Strong to severe storms entering northwest ND out of southeast
SK will keep our attention in the near term. This is being
driven by mid level impulse riding over shortwave ridging, with
additional forcing from low level jet feeding 1000-2000 J/kg of
instability and sufficient low level moisture amidst 50+ kt of
shear. This environment will confidently sustain itself through
sunrise supporting severe convection capable of large hail, and
to a less confident degree, gusty winds to 70 mph.

While this convection has been persistently tracking southeast
at 40-50 mph, and in such a way that it would reach the Devils
Lake basin around 09Z (4 AM CDT), there is questions on whether
the warm sector holding aforementioned instability will advect
with this convection. If the convection becomes detached from
this instability, then convection will tend to lessen in
intensity. Should this happen, the chance for severe hazards
would be lowered.

On the other hand, should instability pool advect with the
the convection`s trajectory, the chance for severe hazards
would be medium-high within the Devils Lake basin through at
least 12Z (7AM CDT), potentially lasting into mid/late morning
hours. This potential outcome also consists of additional
updrafts developing behind ongoing storms, which may open up
potential for multiple robust storms capable of severe hazards.

Another potential outcome features robust convection tending
more south-southeast movement, favoring a tracking that rides
more along the leading edge of instability pool. This would
bring medium-high chance of severe convection starting to enter
into the southern Devils Lake basin / Sheyenne River Valley
between 10Z-12Z (5AM-7AM CDT).

Monitoring radar and satellite trends will reveal which scenario
unfolds, particularly within the 08Z-09Z time period.

UPDATE
Issued at 1000 PM CDT Sun Jun 23 2024

Convection is now starting to form across northeastern Montana
and northwest North Dakota this evening; however, most CAMs are
not picking up on this development. Guidance is temporally
displaced by at least a few hours in most cases, with the HRRR
and NAMNest weakening convection as it approaches eastern North
Dakota. Will continue to monitor the environmental conditions
ahead of these storms as they approach the area. At this time,
current guidance brings the first storms into the Devils Lake
area by around 09Z, then into the Red River Valley by around
12Z.

UPDATE
Issued at 655 PM CDT Sun Jun 23 2024

The forecast remains on track this evening with temperatures in
the low 70s along the International Border and low 80s in the
southern Red River Valley. Isolated cumulus continues to
diminish in coverage across northwest Minnesota with otherwise
clear skies across the region. Watching for development of
convection in western North Dakota in the coming hours in order
to determine timing of any potential morning convection across
eastern North Dakota.



&&

.DISCUSSION...
Issued at 233 PM CDT Sun Jun 23 2024

...Synopsis...

The first 700mb shortwave over the Minnesota arrowhead continues
to push to the east. Haven`t seen any precipitation in this FA
from the wave, but there has been fairly extensive cloud cover.
Brief 500mb ridging follows this wave, although overall it looks
much flatter and a little faster than it did several days ago.
There may be some pieces of shortwave energy (and somewhat of a
low level jet) that eject eastward behind this ridge after
midnight and into Monday morning, which may bring scattered
thunderstorms to portions of the Devils Lake region and eastern
North Dakota. There may or may not be a break as this activity
should weaken over this FA by mid to late morning, before
additional storms fire up during the afternoon. The net result
of the flatter/faster ridging is that the warmest 700mb
temperatures on Monday are squashed a little further south and
east. Even so, by 18z Monday to 00Z Tuesday, 700mb temperatures
look to range from +9C along the Canadian border to +15C along
the Dakotas border. Beyond this, the flow turns more northwest,
with the next substantial wave sometime in the Thursday to
Friday time period.

...After midnight tonight...
The various CAM solutions seem to agree on scattered storms
developing over southern Saskatchewan or western North Dakota
after midnight tonight, with them moving into the Devils Lake
region or portions of eastern North Dakota toward sunrise
Monday morning. The Day 1 SPC Convective Outlook highlights a
slight risk (level 2 of 5) for far northwest North Dakota,
tapering to a marginal risk (level 1 of 5) for the Devils Lake
region. The HREF shows the stronger UH tracks during this period
extending from northwest North Dakota toward the western
fringes of this FA and weakening toward morning. So will keep
the idea of weakening storms and a good amount of cloud cover
moving into at least areas north of the Interstate 94 corridor
in North Dakota and the highway 10 corridor in Minnesota
tonight.

...Monday...
There is not a lot of confidence in what may happen on Monday,
but to start with, what happens late tonight and lingers into
Monday morning will have a big effect. Looking at the various
CAMs, etc., feel there could be several different potential
solutions. One, the convection moving into the Devils Lake
region and portions of eastern North Dakota weakens and there is
a break until more convection develops in the afternoon. Two,
there is no break, and convection continues throughout the
entire day across the entire FA (several CAMs show long duration
UH track across the central and northern FA even during the
late morning through the afternoon. Third, although most CAMs
show a better chance for afternoon convection in the eastern
FA, a few show some development back along the cold front, which
may lag back in eastern North Dakota by 00z Tuesday (which
could be part of the reason the slight risk area was expanded
westward today). Fourth, the development which occurs back along
the cold front quickly becomes severe and turns into a bowing
MCS, producing damaging wind gusts as it progresses across west
central Minnesota along the highway 10 corridor in late
afternoon and early evening hours. Five, much of the capping
holds, and only minimal convection occurs. Overall, there is a
lot of uncertainty.

...Thursday to Friday...
The general 500mb flow pattern should turn more to northwest
flow aloft, with the next decent wave showing up somewhere in
the Thursday to Friday time frame. Overall there is a lot of
uncertainty on the timing and strength of the wave, so don`t
want to put a lot of time into trying to determine what may
occur. Stay tuned.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1145 PM CDT Sun Jun 23 2024

VFR conditions prevail at all sites through most of the period.
Currently watching the progression of scattered showers and
thunderstorms in northwest North Dakota tonight. These showers
and thunderstorms are expected to move into eastern North Dakota
during the late overnight period, impacting KDVL as early as
09Z, then moving off to the east through the remainder of the
morning. Winds are expected to become southerly gradually
through the overnight hours, with wind speeds in the 10 to 15
knot range by mid morning.

&&

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

&&

$$

UPDATE...CJ/Lynch
DISCUSSION...Godon
AVIATION...Lynch