-- Discussion containing changed information from previous version are highlighted. --
986
FXUS63 KFGF 230348
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1048 PM CDT Sat Jun 22 2024

.KEY MESSAGES...

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- Scattered thunderstorms and showers remain tonight in
  northwest Minnesota and northeast North Dakota.

- Severe storms may develop Monday afternoon and evening.
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&&

UPDATE
Issued at 951 PM CDT Sat Jun 22 2024

The occasionally strong to severe convection is waning in
intensity as the sun sets and instability decreases. Showers and
general thunder likely linger towards midnight though the
severe threat appears to be over. Remainder of the forecast is
on track.

UPDATE
Issued at 625 PM CDT Sat Jun 22 2024

Latest radar has shown storms beginning to blossom in eastern
North Dakota this evening with a few storms near svr criteria.
Seems that dry air aloft is suppressing storms from utilizing
the available cape though a few cells have maintained 60 Dbz
above 20kft and thus likely going to stay sub severe tonight
(7-10pm) though an isolated svr cannot be ruled out.

&&

.DISCUSSION...
Issued at 300 PM CDT Sat Jun 22 2024

...Synopsis...
One 700mb wave over the southeast FA continues to progress to
the east, with the regional radar showing a decreasing trend to
echoes over this area. Meanwhile the strongest portion of the
next wave remains around the Dauphin Manitoba area, where there
are some stronger storms and lightning activity. Models are
showing a weaker lobe of vorticity extending southward from this
Canadian wave into our northern FA into the evening which could
be the main focus for any convective activity here. The surface
flow remains pretty weak, although winds have switched to the
northwest from Minot to Bismarck, where the regional radar shows
scattered weak echoes (but no lightning).

...Through early evening...

SPC has maintained a marginal risk (level 1 of 5) for severe
storms for late afternoon into the early evening for the Devils
Lake area into the northern Red River Valley. Any surface
support looks pretty weak, but there is a weak wind shift over
central North Dakota. The better support will remain north of
the border, in Canada. However, the lobe of vorticity mentioned
above may get into the far northern FA this evening. Models
also show a piece of upper jet energy focusing into this area
from 00-06z Sun. There has been a little more sun today over the
northern Red River Valley, where Grafton is at 77F, Cavalier
77F, and Hallock 79F. However, clouds were thicker from the
Turtle Mountains toward Langdon and Devils Lake, so those areas
are cooler. The SPC meso page shows 500-1000 J/kg of MLCAPE
from the Turtle Mountains down through Jamestown. This has
really not been enough of a kick to get much going, other than
the scattered weak showers there so far. Really don`t anticipate
much more CAPE developing, but the effective shear should
increase with the upper jet nosing in. 1 or 2 of the CAMs
develop some very short duration weak UH tracks in our far west
or far northwest FA into the early evening. However, the
majority of anything holds around the wave that will slowly push
eastward from the Dauphin area (in Canada). So can`t completely
rule a strong or severe storm out, but it is not a really
favorable day. There is no low level jet support tonight, so any
storm activity should fade with loss of daytime heating.

...Monday afternoon and evening...

Elevated convection Sunday night due to a 700 mb shortwave
complicates the forecast for Monday. Soundings show MUCAPE values in
excess of 1000 J/Kg across the Devils Lake Basin into parts of the
northern Red River Valley. While the better instability resides more
over north central ND, this convection will likely hold together in
some form Sunday night into Monday morning. The main threat would be
hail in the stronger storms. Even if it is not severe, the cloud
cover it will bring to our northern counties Monday will need to be
monitored, as it could impact severe potential Monday afternoon and
evening.

As we progress into Monday, temperatures will rise into the 80s and
low 90s. This hinges on cloud cover clearing out, especially across
the north after lingering morning convection ends. Dew points will
also increase, with values reaching near 70, especially in the
southern Red River Valley. Bulk shear on the order to 35 to 45
knots, and MLCAPE values of over 2000 J/Kg will provide a more then
sufficient environment for severe storms to take advantage of.
However, if storms can develop currently is the big question. Models
prog the better forcing to be displaced to the north of the FA in
southern Canada. While a eastward propagating cold front should
provide enough forcing to eventually fire convection, the timing of
this front is vital in determine how widespread any severe threat
may be. If the front is quicker, it will arrive before peak heating
which due to a stout cap at 700 mb may keep storms from developing.
If the front is slower, it is more likely to arrive during peak
heating and would give clouds more time to clear out. This would
give us a better chance at seeing the cap break, particularly on the
MN side of the FA. The orientation of the front will also be
important when determining the storm mode and expected hazards.
Discrete supercells are favored currently, but there are still
scenarios where the orientation of the front makes for a bit messier
storm mode. However capping should help limit any messier storm mode
potential until storms propagate east of the CWA. To complicate
things further, a warm front along the international border could be
another focal point for severe convection to develop. In all, the
problem on Monday will be if we can get something to go up, because
once it does the environment will conducive for all types of severe
weather.

Beyond Monday, temperatures midweek will cool down to more seasonal
averages for late June. The risk for thunderstorms does not return
until late in the week, when ensembles are showing another shortwave
propagating through sometime Thursday into Friday. At this time
there is significant spread in the timing and evolution of this
wave. It will be something to watch as we get closer in time.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
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Issued at 1048 PM CDT Sat Jun 22 2024

MVFR ceilings in BJI otherwise VFR until the Early morning
hours. Chance for IFR for the four northern sites as the low
passes in the morning hours through unsure just how low ceilings
get currently. Could see intermittent LIFR but confidence
doesnt yet justify putting it in the forecast. Winds variable
tonight becoming northwest around 10kts and thunderstorms
chances remain past the TAF period Monday morning.
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&&

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

&&

$$

UPDATE...TT
DISCUSSION...Godon
AVIATION...TT