216
FXUS63 KFGF 180033
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
733 PM CDT Fri May 17 2024

.KEY MESSAGES...


- Isolated to scattered severe thunderstorms are possible this
  evening. Damaging wind gusts to 60 mph are the main concern.

- There is a 70 percent chance for wind gusts greater than 40
  mph Saturday afternoon in eastern North Dakota.



&&

.MESOSCALE...
Issued at 731 PM CDT Fri May 17 2024

Mesoanalysis showing the 850 mb front located with the initial
band of thunderstorms from Langdon back to Jamestown to south of
Bismarck. So far only weak 850 mb winds from the south 20-25
kts into the RRV and MUCAPE is weakening to under 1000 j/kg with
surface inversion forming. All in all with main 500 mb system
well to our northwest unsure how long severe storm potential
will be. Outlfow from storms on radar is outrunning the
reflectivity areas, so a sign for moderate wind gusts 40-48 mph
but a sign of a lowering risk of severe wind gusts.




&&

.UPDATE...
Issued at 714 PM CDT Fri May 17 2024


Had a report of 58/59 mph from Devils Lake and Pekin. No hail
has been reported yet from this line of storms near Larimore.
Environment still looks like it will still be able to support
hail growth maybe up to 1 inch instead of 1.5.


&&

.DISCUSSION...
Issued at 336 PM CDT Fri May 17 2024

A cold front is going to move through the region this
evening. Estimated timing looks to be around 00z for the Devils lake
Basin and maybe around 04z for the valley. With scattered to clear
skies across the region will allow for optimal heating to help erode
away our capped environment. HREF is painting a swath of effective
bulk shear between 25 to 35 kts which is normally a little weak but
may provide enough shear to sustain any storm development. Given the
high LCL and LFC`s generally between 1-3km would allow most of our
available CAPE to be utilized in the Hail growth zone resulting in
at least 1 inch hail however there are a few analogs that have
resulted in higher hail size but im just not confident the
environment would sustain anything higher than ping pongs at the
largest. The hodographs are fairly straight supporting the idea that
today is going to be a more hail and wind threat kind of day and not
a tornado type of day. A minor concern or really something to
monitor is some ponding to some minor flooding given the potential
for some training storms and our already saturated ground moisture
especially in the valley.

As far as the gusty wind potential on Saturday, there are some pros
and cons. For the pros, seeing a pretty unidirectional flow from the
surface up to 850mb. Cons are that the winds at 850mb are not all
that strong. Seeing something like 30 to 35 knots across the
northern half of the FA and 25 to 30 knots across the southern half.
The strongest cold advection comes late tonight into early Saturday
morning, when the mixing is not the best. For the late morning and
afternoon time frame, warm advection begins again. Westerly winds
are not the best direction for maximizing gusts. So the thought at
this point would be near advisory criteria wind speeds across the
northern half of the FA, and slightly lower to the south. May mix in
some slightly lower CONSSHORT winds with the slightly higher NBM
winds to capture this.

As far as precipitation chances, there may still be some ongoing
convection Saturday morning. There is a secondary 700mb short wave
that rotates through the FA around the parent low that holds over
central Saskatchewan. CAMs are showing another potential line of
showers/weaker storms following the same track as the ones for
tonight (mainly north of I94 in North Dakota and mainly north of
highway 2 in Minnesota). This would be mainly for the morning hours,
with drying working west to east through the day with the increasing
west winds. The remainder of the long term continues to feature
cooler temperatures and periodic chances for more rain. The flow
remains zonal, with the main differences being the strength and
timing of additional waves. Some ensembles show a closed 500mb low
possibly holding over the FA Tuesday into Wednesday (which would
result in a wetter solution), while others are more progressive
(less wet). These details will come into better focus closer over
the next few days.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 731 PM CDT Fri May 17 2024

VFR conditions out ahead of the area of showers and t-storms
and even when the t-storms move in cloud bases remain in the mid
level range. Gusty west winds come into E ND and NW MN Saturday
with gusts 23-33 kts.

&&

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

&&

$$

MESOSCALE...Riddle
UPDATE...MM
DISCUSSION...Godon/MM
AVIATION...Riddle