254
FXUS63 KFGF 180447
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1147 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.

&&

.UPDATE...
Issued at 1143 PM CDT Fri May 17 2024

Rest of the severe t-storm watch 255 will expire at midnight.
Still have the area of rain and thunderstorms from Jamestown
region into northwest MN. Overall intensities continue a decline
but still getting pockets of wind gusts 45-50 mph at times in SE
ND with a storm moving out of Edgeley. Overall the next few
hours will see pockets of gust winds 40+ mph but chances for
severe wind gusts are low, not zero, but low.


&&

.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 /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1143 PM CDT Fri May 17 2024

VFR conditions will persist throughout the day
tomorrow. Winds will gradually shift to the west after the line of
storm moves through. Some of the model guidance has KTVF or KBJI
dropping into IFR conditions around sunrise. Most of the consensus
was to maintain VFR conditions so that is what I prevailed. For
KGFK, KDVL, KFAR, and KTVF expect winds gusting up to around 30
knots in the afternoon.


&&

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

&&

$$

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