473
FXUS63 KFGF 101736
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1236 PM CDT Fri May 10 2024

.KEY MESSAGES...

- Scattered thunderstorms are forecast for portions of northwest
  and west-central Minnesota this afternoon. A few storms may
  produce wind gusts to 50 mph and small hail. Best chance (50%)
  for strong storms resides east of US Highway 59.

- Gusty northwest winds will develop today. There is a 40%
  chance sustained winds exceed 30 mph and/or gust to 45 mph to
  eastern North Dakota and the Red River Valley. These winds
  along with dry conditions will bring near critical fire
  weather conditions to these areas.

&&

.UPDATE...
Issued at 1236 PM CDT Fri May 10 2024

Starting to get some showers developing over northwestern MN,
although satellite shows only a tiny bit of glaciation so no
lightning yet but could see some in the next few hours. Mixed
layer CAPE is around 250 J/kg and surface based just a bit
higher, so instability is pretty minor and effective shear is
around 20 kts. Not expecting much other than some brief
downpours and gusty winds to 40 mph, but some hail up to peas is
not completely out of the question. Cloud cover and showers
have kept RH values up a bit higher than what we had going so
far on the MN side for fire weather concerns, so even though
some spots have been approaching 25 mph in the Red River Valley,
the humidity has been high enough to keep the near critical SPS
and not upgrade to Red Flag for now.

UPDATE
Issued at 958 AM CDT Fri May 10 2024

Pulled the low POPs out of the Red River Valley this morning as
the shower activity has stayed up around Lake of the Woods and
the Red Lakes, and upstream showers in Canada seem like they
will take a similar path. Amounts still look light and low
impact. Will continue to keep an eye on winds and RH values
in the Red River Valley for fire weather concerns.

UPDATE
Issued at 650 AM CDT Fri May 10 2024

A cold front is moving through the area bringing gusts as high
as 40 mph in portions of the northern Red River Valley and
northwest Minnesota. This is likely tied to an initial bubble of
strong CAA. However, as daytime mixing commences this will
spread.

In coordination with neighboring offices and MIFC, issued an
Special Weather Statement on near critical fire weather
conditions within the Red River Valley.

&&

.DISCUSSION...
Issued at 430 AM CDT Fri May 10 2024

Synopsis..

Water vapor imagery projects a progressive and potent shortwave
trough moving southeast within MB and western ON. This will move
into MN today. Cold air aloft embedded within this trough will
drive thunderstorm chances today by way of steep lapse
rates/weak instability, meager but sufficient moisture, and
strong synoptic lift. Some storms may be strong bringing gusty
winds and small hail. This trough will also bring gusty winds
and dry air over the Dakotas. Behind the quickly departing
trough today will be shortwave ridging tonight into Saturday
ahead of the next progressive shortwave trough expected to brush
our area as it moves through MB into ON. This next trough`s
passage will advect warmer air into the region, along with
bringing an additional chance for showers and storms to the
area, currently favoring northeast ND into MN late Saturday.
Additional progressive shortwave troughs are forecast to move
through the Northern Plains and Upper Midwest through next week,
although predictability in their timing and trajectories remains
rather low. Still, additional chances of showers and storms
exist through next week.

Strong storms in Minnesota today...

The path of today`s trough will place our area in a northerly
flow regime, with increasing winds with height. As daytime
heating commences, convection will start to bubble late morning
through the afternoon. This along with a very deeply mixed PBL
underneath thunderstorms will contribute to convectively driven
wind gusts as high as 50 mph in strongest storms. With such
cold temperatures aloft keeping much of the cloud layer sub-
freezing as well as generally favorable kinematics, storms will
also hold the potential for small hail. Expected hail sizes are
generally under the size of quarters, although a few instances
of quarter sized hail cannot be ruled out. Overall chance for
storms is around 50% mainly east of US Highway 59, which also
holds relatively best chances for these stronger storms.

Gusty winds today..

Deep mixing today (likely at or above 700 mb) will allow
increased winds aloft to mix toward the surface. Overall winds
within the deeply mixed PBL today are not overly strong,
generally in the 20-30 kt range, although some guidance does mix
into a layer where 30-40 kt winds exist. Northwesterly
direction of winds will also favor some locally increased winds
within the Red River Valley. Available CAMs favor the southern
Valley to see best potential in seeing highest winds, with
around a 40% chance of meeting wind advisory criteria.

Dry air mass moving into the Dakotas along with gusty winds also
introduces the potential for fire weather conditions. However,
recent rainfall and green up of fine fuels/grasses should
mitigate the potential for rapid spread of fires. Still, we are
opting to message near critical fire weather conditions based on
weather conditions alone.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1236 PM CDT Fri May 10 2024

Cumulus and showers developing mainly over northwestern MN, but
all sites VFR and will remain so as convective activity
dissipates after sunset. Winds will be the primary aviation
concern with many airports gusting above 30 kts from the
northwest this afternoon. Should see winds slowly taper off this
evening, eventually becoming light and variable overnight. By
the end of the period there will be a shift to the southwest at
less than 10 kts.

&&

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

&&

$$

UPDATE...CJ/JR
DISCUSSION...CJ
AVIATION...CJ