571
FXUS63 KFGF 100301
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1001 PM CDT Sun Jun 9 2024

.KEY MESSAGES...

- Showers and scattered thunderstorms are expected late Monday
  afternoon through Monday night. The main threat will be
  lightning.

- There is a low chance for severe thunderstorms Wednesday
  afternoon and evening.

&&

.UPDATE...
Issued at 1001 PM CDT Sun Jun 9 2024

Forecast remains on track after the last update, with decreasing
winds and the stratus layer almost completely eroded (still a
narrow sliver). Additional minor adjustments were made to near
term trends.

UPDATE
Issued at 632 PM CDT Sun Jun 9 2024

Low stratus is finally eroding in northwest MN, and adjustments
were made to reflect current coverage/timing of eventual
clearing. Winds have been much stronger within the valley aided
by northerly flow maximizing momentum transfer. Decoupling
should start within the next few hours and we should see winds
quick drop, eventually becoming light/variable/calm with
surfaced high centered over our region tonight.

&&

.DISCUSSION...
Issued at 332 PM CDT Sun Jun 9 2024

...Synopsis...

An active pattern continues into next week as several troughs
traverse the region. Shortwave troughing and ridging oscillate
through the area, with H5 heights increasing this evening as an
upper low moves slowly eastward. Moisture is expected to increase
along a narrow ridge axis tonight into Monday morning, with a
shortwave expected to push across the area during the evening hours
and overnight into Tuesday morning. Showers and mainly embedded
thunderstorms are possible with this system, with perhaps an
isolated stronger storm capable of small hail and gusty winds. The
best chance for strong storms Monday evening will be west of the Red
River, mainly the Devils Lake area.

Showers and thunderstorms are expected to move east of the area by
midday Tuesday, with another H5 shortwave ridge building in
during the late evening and overnight hours.

...Potentially Strong Storms Wednesday...

Severe Potential for Wednesday afternoon into the late evening. The
synoptic pattern has a 700mb low pressure system sitting over the
great lakes area a transient ridge over us and another 700mb low
pressure system follow closely behind in Saskatchewan. The severe
potential will be tied to how amplified this ridge becomes over us
to advect enough warm air and moisture into the area. If the second
system speeds up and flatten the ridge the risk for severe storms
decreases. The NBM depicts an 80 percent chance for the maximum
temperature to be greater than or equal to 80 south of Grand Forks.

Global ensembles (GEFS, ECMWF, GEPS) depict a 50 percent probability
for CAPE to exceed 1000 j/kg south of Grand forks. Looking at
deterministic model skew T`s they currently show the potential for
severe storms between 18z and 03z. However, there is disagreement
between models on the storm mode which would alter the types of
hazards that could be present during this event. Some of the models
support tornadoes, however, there is much stronger support for
clusters or discrete storm mode. Another disagreement between models
and model runs. The mid level lapse rate will bounce between 7 and
8.0 degrees with a PWAT between 0.6 and 1.4 inches. These
inconsistent runs lowers confidence for the development of severe
storms on Wednesday.

Thursday morning, a second low pressure system makes its way through
our area to continue our chances for rain. Friday and Saturday looks
to be our needed break from the rain as a broader ridge moves over
our area. The later half of the week will be monitored closely to
determine the severe storm potential risk and any possible threats.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 632 PM CDT Sun Jun 9 2024

MVFR stratus is actively clearing north to south in northwest
MN, with VFR expected to return by the valid TAF time (00Z) this
evening. VFR should then prevail across all of eastern ND and
northwest MN after this stratus erodes/transitions southeast.
There is a low chance for MVFR ceilings to arrive at the end of
the TAF period at KDVL when the next system approaches. Lower
ceilings and rain/thunder chances are more likely Monday evening
at DVL and eastern ND TAF sites (Monday night in northwest MN).
Winds have been a bit higher, but with sunset approaching and
surface high pressure building south, we should see a quick
decrease this evening eventually becoming light and variable or
calm. Southeast winds increase through the day 7-13kt Monday as
low pressure builds to the west. Higher winds and gusts (to
25kt) are more likely at KDVL where gradient is stronger Monday
afternoon.

&&

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

&&

$$

UPDATE...DJR
DISCUSSION...Lynch
AVIATION...DJR