527
FXUS63 KFGF 310823
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
323 AM CDT Fri May 31 2024

.KEY MESSAGES...

- Isolated to scattered severe thunderstorms Sunday into Sunday
  evening.

- Another good chance for showers and thunderstorms on Tuesday
  into Tuesday night.

&&

.DISCUSSION...
Issued at 323 AM CDT Fri May 31 2024

...Synopsis...
Our first departing short wave early this morning has carried
the precipitation east of the FA now. The edge of the thicker
clouds is staying progressive, and should move east of the FA
shortly. There has been some fog along and west of these clouds,
which had appeared like it may linger through the rest of the
night. Now it appears like it may thin out again or shift to the
east, so will monitor and adjust the forecast as needed.

There is another weak shortwave setting up along the Canadian
border today into tonight. Along with some upper jet forcing,
this produces isolated showers and thunderstorms more so this
afternoon into tonight. Isolated showers are also possible
across west central Minnesota. The parade of waves (and
precipitation chances) continues thereafter, with another one
Sunday into Sunday evening and Tuesday into Tuesday night.
Beyond Tuesday night, model spread really increases, so
confidence in the forecast really drops off.

...Sunday into Sunday evening...
Should be able to get decent warming on Sunday, with highs
expected to be in the 70s to around 80. Plenty of moisture
around, with precipitable water values approaching 1.5 inches.
0-6km effective shear values look to be about 30-35 knots.
Models are showing a north/south frontal boundary somewhere
along a Bismarck to Minot line by 18-21z Sunday, shifting into
eastern North Dakota by 00z Monday. So expect thunderstorm
development to break out to the west of the FA initially, with
some sort of linear complex pushing eastward during the late
afternoon and evening. It does look like the low level jet will
kick in Sunday night, helping to keep the line going as it moves
to the east. SPC has placed most of the FA in a slight risk for
severe weather during this period. As far as rainfall amounts,
the NBM is showing about a 70 percent chance for amounts greater
than 0.25 inches along the South Dakota border, to about a 50
percent chance along the Canadian border. Probabilities for
amounts greater than 1 inch drop significantly, about a 5
percent chance along the Canadian border to 20 percent along the
South Dakota border.

...Tuesday into Tuesday night...
This period also features a pretty good chance for showers and
thunderstorms, as the next strong shortwave pushes east along
the northern tier states. Being further out, there is still a
fair amount of uncertainty in how this event may unfold.
However, ensembles are again showing good moisture, with
precipitable water values up around 1.25 to 1.5 inches. There
are questions on cloud cover and potential heating, with the NBM
showing a bit more cloud cover across the northern half of the
FA. This could be why the ensembles are showing more
CAPE/slightly warmer highs across the southern FA. The NBM shows
about a 65 percent probability for rainfall amounts greater
than 0.25 inches, dropping to about a 20 percent probability for
amounts greater than 1 inch. So these 2 events look similar in
that regard.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1035 PM CDT Thu May 30 2024

Showers and thunderstorms along the cold front have moved east
of the area with clear skies settling in. Light west winds
through the night with some gusts around 20 kts in DVL Friday
afternoon. Overall VFR skies across the area with some scattered
cumulus tomorrow above 10 kft.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...Dense Fog Advisory until 8 AM CDT this morning for MNZ029>031-
     040.

&&

$$

DISCUSSION...Godon
AVIATION...TT