144
FXUS63 KFGF 311810
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
110 PM 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.

&&

.UPDATE...
Issued at 110 PM CDT Fri May 31 2024

Mostly sunny skies prevail across the region at midday with
temperatures now in the middle 60s to near 70 degrees. Minimal
adjustments were made to reflect current cloud cover trends
across the southern Red River Valley and west central Minnesota.
Timing of the H5 trough seems to be on track to bring a slight
chance of showers and isolated thunderstorms into the area,
mainly north of Highway 2 this evening.

&&

.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 /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1232 PM CDT Fri May 31 2024

VFR conditions are expected through the TAF period at all
sites. Winds will shift later this afternoon into the evening,
becoming more southerly through the overnight hours. Winds will
shift back towards the west by Saturday mid-morning. Impacts to
aviation are not expected through the TAF period.

&&

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

&&

$$

UPDATE...Lynch
DISCUSSION...Godon
AVIATION...Lynch