329
FXUS63 KFGF 310254
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
954 PM CDT Thu May 30 2024

.KEY MESSAGES...

- Minimal chances for impacts through Saturday. Additional
  chances for showers Friday night into Saturday morning.

- There is a chance for impactful weather on Sunday, with
  isolated to scattered strong to severe thunderstorms possible.

- An active pattern keeps the possibility for showers and
  possibly stronger storms in the forecast heading into the
  first half of next week.

&&

.UPDATE...
Issued at 954 PM CDT Thu May 30 2024

Showers have off into the eastern end of the forecast area with
lightning only in the far eastern counties. This will continue
east clearing our area around midnight. Clearing skies as
evidenced by satellite behind this band of rain with lows
dipping into the 40s for most tonight.

UPDATE
Issued at 635 PM CDT Thu May 30 2024

The cold front is nearly through eastern North Dakota now with
only parts of Cass and Richland counties still seeing southeast
winds. Rain will continue along the front as it tracks east with
a couple of the stronger cells south of HWY 10 maybe capable of
winds to 40 mph and pea size hail. Instability will wane by 9pm
transitioning to the line to only a heavy rain threat.

&&

.DISCUSSION...
Issued at 306 PM CDT Thu May 30 2024

...Synopsis...

Active weather continues through the forecast period as H5 low
pressure strengthens over the northern Canadian Provinces and moves
very slowly to the east. A series of associated shortwaves and
troughs, of various strengths, will serve to bring ongoing chances
for showers and thunderstorms.

...Minimal Impacts Through Saturday...

Today`s showers and embedded thunderstorms are expected to continue
eastward through the afternoon and evening, giving way to relatively
quiet weather heading into Friday morning. Rain chances will
increase through the day, however, with another round of showers and
mainly embedded thunderstorms overnight Friday and early Saturday
morning.

...Severe Thunderstorms Possible Sunday...

A relatively deep H5 trough extends southward into the Northern
Plains late Saturday into Sunday. As this moves east, strong
moisture return prevails out of the south, allowing CAPE to increase
ahead of a sharp theta-e gradient boundary. SBCAPE has an 80 percent
chance to exceed 1000 J/Kg, and a 50 percent chance to exceed 2000
J/Kg in GEFS ensembles. Shear looks supportive at both the low (0-
3km) levels and the deep (0-6km) layers. CSU machine learning
highlights portions of the region as having the potential for severe
thunderstorms, with a probability of around 15 percent. As of this
afternoon SPC is also carrying a 15 percent chance for severe storms
for the southern Red River Valley and west central Minnesota. Model
soundings have been somewhat consistent in showing support for
supercells or hybrid multicell/supercell clusters. Details are
expected to change; however, it is worth noting that guidance has
been consistently in agreement over the past couple of days.

...Active Weather Continues...

Heading into next week, H5 low pressure over northern Canada moves
into the Hudson Bay region. This will allow a somewhat progressive,
but still wavy, zonal pattern to prevail across the northern CONUS.
Our next chance for showers and storms will occur in response to a
trough passage on Tuesday and Wednesday. While there is still a lot
of uncertainty in exact details, a few strong storms could be
supported.

From Wednesday onward, guidance shows a very large range of possible
scenarios involving additional chances for showers and
thunderstorms. Timing has a large degree of variability between
ensemble members, thus details at this time are minimal; however,
large scale pattern support indicates at least the potential for
stronger storms if timing lines up with peak afternoon heating.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 635 PM CDT Thu May 30 2024

VFR conditions post front for ND taf sites already with this
lasting through the forecast period. Rain showers through 8pm
for TVF and 10pm for BJI with VCTS possible. gusty winds not
expected with VFR conditions settling in post rain as winds
become light and WSW through Friday night.

&&

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

&&

$$

UPDATE...TT
DISCUSSION...Lynch
AVIATION...TT