054
FXUS63 KBIS 040600
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
100 AM CDT Wed Jun 4 2025

.KEY MESSAGES...

- Near-daily low to medium chances for showers and thunderstorms
  through Saturday.

- The highest thunderstorm chances on Wednesday are across
  southern North Dakota during the mid afternoon through early
  evening.

- Near to slightly below average temperatures through the
  weekend, except warmer on Saturday.

&&

.UPDATE...
Issued at 100 AM CDT Wed Jun 4 2025

Limited updates needed at this time. A few showers may enter
into the west and north central overnight tonight. Lows tonight
may also be quite cool, and generally in the 40s with some upper
30s possible. Overall the forecast remains on track.

UPDATE
Issued at 1043 PM CDT Tue Jun 3 2025

Just a few stray showers remain across the northern half of the
state late this evening. Will maintain a 15 percent chance of
rain through the night given the cyclonic flow and a shortwave
evident on water vapor imagery now moving through Montana.
Overall though, a quiet overnight period is expected.

UPDATE
Issued at 705 PM CDT Tue Jun 3 2025

Isolated to widely scattered showers will continue across
northwest and north central North Dakota this evening. Very
little lightning has been observed, and only across southern
Canada. Coverage of showers should diminish heading into the
overnight hours, but a few stray showers could persist through
the night. A mid level shortwave approaching from the west
Wednesday morning could then cause an increase in shower
activity across the north, with amounts and intensity remaining
light.

For Wednesday afternoon, CAMs are in general agreement with
scattered thunderstorms developing across southern North Dakota.
The 12Z HREF shows the highest probabilities for thunderstorms
(via neighborhood probabilities of simulated reflectivity
greater than 40 dBZ) from between Dickinson and Hettinger to
between Carrington and Jamestown during the mid afternoon
through early evening hours. Forecast environmental parameters
include around 500-1000 J/kg SBCAPE (with little to no CIN), an
equilibrium level no higher than 30 kft, and effective bulk
shear around 20-30 kts. This could yield a stronger storm or
two, with erratic strong wind gusts being the primary hazard
given forecast inverted-v soundings. The strongest storms could
also produce small hail given a relatively lower freezing level
and shallow depth of the FZL-LFC layer.

&&

.DISCUSSION...
Issued at 215 PM CDT Tue Jun 3 2025

Currently cyclonic flow around a low pressure system way up in
Canada is allowing some isolated to scattered showers across
eastern Montana and northwestern North Dakota. This lower
pressure is also allowing the classic diurnal cumulus clouds to
form across the state. This is also still pulling the wildfire
smoke south into the United State, although the worst of it is
far east of North Dakota. The smoke here is staying aloft.

High temperatures today will be a few degrees below average in
this northwest flow. The isolated and scattered showers will
continue overnight and through Wednesday, becoming more
widespread as a weak upper level shortwave moves in. There is
actually a chance of thunder after 7pm Wednesday in the south
central, otherwise just light showers.

Temperatures will slowly warm up into the mid and upper 70s as
that low pressure system mentioned above slides east. This will
flatten the northwest flow over the Northern Great Plains,
allowing warmer temperatures. By this weekend we could see 80
again.

Thursday another shortwave moves through, bringing another low
chance of showers and maybe a thunderstorm. Saturday the same
thing will occur with chances of showers and thunderstorms. No
severe thunderstorms are expected through the period, however
Saturday evening could be a timeframe when they could. Some
machine learning guidance is hinting at storms Saturday. Next
week the pattern could be active again as a low pressure system
dives south into Wisconsin, putting us in cyclonic flow.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 100 AM CDT Wed Jun 4 2025

VFR conditions are overall expected through the forecast period.
Later tonight through Wednesday morning, a few showers will be
possible in the northwest and north central. Isolated to
scattered showers and thunderstorms could then be possible
Wednesday afternoon and evening across much of the area.
Confidence was only high enough to include PROB30 in the TAFs at
this time. Showers then become more isolated Wednesday night.
Generally VFR, to perhaps brief MVFR, conditions are expected
with any shower activity. The strongest storms Wednesday
afternoon could produce brief visibility restrictions and
erratic wind gusts. A light west to north wind will be found
for Wednesday, becoming light and variable Wednesday night.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

UPDATE...Anglin
DISCUSSION...Smith
AVIATION...Anglin