FXUS63 KBIS 181936
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
236 PM CDT Thu Jun 18 2026

.KEY MESSAGES...

- Chances (20 to 50 percent) for showers and thunderstorms this
  afternoon and evening. The threat for severe weather is low.

- Near to slightly below normal temperatures this weekend, with
  daily chances for showers and thunderstorms.

- A gradual warming trend through next week, along with
  continued chances for precipitation each day.

&&

.DISCUSSION...
Issued at 240 PM CDT Thu Jun 18 2026

Currently, northwest flow aloft with a steady northwest low/mid
level flow across the region. Diurnal instability along with
subtle embedded waves in flow aloft contributing to widespread
CU along with some weak to modest radar returns. Little shear
present limiting so far any stronger updrafts.

A more defined embedded S/WV trough slides across the Dakotas
later today through tonight, and will bring a better coverage of
showers and thunderstorms from west to east across western and
central North Dakota. One can already see this activity to our
west over north central and northeastern Montana. Some increase
in bulk shear values, so a few stronger storms will be possible
with this wave.

Continued unsettled northwest flow for Friday, with enough CAPE
and shear for diurnally driven chances for showers or a few
thunderstorms north central and east.

S/WV mid level ridge building over the Northern High Plains
region within a broader split flow regime Saturday, results in
increasing south-southeasterly flow and WAA, leading to warmer
temperatures to start the weekend. Both a northern and southern
stream S/WV trough then propagate east towards the Dakotas
later in the weekend, with the southern stream feature more
progressive and moving across South Dakota Sunday, keeping
precip chances along the ND/SD border area and south. A sfc
trough associated with the northern stream wave remains along
the MT/ND border, keeping precip chances far west Sunday, with
dry conditions expected elsewhere. The northern stream S/WV is
then forecast to close off over the Northern Plains Sun night
through Monday, and will bring widespread chances for showers
and storms to much of the state this period.

Thereafter, a slow warming trend is favored through the work
week as ensemble means depict zonal flow and/or ridging
developing across the Northern Rockies and into the Northern
Plains. In the wake of this flow pattern, long range ensembles
in fair agreement with a troughing pattern materializing to our
west, which would tend to maintain near normal temperatures and
bring better chances for precipitation.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1242 PM CDT Thu Jun 18 2026

Mainly VFR conditions are expected through the 18Z forecast
period. Increasing cloud coverage this afternoon as diurnal CU
develops and expands, with some low VFR cloud ceilings at
times. Another round of showers and thunderstorms are forecast
as well this afternoon through this evening. Will keep PROB30
groups to account for the precipitation potential. Some brief
MVFR conditions remain possible with these showers or
thunderstorms. Look for steady westerly wind through the 18Z
TAF period.

&&

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

&&

$$

DISCUSSION...NH
AVIATION...NH