Mandan, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

270
FXUS63 KBIS 060939
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
439 AM CDT Fri Jun 6 2025

.KEY MESSAGES...

- Dense fog has developed over portions of southwestern and
  south central North Dakota, therefore issued a Dense Fog
  Advisory until 10 am CDT/9 am MDT.

- 30 percent chance of showers and thunderstorms southwest to 90
  percent chance northeast on Saturday. A few strong to severe
  thunderstorms are possible over south central and eastern
  North Dakota.

- Breezy to very windy conditions this weekend into Monday with
  the strongest winds on Sunday.

&&

.DISCUSSION...
Issued at 439 AM CDT Fri Jun 6 2025

Fog has developed over most of the southern half of the state,
with dense fog in portions of southwestern and south central ND.
Therefore, issued a Dense Fog Advisory until 10 am CDT/9 am
MDT. There is a greater than zero chance the advisory may need
to be expanded another tier of counties over the next hour or
two, so will continue to monitor for ever changing conditions.

Once fog dissipates by mid to late morning, expect mostly clear
skies and dry conditions. Or at least, mostly clear skies in
regard to cloud cover. Another round of elevated smoke is
working its way across the state from north to south and will
likely produce milky looking skies again for most of the state,
most of the day. Any smoke should remain elevated today through
Saturday morning. However, with a passing cold frontal boundary,
near-surface smoke will likely return to the northwest starting
Saturday afternoon while advancing southeastward through
Saturday night.

Speaking of the cold fropa, Saturday afternoon and evening will
be the next best chance for showers and thunderstorms. A few
thunderstorms may be severe. At this time, the primary threat
appears to be winds up to 60 mph and ping pong ball size hail.
One of the questions is the timing of any forcing. It appears
that the front itself will pass through the forecast area rather
quickly... by mid-afternoon. For the frontal passage, marginal
bulk shear vectors at around 30 to 35 kts appear more
perpendicular to the front. This could favor some discrete
cell development, though with only marginal shear, the potential
of these cells may be limited. However, a trailing secondary
surface trough may contain higher bulk shear closer to the 40
to 50 kt range with MUCAPE values around 1500 J/kg (these MUCAPE
values are similar to the initial fropa). Unlike the initial
fropa, bulk shear vectors should be a few clicks closer to
parallel with the forcing, which would favor a more cluster or
linear development. All this combined, believe the biggest
threats are as mentioned with winds up to 60 mph and hail up the
size of ping pong balls. Any larger hail would be highly
conditional (definitely not impossible) based on the ingredients
aligning a little better than mentioned here.

For Sunday, very windy conditions are expected, along with
residual shower chances mainly north and east, with thunderstorm
chances east. Precipitation chances will end from west to east
Sunday night through Monday with breezy conditions persisting.
Dry conditions are then expected Monday night through Tuesday as
winds become light once again. The latter half of the workweek
will feature periodic shower and thunderstorm chances.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1254 AM CDT Fri Jun 6 2025

*update as of 0930Z*

Fog has developed over much of southern North Dakota, with dense
fog over parts of the south central and southwest. KJMS has also
been reporting 1/4 SM recently, although nearby webcams indicate
this is likely shallow and patchy in nature, so have held off
on going 1/4 SM in the TAF for now. That said, conditions may
continue to deteriorate through the early morning before fog
dissipates mid-morning.

Original 6Z aviation discussion:

VFR ceilings and visibility are generally present across the
state, though a few light rain showers maintaining VFR
conditions are present across the far southeast. That said,
patchy fog is starting to develop over parts of the southwest
and south central. KBIS remains the terminal most likely to see
impacts from fog development, although KDIK and KJMS could see
patchy fog as well as some point tonight into Friday morning.
Any fog should diminish by mid-morning, at which point VFR
ceilings and visibility are expected through the remainder of
the period.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 10 AM CDT /9 AM MDT/ this morning for
NDZ034>036-041-042-044>047.

&&

$$

DISCUSSION...Telken
AVIATION...Telken