Mandan, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

971
FXUS63 KBIS 050300
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1000 PM CDT Mon Aug 4 2025

.KEY MESSAGES...

- Isolated severe thunderstorms possible southwest tonight.

- Isolated to scattered severe thunderstorms possible Tuesday
  afternoon and evening.

- Severe weather possible over the area again on Thursday,
  possibly lingering into eastern portions of our area into
  Friday.

- Quieter and seasonably cool weather expected for the upcoming
  weekend.

&&

.UPDATE...
Issued at 955 PM CDT Mon Aug 4 2025

Convection over southern North Dakota has ended with the onset
of dark. Area of showers and thunderstorms now over eastern
Montana will then move into western North Dakota after midnight
central time. There remains a threat for severe weather in the
southwest given projected MUCAPE and shear. Low stratus is once
again starting to spread west from eastern North Dakota, as we
remain in a moist southeast flow regime along with boundary
layer moisture elevated. Some patchy fog is also showing up on
eastern observations east, and expect visibility to drop farther
west with time overnight. With a steady southeast wind forecast,
opted to keep patchy fog wording for now with this product
issuance rather then areas or widespread wording.

UPDATE
Issued at 548 PM CDT Mon Aug 4 2025

Modified POPs to better reflect latest radar imagery and near
term trends, with isolated to scattered storms across southwest
and south central North Dakota currently. Plenty of instability
for storms to work with, but we lack decent bulk shear for
organized and long-lasting convection. However, near 30kts of
effective shear poking into far south central ND at the moment,
and a few robust updrafts in Emmons County are occasionally
approaching severe limits. Otherwise, we await for Montana
storms to push east later this evening into the overnight, with
an isolated severe potential in the southwest.

&&

.DISCUSSION...
Issued at 212 PM CDT Mon Aug 4 2025

Current surface analysis places low over the central Rockies
with high over James Bay, resulting in moist southeasterly flow
over our area. Upper level analysis places ridge stretching
along the lee side of the southern/central Rockies stretching
into the Northern Plains, while compact low pushes through the
Pacific Northwest. A few weak short waves noted in the flow.
Over our area, main concern is some low clouds due to the
elevated moisture lingering over the area which have been
reluctant to dissipate.

For the rest of this afternoon into this evening, isolated
showers and storms are possible over various parts of the area,
mainly the southwest into the south central/James River Valley.
With respect to severe the are of concern continues to be mainly
southwest North Dakota. Still some question on whether the
forcing is available and the timing works out to get a stronger
storm going, but latest guidance continues to indicate elevated
instability over this area with sufficient deep layer shear to
support isolated severe development.

Tuesday brings severe concerns through the area as the
aforementioned compact upper low opens up and pushes towards the
area with guidance still showing elevated instability (CAPE
values ~1500-2500 J/Kg) with around 35-40 kts of 0-6km shear.
The question is the timing of storm initiation given the
possibility of consistent lingering cloud cover, but some
guidance is suggesting convection could develop in the early
afternoon, with others holding the more robust convection more
towards evening.

Quieter weather looks on tap for Wednesday, with the severe
threat returning Thursday. CSU machine learning guidance
continues to show elevated severe threat over much of our area,
with guidance continuing to show strong instability and deep
layer shear. Will have to keep a close eye on how this develops
as plenty of moisture will be available for storms to work
with. The potential for severe continues into Friday over
eastern portions of our area.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 548 PM CDT Mon Aug 4 2025

Areas of IFR/MVFR ceilings over eastern North Dakota early this
evening, with potential redevelopment to the west along with
patchy fog. Isolated thunderstorms possible over parts of
western and central ND this evening, then later this evening and
tonight over southwest North Dakota, spreading northeast
Tuesday morning.

&&

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

&&

$$

UPDATE...NH
DISCUSSION...JJS
AVIATION...NH