Jamestown, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

546
FXUS63 KBIS 071826
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
126 PM CDT Sat Jun 7 2025

.KEY MESSAGES...

- Isolated to scattered showers and thunderstorms today. A few
  strong to severe thunderstorms are possible, over south
  central and eastern North Dakota.

- Breezy to windy conditions today and Monday. Very windy
  conditions expected on Sunday.

- Areas of smoke may return to northern and western North Dakota
  today through tonight.

- Warming temperatures continue for most areas today, followed
  by a cool down on Sunday. Near to slightly above normal
  temperatures expected for next week.

&&

.UPDATE...
Issued at 117 PM CDT Sat Jun 7 2025

There were no major updates with this product issuance. Surface
cold front continues southeast, driven by a potent mid level
S/WV moving slowly south across far south central Canada. Along
the FROPA, we continue to see wind gusts from 35 to near 50
mph, though this only lasts with the initial frontal surge.
Thus, have not issued any wind headlines and do not plan to.
Shower and thunderstorm chances remain on track, with initial
development expected along the front within the next hour or so.
Messaging remains unchanged.

UPDATE
Issued at 927 AM CDT Sat Jun 7 2025

The forecast for today remains on track. Vigorous mid level
S/WV moving southeast across far south central Canada will drive
a sfc cold front through western and central North Dakota this
morning through the afternoon. Along the FROPA, a short period
of gusty northwest winds are probable, with gusts anywhere from
35-45 mph. A few showers northwest and north central currently.

As we destabilize this afternoon, the combination of decent
CAPE, marginal 0-6km shear, and forcing ahead of the mid level
wave will contribute to scattered thunderstorm development along
the front, mainly from south central ND northeast into
northeastern ND, with activity tracking east with the FROPA.
Mean winds perpendicular to the front, so discrete updrafts are
anticipated, with a few severe storms still possible between the
Missouri River in south central ND and east across the James
River valley this afternoon through early this evening.

UPDATE
Issued at 635 AM CDT Sat Jun 7 2025

Limited updates needed at this time. Some shower activity is
possible in the north this morning, although the main push of
showers and thunderstorms still remains in southern Canada.
Meanwhile, some patchy fog has formed in southeastern North
Dakota and may linger into the mid morning hours. Overall made
some minor changes to PoPs and patchy fog mention based on
current trends. Otherwise the forecast remains on track.

&&

.DISCUSSION...
Issued at 432 AM CDT Sat Jun 7 2025

Passing of a cold front will be the main weather maker today.
Currently this cold front is in southern Saskatchewan and should
reach northwestern ND this morning, central ND mid morning to
early afternoon, and eastern ND by this evening. Timing of this
front will greatly determine thunderstorm activity and how
severe these storms may be. Too early of frontal passage would
limit the severe threat while a slight delay could cause for
more widespread severe thunderstorms. Models showing decent
surface based cape developing across central and eastern
portions by early this afternoon, and remaining into the early
evening. With this instability is about 30 to 40 knots of shear,
with the vector perpendicular to the front. This could imply
some discrete cells are possible with this front. Hodographs
show some slight veering at the lower levels, although most are
fairly straight. Thus the main threat with any discrete cell
that can form would be large hail. Have kept the likely hail
size to ping pong ball, although any discrete cells with some
weak rotation could see hail sizes of a golf ball or perhaps
slightly bigger. The wind threat today is limited as DCAPE is
less than 1000 J/KG. 0 to 3 km shear is somewhat elevated, thus
will stick to 60 mph for thunderstorm wind gusts. There is also
a hint at a secondary push of weaker instability behind the
front, with higher shear. The shear vector is more parallel to
the front, implying a more linear mode of convection. Perhaps
some higher wind would be possible if a secondary line can form.
SPC has maintained a Marginal Risk for much of south central
and eastern North Dakota today, yet trimmed off some of the
western extent for now. Overall something to monitor during the
day, and thunderstorms could begin in the early afternoon along
this front then continue through the early evening. Otherwise
look for warming temperatures ahead of this front today, with
many areas in the 70s. Areas in the northwest will see slightly
cooler temperatures near 70 degrees. This front may also bring a
strong push of wind as it passes as indicated by some increased
pressure rises and cold air advection. Blended in some NBM90 to
account for this. HREF Ensemble winds max out over 50 mph along
with front, although the probabilities of these stronger winds
are around 10 percent. These strongest wind gusts would likely
be short lived as the front moves. For now will hold off on any
wind highlights. The combination of increased winds and lowering
RH values behind the front could bring some increased fire
weather concerns across the northwest. Will limit messaging on
this given the green fuels status. Initial showers and
thunderstorms should push east tonight. Wrap around moisture
could then linger showers across the north tonight. Breezy
northwest winds may also be found tonight, with lows in the 40s
to near 50 degrees. Smoke may also return at the surface behind
this front later today through tonight, especially in the north
and west.

Cutoff low behind the front lingers across the area on Sunday.
Chances for showers and perhaps a few thunderstorms will linger
across the north Sunday morning, then perhaps spread across the
central and east Sunday afternoon and evening. Colder
temperatures behind the front can be expected with highs in the
50s northeast to near 70 southwest. The strong gradient aloft
could bring strong northwest winds at the surface on Sunday.
ECMWF EFI values continue to be elevated as well for Sunday.
Blended in some NBM90 to account for this strong wind signal
which gives forecast advisory level winds to much of the CWA.
Will have to monitor this for any potential wind highlights.
Some lowering of RH in the 20s, combined with this strong wind,
in the west could also bring some increased fire weather
concerns although green fuels should limit this as well. With
the northwest flow aloft, smoke may linger at least aloft during
the day Sunday, and perhaps mix down to the surface Sunday night
into Monday. Showers and breezy northwest wind may also linger
across the east Sunday night into Monday, with low temperatures
in the 40s. Breezy winds shift to the east as do the chances for
showers for the remainder of Monday. Temperatures will remain
cool in the eastern half of the state, yet may warm to near
normal for the west. Afternoon RH values in the west could once
again lower into the 20s, although winds in these areas should
be on a diminishing trend. With the lingering northerly wind
could also bring the possibility of smoke returning to the
state on Monday. Dry conditions with diminishing winds can then
be expected for Monday night, with lows in the mid 40s to mid
50s.

Brief upper level ridging with a surface low developing will
bring mainly dry conditions during the day Tuesday. Temperatures
look to warm with highs returning into the 80s for many areas.
This developing low may bring some unsettled weather Tuesday
night, with NBM placing some chances for showers and
thunderstorms. Mid to late next week, clusters indicating the
ridge flattens and opens the door for multiple upper level waves
in west to southwest flow. At the surface, a low pressure system
in the plains could return higher amounts of moisture from the
Gulf. The overall result could be more active weather with near
normal temperatures. NBM currently has chances for showers and
thunderstorms nearly each day mid to late next week. CSU-MLP
showing perhaps some isolated severe weather is possible during
this time period. And depending how open the gulf becomes,
perhaps some heavy rain is possible. Currently WPC has a
Marginal Risk for excessive rainfall in the area for Day 5
(Wednesday). This will all depend on the potential breakdown of
the mentioned ridge, although for the time being perhaps a more
summer like pattern could return mid to late next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 117 PM CDT Sat Jun 7 2025

Overall, VFR conditions are expected through the 18Z forecast
period. A cold front will then move from northwest to southeast
across the state today. This will bring chances for showers and
thunderstorms to most sites. Handled this with TEMPO groups.
Brief MVFR conditions are possible with any shower and
thunderstorm activity. A few thunderstorms may also be strong to
severe with gusty winds and large hail possible, especially in
south central and eastern North Dakota (KBIS/KJMS). Showers and
thunderstorms look to diminish this evening, with some lingering
mid to high level clouds and perhaps a few showers in the north
central through tonight. Winds during the forecast period will
be breezy to windy. Look for a breezy southerly winds ahead of
the front becoming west/northwest and increasing along and
behind the front. Areas of smoke may filter in behind this front
as well. Gusty northwest winds through Sunday expected.

&&

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

&&

$$

UPDATE...NH
DISCUSSION...Anglin
AVIATION...NH