Jamestown, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

930
FXUS63 KBIS 042340
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
640 PM CDT Sat Jul 4 2026

.KEY MESSAGES...

- Isolated thunderstorms possible this afternoon and early
  evening, severe weather is not expected.

- There is a marginal risk (level 1 of 5) for severe weather
  late Sunday afternoon into Sunday evening. The main hazards
  are ping pong ball sized hail and 60 mph winds.

- Near daily chances for showers and thunderstorms continue next
  week.

- High temperatures in the upper 80s to mid 90s Sunday. A modest
  cooling trend then develops through mid-week.

&&

.UPDATE...
Issued at 629 PM CDT Sat Jul 4 2026

Skies over much of western and central North Dakota features
gradually diminishing shallow cumulus, while isolated convective
activity continues from Devils Lake south towards the northern
James River Valley. This eastern activity should also diminish
or exit eastward through the early evening as both loss of
daytime heating and an eastward exiting impulse will reduce
thunderstorm chances in the James River Valley area. The 00Z BIS
sounding looks fairly capped and with the loss of a synoptic
trigger, the remainder of the night across the area will remain
quiet.

&&

.DISCUSSION...
Issued at 113 PM CDT Sat Jul 4 2026

Latest satellite imagery shows Mostly sunny skies across western
and central ND early this Independence Day afternoon. There is
and area of agitated Cumulus development in southern Emmons
county, near the McIntosh county line. This is in an area of
very unstable air, with MLCAPE values 2000-2500 J/kg, as is much
of central ND along and east of the Highway 83 corridor and Cin
is minimal. Shear across the area is minimal, but effective
shear near the aforementioned Cu is around 20-25 knots. Hail
Cape over central ND is high enough (700-800 J/kg) that an
updraft that can sustain itself could produce some marginally
severe hail. Mid-level lapse rates are not great, but better in
the far south central than the rest of central ND. Lapse rate
are not really forecast to steepen much, if at all this
afternoon, but again, there may be a small window of opportunity
early to mid afternoon for a strong or marginally severe storm
in the far south central into the southern JRV. By this
evening, thing should quiet down, with little or no chances for
thunderstorms.

Sunday will bring our next chance for strong to severe storms as
an upper level shortwave trough tracking east through southern
Canada, skirts the area. Steepening lapse rates and marginal
moisture will produce an area of instability over eastern
Montana Sunday afternoon. Vertically veering wind profiles and
increasing shear will provide sufficient shear that
thunderstorms may become supercells with the potential for
large hail up to golf ball size and wind gusts to 60 mph. Shear
vectors are not ideal for supercell development but there`s
enough of a cross component to the surface trough that they
can`t be ruled out. SPC continues a marginal risk for severe
storms over a good portion of western and north central ND
Sunday. At this time it looks like it will be a late afternoon
into the evening timeframe. It will also be a hot day Sunday
with highs in the upper 80s to mid 90s. Current Apparent
temperatures remain in the mid 90s. Will monitor but no heat
related hazards are planned at this time.

We cool down and dry out on Monday with upper level ridging and
surface high pressure traversing the forecast area. A quasi-
zonal upper flow continue through much of the work week,
bringing near daily chances for showers and thunderstorms. After
the hot day tomorrow, we cool down into the 70s most areas by
Wednesday, then see a gradual warmup through the rest of the
work week.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 629 PM CDT Sat Jul 4 2026

VFR through the TAF period. Very small chance of a thunderstorm
near KJMS through 02Z but not enough to include in TAF. Light
and variable winds early this evening become south to southeast
5-10 kts after 03Z becoming south 12-18 kts with gusts 18-25 kts
after 18Z. A front will move in from the northwest after 21Z,
turning KXWA winds west to then northwesterly through 00Z
Monday. Chances for showers and thunderstorms begin to increase
with this front after 21Z, initially mainly near KMOT-KXWA-KDIK,
though not with enough confidence at this point to include at
any one TAF site.

&&

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

&&

$$

UPDATE...Edwards
DISCUSSION...TWH
AVIATION...Edwards