713 
FXUS63 KBIS 260910
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
410 AM CDT Tue Jul 26 2022

.SHORT TERM...(Today and tonight)
Issued at 409 AM CDT Tue Jul 26 2022

An upper level low sits over northern Manitoba this morning, with 
shortwave energy rounding the base of the trough through the 
Northern Plains. A surface trough is also analyzed from the northern 
Red River Valley to western South Dakota. Convection along the 
surface trough has completely dissipated as of 330 AM CDT, but 
isolated showers and a few rumbles of thunder continue along a 
trailing boundary from the Devils Lake Basin to the southwest corner 
of the state. Behind the secondary boundary, an area of fog has 
developed over far northwest North Dakota, with Crosby reporting 
visibility as low as 3/4 mile.

Aside from diurnal cumulus clouds, expect gradually clearing skies 
throughout the day as surface ridging begins to nudge into western 
North Dakota. The continued cyclonic flow aloft may allow a few 
afternoon and early evening showers and thunderstorms to develop, 
with better chances across the north where another lobe of vorticity 
is forecast to advect in. SBCAPE could build as high as 500 J/kg 
along the Canadian border late this afternoon, but low equilibrium 
levels per RAP soundings should limit effective bulk shear below 30 
kts and preclude any severe weather from happening. Little change is 
anticipated in the synoptic pattern overnight, with persistent 
cyclonic flow to the north and east, and surface high pressure 
continuing to strengthen along the eastern slope of the Northern 
Rockies. Highs this afternoon are expected to be in the 70s. 
Forecast lows tonight are in the 50s, though low lying areas that 
experience a cloud-free sky overnight could fall into the 40s.

.LONG TERM...(Wednesday through Monday)
Issued at 409 AM CDT Tue Jul 26 2022

Below normal temperatures through the middle of the week are 
expected to transition back to above normal by early next week.

The upper low spinning near Hudson Bay is forecast to kick another 
lobe of vorticity into the Northern Plains on Wednesday. A slight 
chance of showers was added to the forecast Wednesday afternoon for 
all areas except the southwest, in line with forecast instability. 
Once again, there does not appear to be enough CAPE or effective 
shear for strong to severe convection. The associated height falls 
will act to further cool the low level air mass, with highs possibly 
limited to around 70 across far northern North Dakota. 

From Wednesday night into Friday, a large area of surface high 
pressure is forecast to migrate from the southern Canadian prairie 
provinces to the lower Missouri River Valley while the upper low 
spins from Ontario towards the eastern Great Lakes. This will bring 
us a prolonged period of quiet but cool weather. Overnight 
temperatures could be quite chilly by late July standards, 
especially near the center of the high. The ECMWF EFI depicts strong 
cold anomalies in surface minimum temperatures over western North 
Dakota Wednesday night, and from south central North Dakota into 
eastern South Dakota Thursday night. Widespread lows in the mid to 
upper 40s seem plausible across western North Dakota Wednesday 
night, and would not be surprised to see typical cold spots approach 
40. Given high confidence in the synoptic pattern, we elected to 
utilize the 10th percentile of NBM temperature guidance for lows 
Wednesday night, which still might not be cold enough in some areas.

Ensemble guidance favors a return to mean ridging over the western 
CONUS this weekend into early next week, with various shortwave 
passages rounding the top of the ridge. The key takeaway is that 
this pattern shift will quickly drive temperatures back above 
normal. NBM high temperature guidance calls for upper 80s to mid 90s 
for all but far north central North Dakota Saturday through Tuesday. 
It is too early to know for certain what degree of humidity can be 
expected with this round of heat. This pattern is also likely to 
bring chances for thunderstorms back into the forecast. 
Predictability on the timing of any wave remains low, but there is a 
signal starting to emerge that late Saturday could be a period of 
interest. 

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 409 AM CDT Tue Jul 26 2022

Isolated showers and thunderstorms will remain possible through
the early morning hours, mainly now limited to southern North
Dakota. MVFR ceilings have moved over KXWA, and confidence on how
long they will persist is low. Think that these low ceilings are
likely to scatter out by late morning. Other terminals could also
experience a period of MVFR ceilings early this morning, with
higher probabilities at KJMS than elsewhere. By this afternoon, 
VFR conditions should prevail. Northwest winds will become 
sustained around 10-15 kts today, with some afternoon gusts 
around 20 kts.


&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Hollan
LONG TERM...Hollan
AVIATION...Hollan