644 
FXUS63 KBIS 062118
AFDBIS

AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
318 PM CST Sun Nov 6 2022

.SHORT TERM...(This Evening through Monday)
Issued at 317 PM CST Sun Nov 6 2022

The main concerns in the short term will be winds along with snow 
chances. 

Surface observations from across western and central North Dakota
continue to show wind gusts approaching 60 mph at times in the 
central parts of the state and towards the James River Valley. 
Winds in the west have begun to settle down a little with most 
locations staying below 50 mph over the past couple of hours. The 
first question was how to handle the High Wind Warning. We decided
to cancel it in parts of the west from roughly McKenzie and Dunn 
counties south, where winds have fallen enough that they are now 
even below advisory levels. We considered cancelling it all the 
way north to the Canadian border, but Williams and Divide counties
still have gusts close to 50 mph. 

Winds overall should subside late this afternoon / early this 
evening as surface low pressure across southern Canada moves east.
Momentum transfer from area BUFR soundings also support the 
general idea of lesser mixing and gradually decreasing winds.

Light snow continues to rotate around the low into northern parts 
of the state.  Short term models have been a little quick to get 
rid of the snow, and will continue to carry a small pop for another 
few hours this afternoon.  

Once the snow ends and winds subside, it should be a fairly quiet, 
but cold night with lows in the single digits above zero and teens. 

Increasing warming air advection / isentropic lift on Monday will 
bring another chance of snow to much of the area.  Overall, amounts 
look to stay an inch or less in most locations which is supported by 
the latest HREF and NBM 4.1 probabilities for snow amounts of an 
inch or greater.  The far north looks to have the best chances 
of seeing an inch with NBM 4.1 values for an inch or greater 
approaching 50 percent in that area.   

Winds will be another concern for Monday, especially in the 
southwest during the afternoon. There are some conflicting signals
how strong wind will get with the initial warm air advection and 
clouds limiting mixing. Once the better warm air advection lifts 
out of the southwest part of the state, it appears they could mix 
a little better in the afternoon potentially pushing speeds to 
near advisory levels. For now have opted to hold off on another 
wind headline, but it will be something to monitor for later 
updates.

.LONG TERM...(Monday Night through Sunday)
Issued at 317 PM CST Sun Nov 6 2022

Possible winter storm in the long-term, but lots of uncertainty on 
the track of this system has models continue to shift the system.

Wednesday a broad trough is going to dig into Western CONUS with a 
ridge out over the Southeast. This trough will progress into the 
Great Plains Thursday with an upper located around the Wyoming 
Nebraska border. This is where model guidance solutions begin to 
diverge with two different solutions. 

1) GEFs ensembles have a more southern track for the upper low 
slowing down by the South Dakota and Minnesota border. Thus 
forming a potential deformation band across eastern and south 
central North Dakota. This could cause widespread snow 
accumulations across the James River Valley. However, there is a 
majority of the GEFs members speeding up the upper low which would
cause lower snow amounts across the south central portion of the 
state.

2) EPS ensembles have more a northern track with a faster 
progression through the Northern Plains. The latest run for this 
solution has moved the track a bit further west increasing snowfall 
probabilities for southwestern, south central, and the James River 
Valley.

Model solutions are closer in solution than the previous runs, but 
there is still a lot of uncertainty for the track of the upper low. 
Ensembles have shifted the track of this system multiple times so a 
lot could change for this event. Substantial snowfall should be 
expected somewhere in the Northern Plains. The question is where 
will the heaviest bands set up?

Temperatures will continue to decrease after Tuesday dropping below 
freezing by Thursday as the system moves into the region. A wintry 
mix is possible across south central and southeastern North Dakota 
early as the low moves into the region. Winds are also coming in 
fairly breezy on the NBM for Thursday possibly blowing snow and 
reducing visibilities.

After the aforementioned system northwesterly flow and cold 
temperatures will linger across the region.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 317 PM CST Sun Nov 6 2022

A little light snow continues to wrap around low pressure moving
across southern Canada. It appears any impacts to the terminals
from the snow should be minimal, but MVFR clouds and could linger
for a few more hours. Gusty northwest winds will continue this
afternoon, but some decrease this afternoon in the west is
expected before things diminish even more this evening across all
of western and central North Dakota. Another chance of snow 
arrives late in the TAF period, especially towards Dickinson. It 
may take until just after this forecast period for it to arrive at
any of the other terminal locations. 

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until 6 PM CST this evening for NDZ001>005-
009>013-019>023-025-034>037-042-045>048-050-051.

&&

$$

SHORT TERM...King
LONG TERM...Johnson
AVIATION...King