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