361 FXUS63 KGRR 071741 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 1241 PM EST Sun Dec 7 2025 .KEY MESSAGES... - Light snow event tapers off today - Light snow Mon night/Early Tue; Mixed Precipitation Wed - Another system Friday with reinforcement of colder air next weekend && .DISCUSSION... Issued at 327 AM EST Sun Dec 7 2025 - Light snow event tapers off today The next part of the ongoing clipper train is arriving here this morning on time with light snow spreading across the area. This light snow is out ahead of the next short wave of the series currently over MN. In addition, we have coupled jet forcing from a departing jet streak over the UP and Eastern Ontario, and the upper jet streak coming in on the backside of the wave over MN. The forcing from the jet coupling will be tapering off this morning. This will help to diminish the snow intensity and amounts compared to areas to our WSW where the advisories and warnings are in place. We are looking at higher end amounts being 2-3 inches across the southern half of the forecast area, with less further north and inland. The snow will come to a fairly quick end this morning as the MN wave moves through by 18z this afternoon. A few light lake effect snow showers may linger over the NW corner of the area this afternoon as nrly flow will bring some snow showers to Big and Little Sable Points, and downwind from Grand Traverse Bay. These will be transient, with little additional accumulations. - Light snow Mon night/Early Tue; Mixed Precipitation Wed We will see a little longer relative break in between systems from this afternoon through Monday compared to the last couple of short breaks. We do see a short wave that comes through Monday afternoon, but the bulk of this forcing goes south of the area, and broader scale upper ridging results in sfc ridging remaining in place, and will limit precipitation during the day. Not far behind the Monday afternoon short wave will be another short wave that is currently offshore of British Columbia that will approach the area Monday night. This one will be a more direct hit than the Mon wave. Even though it is a direct hit, it will once again be moisture starved. Much of the area will see an inch or two of snow accumulation. The best snow will fall once again across the NW corner of the forecast area toward Ludington. This is due to enhancement of moisture and instability coming in off of Lake Michigan with the flow from the SW with the sfc low over Lake Superior. An advisory for the NW corner of the area is not out of the question for Mon night/Tue morning. We see a break in the snow Tuesday afternoon, with additional precipitation developing quickly Tuesday evening. This wave has been well advertised to be a bit stronger by all of the model data over the past few days. This is the result of the upper flow buckling a bit, and the jet streak being a bit stronger, around 145 knots feeding this wave. What is interesting, and a bit counter-intuitive, is the low will be a bit further south that the Monday night system. However, the strength of the low will draw warmer air ahead of it, and change some of the snow to rain south of the low track late Tuesday night into early Wednesday afternoon, before it goes back to snow as colder air comes in later Wednesday behind the system. Just north of the sfc low, a band of better snow is expected to fall, on the order of likely a general 3-5 inches or so. The track of the low has been fluctuating a little bit by 20-40 miles, which makes a big difference in this case. We expect this to continue, but the trend over the last 24 hours for it to go a little further north across Central Lower. A break bout of lake effect will be possible behind the Wed system as the flow aloft will remain cyclonic for a bit along with a shot of colder temperatures. This looks like right now to be more of a flow from the NNW, favoring mainly the lakeshore counties. - Another system Friday with reinforcement of colder air next weekend The train of short waves only continues late in the week too, as yet another more potent short wave takes aim on the area on Friday. It will be another system with limited deep moisture with no good moisture source being tapped, but the lakes helping things out a bit. Then, another reinforcing shot of colder air comes in with 850 mb temperatures dropping to the negative mid teens C. This will get the lake effect machine going again then going into next weekend. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1241 PM EST Sun Dec 7 2025 Low clouds and light snow to continue this afternoon as light northwesterly winds persist...bringing mostly prevailing mvfr conditions to the terminals. winds will gradually shift to the northeast by this evening with clearing skies and vfr conditions building in. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory until 11 PM EST this evening for LMZ844>849. && $$ DISCUSSION...NJJ AVIATION...Maczko

NWS GRR Office Area Forecast Discussion