312 FXUS63 KGRR 040813 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 313 AM EST Wed Feb 4 2026 .KEY MESSAGES... - Light snow Thu-Fri with a chance of freezing drizzle Thu evening - Colder this weekend with light lake effect along the lakeshore - Moderating temperatures next week && .DISCUSSION... Issued at 313 AM EST Wed Feb 4 2026 - Light snow Thu-Fri with a chance of freezing drizzle Thu evening Plenty of stratocumulus clouds over the area this morning, with the radar showing plenty of flurries accompanying the clouds. High pressure is building in, but this moisture is trapped under the subsidence inversion. It is rather shallow with cloud bases around 2500-3000 ft and the tops of the clouds 4-5k ft per the KGRR VWP. Even though the moisture is shallow, the DGZ is squarely in the cloud layer, leading to the flurries. There are likely some shallow lake effect snow showers over the lake that will move onshore today as the low level flow becomes westerly later today. After a few flurries persisting through most of tonight, we will see the next widespread light snow spread over the area from NW to SE Thursday morning ahead of the next short wave coming in on the NW flow aloft. This event does not look to be anything special, considering what the area has endured over the last month. The duration looks to be a few hours from the time the lower portion of the column saturates sufficiently, to when we lose the mid and upper level moisture Thursday afternoon. There continues to look like there will be some lake enhancement for the lakeshore, but nothing strong with low inversion heights due to the deep cold air and cyclonic flow aloft staying north of the area. One concern that continues to be possible centered around Thursday evening will be a chance of some freezing drizzle. As mentioned above, we lose the mid and upper level moisture by about 21z Thu. We see a warm front approach the area at the sfc, while we will be in between upper waves aloft. Forecast soundings and RH overviews indicate that the DGZ will become unsaturated. The question is do we continue to precipitate or not. If we do, then the type will likely be freezing drizzle until about 06z or so when we see the mid and upper level moisture return with the next short wave and cold front. Then any precipitation is expected to change back to light snow. Then as the front moves through, we will see snow end inland, and some lake effect take shape along the immediate lakeshore. - Colder this weekend with light lake effect along the lakeshore We will see much colder air move back in over the area behind the system coming through on Friday. 850 mb temps will drop from -5C Friday morning, to almost -19C Friday night. We will see highs on Friday well into the 30s, and then dropping to the single digits above zero Friday night. Obviously this is ideal instability for lake effect to take place. However, a big lake effect is not expected with many factors working against it. In the big picture, we do not see cyclonic flow take shape as the upper jet core will stay east of the area. This will limit vertical extent of the lake effect columns with lower inversion heights. Ridging building at the sfc will also be a result of this, and will work against good lake effect. We will also see the flow from the NNW, which will keep lake effect close to the lakeshore. A weak short wave looks to approach the area on Sunday, but it will be moisture starved, and all of the limiting factors mentioned for Saturday will persist into Sunday. Max temps on Sunday will start to modify as the coldest air aloft moves out of the area. - Moderating temperatures next week We will see the flow aloft from the NW persist into early next week, but the origin of the flow will be from the Pacific at that time with the upper ridge axis just west of our region. Another short wave comes through, but the main forcing from it will stay more north, and likely not affect our forecast area much, if at all. The ridge axis will then be over the area on Tuesday. Return flow at the sfc from the south will help to warm our sfc temps nicely for Monday and Tuesday. 850 mb temperatures warm to near 0 to +6C by Tuesday afternoon. This will help drive max temps to near 40. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 1208 AM EST Wed Feb 4 2026 Satellite images show much of Lower Michigan under MVFR clouds but for some patchy clearing. These clouds are persisting under weak north flow and moisture added by the Great Lakes. Very light snow flurries are occurring especially and GRR and MKG all the way north to Lake Superior. There is not much indication that the broader weather pattern will suppress these clouds on Wednesday. In general, models were underdoing the cloud cover this evening. Latest short-term models, including the HREF, maintain mostly cloudy conditions with MVFR ceilings through Wednesday. The ECMWF is broadly painting a trace of precip all day too, to support the idea of just very light snow flurries persisting. This is certainly the pattern and the time of year to be pessimistic with the cloud forecast. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...NJJ AVIATION...CAS

NWS GRR Office Area Forecast Discussion