textproduct: Grand Rapids

KEY MESSAGES

- Wintry mix and thunderstorms possible Wednesday

- More seasonable temperatures and precipitation return Friday

DISCUSSION

Issued at 306 PM EST Sat Feb 14 2026

- Wintry mix and thunderstorms possible Wednesday

Wednesday is looking more and more like a dynamically potent day. Precipitation starts as early as Tuesday night. A warm front is expected to lift north across Lower MI coupled with a cyclonically breaking upper wave that could provide significant upper diffluence and inferred upper divergence. The sharp thermal gradient associated with the warm front will offer a range of possible precipitation types to the area.

Starting with far southern Lower MI...there is a strong consensus among Machine Learning (ML) models regarding a chance for thunderstorms Wednesday afternoon. The 14/00Z run of the GEFS ML model (produced by the NSSL) indicates a greater than 40 percent chance of thunderstorms over south-central and southeast Lower MI and a greater than 10 percent chance of severe thunderstorms. A similar solution is presented by both the CSU ML model and Weathernext2 (based on Google DeepMind). This is not surprising given that MUCAPE approaching 1000 J per kg will be well juxtaposed with a belt of strong westerlies. Thunderstorms are not yet explicitly mentioned in the forecast, but expect that to change if current trends hold.

Moving farther north towards central Lower MI, including our northern CWA...there is a signal for mixed precipitation, which may include freezing rain (FZRA). Guidance such as NBM v5.0 and the ECMWF ensemble gives about a 10 percent chance of accumulating a couple hundredths of FZRA. That said, a FZRA ingredient that is conspicuously absent is near-surface cold/dry advection from the northeast, so a rain/snow mix seems a more plausible outcome, and all rain is yet even more plausible based on forecast highs in the 50s to lower 60s for much of Lower Michigan Wednesday afternoon.

Finally, it should be noted that the evolution, position, and timing of all the features mentioned above are subject to change with subsequent guidance. It's reasonable to assume that a fairly narrow band of highly varied weather will occur somewhere in the region; exactly where that is in relation to southwest Lower MI remains to be seen.

- More seasonable temperatures and precipitation return Friday

After a very warm Wednesday and Thursday, another low originating from the Rockies will bring precipitation to the area. As noted before, this could be a rain/snow mix. Predictability is quite poor due in part to dependence on how the mid week system evolves. There is a range of solutions regarding the track of the surface low relative to Lower Michigan, and this has bearing on precipitation types and amounts. By late Friday, a minor incursion of colder air will bring temperatures back down into the 30s and this will last into Saturday.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 1124 PM EST Sat Feb 14 2026

IR satellite at 0420z shows a thick layer of high clouds across the I-94 terminals, with some clouds up along the I-96 terminals. Some light fog is also starting to form as a result of lighter winds and added moisture from the melting snow during the daylight hours. We expect the fog will be a little more extensive away from the high clouds. In addition, there is a light wind of 3-5 knots expected to hold up at the sfc or just above it. This should help to mitigate the fog some. Some IFR is possible at the northern terminals toward daybreak, so have gone with a tempo group to cover that.

Once the fog burns off Sunday morning, skies will be partly to mostly sunny. High clouds will move out, and some mid clouds may float through. Otherwise VFR conditions will persist likely through the end of the forecast period. There is a small chance of a little light fog developing tomorrow night just prior to 06z, but it is too low at this time to add it to the forecast.

GRR WATCHES/WARNINGS/ADVISORIES

MI...None. MARINE...None.