Grand Rapids forecast discussion

Discussion

Issued at 300 AM EDT Fri Oct 16 2026

- Wet, windy, and colder today; Frost tonight

No surprises thus far with the ongoing system over the area this morning. The main batch of rain showers came through earlier with the nose of the strong low level jet passing through. This has exited east, and the initial cold front has just about cleared the area to the east as of 230 am.

Plenty of forcing remains and continues to bring showers to the area as the large northern stream trough is now approaching with large scale upper divergence ahead of it moving over the area. In addition, the RRQ of a 140 knot upper jet will aid in the rain development this morning.

We continue to watch the secondary front/cold conveyor belt that is expected to drop through from mid morning into the early afternoon hours. This will bring more showers to the area, highly concentrated near the lakeshore where cold enough low level air and cyclonic flow/cold air aloft moves in. We continue to see good signs that a few storms will be possible close to the lakeshore with this feature due to the strong instability over the lake feeding this.

The flow will quickly shift to become more from the NNE behind this front. We will see the gusty winds behind this, which look to peak around 40 mph for a brief time. No wind advisory looks to be needed at this time. Even along the lakeshore where it will be slightly offshore. We will see a few pop up rain showers continue to be possible inland, but nothing looks to be organized.

Once we lose the diurnal boost of the instability, the threat for showers will drop significantly or end. The upper cyclonic flow will exit the area after 00z, allowing ridging to build in through the night. Winds will be up in the evening, but will settle down quite a bit overnight. We could decouple well at that time, and see a fair amount of frost for much of the interior. A frost advisory may be needed, and can be issued by the day shift.

- Tranquil weather for Sat and beyond with moderating temperatures

Confidence continues to increase that we will see an extended period of tranquil weather from Saturday through the upcoming week, and likely beyond.

The increased confidence comes as we see the pattern expected to be even more amplified than previously thought, and the favorable weather under the upper ridge expected to be over our region. The upper trough/low to our west is expected to close off now and slow up in trying to move east. This is likely at least partially due to the closed low off of the east coast and upper ridge slowing down the progression of the upper air flow over the CONUS.

The majority of the time, pops will be near zero with strong subsidence overhead. There is a period on Thursday and Friday where the ridge is temporarily flattened by energy over Canada. These short waves will have no decent moisture to advect in, and little to no moisture to start with.

Temperatures will start out cool on Saturday in the 50s with the cool flow from Canada remaining in place immediately behind the Friday system. We will see heights build, and a return flow advect warmer air gradually over the area. We are likely to see temperatures approach 70 by mid week, and stay mild through the end of the week, with just a slight cool down with the ridge flattened briefly.

Aviation /12Z Tafs Through 12Z Saturday/

Issued at 630 AM EDT Fri Oct 16 2026

We are seeing scattered showers around the terminals at the beginning of this forecast period. Conditions are mainly MVFR with ceilings around 1500-2500 ft agl. We expect these conditions to generally continue for a few hours, until the next front drops through. This will enhance the showers, and even possibly cause a few storms at KMKG given the instability over the lake. This will be a 2-3 hr window. Behind this will be the strongest of the winds from the north that will continue until sunset.

The MVFR conditions will improve to VFR later as the showers will push offshore as the wind becomes from the NNE this evening. Wind gusts will steadily drop off this evening. Skies are likely to clear overnight given the northerly wind.

Marine

Issued at 300 AM EDT Fri Oct 16 2026

Everything looks to be on track with regards to headlines this morning, so no changes are necessary at this time.

We have solid Small Craft Advisory conditions ongoing behind the initial front that passed through around midnight. The Gales are expected to arrive by noon with a secondary front dropping through that will bring a nice cold surge with it. Solid Gales remain expected, with a small chance of a brief Storm Force wind gust. Not enough to need a Storm Warning.

Winds will steadily diminish then this evening as we see a sfc ridge axis pass through. This will be short lived as another strong area of gradient winds drops down over the area late Saturday through most of Sunday. Those winds and waves will require another Small Craft Advisory to be issued.

Grr Watches/Warnings/Advisories

MI...None. MARINE...Small Craft Advisory until 11 AM EDT this morning for LMZ844>849. Gale Warning from 11 AM this morning to 2 AM EDT Saturday for LMZ844>849.

DISCUSSION...NJJ AVIATION...NJJ MARINE...NJJ