textproduct: Grand Rapids

KEY MESSAGES

- Cooler today, with lake effect showers near the lakeshore and far north.

- Much more typical temperatures and dry Saturday onward

DISCUSSION

Issued at 321 AM EST Fri Nov 6 2026

- Cooler today, with lake effect showers near the lakeshore and far north.

Now that the cold front has passed through the area, attention turns to the establishment of lake effect rain (mostly) bands along the immediate lakeshore and the northern lower peninsula. Cold air advection has begun in earnest with north-northwesterly cyclonic flow, and 850 mb temperatures have fallen to between -2 and -4C already as of 3am, and may drop another 1-3 degrees over the next few hours. With lake temperatures still quite warm (12-15C), this is producing a temperature difference of 14-16C, which may reach as high as 19C when the core of the cold air moves overhead. Meanwhile, inversion heights are expected to rise to around 8k-9kft, and a prominent lake effect rain band has already formed along the immediate lakeshore in an area of enhanced convergence. Further north, numerous additional lake effect bands are also forming downstream of the northern lakes, and one particular band emanating from Grand Traverse Bay may be relevant to us later this morning.

In any case, these lake effect showers will mature this morning, continue through the day, and diminish gradually this evening. Temperatures currently are still too warm for snow where precipitation is falling (low 40s near the lakeshore), and we remain confident that the vast majority of this will fall as rain, particularly within the primary band along the lakeshore. Instead, expect another 1/4-1/2 inch of rain in western Mason/Oceana counties, and possibly western Allegan/Van Buren counties as well. Lighter amounts are also possible across our northern row of counties as the remnants of lake effect bands from the northern lakes expand further downstream, but precipitation rates with these bands should be much lower than the lakeshore band. We may also be grazed in our northeast by more synoptically driven, lake enhanced precipitation as the upper low moves along the length of Lake Huron, but this would likely be very light as well.

We will also need to keep an eye out for a few wet snowflakes with this activity later this morning as cold air deepens and the upper part of the cloud layer cools to near -10C (enough for cloud ice formation). If this occurs at all, it will be most plausible in the higher terrain of Lake/Osceola counties if the previously mentioned Grand Traverse Bay lake effect band can become established. Even if this occurs, about the most we could expect with this band would be a thin layer of slushy snow almost exclusively on grassy surfaces, due to a combination of warm surface temperatures, modest precipitation rates that far inland, and very low snow-liquid ratios. More likely is that snow will melt before accumulating at all.

- Much more typical temperatures and dry Saturday onward

Once lake effect showers diminish this evening, a dry pattern will become established for the foreseeable future, with little opportunity for precipitation of any variety. This weekend will see cool, but near seasonal average temperatures, with morning lows near or slightly below freezing both Saturday and Sunday, and highs rising from the low 50s Saturday to the mid/upper 50s Sunday. A modest shortwave passes the area to the northeast Sunday, but again is not expected to produce precipitation. Transient upper ridging is expected to boost temperatures slightly above average early/mid week.

In the longer range, ensemble guidance has trended toward the development of a longwave trough across the eastern CONUS late in the week, opening the door for cooler air to return south into the Great Lakes. Ensemble temperature spreads remain large during this period, but the overall trend back toward cooler (or at least near average) temperatures is clear nonetheless.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 622 AM EST Fri Nov 6 2026

The primary concern during the 12Z TAF period continues to be low ceilings, in addition to a few light rain showers mainly at MKG. At the start of the period, periodic MVFR ceilings are expected at all terminals, but should be most frequent at MKG/LAN/JXN. By mid to late afternoon, clouds are likely to fill in, and MVFR conditions will become more common at GRR/AZO/BTL as well. This is expected to continue through the end of the period, although we may see more breaks in the clouds early Saturday morning. Lake effect rain showers will continue near MKG through at least early this afternoon, but should move further offshore by mid/late afternoon.

MARINE

Issued at 321 AM EST Fri Nov 6 2026

Northerly gales or near-gales are expected to persist through the day today in the nearshore waters north of Whitehall, with the strongest winds and largest waves (perhaps as high as 10 feet) near Big and Little Sable points. Small Craft Advisory conditions will also persist in the remainder of the nearshore waters, although there is the possibility for sporadic near-Gale force gusts in the waters south of South Haven as well. Waves are also expected to become particularly large here due to the northerly winds, and may reach 10-12 feet during the afternoon today. Winds will slowly subside this evening, allowing waves to settle overnight.

GRR WATCHES/WARNINGS/ADVISORIES

MI...None. MARINE...Small Craft Advisory until 10 AM EST this morning for LMZ844. Gale Warning from 10 AM this morning to 7 PM EST this evening for LMZ844. Small Craft Advisory until 7 PM EST this evening for LMZ845>847. Gale Warning until 7 PM EST this evening for LMZ848-849.