textproduct: Gaylord

KEY MESSAGES

-Scattered rain showers to diminish with time into the morning, with peeks of sun prevailing by afternoon.

-Squeaking out a dry Friday before rain chances return Friday night into Saturday. Greatest rain / shower coverage and heaviest rainfall generally favor areas along and south of M-72.

-Largely dry next week with a true autumnal feel

DISCUSSION

Issued at 255 AM EDT Thu Sep 17 2026

Pattern / Forecast Synopsis:

Moisture-starved northern stream wave currently zipping eastward across the US-Canada border will traverse the region tonight, bringing what will likely be a decaying batch of showers. Meanwhile, a robust thermal ridge over the southeastern CONUS (contributing to record heat in the South) to retrograde westward with time the rest of this week, in turn inducing a WNW flow pattern across the Midwest and Great Lakes region into this weekend. Stationary front setting up shop well to the south, currently remaining the focus for deeper moisture and resultant robust convective responses spanning from roughly Missouri to eastern Ohio. This particular corridor will remain the focus for southern stream wave activity through the weekend.

These waves will likely come in abundance... longwave troughing over the Pacific Northwest to draw tropical Pacific shortwaves out of the Gulf of California via deep return flow. These waves are set to zip through the Four Corners region (where there are already ongoing hydrologic issues) and into the central and northern Plains... riding the stationary front and associated WNW flow regime through the Midwest and into the Great Lakes region. How far north the return flow can force a ridge axis and the ejection point of these waves will mark the difference between northern Michigan seeing a robust period of rainfall or a glancing blow from these systems spanning the weekend and into next week.

Details:

Not a whole lot of change to highlight from previous forecast cycle. Aforementioned northern stream wave well within sight, with showers blossoming over northern Minnesota and the Wisconsin Highlands, zipping east into the western Yoop. Eastward progression of these showers to continue through the rest of the night, reaching the northwest lower lakeshore and eastern upper after 09z. With hostile airmass in place characterized by a complete and utter lack of moisture and instability, anticipation is that these already diminishing rain showers will decay further as they progress ESE through the CWA, with shower activity out of the picture by late morning for most. Perhaps a few sprinkles or a light shower lingers for our friends in the Saginaw Bay region by early afternoon, but should clear by 18z at the latest.

Rest of the day looks dry as surface high pressure centered over NW Ontario intrudes with subsidence aloft and restores meteorological order... with peeks of sun likely. Highs top out in the upper 60s to mid 70s. Clear conditions tonight with the influence of the surface high should lead to another comfortable night with lows in the 40s inland and 50s along the immediate lakeshores. Dry weather to continue Friday, but as the first of several waves of energy approach, anticipation is that clouds increase through the day. At this juncture, the big rainfall extravaganza set to manifest just to our south as the stationary front fails to lift sufficiently north enough to draw rich tropical Pacific moisture into the region... but could come close enough to give us fringe impacts.

Most guidance wants to nose some efficient rainfall into the far southern reaches of the CWA Friday night through Saturday... with much less prolific rains the farther north one goes. This is echoed by the latest WPC Excessive Rainfall Outlooks, which continue to pinpoint the southeastern MN / northeast IA through downstate MI / northern OH corridor for the greatest rainfall amounts and associated impacts. That notwithstanding, current trends depict a marked increase in rainfall intensity and frequency the farther south one goes from the M-72 corridor... where some guidance members are hinting at 1.00-2.00"+ of steady rainfall over that Friday night - Saturday timeframe... with quickly reducing rainfall amounts the farther north one goes. Pattern recognition says this probably winds up being a "Manistee Special(TM)", where the Manistee County area sees the overwhelmingly best shot at the aforementioned rainfall amounts, with a sharp gradient of lesser rainfall to the north / east. Honestly wouldn't be overly shocking to see little to no rainfall near and north of M-32 if this scenario manifests.

Once this initial wave passes by Sunday, guidance is bullish on a further southward suppression of the stationary front... which should bring us cooler and drier air into next week, with rain chances minimal at best and confined to the bottom row or two of counties within the APX CWA.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 540 AM EDT Thu Sep 17 2026

VFR conditions will continue through the period, with decreasing clouds today giving way to mostly clear to partly cloudy skies tonight. Light winds, with local lake breeze development this afternoon.

APX WATCHES/WARNINGS/ADVISORIES

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