textproduct: Gaylord

KEY MESSAGES

- Rogue shower possible today

- Rain/storm potential this weekend into early next week, with heavy rain possible

- Warmer and more humid likely next week...

DISCUSSION

Issued at 312 AM EDT Fri Aug 28 2026

PATTERN SYNOPSIS/FORECAST:

Troughing churns over the PacNW, with energy lifting up into Alberta; ridge axis stretches from the SW US up into Saskatchewan...and troughing stretches from 550dm 500mb low over Hudson Bay down through the Great Lakes and back into the Mid MS Valley. Various bits of energy zipping through our trough...including a bit that is crossing from NW to SE across NE Lower MI and the EUP as of 4z, on the nose of an 80kt meridional upper jet, resulting in some mid-level clouds and light radar returns that may or may not be reaching the ground. Overall, drier air is wrapping down into the Great Lakes attm compared to previous days, but nothing too dramatically dry attm...as moisture is still wrapping around the backside of the upper low into northern Ontario on a 20-30kt low-level jet. Coldest air is beneath/SW of the upper low, with 4C air focused mainly over northern Ontario, near/behind a surface cold front stretching from northern Quebec/NE CONUS to the OH Valley. Expansive surface high pressure building into the Upper Great Lakes attm, with S/SE low-level flow from the Plains up into the Canadian Prairie Provinces, and generally not favoring eastward low-level warm advection along a baroclinic zone in this region attm.

Ridging builds in over the next couple days...as downstream upper low tracks eastward...and western troughing energy slowly tries to make its way eastward across the Rockies as well. Pattern out west turns a little more troughy for the weekend into early next week, with signals for the ridge axis to shift into the south-central or perhaps even southeast US; while this generally signals a warming trend...think it also signals an unsettled trend, with potential for warm advection convection, particularly as any more noteworthy niblets track through the flow. This latter idea attm is most likely toward the Monday night/Tuesday timeframe...as an upper low churns its way across southern Canada. Attm...appears this feature will cross the Upper Great Lakes/Upper Midwest in the mid-week timeframe next week, though it remains a bit unclear if the upper low will end up getting shunted north by a stronger ridge axis over the southeastern US...or remain more zonal, if the ridge axis remains more over the south-central Plains. Global guidance suggests potential for a strong upper low to develop over eastern Russia with sharp ridging ahead of it over the north-central Pacific and/or Gulf of Alaska...which, if this trend holds, suggests a pattern shift and potentially warmer weather for us for early September. Bottom line...it looks unsettled and generally more humid through the bulk of the forecast period.

FORECAST DETAILS...

Rogue shower today?....Subtle theta-e advection plus some mid-level lift suggests a shot at development of a few showers, particularly along whatever lingering mesoscale boundary is left in the region from the current early morning "activity" (mostly still clouds as of 5z, not really reaching the ground if at all), and particularly in the afternoon with diurnal heating. Not expecting these to become too deep, with a strong subsidence inversion around 4km, but could produce a few hundredths of rainfall, esp across NW Lower MI where the moisture and forcing should be a little more substantial. Think we will at the very least have a "nice" deck of clouds around, but soundings also suggest low-levels may be too dry to preclude much more than virga unless activity ends up vigorous enough to moisten up the column a little better.

Rain/storm chances this weekend into early next week...persistent return flow across the central Plains and Upper MS Valley for the next few days suggests an increasingly moist airmass will develop upstream along the perimeter of the ridge axis (pwats may reach/exceed 1.5in again...a combination of both Pacific and Gulf moisture). Think this setup will be supportive of MCS activity (especially nocturnal) across the Upper Midwest, as it should lead to destabilization along the periphery of the ridge...which should reach into the Great Lakes by Saturday night/Sunday, and perhaps as early as Saturday afternoon. Current pattern suggests these may initially follow the thickness gradient just to our southwest, and could keep the most agitated activity to our southwest...but could also leave us open for stratiform rain. Signals for convective instability are not overly strong attm, but setup does favor destabilization off the ridge axis to our west/southwest, especially Sunday for us. However, lapse rates aloft appear reasonably steep with a lot of deep moisture aloft...further suggesting a heavy rain threat, and warm advection should bring freezing levels up above 3km again for efficient warm-rain processes.

One potential sticky-wicket is that the low-levels may remain dry, which could limit rainfall totals somewhat. Attm, with the upper low still generally swirling to our northeast, there remains some potential for an east-west baroclinic zone just to our north, which could focus heavier rainfall and better low-level moisture to our north Saturday night into Sunday...though there are signals for some kind of west-east boundary (warm front?) to settle across Michigan on Sunday. This latter idea would certainly be of concern for heavy rain potential for some portion of Michigan (potentially northern Michigan), as east-west boundaries can be quite dangerous, as it were, with deep moisture afoot. From a pattern recognition standpoint...would be inclined to suspect somewhere will get over an inch of rain Sunday into the start of the week, and the bullseye(s) could certainly get much more if multiple rounds of training convection track through in this setup from Sunday into the start of the week...but with model guidance struggling to resolve this scenario (as it is wont to do in these types of setups), it is hard to necessarily back up this idea with probabilistic guidance that is either washing out the placement (or lack thereof) of anticipated convection.

Warmer/more humid next week...increasing moisture for heavy rain purposes means increasing moisture for mugginess purposes...and think it could get quite sticky again across the Northwoods through at least the middle of the week, and could hang on into the latter half of the week if midweek trough exits quick enough. There is also an increased likelihood of summer-like temps returning for the early/middle portion of the week (and again, perhaps beyond...especially if current signals hold). Heat indices could certainly creep up into the upper 80s to lower 90s again at times if we maximize temperature potential... but with the setup favoring rounds of convection/nocturnal convection...do wonder if we will end up cloudy and much cooler than currently anticipated (though likely still humid). Think the best shot at storms will be the Monday night- Tuesday timeframe attm, with that next bit of energy approaching, with better signals for instability and deep layer shear...though still a lot of questions as to how this will all evolve.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 152 PM EDT Fri Aug 28 2026

VFR conditions are expected to continue across northern Michigan through the issuance period. Light winds this afternoon will go calm tonight. While this may lead to patchy FG/BR across parts of the area, low confidence precludes explicit mention in the 18Z TAFs at this time -- especially since winds may begin to increase out of the south late tonight/early Saturday morning. Rain showers look to hold off until after 18Z Saturday.

APX WATCHES/WARNINGS/ADVISORIES

MI...None. MARINE...Small Craft Advisory from noon to 10 PM EDT Saturday for LHZ345. Small Craft Advisory from noon to 10 PM EDT Saturday for LMZ323-341-342-344>346.