textproduct: Gaylord

KEY MESSAGES

- Rogue showers possible today/Saturday?

- Periods of showers/storms starting later this weekend into next week

- Potentially dangerous heat/humidity next week.

DISCUSSION

Issued at 400 AM EDT Fri Jun 26 2026

PATTERN SYNOPSIS/FORECAST:

Upper low spinning just off the PacNW coast...with split flow across the Intermountain West. Generally zonal flow across the central US though upper ridging is beginning to build over the Upper Midwest, with a 100kt upper jet stretching from the Upper Great Lakes to the Mid Atlantic attm. Overall troughing still hanging on across central/eastern Canada, with the trough axis that dumped rain on parts of the area yesterday finally exiting stage right into New England. Deepest moisture focused across the central US attm, where pwats reach or exceed 2in across the Mid MS Valley, even poking into the OH Valley a bit along a more-or-less east-west baroclinic zone stretching from NM to Lake Erie. An increase in low-level return flow into this east-west boundary certainly helping with convection ongoing out there as of 4z...and also helping transport a bit of moisture northward as well, though perturbation tracking into the northern Plains likely helping with that as well. Coldest air attm is beneath the trough axis in our vicinity, with 850mb temps as cool as 8C; 850mb temps above 20C across the western US. High pressure slowly trying to settle into the Upper Midwest attm, but only for a time.

High pressure to remain generally in control of our weather today...though whatever is left of activity over the northern Plains will try to make it in here this afternoon (some sort of perturbation from activity over the central Plains/Mid MS Valley may also try to sneak by to our south). This should leave us with slight northwesterly flow aloft tonight...as trough axis digs out west and strengthens the ridge over the Upper Midwest. This should intensify return flow across the central Plains and lead to some activity out there...though we should still be largely under the control of high pressure on the downstream side of the ridge. Ridge will build further eastward Saturday night into Sunday with an increase in southerly flow (and humidity) expected to wrap up the weekend. Low pressure center slowly meanders northeast out of the Plains into Canada Monday into Tuesday as the upper low ejects from the longer- wave trough axis; this should drag the warm front into our area and likely leave us under or near the perimeter of the ridge axis. Greater than 590dm 500mb upper ridge expected over the OH Valley by midweek, and still somewhat unclear how strong this will be despite energy trying to track into Hudson Bay (and thus, how much we will be impacted by convection associated with this). Attm, not a ton of change to the pattern going into the Holiday weekend, with signals for strong ridging to persist over the eastern US through the end of the period.

FORECAST DETAILS...

Rogue shower today and Saturday? After morning fog/drizzle burns off and departs...expect lake breeze development this afternoon, which, with light low level flow turning a little more to the northeast this afternoon suggests some potential convergence across the interior higher terrain, perhaps a little closer to the US-131 corridor? In any case, whatever develops would likely be shallow diurnally-driven showers, and the most likely scenario is that the bulk of the area will remain dry. Think a similar situation is possible on Saturday as well with very little change overall to the airmass...though warming aloft could be a little too much for diurnal heating to do much.

Shower/storm chances as early as Sunday? Continuing off/on into next week... Upstream setup Saturday night could support upstream convection drifting into our area by Sunday morning; increasing theta-e advection over WI along warm front could well develop convection on the other side of the lake Sunday afternoon/evening that may want to drift across the Lake...or perhaps continue (as elevated convection) right on through the overnight hours into Monday morning. Steep lapse rates aloft (associated with elevated mixed layer advection from the Desert SW) look to knock on our doorstep by this time and think this further suggests the development of somewhat more organized convection late Sunday into Monday over the region (particularly to our west/northwest). Will need to keep an eye on warm advection junk into Monday as well, though once we start to get under the warm air aloft (700mb temps 12C or better), we stand a chance to become increasingly capped, making it more difficult to pop diurnal convection without strong forcing. Suspect convection will continue to plague the Upper Midwest/Great Lakes off and on through early next week, with potential for periods of afternoon and/or nocturnal convection, as the ejecting upper low tries to track over the ridge axis through Ontario. Fortunately? Unfortunately? for us, this idea would keep the core of the anticipated 590+dm heat dome centered to our south and may keep us from getting quite as hot...though the humidity will indeed be an issue.

Uncomfortable to downright dangerous heat/humidity next week... As discussed above, the potential convection along the perimeter of the heat dome could very well keep our high temperatures from maxing out up here in the Northwoods. Air mass certainly will have the potential to be very warm, with 850mb temps above 20C (perhaps well above 20C) supportive of highs reaching into the 90s, and west/southwest flow downsloping in our usual hot spots could push some areas closer to 100F or better -- in this worst case scenario, apparent temperatures could exceed 100-105F for multiple days in a row into the Holiday weekend. Regardless of how hot it gets during the day, though, the soupy Gulf air mass will likely keep dewpoints, and therefore, low temperatures, from getting too far below 70F for much of next week... and multiple days/nights of this in a row will make it difficult to cool off. Great Lakes water surface temperatures are still largely at or below 60F, which is still in the hypothermia threat range...which could also complicate trying to cool off, and somewhat stronger flow next week could also lead to some swim risks at times.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 1149 PM EDT Thu Jun 25 2026

But fog/stratus (especially stratus) is expanding late this evening, and that will continue. Have LIFR conditions overnight/ early Fri morning at APN/PLN/MBL, IFR elsewhere. VFR all sites by late Fri morning. Light winds.

APX WATCHES/WARNINGS/ADVISORIES

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