textproduct: Gaylord

KEY MESSAGES

- Showers and storms possible today and perhaps into Sunday, but most areas should stay dry.

- Lower humidities ahead.

DISCUSSION

Issued at 320 AM EDT Sat Jul 4 2026

PATTERN SYNOPSIS/FORECAST:

Northern stream omega block centered on a 579dm ridge over east- central Canada...with conveyor belt of PV across western Canada on the nose of a 100kt zonal jet poking into British Columbia. This leaves the northern tier of the CONUS on the southern fringe of the blocking pattern, where flow is typically messy/nebulous, which is generally the case attm...with a broad col region over the Upper Midwest upstream of a deformation axis; surface reflection is a boundary draped largely E-W across the northern Plains, through the Straits, and into eastern Canada where there is more of a northerly flow able to take precedence over the motion of the boundary as opposed to staying relatively stagnant. Trends with this boundary have largely been southward over the last 24+hrs, though, and can attest to this given noticeably cooler/drier conditions overall across the Northwoods, particularly in comparison to the oppressively muggy early week conditions. With 595dm 500mb high now suppressed southward but still hanging on over VA/NC, some general southwesterly flow remains across the central US, keeping a feed of Gulf moisture (pwats still 1.5+in) into the nebulous pattern across the Upper Midwest; bulk of the convective activity attm is along this, and focused most notably along a theta-e gradient stretching from Nebraska to SW MI...save for some activity associated with a wave on that zonal boundary across the northern tier of the country. Here in northern Michigan, atmosphere remains capped (we had a nice 850mb warm nose that did not mix out today, per the 0z sounding) and generally stable aloft, with little in the way of significant forcing to overcome this.

Nebulous flow aloft will continue for today...with that upstream energy from Saskatchewan slowly meandering its way into the Upper Midwest later this afternoon into tonight; given nebulous flow, expect this will more or less end up trapped/slow-to-move over the Midwest this weekend into early next week. Current guidance suggests this should remain south of us, with some semblance of ridging trying to build in...though it will be ahead of some more potent energy swinging across central Canada as the blocking pattern up there quickly breaks down. Attm, guidance suggests this shortwave trough/ridge combo will try to shunt the cut-off energy eastward through the OH Valley and toward the northeast...with flow across the northern tier of the country becoming a little more zonal again, with potential for additional waves in the flow through midweek, and perhaps beyond. Attm, signals point toward a parade of shortwave troughs crossing central Canada late next week, which could keep things a little on the active side here in the Great Lakes, though quite unclear on how this will evolve.

FORECAST DETAILS...

Shower/storm chances today...Not surprisingly, guidance attm is struggling with the convection across IL/IN at 6z, which is driven by old outflow boundaries from the earlier convection (most suggestion of this appears too far north)...though doing a little better over IA/Nebraska where the pattern is a little bit more straightforward from a synoptic standpoint. Do wonder how much this will impact today's forecast at all. However, the primary idea is for cooling in the mid/low levels, which could keep the cap reduced a bit more today; some signals for 500mb temps to cool off a smidgen, esp the further north you go, which should also help the case. Think we will need to keep an eye out for activity near and south of the boundary today, perhaps even through the morning hours. Any perturbations from the overnight convection will also aid this idea. Think the better shot, though, will be for some pop up showers/storms this afternoon with lake breezes likely amid some diurnal heating (assuming this plays out as currently expected)...and think the focus for showers/storms will be across the southern half of the forecast area, especially toward the interior where that boundary lies...and wherever lake breezes develop (most likely area for enhanced convergence would be near and west of I-75). Steering flow should remain light, and any storms that pulse up could result in outflow boundaries that trigger other storms...which suggests the localized heavy rain threat will continue today, as the atmosphere should remain reasonably moist. If we end up with diurnal heating (and not blobs of leftover convective clouds), highs could reach into the lower or perhaps mid 80s. If we end up with more cloud cover, it should remain cooler and we will have a lessened chance overall of developing convection.

Shower/storm chances could hang on into tonight and Sunday; right now, signals point toward the better action remaining to our south across southern Lower MI for tonight. Increasingly northeasterly flow, at least in the low-levels, should support an overall slight cooling/drying trend for Sunday...which suggests we could struggle to overcome potential mid-level inversion to get any kind of action going...unless the trough axis ends up having a little more cooling aloft than currently expected. Have some lower chances for afternoon showers and storms, especially focused near and east of I-75 again where lake breeze convergence should be maximized. Highs Sunday look a touch cooler, likely in the upper 70s to lower 80s; with easterly low-level flow, would expect warmest temps to be largely west of I- 75 with downsloping over there. Winds should pick up a bit more on Sunday as well, which should result in a little more wave action and an increased swim risk to wrap up the holiday weekend.

Lower humidity ahead...while we have been wet recently (especially in some swaths across the Leelanau/Old Mission Peninsulas...and north of Little Traverse Bay)...easterly flow during the early part of the period suggests an overall drier air mass will be on scene. Coupled with temps remaining in the upper 70s to perhaps mid 80s at times...think afternoon humidities could drop below 30 percent. Expected pattern right now does not suggest we will get a good tap of moisture, save for anything coming off the Pacific, and we could end up with an overall drying trend through the week apart from any showers/storms that may develop with the various perturbations trying to track through the flow...though a drier antecedent air mass could limit rainfall totals to some degree, especially initially.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 1149 PM EDT Fri Jul 3 2026

Strong storms to our south will continue to send periods of mid and high clouds to the northern MI TAF sites. Some showers are also forming over northern Lake MI, with rain possible overnight at MBL/TVC. This will contribute to lower cloud development, MVFR at TVC and IFR at MBL. CIU could also see MVFR fog. Light winds.

APX WATCHES/WARNINGS/ADVISORIES

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