textproduct: Detroit/Pontiac

KEY MESSAGES

- Dry and warm through tomorrow. - Periods of scattered to numerous rain showers with some embedded thunderstorms likely Friday into Saturday.

DTW THRESHOLD PROBABILITIES

* Medium for thunder Friday evening.

PREV DISCUSSION

Issued at 342 AM EDT Thu Jun 4 2026

DISCUSSION...

Today will be the last day of what will end up being a 10 day stretch of dry weather spanning across the end of May and beginning of June. Surface low has continued drifting southeast of the region centering itself now over the Mid-Atlantic coast but still remaining in control locally as the 590dam 500mb ridge is still sitting over the Great Lakes. Several waves tracking through Canada continue to suppress the ridge which will really just increase the wind field a bit today. Most models are very dry but some do offer a few lower clouds in the 7kft range at the strengthening inversion this afternoon. Little overall clouds with a boost in southwesterly flow warm air advection will lead to another warm day with highs in the mid to upper 80s. Dewpoints will remain around 50F which will help keep apparentT in check.

Friday and Saturday continue to offer the best chances for showers and thunderstorms as the wave train finally breaks down the ridge and allows the next trough to pass right over the Great Lakes Saturday. But first a slow moving cold front will drop into northern MI with moisture funneling up along it Friday bringing increase humidity, especially later in the day. A low level jet will nose into the region after 18Z bringing a surge a theta e through Mid MI. Model soundings offer a decent cap through most of the afternoon but hint at possibly breaking the cap in the late afternoon and evening with a wave rippling along the front which will bring the first chance of showers. Some embedded thunderstorms will be possible with a couple hundred J/kg (at best) of MUCAPE and strong low level lapse rates. Shear will be weak so not expecting organized storms. SPC Day 2 outlook is for General Thunderstorms with Marginal Risk trying to nose in from SW lower MI.

As the wave rides along the front, a surface low will begin to develop keeping rain chances Friday night. The best CAPE actually moves in overnight with a prefrontal trough ties to the developing low. So thunderstorm chances remain overnight with hires models pointing to a 03-09Z window for best coverage. The main cold front then drops through later in the day Saturday passing through the eastern half of the CWA during peak heating offering a bit of a recharge to the atmosphere. CAPE values could exceed 1000 J/kg with shear increasing to around 30 knots but with poor lapse rates. So after a possible brief lull in precipitation the first half of the day, we could deal with a few hours in the afternoon/evening with more thunderstorms.

Amplified upper level ridge builds back in quickly for Sunday with the southern extent of a surface high over Canada dropping through behind the cold front bring drier conditions back for Sunday. The narrow ridge will have a neutral tilt with southerly flow through the central conus creating channel of moisture through that region with a cutoff low over Texas drifting north and becoming absorbed by the next trough passing over the Rockies. Models were previously very dry through the first have of the week but now suggest the approaching trough could be strong enough to push farther east into the Great Lakes which could bring rain chances back Tuesday and Wednesday.

MARINE...

Influence of high pressure begins to wane today as it shifts over the Appalachians. In response, initially light winds organize out of the southwest this morning while gradually strengthening through the remainder of the day towards 15-20kts. Weak area of low pressure ejects out of the Plains over the northern Great Lakes by Friday afternoon offering the area's next chances for showers and thunderstorms through Saturday. A slight further uptick in SW wind occurs Friday with peak gusts reaching the lower 20kt range with near 25kt gusts possible in the Saginaw Bay due to shoreline effects. Passage of a weak cold front daytime Saturday shifts flow to the north-northeast with winds weakening as northern Ontario high pressure attempting to build into the central Great Lakes.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None.