textproduct: Detroit/Pontiac

KEY MESSAGES

- Isolated to scattered chances for showers and thunderstorms today through the weekend. Better coverage of showers and storms possible Monday.

- Temperatures remain seasonable through the weekend, with highs mainly in the 80s.

DISCUSSION

We currently reside under a broad upper level trough downstream of the primary trough axis located over MN. We are in a relative lull in the pattern with thunderstorms along the main trough axis well to the west and also to our east with the shortwave that passed through overnight. Locally, a narrow axis of mid level forcing seen on water vapor imagery passing over the state this afternoon is expected to help touch off isolated showers and storms utilizing the 1000-2000 J/kg of CAPE building up. Shear remains weak, topping out around 20 knots currently so not expecting much in the way of stronger storms organizing. Wealth of dry air in the mid levels should also help keep storms from getting too strong. SPC Meso Analysis does have DCAPE up around 1100 J/kg so any stronger storm will have capabilities to produce a microburst. Additional isolated storms will be possible overnight as models indicate some strengthening in the mid level vorticity band over far southern MI. Loss of daytime heating should help minimize coverage during this time.

Saturday again poses a risk of isolated showers and storms although latest guidance has trended down with expected coverage. As the main trough axis arrives, a weak cold front will be tracking across souther MI. The system looks to be disjointed with strong mid level support arriving prior to 12Z, weak low level jet arriving after 12Z coincident with a potential prefrontal trough which will push the bulk of the instability east of the region, before the front sweeps through in the early evening. There are enough pieces that could briefly overlap with model estimates of around 1000-1500 J/kg of CAPE building early in the day. SPC Day 2 outlook is for general thunderstorms.

Sunday looks mostly dry as ridging to the south folds over through southern MI. We will be watching to the west as the next strong shortwave starts advancing across the Plains with surface low pressure setting up around Iowa and the warm front extending across IL and IN. Models are already indicating ridge running type MCS activity with a complex possibly pushing across southern MI Sunday night into Monday morning. For this setup along the warm front, SPC has already put locations south of a line from Grand Rapids to Detroit in a Slight Risk for severe weather.

General troughing and northwesterly flow across the region should lead to cooler temperatures for the latter half of the week, with highs back down in the upper 70s. This setup will also lead to periodic rain chances.

MARINE

Most marine areas will remain relatively dry for the remainder of the day. There is a chance for isolated shower and thunderstorm activity overnight and into Saturday as a cold front pushes across the region. Winds will generally remain on the lighter side outside of any thunderstorm activity that does occur. Southerly flow will turn northwest going through the day on Saturday behind the departing cold front and may briefly top at or above 20 knots over northern Lake Huron. High pressure then builds back in late Saturday into Sunday before switching back to the south ahead of another system set to impact the region Monday. Rain and thunderstorm activity will remain low through the weekend, with better chances for unsettled weather coming in at the start of next week.

PREV DISCUSSION

Issued at 146 PM EDT Fri Aug 7 2026

AVIATION...

A series of weak mid-level disturbances will impact the airspace this afternoon and evening, attempting to generate isolated-scattered showers/thunderstorms within a weakly capped environment. Low coverage of thunder limits confidence in direct impacts to terminals, thus did not include -TSRA in this TAF issuance. Otherwise, a mix of SCT-BKN coverage of low VFR persists through the evening alongside light southwest flow. Attention turns to the inbound cold front overnight into Saturday, which again presents opportunities for showers and thunderstorms as moisture lifts into the airspace amidst increasing southwest winds to 10-15 knots. The added moisture ahead of the front may briefly result in MVFR ceilings Saturday morning, but quickly lifts to low VFR with daytime mixing and the frontal passage. The frontal passage between 16z and 22z will be the most likely timeframe for thunder, although hi-res models continue to be lean on thunderstorm chances. The fropa also gradually shifts SW winds to the W in the afternoon.

D21/DTW Convection... Low potential for a thunderstorm this afternoon and evening. Another chance for thunderstorms exists Saturday afternoon between 16z and 22z as a cold front tracks across the airspace.

DTW THRESHOLD PROBABILITIES...

* Medium for ceiling aob 5000 ft early this afternoon and Saturday morning. Low for the rest of the period.

* Low for thunderstorms this afternoon and evening. Low Saturday afternoon.

DTX WATCHES/WARNINGS/ADVISORIES

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