textproduct: Detroit/Pontiac

KEY MESSAGES

- Seasonably average temperatures again today.

- A few light showers possible late tonight into early Saturday morning.

- Much warmer Saturday with temperatures in the upper 70s.

- Next significant chance of rain arrives Sunday, focused over the southeasternmost areas, tied to the remnants of Isaias.

DTW THRESHOLD PROBABILITIES

* None

PREV DISCUSSION

Issued at 325 AM EDT Fri Oct 9 2026

DISCUSSION...

SE MI continues to reside on the northern edge of Ohio Valley high pressure today maintaining light winds and limited cloud cover. With no change in airmass, temps will be similar to yesterday with highs topping out in the upper 60s to near 70.

Upper level pattern shift begins by this evening with ridging across the central CONUS fully expanding over the Great Lakes as the surface high shifts towards the Northeastern seaboard. As this occurs, a weak mid-level shortwave riding the warm front lifting out of the Midwest is progged to track into the western, and eventually central, Great Lakes. Initially this wave is supported by strengthening low level jet pushing out of the Plains into the upper Midwest resulting in a modest area of showers while over IA/WI/IL. However with the LLJ fixed west of Lake Michigan, overall synoptic support lessens as it reaches lower MI likely leading to a steady diminishing shower coverage trend as it crosses west MI tonight. That said, can't completely write off light shower chances late tonight-early Saturday morning as the warm frontal boundary draws a respectable ribbon of theta-e overhead. As such, have added entry- level slight chance/isolated PoPs (15%).

Region is firmly entrenched within low/mid level southwesterly flow daytime Saturday with strong warm advection pushing 850mb temps into the mid-teens C resulting in highs reaching the mid to upper 70s. Core of this airmass (upper teen C 850mb temps) is still favored to be directed over the far western Great Lakes/upper Midwest reducing chances areas within SE MI manage to reach 80. Remnants of Isaias reach the Ohio Valley Sunday before being shunted towards the mid- Atlantic Monday. Despite this track well to our south, model solutions continue to advertise the northern edge of the associated rain shield clipping portions of the area. Greatest rain chances favored over the southeastern/easternmost areas (ie counties along the Huron-Erie corridor) with potential QPF hinging on the extent moderate showers are able push out of Ohio before the low starts to eastward drift.

MARINE...

High pressure becomes firmly established over the central Great Lakes today as a ridge spills eastward and the upper level trough overhead exits. Markedly lower gradient winds with the surface ridge axis oriented from the UP to the Mid-Atlantic. Return flow eventually leads to a brief southerly wind shift this evening before the pressure field adjusts to a strong and broad low pressure system over the Mountain West. The next forecast concern depends on the timing and track of the remnants of Hurricane Isaias. Winds are generally expected to hold below threshold criteria once the system lifts into the Ohio Valley, conflated by the advance of the upstream low. Can't completely rule out a few gusts near gale-force over the northern Huron basin later on Saturday.

DTX WATCHES/WARNINGS/ADVISORIES

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