textproduct: Detroit/Pontiac

KEY MESSAGES

- Below normal temperatures today with most areas seeing low to mid 40s. Winds off Lake Huron likely keep the Thumb and Saginaw Valley cooler in the mid 30s to around 40.

- Warm front lifts through the area Thursday morning bringing shower chances. A brief period of wintry mix possible in northern Midland/Bay- little to no ice accumulation forecast.

- Another low pressure system brings a chance of thunderstorms Thursday evening. A couple strong to severe storms possible west of US-23.

- Yet another low lifts through the Great Lakes Saturday supporting additional showers and a few thunderstorms.

- Below normal temperatures return Sunday into the new work week.

DTW THRESHOLD PROBABILITIES

* High for ceiling at or below 5000 ft this morning, moderate this afternoon, and high tonight and Thursday morning.

PREV DISCUSSION

Issued at 351 AM EDT Wed Apr 1 2026

DISCUSSION...

Much cooler start today following last night's cold front with all but the southernmost areas sitting in the 30s. This boundary remains stalled over northern IN/OH today offering potential for scattered showers to creep north of the state line over areas south of I-94, particularly in the afternoon as a wave ripples along the front. Otherwise, the bulk of SE MI stays dry today with anticyclonic flow under northern Ontario high pressure. Lingering cloud cover and northeasterly wind off Lake Huron keep highs firmly below average to start April with widespread low to mid 40s. As is typical in this flow pattern, Saginaw Valley and Thumb will be the coldest instead topping out in the mid 30s to around 40.

Stalled frontal boundary begins to lift back north into southern lower MI late Wednesday night-Thursday as warm front in response to the next mid-upper wave ejecting out over the central Plains. Isentropic ascent increases through Thursday morning focusing greatest precip coverage/intensities over areas north of M-59. Models have continued to trend warmer for late Wednesday night- Thursday morning favoring above freezing temperatures for nearly all of SE MI keeping p-type as (liquid) rain. As it currently stands, only potential exception is the northernmost portions of Midland/Bay counties where guidance hovers right around the freezing mark for a couple hours at precipitation onset before warming. This offers a brief window for a lead edge light wintry mix though probabilities for these areas to see measurable ice (0.01") is only 15%.

While the elevated portions of the warm frontal slope largely clear north of the CWA Thursday afternoon, the surface boundary likely lags. Good signal across the model suite for preceding east- southeasterly flow off Lakes Erie/St Clair acting to partly inhibit/slow the surface front until Thursday evening when a prefrontal trough lifts through the state finally forcing the front north. This outcome would result in areas north of I-94 holding in the 40's and 50's for most of the daylight hours before the 60s/low 70s over the far south finally advance northward. This also would confine SBCAPE (500-1000 J/kg) to the southernmost counties and just to our west as the arrival of the prefrontal trough feature latter half of the evening only allows decaying surface instability to ooze north. While the strong column wind field (45-55kts above 925mb) provides more than sufficient shear, it will be difficult for convection to stay rooted in the surface layer north of I-94/east of US-23. For areas south of 94 and into western Livingston/Shiawassee, severe potential looks more dependent on when convection arrives from the west, whether late evening (better instability still available/better chance for a severe storm) or overnight (lesser instability available/lower chance for a severe storm). Damaging wind gusts would be the primary hazard with a chance for an isolated tornado, given the surface boundary in the vicinity. Weak cold front eventually tracks into lower MI Thursday night generating scattered (thunder)showers.

Another, stronger mid-upper wave ejecting out over the central Plains Friday induces a downstream height rise response across the Great Lakes likely stalling the aforementioned cold front over SE MI. This trough/surface low take a similar track to Thursday's system placing the CWA again within the warm sector as the stalled boundary lifts back north. Showers and a few thunderstorms are likely Saturday as the low works across the central Great Lakes with its cold front eventually crossing Saturday night. Below normal temperatures follow to close out the weekend/start the new work week as 850mb temps fall to -8 to -10C keeping highs generally in the 40s to around 50.

MARINE...

The northeast gradient will increase today as the surface high departs to the east and a warm front approaches from the south. This will bring elevated waves into Saginaw Bay and across the Lake Huron shoreline, where Small Craft Advisories are in place. Low pressure is then forecast to track from the western Great Lakes into the northern Great Lakes tomorrow into tomorrow night. Easterly gale force winds carry a low probability across the north half of Lake Huron as this low approaches. Rain showers will be likely through the morning and afternoon along a warm front Thursday with increasing chances for showers and thunderstorms later in the day leading into Friday morning. Some isolated thunderstorms may be strong to severe, leading to wind gusts aoa 34 knots.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None.

Lake Huron...Small Craft Advisory until 8 PM EDT Thursday for LHZ421-441>443.

Small Craft Advisory until 8 PM EDT Thursday for LHZ422.

Lake St Clair...None.

Michigan waters of Lake Erie...None.