textproduct: Detroit/Pontiac

KEY MESSAGES

- Dry and cool today

- Rain returns tomorrow morning. Locally heavy rainfall around an inch is possible from Monroe to Port Huron.

- Warming trend next week with temperatures back to normal values.

DTW THRESHOLD PROBABILITIES

* Low for ceilings at or below 5000ft through early afternoon, high by late afternoon into Saturday.

PREV DISCUSSION

Issued at 344 AM EDT Fri May 22 2026

DISCUSSION...

The 1030 mb high pressure system centrally located over the border of Ontario and Quebec will continue to track east-northeast over Quebec through the day. Southwestern periphery of this system will maintain dry conditions across SE MI under east flow which will bring slightly below normal temperatures with highs in the mid to upper 60s. Development of low pressure around Ark-La-Tex will bring the next round of rain as low pressure progresses northeast into the Ohio Valley, centering over the southeastern corner of Michigan/west Lake Erie by Saturday afternoon.

Widespread rain will move into SE MI through the morning hours as a strengthening low-level jet draws higher theta-e air northward into the region. Isentropic ascent through the low-levels and added support from an associated mid-level wave will generate a wide footprint of of rain showers across the cwa. Locally higher rainfall totals are expected generally along or south of a line from Port- Huron to Adrian. This will be tied to the possibility for enhanced rainfall rates from the 850-700 mb frontogenetic response northeast of the surface low, where this low-level jet and isentropic ascent is maximized. The recent 00Z guidance does place the better fgen potential just east of the forecasting area, lowing confidence for a swath of highly localized rainfall exceeding an inch, however, ensemble guidance and some CAMs still support this lower end potential to achieve an inch rainfall. Please see the hydrology section for additional details. Otherwise, slightly breezy for both today and tomorrow with wind gusts ranging between 20 to 25, isolated 30 mph.

Rainfall rates decrease through the afternoon and evening hours but light rain shower potential persist as low pressure tracks into Lake Huron, washing out across Lake Ontario. Limited thermal advection and rain chances hold temperatures below normal tomorrow. It would not be surprising to see daytime temperatures struggle to move out of the 50s with copious cloud cover and rain. A lull in rain chances will be likely overnight, with renewed chances again Sunday afternoon and evening as a mid-level wave and very weak cold front traverses over the state. Confidence in coverage of any rain showers is much lower on Sunday given the more nebulous forcing. A return to more normal temperatures will be most likely by Sunday, and then back into the upper 70s to low 80s through the early to mid week period as high pressure builds into the Great Lakes. There will be some low-end rain chances from glancing shortwaves, but there is no strong signal for widespread rain/severe weather in the forecast period after the weekend.

MARINE...

High pressure centered to the northeast of the Great Lakes region will slowly shift eastward through the day. This will continue to allow for dry conditions across the marine zones through the early evening. Northeast winds shift to more easterly and increase going through the day on Friday as a low pressure system lifts towards the region from the south. This will allow the pressure gradient to tighten, allowing for winds to strengthen as the region resides in between the departing high pressure and low pressure systems. Rain and thunderstorms chances increase late Friday into Saturday as the center of the low approaches the southern Great Lakes region. Easterly winds will continue to be gusty through Saturday, with potential for gusts to reach up to 30 knots. Small Craft Advisories are in effect for all the nearshore marine zones through Saturday morning.

HYDROLOGY...

A round of steady soaking rainfall is forecast to spread across southeast MI from south to north Saturday morning as low pressure lifts in from the Mid Mississippi Valley. Forecast rainfall totals range generally between a quarter inch and three quarter inch during this event. Locally higher rainfall totals of an inch or greater are possible from Monroe to Port Huron. Overall dry conditions for much of the area over the past 30 days suggests the potential for flooding is low.

DTX WATCHES/WARNINGS/ADVISORIES

MI...Beach Hazards Statement from 10 AM EDT this morning through Saturday afternoon for MIZ048.

Beach Hazards Statement through Saturday morning for MIZ083.

Lake Huron...Small Craft Advisory until 10 AM EDT Saturday for LHZ422.

Small Craft Advisory from 4 PM this afternoon to 10 AM EDT Saturday for LHZ421-441.

Small Craft Advisory from 10 PM this evening to 10 AM EDT Saturday for LHZ442-443.

Lake St Clair...Small Craft Advisory until 10 AM EDT Saturday for LCZ460.

Michigan waters of Lake Erie...Small Craft Advisory until 10 AM EDT Saturday for LEZ444.