textproduct: Detroit/Pontiac

KEY MESSAGES

- Drier and a little cooler weather will dominate the mid week period.

- The next chance of showers/thunderstorms is Friday night and Saturday.

DTW THRESHOLD PROBABILITIES

* High for ceilings 5000 feet or less this morning. Low by this evening.

PREV DISCUSSION

Issued at 303 AM EDT Tue Jul 28 2026

DISCUSSION...

A compact mid level short wave along the nose of an upper jet streak is now exiting to the southeast of the forecast area, taking lingering showers and scattered thunderstorms with it. Potent mid level subsidence in its wake will expand across Se Mi during the course of the morning, reflected in model soundings depiction of a deepening subsidence inversion. Sfc dewpoints are shown to remain in the 60s into the afternoon. This will sustain enough low level moisture to support a fairly healthy stratus/strato cu field today. There are at least some indications in NAM and HRRR soundings that some low stratus development in the morning may lend to some sprinkles or areas of light drizzle before diurnal boundary layer growth lifts cloud bases. Slight cool air advection within northerly flow and the cloud cover will warrant highs from the mid 70s to lower 80s today.

A push of low level dry air from the northwest will then commence this evening and persist into Wednesday as high pressure begins to expand into the region from the west. This will be in response to building heights across the upper midwest and Great Lakes region. Mid level anticyclonic flow and sfc high pressure will sustain dry conditions into Thursday. The drier air will promote a little better mixing Wed and Thurs, with the opportunity for decent radiational cooling, thus leading to greater diurnal spread in temperatures.

Deterministic model solutions show reasonable agreement in forecasting a deepening of a slow moving mid level wave from the upper Midwest into the Mid Mississippi/Lower Ohio Valley Friday into this weekend. The extent to which corresponding mid level troughing, deep layer moisture and diurnal instability impact Se Mi carries a little more variability among model ensemble members. Probabilistic guidance has at least trended a little higher with rain chances Friday night and Saturday, warranting the chance of showers/thunderstorms in the forecast.

MARINE...

Low pressure departs the Lake Huron vicinity this morning, dragging a cold front across the region that allows any convection to taper off by mid-morning. The low deepens and stalls over the eastern Great Lakes today as high pressure quickly builds in over the western Great Lakes. This sets up up a tightened pressure gradient locally that produces gusty north-northwest wind today, tonight, and into Wednesday. Winds of 15 to 25 kt will be common, with gusts up to around 30 kt possible in the southern basin of Lake Huron. Small Craft Advisories are in effect due to the winds and increasing wave heights. The high pressure will slowly advance eastward Thursday and Friday, allowing winds to diminish and ensuring dry conditions. The weekend presents another window for scattered showers and storms ahead of the next cold front.

DTX WATCHES/WARNINGS/ADVISORIES

MI...Beach Hazards Statement through this evening for MIZ049-055-063.

Lake Huron...Small Craft Advisory until 8 PM EDT Wednesday for LHZ421.

Small Craft Advisory from 10 AM this morning to 8 PM EDT Wednesday for LHZ441>443.

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