Marine Weather and Tide Forecast for Mount Clemens, MI

AVIATION

A low pressure system exiting the Plains will lift northeastward through northern MI later this afternoon, after pulling a warm front up through the region. Later Friday night, a cold front will advance across the region. This setup will lead to several aviation concerns in the next 24-36 hours starting at press time with a developing low level jet over the elevated warm front which will lead to a period of low level wind shear to around 45 knots down to 2kft through about 14Z this morning. In addition, there may be a period of showers and possibly thunderstorms that advance across mbS (maybe down to FNT) as the first of several waves exits the low through the Great Lakes. There may be an additional round of showers/storms or two through Mid MI through the day making timing each event difficult. More notable wave could produce showers down through DTW in the 14-16Z window so prob30 included for that. Most of the afternoon south of FNT looks dry with strong southwesterly winds for all locations gusting to around 30 knots. The cold front will bring the next chance of showers/storms for all locations but looks to impact the region around/after 06Z so will only be noted in DTW taf at this time.

For DTW...Main aviation impact this period looks to be LLWS through the morning hours. Very low confidence in warm frontal showers as far south as DTW through morning with a low chance around 14-17Z so will continue a prob30. The better coverage is likely to occur north of DTW. Strong capping favors a dry forecast through daytime Friday with best chance of convection occuring around/after 06Z with an approaching cold front.

DTW THRESHOLD PROBABILITIES

* Medium for ceiling 5000 ft or less Friday morning and afternoon, high Friday night.

* Low for thunderstorms Friday morning, medium Friday night.

PREV DISCUSSION
Issued at 314 PM EDT Thu Apr 17 2025

DISCUSSION...

Ongoing long wave trough amplification across the northern and central Rockies will result in downstream strengthening of the deep layer west-southwest winds across the Mississippi Valley and Great Lakes region tonight into Friday. This will drive a plume of mid level moisture across Se Mi this evening into the overnight. This in conjunction with steepening mid level lapse rates will be at least supportive of ample returns on radar. Residual dry air in the low levels associated with departing sfc high pressure will be a limiting factor for how much if any showers will be able to reach the sfc. There will be some degree of stability in the nocturnal boundary layer to keep the stronger winds elevated (35-40 knots at 1k feet). The gradient flow will limit nighttime lows in the upper 40s/low 50s. Hi res model solutions are in reasonable agreement in driving a convectively induced short wave across cntl/nrn Lower Mi late tonight/early Fri morning. Increasing elevated instability along the nose of the low level jet will sustain some degree of convection across Lower Mi. While the better forcing will be across central Lower Mi, convective chances will extend south into metro Detroit along the mid level instability axis.

The deep elevated mixed layer(EML) observed across the southern Plains this morning is forecast to lift into Se Mi late Fri morning into the afternoon. Model soundings across Se Mi indicate this will result in a strong capping inversion, inhibiting convective through the afternoon. While there will be low level moisture advection through the day, the NAM remains much more bullish with the low cloud development under the capping inversion. GEFS members are more supportive of less low clouds, with a warmer better mixed boundary layer. This suggests highs over most of the area well into the 70s (it is noted that there are a few ensemble members that drive highs into the low 80s) and windy conditions (sfc gusts over 30 MPH). The elevated mixed layer is forecast to exit to the east Friday night.
This will open the door to convective development along a slow moving sfc cold front forecast to move into Se Mi overnight. Deep layer sheer will remain strong through the night (bulk shear of 50- 60 knots). Waning surface based instability due to the loss in diurnal heating will limit the severe wx risk, which is why a portion of the area was downgraded from Slight to Marginal in the SPC Day2 Outlook.

The northern branch of the mid level trough axis will traverse the northern Great Lakes Saturday and Saturday night, driving high pressure into the region from the north in its wake and bringing cooler and much drier conditions to Se Mi. This will also force the sfc cold front south of the forecast area. However, the elevated portion of this front will warrant continued chances for showers through the first half of the day Saturday across the southern portions of the forecast area. A compact mid level low and associated surface occlusion is forecast to lift into the Great Lakes region late Sunday into Monday. Recent trends have been more westward with this system, taking is across the upper Mississippi Valley/wrn Great Lakes. This solution would still drive the warm conveyor into Se Mi and support a chance of showers Sun night and Monday.

MARINE...

Benign marine conditions continue through the evening as departing 1024 mb surface high pressure reaches the mid-Atlantic. A pattern shift then begins overnight, first indicated by increasing southeast gradient flow. This brings wave heights to Small Craft Advisory thresholds, while influx of the low level jet also increases wind gusts toward 25 knots for most of Friday. First round of showers and possible thunderstorms arrives with this low level jet early Friday morning, with a longer duration period of precipitation possible Friday night into Saturday morning along the slow-moving system cold front. A few of these storms may be strong to severe, more likely over northern Lake Huron where the front arrives earlier Friday night. An active frontal zone and upper level pattern keeps precipitation chances going through the evening, though wind and wave action will subside below advisory thresholds.

DTX WATCHES/WARNINGS/ADVISORIES
MI...None.
Lake Huron...Small Craft Advisory until 4 PM EDT this afternoon for LHZ421-422- 441>443.

Lake St Clair...Small Craft Advisory from 8 AM this morning to 10 PM EDT this evening for LCZ460.

Michigan waters of Lake Erie...Small Craft Advisory from 8 AM this morning to 10 PM EDT this evening for LEZ444.