textproduct: Detroit/Pontiac

KEY MESSAGES

- Breezy and mild on Tuesday with a slight chance of wintry mix in the morning followed by scattered light rain showers.

- Snow showers Wednesday and Wednesday night as arctic air moves into the region. Accumulations between a dusting and 2 inches for most locations, with 3 inches possible along the Lake Huron shoreline.

- Much colder late this week and into next weekend. Thursday and Friday morning wind chill around zero degrees.

- Periodic chances for snow will exist Friday through the weekend.

AVIATION

VFR conditions this evening through tonight as ridging builds across the area in advance of the next system. Patches of mid/high cloud will stream across the area at times through tonight. A warm front will develop over the area on its way north on Tuesday. This will bring lowering of the clouds but mainly still VFR. Some signal for the front to produce light rain during the day but the wealth of dry air in the lower levels will make anything more than virga hard to come by. Chances of precip are less than 20% for most sites so will not mention at this time. Winds will become gusty once again in the afternoon with gusts to 25 to 30 knots. Chance for MVFR CIGs late in the forecast as a cold front approaches.

DTW THRESHOLD PROBABILITIES...

* Low for cigs aob 5000 feet through Tuesday, medium for Tuesday night.

PREV DISCUSSION

Issued at 338 PM EST Mon Jan 12 2026

DISCUSSION...

A mid-level shortwave ridge supports benign conditions the rest of the day into tonight with NVA and anticyclonic flow maintaining higher stability across the area. Wind becomes less gusty overnight but a persistent gradient keeps southwest wind and elevated warm advection active overnight. Lows will be mild, near 30.

The next low will be steered across the northern Great Lakes on Tuesday by a mid-level wave dropping in within larger scale troughing over the eastern CONUS. An elevated warm front will develop overhead and attempt to produce light precipitation during the morning, but will have to contend with a lot of dry air in place. Temps will sit tenuously close to or just below freezing through around 9AM, which brings potential for light wintry mix should precip develop. Given the limited moisture during this window, virga will be the most likely outcome. Any additional precip that develops through mid to late morning would trend from a rain/snow mix to just rain as temps rise toward the upper 30s and lower 40s for a high.

The gradient will tighten further ahead of the inbound low, producing breezy conditions through the daylight hours tomorrow. Latest guidance has trended upward for wind magnitude, and boundary layer wind progs will support gusts to 35 to 40 mph from late morning to mid afternoon. The mid-level vort max passes overhead mid to late afternoon with trailing filaments of PV following throughout the night. With slightly more moisture to work with, this will warrant a chance for scattered light rain showers into Tuesday night.

Amplified ridging over the western CONUS directs a potent wave southward across the Great Lakes on Wednesday. An attendant arctic front will track north to south across the state Wednesday morning with 850mb temps plummeting from around 0C to around -20C by Wednesday night. Early day highs in the 30s fall to the teens by the evening hours. The front will provide a focus for snow showers with steepening lapse rates, increasing low-level fgen, and even some instability developing ahead of it suggestive of potential for a brief burst of heavier rates for parts of the area. Snow Squall Parameter has shown an increasing trend, so this period bears monitoring for possible localized impacts to the Wednesday morning commute. Accumulations of a dusting to around 1 inch would be possible along with drops in visibility.

The continued cold advection will maintain a chance of additional snow showers Wednesday afternoon into Wednesday night. Attention during this period turns to the eastern shoreline of the Thumb where N to NNW wind off Lake Huron may bring lake effect activity onshore at times. Ensemble data supports accumulations of around 2 to 3 inches for this area by Thursday morning. A relative lull in snow showers is likely on Thursday but then wintry weather continues Friday and all the way into early next week as a series of low amplitude waves track through the resident longwave trough. This offers fairly high confidence in snow shower activity, but low confidence on timing and amount specifics for now. The pattern reinforces the arctic air supply with 850mb temps held 5 to 10 degrees below normal as we approach the climatological coldest part of the season. Wind chills will generally range from -10 to 20F through early next week with values near 0 on Thursday and Friday mornings.

MARINE...

Modest southwesterly flow decreases this evening, before the gradient tightens ahead of the next clipper system. The Small Craft Advisories will be allowed to expire. Flow increases and turns southerly Tuesday which brings potential for renewed Small Craft Advisories across portions of the southern Lake Huron nearshores. 35- 50 knot flow moves into the lowest 3 kft, but gusts may be held in- check by lower column stability. Still, cannot completely rule out isolated gusts to gales Tuesday. The low ejects into Quebec by Wednesday morning which forces a rather potent cold frontal across the central Great Lakes. Potential exists for a post-frontal gales on Wednesday with the ensuing cold advection, but the low-level wind field is weaker and displaced further south. Winds speeds decrease Thursday, then flip southerly by Friday.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...Small Craft Advisory until 10 PM EST this evening for LHZ421-441.

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