textproduct: Detroit/Pontiac

KEY MESSAGES

- Winter Weather Advisory today through Tuesday morning for a combination of winter hazards.

- Snow showers today expected to produce 1-2" inches of accumulation. Best chances for higher amounts will be between M 59 and I 94 where a lake effect band looks to develop as well as the northern Thumb where a second band pushes through.

- Frigid and blustery conditions today with potential for snow squalls and winds gusting 40+ mph.

- Dangerously cold wind chills of -5 to -15F tonight into Tuesday morning.

- Another round of accumulating snow on Wednesday, impacting the AM commute.

- Another arctic outbreak looks to impact the region this weekend. Single digit high temperatures with lows below zero will be possible.

UPDATE

Peak in large scale forcing associated with inbound governing arctic wave and attendant frontal zone providing the necessary focus for a corridor of higher magnitude snow showers this morning. This activity will sweep to the east through late morning, as the secondary focus shifts toward the lake Michigan response as overlake convective depth grows with time under stout cold air advection. Standard signal for convergence to emerge off the south end of the lake within pervasive west-northwest low level flow and mid level cyclonic flow, effectively directing pockets of snow showers downstream and into the typically prone belt between I-69 and I-94. Expectation for a more chaotic coverage during the diurnal window as bands or fragments funnel downstream. Forecast continues to highlight additional accumulation potential anywhere from a dusting to locally around an inch through the rest of the day. This will occur within an increasing gusty west wind, reaching 35 to 40 mph at times this afternoon. This will contribute some degree of blowing of falling snow and rapid reduction to visibility. Invasion of the arctic airmass keeps temperatures in the teens this afternoon, with wind chill generally around zero to 5 below. No major changes planned with the morning update.

PREV DISCUSSION

Issued at 624 AM EST Mon Jan 19 2026

AVIATION...

An arctic cold front will sweep across SE MI this morning, marked by a wind shift to west and a corridor of enhanced snow shower activity through around 14Z to 15Z. Wind magnitude gradually ramps up as the colder air arrives, peaking mid morning to mid afternoon with gusts 30 to 35 kt. Additional snow showers with highly variable conditions continue through the afternoon and evening with highest impacts tied to placement of the dominant Lake Michigan band(s). Hi-res guidance favors a transient band in the MBS vicinity and Thumb early this afternoon, and a more persistent band within the I-94 to M-59 corridors through the afternoon and evening. This band will be highly sensitive to subtle changes in wind direction through the period. Intervals of IFR/LIFR visibility in BLSN will be a concern at any site given the wind magnitude. Wind subsides overnight but lake effect snow showers are likely to persist, again most focused within the I-94 and M-59 corridors.

For DTW...Scattered snow showers move through the vicinity through 14Z, some of which may be heavy with snow squalls. West winds then increase in excess of 30 knots with restrictions to visibilities due to BLSN. Lake effect banding is likely to extend into the vicinity this afternoon and evening, but with low confidence in duration at DTW. There is signal for the band to slowly drift north of DTW overnight.

DTW THRESHOLD PROBABILITIES...

* High in ceilings aob 5000 feet today and tonight.

* Moderate to exceed crosswind threshold this morning and afternoon.

* Low in visibility below 1/2SM in blowing snow through 21Z today.

PREV DISCUSSION... Issued at 338 AM EST Mon Jan 19 2026

DISCUSSION...

Winter Weather Advisory remains in effect through Tuesday morning for the combination of snow, blowing snow, possible squalls, wind gusts to around 40 mph, and dangerous wind chills. Bulk of the forecast remains on track with most adjustments in terms of location and timing of POPs and snow amounts as we try to refine the lake effect bands with additional hires model data.

The low pressure system is currently centered over eastern Lake Superior with an arctic cold front now beginning to enter southern MI from the west. Timing of the front through SE MI should be around 11-13Z. In advance of the front we have lingering light snow after the exit of the leading area of synoptic snow overnight. Radar returns and obs support light snow with minimal accumulations through about 12Z. Arctic front will then open the door for the next round of snow showers as it pulls the ongoing SW to NE oriented lake effect convergence axis across lower MI. Deep mixing depths with strong low level lapse rates will aide in stronger showers developing in the wake of the front. Though model sounding show mixed layer has lowered slightly to around 8kft (vs the 9-10kft advertised previously), this will still be ample depth to result in a decent lake effect setup today and tonight. Initially today activity will be a bit more widespread as the lake convergence gets pulled through oriented N to S. Then westerly flow sets up which will then reorganize the convergence axis W to E in the typical area from around M59 south to I94. Though moisture quality will not be great with only around 1 g/Kg of specific humidity in the mixed layer, Omega will be on the stronger side as will lapse rates. With strong winds gusts today to around 40 mph, blowing and drifting of snow will be likely which will reduce visibilities. It will also make for potential snow squalls with any stronger showers that develop. Overall snow amounts are on par with the inherited forecast with mainly a refinement to narrow the corridor of best lake effect banding. In addition, slightly higher amounts and pops have been given to area north of M46 as hires models have been consistent the last few runs with the trailing trough axis organizing an additional convergence band from northern Lake MI and Lake Superior getting pulled into the region.

Though the mixed layer shrinks overnight to around 4-5kft, the westerly flow should continue to advect moisture along convergence boundary which will keep clouds and light snow going through the night. Amounts should be subdued as the band wavers around slightly and conditions are not as favorable with cold air advection forcing the moist layer out of the DGZ leading to more powdery snow flakes. Some locations could still see up to an inch overnight with the persistence of the band.

The lake effect cloud cover is going to help keep wind chills values from cratering between I69 and I94 but the airmass will be so cold, lows are still forecast into the single digits under the clouds so wind chills in that region should still drop to around -5 to -10F. The Thumb region and locations around the Ohio border will have clearing skies and should get down to -10 to -15F. In addition, wind chills today and Tuesday should be around 0F making for nearly 36 hours of possible negative wind chills.

High pressure sliding through the Ohio Valley Tuesday in addition to a lack of upper level energy advancing through the trough aloft, will lead to a brief reprieve in snow chances (outside of any lingering light snow in the lake effect band). This will be short lived as the next southward diving jet brings another shortwave through the region Wednesday morning through the evening. Better moisture quality and period of isentropic ascent ahead of the low will provide a chance for accumulating snow on the order of 1-3 inches. Looking into next weekend, there looks to be another round of arctic air, colder than the current airmass, which could lead to high temps in the single digits with overnight lows below 0F.

MARINE...

Mature low pressure slides along the far northern Lake Huron shoreline into eastern Ontario this morning. Strongest gradient response occurs over the southern Great Lakes during this time bringing potential gales across Lakes St Clair and Erie through the afternoon. For Lake Huron, gale potential remains tied to the arctic cold front offering a 3-5hr window to see gusts in excess of 34kts. Given its proximity to the low center, the far northern waters continue have the lowest chance to see gales with the bulk of strongest winds expected over the central/southern open waters. Due to the stronger winds and cold airmass, heavy freezing spray is likely in all non-ice covered waters of Lake Huron. While gales taper off by Monday evening with the departure of the clipper, the region will remain under broad troughing over the eastern continent allowing additional systems to track over/near the region maintaining at least moderate winds (>20kts), snow showers, and freezing spray through most of the week.

DTX WATCHES/WARNINGS/ADVISORIES

MI...Winter Weather Advisory until 10 AM EST Tuesday for MIZ047>049- 053>055-060>063-068>070-075-076-082-083.

Lake Huron...Heavy Freezing Spray Warning until 10 PM EST this evening for LHZ361>363-462>464.

Gale Warning until 10 PM EST this evening for LHZ362-363-421-422- 441>443-462>464.

Lake St Clair...Gale Warning until 7 PM EST this evening for LCZ460.

Michigan waters of Lake Erie...Gale Warning until 7 PM EST this evening for LEZ444.

Low Water Advisory until 10 PM EST this evening for LEZ444.