textproduct: Detroit/Pontiac

KEY MESSAGES

- Chance of snow showers tonight with additional accumulations up to an inch for most areas. Areas along/between the M-59 and I-69 corridors could see heavier snow showers resulting in locally higher amounts towards 2 inches.

- Flurries or light lake effect snow showers daytime Thursday. An arctic cold frontal passage in the evening brings wider spread snow showers with accumulations up to an inch.

- An Extreme Cold Watch is in effect late Thursday night through Saturday morning due to dangerously cold conditions. Minimum wind chills below -15F expected both Friday and Saturday mornings.

AVIATION

A pocket of dry air within southwest flow is resulting in an area of VFR ceilings across the southern metro terminals while MVFR ceilings reside across PTK and points north. A quick passing clipper system and associated cold front will them move through southeast Michigan bringing another round of widespread light accumulating snowfall tonight and lower ceilings. Lake Michigan has been activated along the lead frontal boundary bringing light lake effect snow showers across much of the area to start this TAF period. The trailing wave now approaching southern Lake Michigan will move in tonight roughly between 05Z to 09Z bringing a period of high variability in CIGs and VSBYs. Expecting conditions to drop to mostly MVFR/IFR VSBYs under the heavier snow showers during that time. West winds and cold advection will keep Lake Michigan activated and maintain low VFR/MVFR ceilings with light lake effect snow showers tomorrow morning and afternoon.

For DTW...Another round of accumulating snow expected between 05z and 09z tonight. Accumulations of a dusting to an inch is most likely. Closer to 2 inches will be possible if a more intense band sets up over DTW.

DTW THRESHOLD PROBABILITIES...

* Medium for ceilings aob 5000 feet this evening. High after 05z through Thursday morning.

* High for precip type as snow through the TAF period.

PREV DISCUSSION

Issued at 332 PM EST Wed Jan 21 2026

DISCUSSION...

Following the scattered light snow showers/flurries in the north this evening, a secondary shortwave/cold front is set to sweep through southern lower MI tonight. Stronger frontal boundary affords both better coverage, relative to evening, and intensities for snow showers between midnight and 5AM. Heaviest snow showers, including potential squalls, expected along/between the M-59 and I-69 corridors where the parent vort max crosses enhancing local f-gen response along the frontal circulation. Most areas see between 0.5- 1" of new snowfall tied to this wave, however, areas under the area favored for stronger f-gen have potential to see locally higher totals up to 2" especially if a more W-E component of the orientation develops- like what is seen in the HRRR and to an extent ARW.

Colder air, 850mb falling to -18C, settles over lower MI by Thursday morning kicking off the typical lake response. That said, the arrival of another clipper over the northern Great Lakes daytime Thursday causes the lower level wind field to shift from WNW back to WSW hampering continuity in bands and overall limiting activity over SE MI to more flurries or brief light snow showers with minimal accumulation. A bit better accumulation potential comes Thursday evening when the associated arctic front is driven across the state. This boundary provides a focal point for the release of lake moisture east over our area supporting a healthier coverage of snow showers and a few embedded snow squalls capable of a quick half to one inch of new snow.

Coldest air of the winter thus far follows the front as 850mb temps bottom out near -30C. Cold advection through the day Friday maintains blustery winds with gusts 20-30mph throughout the day. Resultant wind chills Friday morning reach well into the negative teens to 20 below with little if any improvement during the daylight hours as actual temperatures remain in the single digits for most areas. Strong arctic high pressure establishes itself over the central Great Lakes by Saturday bringing calmer winds though no thermal recovery. In fact, the high promotes clearer skies Friday night allowing overnight low actual temperatures to fall below 0 towards -10F. In coordination with neighboring offices, an Extreme Cold Watch is in effect from Thursday night through Saturday morning due to the potential for wind chills to reach 25 below zero. Ridge axis crosses SE MI by the latter half of Saturday offering a marginal improvement in temperatures with highs back into the teens and lows in the positive single digits for Sunday and Monday. Will need to keep an eye on a broad southern CONUS winter storm as a portion of ensemble and deterministic guidance favor a more northerly track at least partially clipping southern lower MI. This northward shift in track is reflected in the latest NBM extended PoPs which increased this cycle to 40-50%.

MARINE...

For the remainder of today, a low pressure system will travel from the northern Great Lakes into Quebec by tomorrow morning. This will sustain light snow for portions of the northern Great Lakes and will veer wind direction from southwest to west. The continued departure of the low pressure system will push a very strong arctic cold front across the Great Lakes through Thursday and Friday which will bring the continuation of active weather and breezy conditions.

The combination of the strengthening pressure gradient and strong over lake instability will support sustained winds around 25 knots with gust potential around 30 to 35 knots. The signal for prolonged gales remains borderline at this time with highest probability of achievement located across southern and central Lake Huron tomorrow evening to Friday morning. Will preclude any gale products noting the possibility for a short-fused upgrade if model trends increase leading into the evening. A Heavy Freezing Spray warning has been issued given the intrusion of arctic temperatures and sustained elevated winds.

Snow squalls will be likely Thursday and Friday, especially across central and northern Lake Huron where surface convergence is enhanced. Expect rapid reductions to visibility within any squall. A very strong high pressure system to then settle across the Great Lakes this weekend which will maintain arctic temperatures but will allow wind speeds to rapidly diminish.

CLIMATE...

The record low max temps for Friday, January 23rd.

Detroit: 6 Degrees (Set in 1883) Flint: 6 Degrees (Set in 1959) Saginaw: 3 Degrees (Set in 1963)

The record low min temps for Saturday, January 24th.

Detroit: -13 Degrees (Set in 1963) Flint: -13 Degrees (Set in 1963) Saginaw: -13 Degrees (Set in 1963)

The record low max temps for Saturday, January 24th.

Detroit: 4 Degrees (Set in 1963) Flint: 5 Degrees (Set in 1963) Saginaw: 8 Degrees (Set in 1961)

DTX WATCHES/WARNINGS/ADVISORIES

MI...Extreme Cold Watch from late Thursday night through Saturday morning for MIZ047>049-053>055-060>063-068>070-075-076-082-083.

Lake Huron...Heavy Freezing Spray Warning from 6 AM Thursday to 6 AM EST Saturday for LHZ361>363-462>464.

Gale Warning from 10 AM Thursday to 4 AM EST Friday for LHZ363- 462>464.

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