textproduct: Detroit/Pontiac

KEY MESSAGES

- High-end to likely chances (50-60%) for snow showers this morning to early afternoon. Snow accumulations hold under an inch, likely a dusting to a half-inch.

- Below normal temperatures persist through most of the week.

- Next likely chance for accumulating snow arrives Thursday night through Friday.

DISCUSSION

A weak shortwave and extended PV filament is moving across western Great Lakes into the central Great Lakes this morning. Increasing cloud cover will arrive first with a period of light snowfall to follow. Snowfall will move across southeast Michigan from west to east between 7 am this morning to about 1-2 pm this afternoon. The resident dry airmass and overall weak forcing with this trough will limit total snowfall accumulations through this afternoon. Meager QPF on the order of trace amounts to a couple hundredths should keep accumulations below an inch with most areas seeing a dusting to a half inch snow accumulation.

Veering low level flow turns out of the west with the passing of the trough opening the door for lake effect off of Lake Michigan into the evening. Instability/low level lapse rates are not conducive to a strong lake enhanced response, but mid-level subsidence should support flurries during the late afternoon and evening. Confidence is pretty low to see much in the way of accumulation.

A secondary shortwave trough swinging into the central/northern Great Lakes early tomorrow will offer another shot at flurry/light snow activity along a southward sagging weak cold front. Frontal boundary becomes more diffuse as it progresses south of I-69, so best chance for light snow shower will be north of I-69 prior to 7 am with a chance of flurries for most of southeast Michigan through the remainder of Tuesday morning into the early afternoon. Continued lack of moisture precludes mention of any snowfall accumulation at this time.

Surface high pressure builds into the region mid-week while the region remains under the influence of the cold thermal trough. Little change in the airmass Wednesday and Thursday will keep daytime high temperatures in the 20s, similar to today/Tuesday. Persistent low level flow out of the northwest will bring at least some potential to see occasional insignificant flurries.

A deeper trough will emerge out of Hudson Bay with a weak clipper system out ahead of it Thursday night into Friday. This will bring the next chance for a widespread light snow accumulation. Accumulations still depend on the exact placement and strength of the associated low, which still has some variation in the ensemble space. Latest NBM guidance maintains a general 50-70% chance to achieve 1 inch of snowfall for much of southeast Michigan over the course of Friday. An arctic cold front will then come crashing through the Great Lakes with 850 mb temperatures plummeting to -20C and below by 00Z Saturday. This will again lead to lake effect snow shower activity Friday night into the weekend. The airmass will support low temperatures down to around zero degrees Saturday morning with wind chills currently forecast to -10 degrees and below. Temperatures will only rise into the teens for Saturday afternoon with a similar story for Sunday morning and afternoon.

MARINE

Winds organize from the southwest and strengthen through the morning towards 15-20kts as a weak clipper arrives over the Great Lakes. Low slides over the central Great Lakes latter half of the day bringing scattered light snow showers. Winds back to the northwest late this evening with the departure of the low with most waters seeing gusts remaining in the 15-20kt range, though some lower 20kt gusts are possible over northern Lake Huron given the favorable fetch. High pressure dropping out of Canada then expands over the region through midweek promoting drier weather and lighter (<15kt) winds.

PREV DISCUSSION

Issued at 1129 PM EST Sun Feb 1 2026

AVIATION...

An upper trough will move across Se Mi late this morning and early afternoon. An axis of deep layer moisture accompanying somewhat limited large scale forcing will support areas of light snow associated with this moist axis. There will be an abrupt arrival to the moisture between 12Z and 13Z. Due to some residual dry air, ceilings may not drop to MVFR until roughly 15Z. The weak nature of the ascent will only result in a dusting to a half inch of accumulation. While the mid level trough will depart to the east Monday afternoon, lingering low level moisture within a surface trough will sustain low clouds and flurries/light snow showers through at least late Monday afternoon.

For DTW...Latest model guidance suggests the onset of light snow occurring around 13Z. Limited forcing indicates just a dusting of accumulation Monday morning.

DTW THRESHOLD PROBABILITIES...

* High in ceilings below 5000 feet Monday and Monday evening.

* High for ptype as snow Monday.

DTX WATCHES/WARNINGS/ADVISORIES

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