Marine Weather and Tide Forecast for Omena, MI

UPDATE
Issued at 1038 AM EST Mon Feb 17 2025

Ongoing forecast theme remains well on track. Northern Michigan is currently in the beginning stages of being in the tight grip of another arctic airmass, and that arctic cold flowing over those largely-still-open-for-business lakes has drummed up yet another round of lake effect snowfall. Little bit of a different story today... the core of the cold airmass has settled in (current temps range from lower single digits to lower teens), so despite good saturation and lift for lake effect snowfall, much of this is located **above** the DGZ, and is thus resulting in more of a gunpowder composition to the snow, as opposed to the big fluffy high ratio flakes. As such, ratios will be somewhat lower, but impacts from blowing / drifting snow will be higher due to the powdery nature of the snowfall. As far as headlines go, not really seeing much to sway impacts from wintry weather through tomorrow morning, so have gone ahead and elected to extend winter weather headlines through 12z Tuesday.
In addition, snowfall amounts are looking to be highest for Antrim County, approaching Warning criteria through Tuesday morning. Given the amplified impacts, have elected to upgrade Antrim to a Winter Storm Warning. Deliberated about Kalkaska and western Mackinac as well, but just not enough confidence at this juncture to push that big red button, so will hold an advisory in place there for the time being. Could be a different story by later this afternoon. Stay safe, everyone!

SHORT TERM /THROUGH TONIGHT/
Issued at 407 AM EST Mon Feb 17 2025

Pattern/synopsis: Deep low pressure will remain near New Brunswick today, before exiting eastward tonight. Very cold air continues to invade the northern lakes, resulting in lake aggregate troffing over northern Lk Huron and se Superior.
Aloft, a 500mb closed will gradually fill crossing Superior today, opening up into a sharp trof tonight.

Forecast: Cold advection continues today. By early evening, 850mb temps reach -23/-24C, and remain there tonight. Abundant instability for lake effect processes of course, and moderate to at times heavy banding is already occurring in the northern lakes. Some very skinny stronger bandlets are in place in northern lower MI (eastern Charlevoix Co and ne Kalkaska Co, in particular). A more northerly fetch on Superior is focusing banding into eastern Alger Co (and is the ultimate origin of the northern lower MI bands).

Moisture availability is sparse, in both a relative and absolute sense. Outside of lake effect clouds, skies are largely clear, though some colder clouds are seen north of Superior.
Models are showing a slight moisture increase late tonight in eastern upper MI, associated with those colder cloud tops.
Another limiting factor: the DGZ will be very shallow and very low to the ground. Stronger bands will still have ok dendrite generation today, especially early. But otherwise snowflakes will turn smaller/ powdery. That hurts SLRs and snow accums, though the small flakes are easier to blow around in our brisk nw winds.

Snow shower coverage will increase by late morning, as diurnal 'heating' further steepens low-level lapse rates. Accums will be broadly 1-3" today in the snowbelts (wnw/nw in northern lower, nw/nnw in eastern upper MI). Locally higher amounts remain possible. Have extended the nw lower MI advisory into this evening. Though the flow is a bit too northerly (and upstream waters too icy) for western Chip Co to be hit hard, western Mack Co will be impacted by the stronger banding coming onshore to the west. Have issued an advisory for the western Mack Co zone.
Will also need to keep an eye on the Presque Isle Co coast today.

Tonight, winds to veer somewhat on Superior, and lake effect should make more of a push in western Chip Co. 2-5" forecast there and in far nw Mack Co. Kalkaska Co and nearby counties should be the main focus in nw lower MI, with 2-5" totals there as well. Up to 2" in the broader snowbelts. Will let later shifts evaluate trends further, and the potential need for advisories tonight. Also: wind chills drops to mid minus teens in n central and ne lower MI late tonight, and perhaps -20 at the Sault. This reaches "cold weather advisory" thresholds in both areas, and such headlines are distinctly possible later on.

High temps today near 10 above to the mid teens. Lows tonight slightly above zero near Lake MI, to as cold as -10f near the Sault.

LONG TERM /TUESDAY THROUGH SUNDAY/
Issued at 407 AM EST Mon Feb 17 2025

Pattern Synopsis/Forecast:

Cold arctic air will continue to advect into the Northwoods with the core of coldest air reaching northern Michigan Monday/Tuesday.
Northwest winds look to persist as pressure gradients orient northwest from a departing low pressure system and high pressure trying to build in its wake. Cold air seeping into the region, along with aformentioned persistent northwest flow, will potentially keep lake effect snow showers lingering through mid-week. With moisture slowly being eroded away by the aforementioned cold air and wrap around moisture in shorter supply as the aformentioned low pressure departs, this should keep snow amounts lighter. All this to say, the typical NW flow snowbelts can probably expect a few more inches by mid-week. Winds will continue to be breezy into Tuesday with gusts 20-25 mph, making blowing/drifting snow and lowered visibilities likely during this timeframe, especailly given the nature of the snow (fine, small flakes). An upper-level low looks to bring a period of widespread light snow Wednesday night/Thursday with perhaps some lingering light lake effect snow showers the later half of the week into the weekend. However, overall a drying trend is expected as heights build at the surface and aloft, which should shut off lake effect showers.

Daytime high temperatures look to be in the teens with negative teens for wind chill values, especially heading into Tuesday morning. Temperatures look to moderate by mid-week with values slowly creeping back into the mid to upper 20s, and potentially even low 30s by the weekend.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
Issued at 1231 PM EST Mon Feb 17 2025

Lake effect snow showers are set to continue this afternoon across all TAF sites in northern Michigan, with the exception of CIU.
Largely MVFR CIGs across the board, with the occasional drop to IFR during any given passing snow shower. Tonight, clouds thin closer to APN and PLN, perhaps bringing some brief VFR conditions, while lake effect snow showers continue at all other sites, including CIU, who could see some increasing snow shower activity later tonight.
Generally WNW to NW winds this afternoon gust to 25kts, tapering but remaining persistent with sustained winds of 10-15kts. Looking into Tuesday, those NW to WNW winds flare up again by mid-morning, with snow shower activity again ramping up. There may be some longer lasting VFR CIGS at times on Tuesday, but the overall prevailing conditions will largely be MVFR with continued lake effect snow showers.

APX WATCHES/WARNINGS/ADVISORIES
MI...Winter Weather Advisory until 7 AM EST Tuesday for MIZ016-017- 020-022-025>028-031>033-095-099.
Winter Storm Warning until 7 AM EST Tuesday for MIZ021.
MARINE...Small Craft Advisory until 5 AM EST Tuesday for LHZ346-347.
Small Craft Advisory until 5 AM EST Tuesday for LMZ323-344>346.