Marine Weather and Tide Forecast for Prudenville, MI

SHORT TERM /THROUGH TONIGHT/
Issued at 325 AM EST Mon Dec 9 2024

Pattern/synopsis: Complex low pressure is to our west, with a triple-point 998mb low in w central WI, and a parent 997mb low in nw MN. A surface warm front is advancing into central lower MI, with more southerly surface winds to the south. Easterly winds are in place here, feeding in air off a cool/dry high pressure to our ne. For most of the area, Lk Huron is substantially modifying this incoming airmass. Not as much in eastern upper MI, where upstream temps in the mid-teens are common in Ontario.

Forecast: warm air is deepening across northern lower MI, even north of the surface warm front. The warm-frontal band of precip has lifted into eastern upper MI, almost all snow to this point.
Where the surface layer was more substantially marine (like Mackinac Isl), precip turned to rain before it lifted north. A few convective elements were bubbling on radar near MOP, while some banded features were developing just trailing the frontal band over the ESC/ISQ/Beaver Isl area.

The most widespread precip will gradually exit eastern upper MI thru 12Z. However, the triple-point surface low center will be reaching ne WI by then, with a cold front extending toward central/southern Lake MI. Continued warm/moist advection at relatively low levels, with falling heights aloft, will steepen lapse rates over northern MI. Showers will redevelop and grow upscale as these height falls advance into the region. Pops will be highest this morning/midday in eastern upper MI, and in northern lower near/east of M-66. With deep above freezing temps, this will fall as all rain in northern lower MI. But the warm nose aloft will make uncertain progress into eastern upper MI, while overrunning a much cooler BL (especially inland from Lakes MI/Huron). The kitchen sink of p-types is in the grids today in eastern upper MI. This starts as snow and perhaps sleet in northern parts (like the Sault and Paradise), with FZRA entering the picture by midday. Further south (Trout Lk and Pickford), all p-types are possible before a transition to sct rain showers by mid afternoon.

Additional snow/sleet accums could flirt with 1" in parts of Chip Co. The bigger concern is FZRA, with ice accums of 0.05-0.10" across a good chunk of eastern upper. A winter wx advisory has been issued for much of eastern upper MI, with a 1 pm expiration for eastern Mack and se Chip, and 4 pm in western and central Chip. Western Mack Co was not placed in the advisory; the extreme ne corner of that zone does have some small ice accums this morning, but the huge majority of the zone (including the US-2 corridor) is too warm/rainy for ice hazards.

The band of showers will gradually lift ne-ward, exiting ne lower MI by 4pm, and eastern upper by 7pm. Low level cold advection will be in place this evening, and 850mb temps quickly tumble back below 0C (reaching -5C south to -8C north by daybreak). With cyclonically curved flow, marginal overlake instability, and gradually increasing moisture, there is a chance of showers in the w to nw flow lake effect tonight. This will be mostly rain this evening, turning to snow overnight in eastern upper MI and the higher terrain of northern lower MI. A slushy dusting of new snow may be possible by morning.

Max temps today mid 30s to mid 40s. Lows tonight mid 20s to near 30f.

LONG TERM /TUESDAY THROUGH SUNDAY/
Issued at 325 AM EST Mon Dec 9 2024

Pattern Synopsis / Forecast:

Current look at the overall pattern shows budding longwave troughing associated with the core of a deep arctic airmass over Nunavut, Canada, with the current shortwave moving overhead being directed north and east into Ontario and Quebec along the southeast reaches of the aforementioned longwave. Core of this arctic airmass will dig south into the northern Plains, and with robust 1035mb polar surface high, should allow for this deep arctic airmass to surge into the Great Lakes region Tuesday night through Thursday. Coupled with this uptick in vorticity, and colder air spilling over the Great Lakes, this should reactivate the lake effect snow machine over that same timeframe, and subject the region to the coldest airmass thus far this season... Eventually, surface high pressure should suppress this activity going into Friday, and bring about disorganized lake effect activity, with winds turning more southerly, moderating the airmass into the weekend. Extended guidance shows another wave approaching from the south to close out the weekend, and with the moderating airmass in place, could bring about p-type issues to close out the weekend.

Primary Forecast Concerns:

Lake Effect Machine Fires Back Up: Following the ingestion of too much antifreeze due to the ongoing warmup, the lake effect machine looks to recover and refuel in a couple days... and will be running wide open, just like those lakes, which remain at about 10C. Coupled with 850mb temps plummeting, it sure looks like delta-Ts (doggone near 30C) will be plenty high enough to generate lake effect snows.
This time, it doesn't look like we will be dealing with quite as much of a long duration event, but with surface temps plummeting into the teens, this should deliver a bit of a shock to the system nonetheless around the midweek timeframe. Trends definitely point the potential for another round of significant snow accumulations in the snowbelts of northern lower and eastern upper Michigan to pile on top of the snow that survives this ongoing thaw. Furthermore, given the core of the 500mb trough gets over the top of us on Thursday and surface flow becomes more dictated by lake aggregate troughing, there is a signal for some mesolow-mania if that trend holds, which could put locales closer to the lakes in play for some good snow totals. One final note, if guidance trends hold, we could be staring down our first instance of below zero wind chills Thursday morning as temps drop into the single digits and winds remain persistent. Unlike last winter, we certainly have our fair share of cold shots to start the winter following what was a top ten warmest fall (in some cases, the warmest fall on record). Definitely more to come as data gets clearer, but certainly looks like this stretch will be the next snow-driven headline hoisting event for the region.

Rest of the Period: Surface high pressure should put a lid on the lake effect snow by Friday, with just some continued, albeit pseudo- disorganized activity into the weekend. In addition, the core of the arctic airmass should be on the way out, so surface temperatures should recover to the upper 20s to near 30 by Saturday, bringing what should be a great start to the weekend for winter recreation for those that (correctly) choose to get out and embrace all that this region has to offer (I'm not a heavily biased snow enthusiast or anything...). The narrative does change to close out the weekend, and we could be looking at another brief warmup Sunday into Monday... this also could coincide with a weaker synoptic system.
Given the marginal temperatures set to be in place during the passage of this system, could be a snow-to-rain setup.... but this is almost 6-7 days out, so details are a bit murky regarding this system's evolution at this juncture.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
Issued at 1128 PM EST Sun Dec 8 2024

Batch of predominantly -SN slowly continues to move northward, focusing on the E UP thru the rest of tonight. Additional -SHRA develops farther south across N lower MI. Most locations MVFR to IFR CIGs through tonight and into Monday, brief instances of LIFR CIGs possible on Monday. Breezy conditions at times tonight into Monday, gusts 20 to 25 KTs. Switch to wintry mix, with FZRA/FZDZ between AOB 12Z for eastern UP. Precipitation wanes through the day on Monday with lingering low clouds.

APX WATCHES/WARNINGS/ADVISORIES
MI...Winter Weather Advisory until noon EST today for MIZ086>088- 096.
MARINE...Small Craft Advisory until 7 PM EST this evening for LHZ345>349.
Small Craft Advisory until noon EST today for LMZ323-341-342- 344-345.
Small Craft Advisory until 7 PM EST this evening for LSZ321- 322.