Marine Weather and Tide Forecast for De Tour Village, MI

UPDATE
Issued at 842 PM EDT Thu Apr 17 2025

Deep layer moisture advection will continue, eventually becoming deep enough to spread scattered to numerous showers from west to east across the area tonight. Plume of limited elevated instability looks to be enough to kick off a few embedded thunderstorms, but any severe threat looks to remain well to our west. A fairly mild night with those clouds and showers, with lows only dropping into the 40s and lower 50s.

SHORT TERM /THROUGH FRIDAY/
Issued at 216 PM EDT Thu Apr 17 2025

Pattern Synopsis and Forecast:

Upper-level ridging will be centered overhead by this evening which has been providing today's beautiful mostly clear skies and warmer temperatures. However, as high pressure exits the region, upstream amplified troughing anchored near Hudson Bay, extending southwestward across the Rockies to Baja California, will gradually track towards the region through the weekend. Low pressure development today lee of the Rockies will support warm/moist advection driven waves of showers/ storms to begin late this evening/night continuing into Friday as low pressure crosses overhead late in the day Friday. A good swath of moisture is expected to be advected into the region with PWATs 1.10"+ and dewpoints increasing into the low-mid 50s.

The primary focus continues to be on Friday through Friday evening as steepening lapse rates aloft support instability folding across lower Michigan. MUCAPE values between 500-1,500 J/kg Friday afternoon/evening over northern lower show storms should be mainly elevated in nature, but some guidance still wants to show hints of surface based cape south of M-32. Given 50-60+ kts of deep layer shear on Friday, any scattered thunderstorm development as low pressure tracks overhead will be capable of becoming strong to severe. The main threat with these storms look to be large hail, given the elevated nature of instability. However, if/where storms are able to become more surface based, strong wind gusts would likely become a component as well, along with not being able to rule out low chances for a tornado.

Temperatures tonight will dip into the 40s and will rebound into the 60s for most of northern Lower Friday, with areas near Saginaw Bay possibly reaching the low 70s...Areas across eastern Upper look to reach the 50s.

LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/
Issued at 216 PM EDT Thu Apr 17 2025

PATTERN SYNOPSIS/FORECAST:

Return flow overtaking the Upper Midwest...with ridge axis building in from the west on the backside of cool, dry surface high that crossed the region overnight. SW-NE oriented trough axis and BCZ stretching from the SW US up into the vicinity of Hudson Bay as a 100+kt upper jet slithers in from the Pacific.
Attendant surface reflection of this boundary looks a bit like a stick man jumping over a dryline log located in the southern/central Plains...with front leg stationary front stretching from a surface low in southeast SD to western AR, rear leg cold front extending from this low back to another low over SW WY (associated with a more potent niblet of energy that has cut loose from the northern stream). Stick man cold front's body stretches up into eastern Manitoba...with one arm over western Ontario generally noting the 0C line at 850mb...and a long cold front arm looping back into the Canadian rockies, delineating the coldest air (850mb temps less than -5C).

Stick-man system to cross the Midwest tonight into Friday...bringing warmth and potential for active weather during the day Friday...with cold front finally sweeping through the area Friday night into Saturday. Potent PV max scrapes our northern sections Saturday...with cold air flooding in to try to bring the lake aggregate trough back into the picture for Easter weekend. Resulting split flow setup lagging across the central US should result in a stationary boundary stalling out somewhere across the eastern US (attm, most likely in the vicinity of the Great Lakes/OH Valley)...along which some cyclogenesis looks to occur going into the start of next week...keeping things on the active side. A fair bit of uncertainty regarding how warm it gets here in Northern Michigan with this...as it will depend on how wound up and how far north the resultant surface low can get...so do not have much confidence in the temperature forecast for later Sunday into Monday with that potent boundary in the region. Additional northern stream energy hanging out across the northern Plains/southern Canada will likely keep things much more on the active side for our area as we go into the latter half of the month of April.

Primary Forecast Concerns:

Thunderstorm potential lingering into Friday night...expect thunderstorms will still be ongoing Friday evening...with the cold front not likely to exit our SE till after 6-9z. While any potential for diurnal heating will be on the wane...think the setup will still be favorable for storms to continue as signals point toward potential for frontal lift to keep the instability going into at least the evening. Some potential we could hang onto rain showers and some rumbles of thunder after 6z...though most areas should be winding down to drizzle, if anything by then. While there are signals for some low-level stability, particularly in marine environments...do think it's not impossible we could pull down some of the 50-60kt winds that should be up a few thousand feet off the deck, given setup is somewhat favorable for gravity waves to develop that could help with downward momentum transfer and enhance storm activity; additionally...wind concerns may very well be on the table if activity turns more linear with time going into the evening/overnight. Lingering weak stability aloft suggests we will still be toying with some hail threats into the evening, especially on the earlier side. Think heavy rain could still be a threat with pwats still up on the higher end of climo for this time of year (1- 1.5inches)...though do think that with the cold front coming in...things will become more progressive and head on out with time.

Rain/snow chances Saturday...expect we will see some cold-air instability showers...or at least, clouds, with the cold air moving in...though attm it doesn't look like it will be cold enough for overlake instability to much of a depth at all, if any. Could be cold enough, though, to support some flakes mixing in with any showers, especially across the EUP and Tip of the Mitt.

Weekend/early week system...certainly potential for this to be breezy, with signals that the system could get quite wound up...though strongest winds will be determined by the position of the low. Looks like some instability could lend itself to potential for thunder...as we currently appear to be more in the warm sector of this system compared with other systems in recent memory.......with best chances for p-type concerns currently looking to hang over parts of western Upper on the backside of the low going into early next week...and otherwise, generally north of the eastern UP...though if the system ends up a little weaker, it's possible the colder air on its backside could traverse our area.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
Issued at 1141 PM EDT Thu Apr 17 2025

Clouds will continue to lower and thicken, with cigs trending to IFR this morning. Showers will accompany these lowering cigs, spreading from west to east. May have a few rumbles of embedded thunder, but any storms should not be too impactful this morning. Showers coverage will dissipate later morning, but lower visibility with mist is looking likely. Another round of showers and embedded thunderstorms are expected to develop this afternoon. A few of these storm could be strong, producing brief gusty winds and hail. Low level wind shear expected at all locations through early this morning.

APX WATCHES/WARNINGS/ADVISORIES
MI...None.
MARINE...Small Craft Advisory until 6 PM EDT Friday for LHZ346>349.
Small Craft Advisory until 11 AM EDT Friday for LMZ323-346.