Marine Weather and Tide Forecast for Greilickville, MI

UPDATE
Issued at 922 AM EDT Sat May 17 2025

Inherited forecast remains on track. Mammoth upper level low pressure has finally made it into the area, and the warm, summer- like temperatures and thunderstorms are now just a distant memory for folks up here in APX land. Cold air advection well underway with temperatures likely rising minimally from their current standings, into the 50s, with some areas near Lake Huron in northeast lower making a run at 60. Lack of pinched pressure gradient due to the center of the low being right over our heads will lead to lesser wind potential than those to the south and west... though we will still contend with some breezy cyclonic W to SW flow, with some gusts as high as 25 mph, which will add an element of chill to the air. Well defined moisture pool wrapped around the system will keep us in generally mostly cloudy to overcast skies given our position in the immediate vicinity of the surface low. Some breaks in the clouds evident across NE Wisconsin will make a run at the southern CWA, which could lead to some peeks of sun later this morning into the afternoon in those locales. Closer to home, synoptic precip shield will continue to slowly pinwheel across the region this morning, with activity becoming a bit more scattered in the afternoon. With moist adiabatic lapse rates / well saturated airmass in place, minimal diurnal heating will be required to force some shallow convective showers later today. No thunder is expected at this juncture.

SHORT TERM /THROUGH TONIGHT/
Issued at 306 AM EDT Sat May 17 2025

Pattern Synopsis/Forecast:

All attention early this morning directed at deep and vertically stacked low pressure working east across northern Wisconsin/western upper Michigan. System attendant cold front in the process of sweeping across the Northwoods, drumming up some shower with embedded thunderstorms in the process. Some gusty winds and small hail earlier with some of this activity, but nothing too noteworthy.

Upstream low pressure will continue to work steadily east directly across our area today, reaching vicinity New England Sunday morning.
This will bring much cooler and occassionally damp weather to the Great Lakes through tonight.

Primary Forecast Concerns:

Temperature trends and addressing shower evolution through tonight.

Details:

Big story today will be the arrival of much cooler temperatures as cold air advection intensifies on backside of passing low. Will definitely feel more like April then the middle of May (especially after the recent very warm temperatures), with highs today mostly ranging from the middle 50s to lower 60s. Southwest to west winds will steadily increase as well today, adding a bit more chill to the air. Pockets of enhanced moisture and forcing wrapping around parent low
along with some weak diurnal support
will result in scattered mostly light showers at times today. Vertical moisture profiles begin to thin with time tonight as system departs to our east. May see some lingering light showers/areas of drizzle within a still relatively moisture rich low level environment and upslope enhancement via gusty northwest winds. Cooling trend continues, with lows tonight down into the lower and middle 40s.

LONG TERM /SUNDAY THROUGH FRIDAY/
Issued at 306 AM EDT Sat May 17 2025

Pattern Synopsis/Forecast:

Midlevel pattern begins to shift at the start of the long term from active weather to a more dry pattern through the first half of the week. Surface high pressure will build this Sunday and Monday.
Pressure graident force winds from the departing/downstream low will pull a chilly dry air mass from the north. Temperatures this Sunday remain much cooler than normal for mid May with highs remaining in the 50s for most locations across the CWA Monday remains pretty much the same except subsidence aloft will begin to really dry out conditions and resulting in very low RHs. Fire weather remains a concern as efficient mixing in the low levels could keep RHs well below critical thresholds. Luckily; winds remain calm and only gusting up to 15-20mph which keeps us out of headlines for now, but elevated fire weather conditions are still expected even with these early spring-like temps.

Closed mid-level low pressure currently over the Pacific Northwest will begin to advect across the country and stalling out over the Upper Great Lakes this Wednesday through the rest of the week. This disheveled set up will remain disorganized but with enough energy and moisture to deliver rounds of scattered showers. Not a lot of QPF this system with most showers only having enough water to wet pavement, but deary and cool conditions will finish off the week making the second half of May feeling more like April for Northern Michigan.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
Issued at 532 AM EDT Sat May 17 2025

Widespread MVFR to IFR producing low clouds, mist, and showers expected across all taf locations today. Some slow improvement tonight as showers dissipate. West to southwest winds become gusty today, with winds veering northwest and remaining gusty tonight.

APX WATCHES/WARNINGS/ADVISORIES
MI...None.
MARINE...Small Craft Advisory until 11 PM EDT this evening for LHZ349.
Small Craft Advisory until 2 AM EDT Sunday for LMZ323-341-342- 344>346.