Sunrise 6:34 AM   Sunset 8:38 PM Moonrise 12:00 AM   Moonset 7:21 AM

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LMZ344 Sleeping Bear Point To Grand Traverse Light Mi- Point Betsie To Sleeping Bear Point Mi- 235 Pm Edt Sat Apr 27 2024
.small craft advisory in effect until 2 am edt Sunday - .
Tonight - Southwest wind 10 to 15 knots early in the evening becoming variable 10 knots or less, then becoming north 5 to 10 knots early in the morning. Chance of showers and Thunderstorms. Waves 3 to 5 feet subsiding to 2 to 3 feet after midnight. Sunday - Northeast wind 5 to 10 knots. Rain showers. Waves 2 feet or less. Sunday night - East wind 10 to 20 knots. Rain showers. Waves 2 to 3 feet. Monday - Southeast wind 10 to 20 knots. Rain showers. Waves 2 to 3 feet.
winds and waves higher in the vicinity of Thunderstorms.
see the open lakes forecast for days 3 through 5.

LMZ300
No data

FXUS63 KAPX 271825 AFDAPX

Area Forecast Discussion National Weather Service Gaylord MI 225 PM EDT Sat Apr 27 2024

KEY MESSAGES

- Scattered showers and thunderstorms expected to develop along a cold frontal boundary this evening into tonight across northern lower Michigan

- Any storms that can become more organized have the potential to be severe, with the primary hazards being large hail and damaging winds. A tornado or two cannot be ruled out across the greater area.

- Occasional periods of showers and isolated thunderstorms Sunday into Monday.

- Light rain showers possible late Tuesday night - Wednesday.

- More active wet weather possible late next week.

SHORT TERM /THROUGH TONIGHT/
Pattern Synopsis / Forecast: Shearing 500mb vort max currently moving over western Lake Superior, with associated weakening ~1000mb surface low pressure moving toward the Wisconsin Highlands. Surface warm frontal boundary beginning to enter the Straits set to continue its northward trek into the eastern U.P, while better moisture (dewpoints near 60) and warmer temperatures (near 70) have already encompassed coastal areas along Lake Michigan south of Petoskey.
Result will be temperatures warming considerably well into the 70s across northern lower Michigan, and 60s across the eastern U.P., all ahead of the approaching triple point associated with the surface low and respective cold / warm frontal boundaries. Visible satellite trends to note are partial clearing, resulting in less aggressive mixing of low level moisture with simultaneous warming temperatures in the lower levels amid a capping inversion overhead. Potential is increasing for a quickly destabilizing atmospheric profile as we head later into the afternon, which, coupled with forcing, should be enough to initiate convective processes across northern lower and eastern upper Michigan this evening into tonight before the front clears the area to the south by Sunday morning.

Primary Forecast Concerns:

Conditional severe thunderstorm threat still well in play this evening into tonight across northern lower Michigan as favorable dynamics aloft move into northern Michigan. CAMs have gone from a more meager initiation to a slightly more robust solution across northern Michigan. While things are slowly beginning to tilt in favor of increasing severe weather potential, there are still a couple things that need to be sorted out.

Forcing timing: Current better forcing noted by convective processes commencing northwest of Green Bay, WI will continue its eastward trend, moving into the CWA first across the eastern U.P. mid-to-late afternoon before the front becomes more strung out and begins to crawl across northern lower later this evening. In the event this trends slower / later, potential for storms diminishes. The magic timing of this feature looks to spark off deeper surface based convection later this evening would be if the front moves into northwest lower Michigan some time between 6-8pm in order to maximize surface based heating contributions to instability.

Dewpoints: Most guidance continues to draw dewpoints in the 60s across much of northern lower Michigan as we progress through the afternoon. As of 1630z, dewpoints have swelled well into the 50s across the board (with the exception of those near the Soo), and even into the 60s at both Manistee and West Branch. How much of this moisture is scoured out in any clearing could become negligible with partly sunny skies, and barring any robust convective outbursts upstream in Iowa / Illinois / Wisconsin, deeper moisture advection should continue (in theory) into the evening ahead of the frontal passage.

Instability: The atmosphere is capped as of 1630z based off of the lack of overly agitated CU across the board, including in places that are seeing partial sunshine closer to Manistee and Grand Traverse Bay. Breaking through this cap will have to require better moister lingering with the frontal boundary moving into the region.
Latest HRRR guidance shows most convective allowing models (CAMs)
successfully initiate along the front some time between 21z - 00z as the forcing erodes the capping inversion. Latest guidance displays anywhere from 1000-1750 J/kg of MLCAPE across the region, providing enough buoyancy for updraft initiation to occur.

Dynamics aloft: The one thing that seems to have remained rock- steady in this setup is favorable windfields aloft to support tilted updrafts. Ample bulk shear (45-50kts) will remain in place, with SRH values approaching 250 m^2/s^2 along and ahead of the frontal boundary. This is plenty to support tilted updraft potential to help keep sustained convection in the cards. As far as shear vectors go, what was once parallel to the boundary has suddenly trended slightly more normal to the boundary, suggesting that discrete or at least semi-discrete convection remains possible, especially if right- moving storm motions can be had with storms moving away from the boundary instead of along it.

Storm Mode and Possible Hazards: Discrete storm mode is not off the table, including supercell thunderstorms. Expectation is that the most discrete nature of the convection is closer to initiation before transitioning to more of a cluster of bowing segments. This keeps ALL hazards in play, with the greatest hazards being large hail and damaging wind gusts. Tornadic potential is creeping back into the picture as well for any potential discrete cells near initiation (as well as within any potential embedded mesovortices within any bowing segments). While high end severe potential is still low, the risk is non-zero at this juncture. As far as where the most favorable parameters come together to suggest a "favored" area for severe potential, this would be spots south of M-32, with emphasis on spots closer to the US 131 corridor... matching the latest SPC update which continues to paint a Slight Risk (Level 2/5), generally from M-32 and points south.

Heavy Rain: As the front slowly forces its way south, there is potential for repeated rounds of storms to occur, which could bring about a heavy rain threat, favoring the M-55 corridor. It's not impossible for 1.00 - 2.00" of rain to fall in a short time, so a minor flooding risk may briefly materialize.

LONG TERM /SUNDAY THROUGH SATURDAY/
Pattern Synopsis/Forecast: By early Sunday morning, an amplified pattern exists across the CONUS with mid-upper level ridging draped over the eastern half of the CONUS. Pronounced troughing over the Intermountain West into the central Plains. At the surface, several areas of low pressure to note -- one departing well off to our northeast over Quebec and another to the southwest over central KS.
A myriad of boundaries expected to emanate from these features with locally a cold front likely draped across central lower MI back southwestward into the central Plains. Unsettled weather remains the rule with that boundary to our south gradually lifting back north as a warm front by later Sunday night into Monday. Central Plains low eventually meanders toward the upper MS Valley/arrowhead of MN by late Monday, dragging a cold front across northern MI in the process.

Generally less active conditions are favored Tuesday into at least Wednesday with more active weather potential again heading into later next week.

Forecast Details: Mid-level energy amidst southwest flow aloft is expected to pinwheel across northern Michigan Sunday into Monday with the aforementioned boundary to our south gradually lifting northward by midday Monday. This will keep occasional showers and perhaps some embedded/isolated thunderstorms in the forecast -- especially Sunday afternoon into Sunday night. Cold front progged to cross west to east Monday afternoon with additional precip chances tied with it. Not anticipating much in the way of a severe storm threat Sunday/Monday given meager instability (if any at all), although worth keeping an eye on both afternoon's for later trends.

Generally quieter weather anticipated Tuesday - Wednesday, although a weak boundary associated with another area of low pressure spinning well to our northwest may provide enough support decaying showers Tuesday night/early Wednesday. Lots of uncertainty riddles the forecast Thursday and beyond with at least some potential for more active weather to return to western Great Lakes as low pressure lee of the Rockies ejects northeast across the nation's midsection.

Fairly mild temperatures expected through the long term forecast period. 50s and 60s on Sunday give way to a wide range of temps on Monday with 50s expected across the U.P. with 60s and low 70s south.
Warmest day of the week expected to Wednesday with latest trends supporting widespread mid-60s to mid/upper 70s for high temps.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
Clouds continue to scatter out early this afternoon with lingering MVFR giving way to primarily VFR conditions expected through this evening. Chances for showers and storms return early this evening into tonight. Any storms will be capable of producing hail and strong winds, along with locally heavy rain, which may briefly drop CIGs /VSBYs to IFR/MVFR. Higher chances for more widespread MVFR cigs arrive after midnight through the remainder of the TAF period.
Occasionally breezy southwest winds turn out of the northwest later this evening into tonight and diminish in speed.

APX WATCHES/WARNINGS/ADVISORIES
MI...None.
MARINE...Small Craft Advisory until 2 AM EDT Sunday for LHZ345>349.
Small Craft Advisory until 2 AM EDT Sunday for LMZ323-341-342- 344>346.
Small Craft Advisory until 2 AM EDT Sunday for LSZ321-322.

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