Sunrise 6:31 AM   Sunset 8:35 PM Moonrise 12:00 AM   Moonset 7:14 AM

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LHZ441 Port Austin To Harbor Beach Mi- 957 Pm Edt Fri Apr 26 2024
.small craft advisory in effect through Saturday afternoon - .
Rest of tonight - Southeast winds 15 to 20 knots. Gusts to 30 knots early in the morning. Partly cloudy this evening becoming mostly cloudy. A chance of showers this evening, then showers likely after midnight. Waves 3 to 5 feet. Waves occasionally around 7 feet. Saturday - South winds 20 to 25 knots with gusts to 30 knots diminishing to 15 to 20 knots in the late morning and afternoon. Mostly cloudy. Light showers likely and a slight chance of Thunderstorms in the morning, then a chance of showers and Thunderstorms in the afternoon. Waves 4 to 6 feet. Waves occasionally around 7 feet. Saturday night - Southwest winds 15 to 20 knots. Partly cloudy in the evening becoming mostly cloudy. A chance of showers and Thunderstorms. Waves 2 to 4 feet. Sunday - West winds 10 to 15 knots veering to the northeast early in the afternoon. Mostly cloudy. A chance of showers in the morning, then showers likely in the afternoon. Waves 2 to 4 feet subsiding to 1 to 3 feet in the late morning and afternoon.
see lake huron open lake forecast for days 3 through 5.

LHZ400
No data

FXUS63 KDTX 270343 AFDDTX

Area Forecast Discussion National Weather Service Detroit/Pontiac MI 1143 PM EDT Fri Apr 26 2024

KEY MESSAGES

- Showers arrive this evening with a chance for a few embedded thunderstorms starting late tonight.

- Southwest winds gusting around 35 mph Saturday afternoon north of Metro Detroit.

- Some additional thunderstorms are possible Saturday evening with an isolated severe storm possible northwest of Metro Detroit.

- Additional showers and a few storms are possible Sunday as above normal temperatures continue through mid-week.

AVIATION

Several inbound short wave impulses along with increasing low level southwest flow along an advancing warm front will drive another round of showers across Se Mi late tonight into Saturday morning.
This will also be accompanied by weak elevated instability, enough to suggest a 20 to 30 percent chance of a thunderstorm embedded within the broader region of showers. Moistening in the low levels will also support high probabilities for MVFR based ceilings. The warm front will lift northeast of the terminals late Sat morning as associated surface low pressure approaches western Upper Michigan.
This will drive the warm sector into Se Mi. Deepening of the daytime mixed layer and the strengthening SSW wind fields will push wind gusts up to or over 25 knots at times during the afternoon Saturday.
Late day convection on Saturday/Saturday evening is forecast to initiate across northern and central Lower Mi.

For DTW/D21 Convection...Numerous showers are expected to move into and redevelop across the airspace overnight and last into late Saturday morning. Recent model guidance remains lean on the amount of available instability, so only isolated thunderstorms are expected across the airspace, primarily between 09Z and 13Z.

DTW THRESHOLD PROBABILITIES...

* Low in thunderstorms tonight into early Saturday morning.

* High in ceilings aob 5000 feet tonight into Saturday afternoon.

PREV DISCUSSION
Issued at Issued by National Weather Service Grand Rapids MI

DISCUSSION...

Main changes to this forecast was to increase wind gusts Saturday afternoon primarily north of Metro Detroit. The other was to maintain dewpoints/relative humidities below guidance overnight into early Saturday. Still expect rain to reach southeast Lower MI region chiefly after 8 PM. However, the antecedent lower troposphere is exceptionally dry and it should take longer than usual to rebound in spite of robust lower to mid level tropospheric pressure/moisture advection associated with isentropic ascent. In fact, Metro Detroit may not even experience accumulating rainfall until after 11 PM.

In terms of thunder prospects, it appears that MUCAPE for the Metro area rapidly increases towards noon Saturday with a slightly earlier onset and larger instability magnitude farther northwest towards the Tri-Cities region. SPC reasoning for the Marginal Risk area northwest of Metro Detroit has not changed much and the interested reader is encouraged to check out the latest SWODY2 outlook for additional details.

Additional showers and storms are likely Sunday into Monday associated with forcing from an upper-level jet streak and aided by a frontal boundary sitting across northern Michigan and a shortwave from the parent trough ejecting through the region. Convection will be favored across Central Lower for our CWA closer to the warm frontal boundary, with MUCAPE values north of 500 J/kg suggesting there will be an attendant thunder risk. SPC currently has the region in general thunder which is reasonable given that the favored region instability is separated from deep later shear and the highest likelihood of showers/storms.

Widespread showers then expand into the remainder of the CWA Sunday night and continue into early Tuesday as a cold front drifts across the area. MUCAPE suggest thunder chances continue. By Monday night accumulated rainfall looks to range from a quarter of an inch around Metro Detroit to around an inch west of Saginaw Bay. Additional amounts after this into the remainder of Tuesday look negligible.

Dry conditions then take over late Tuesday into Tuesday night as a high pressure system quickly pushes through the area. Conditions then become more active Wednesday as we see a cold front driven through Lower Michigan by a northern stream shortwave followed by additional rain chances into Thursday as a surface low ejects north into the upper Ohio Valley.

Temperature wise, highs in the 70s are expected to continue into mid week. By late week, expect highs to fall back to near normal in the 60s as a thermal trough slides into the central Great Lakes.

MARINE...

Strong low pressure moves from the central Plains to the upper Midwest tonight and then across Lake Superior on Saturday. The strengthening pressure gradient ahead of this system results in southeasterly flow ramping up tonight, peaking late tonight into Saturday morning. Wind veers southerly on Saturday with gusts touching gale force during the morning before gradually weakening through the day as much warmer air moves into the region to stabilize flow over the cold lake water. The warm air also fuels thunderstorm potential Saturday through Sunday as the associated cold front stalls over the region. The front awaits yet another low pressure system moving in from the Plains Sunday into Monday.
Outside of the brief window Saturday morning, winds are expected to remain below gale force.

DTX WATCHES/WARNINGS/ADVISORIES
MI...None.
Lake Huron...Small Craft Advisory until 4 PM EDT Saturday for LHZ421-422-441>443.

Lake St Clair...None.
Michigan waters of Lake Erie...None.

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