Bay City, MI Marine Weather and Tide Forecast
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Marine Weather and Tide Forecast for Bay City, MI

June 20, 2024 2:54 AM EDT (06:54 UTC) Change Location
Sunrise 5:52 AM   Sunset 9:22 PM
Moonrise 7:39 PM   Moonset 3:13 AM 
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NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.

Marine Forecasts
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LHZ422 Inner Saginaw Bay Sw Of Point Au Gres To Bay Port Mi- 946 Pm Edt Wed Jun 19 2024

Rest of tonight - North winds 10 to 15 knots veering to the northeast after midnight. Partly cloudy. A chance of Thunderstorms and a slight chance of showers this evening, then a slight chance of showers and Thunderstorms after midnight. Waves 2 feet or less.

Thursday - Northeast winds 10 to 15 knots. Partly cloudy. A slight chance of showers and Thunderstorms in the morning, then a chance of showers and a slight chance of Thunderstorms in the afternoon. Waves 2 feet or less.

Thursday night - Northeast winds 10 to 15 knots diminishing to 5 to 10 knots after midnight. Partly cloudy. A chance of showers and a slight chance of Thunderstorms in the evening. Waves 2 feet or less.

Friday - Northeast winds 5 to 10 knots. Partly cloudy with a chance of showers. Waves 2 feet or less.
see lake huron open lake forecast for days 3 through 5.

No data

7 Day Forecast for Marine Location Near Bay City, MI
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Area Discussion for - Detroit/Pontiac, MI
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Area Forecast Discussion National Weather Service Detroit/Pontiac MI 1150 PM EDT Wed Jun 19 2024


- Hot and humid conditions will exist again Thursday, particularly across areas along and south of the M-59 corridor where a Heat Advisory remains in effect. To the north, a weak cold frontal boundary will briefly bring slightly cooler and less humid conditions.

- The heat and humidity builds back into the entire region Friday and Saturday.

- Chances of thunderstorms continue each day of the week, some of which may be strong to severe with locally heavy downpours and isolated damaging wind gusts.


A moist and weakly unstable nocturnal environment will continue to support isolated convective development throughout the night. Any development locally will tend to focus north and west of earlier activity, affording FNT/MBS with at least a low end possibility for thunder overnight. A weak frontal boundary remains forecast to ease southward into the region overnight and Thursday. A generally light wind field will favor a northeasterly trajectory with this frontal passage. Retention of an adequately unstable environment will again present potential for diurnal convective development targeting the late day period Thursday. Similar to recent days, overall coverage and placement of possible development remains quite ill-defined at this stage.

For DTW/D21 Convection...The overall environment will again be favorable for some degree of thunderstorm development Thursday afternoon and evening, but with usual uncertainty at this stage on timing and coverage.


* Low in thunderstorms impacting the airspace Thursday afternoon and evening.

Issued at 344 PM EDT Wed Jun 19 2024


Retainment of the anomalously strong subtropical airmass characterized by ~594 dam h500 heights (99.5th percentile to outside of all climatological values wrt CFSR data set) continues through the day today. In terms of surface impacts, the return of temperatures highs back into the lower 90s with dew points in the upper 60s to lower 70s, have bolstered afternoon heat indices in the mid to upper 90s, where a heat advisory remains in effect. For the remainder of the afternoon and evening, attention will be focused on thunderstorms chances, specifically along land/lake differential heating boundaries and from inland locations, where an enhanced ribbon of h850-h700 theta-e will expand in from the Toledo area.
differential heating along the demarcation of clouds, and/or the slight surface convergence along the glacial ridge can also be focal point for initiation. In subtropical conditions with h850 dew points aoa 10C, it will not take much for storm initiation, but confidence on the exact initiation point is lowered.

The main hazard for any thunderstorm development will be precipitation loading that can result in wind gusts up to 60 mph.
MUCAPE approaching 2,000 J/kg along with theta-a indices around 25 and PW values of 1.80 inches support heavy downpours with any thunderstorms. Strong 0-3 km lapse rates around 9C/km and a mini- inverted V sounding with DCAPE values aoa 1000 J/kg support strong downward momentum transfer with evaporative cooling potential. Hail to an inch would be a secondary concern, but as is common in humid airmass, high freezing levels and warm rain processes will contribute to melting. The overall kinematics are poor with bulk shear values around 20 knots with pulse to multicell clusters as the main storm mode. Last, LCL-EL (cloud layer) mean wind sits at around 15 knots. Slower storm motion with heavy downpour and thunderstorm training potential brings the risk for highly localized precipitation accumulation which may lead to localized flooding concerns. Please see the hydrology section for additional details.
Any shower or storm development will taper off very late tonight.

Warm overnight lows continue with temperatures only dropping into the mid to upper 60s overnight. Relief from hot temperatures will be felt across the Tri-Cities and Thumb, especially along the shorelines, as a backdoor cold front advects inland. Communities along the shoreline will likely not break the 80 degree mark, while locations more inland across the Tri-Cities and Thumb have high probabilities of staying capped below the 90 degree mark. There remain uncertainties with how far inland the cooler air will expand through, but the latest NBM output holds a 60% or higher probability to achieve 90 degrees for a daytime high along and south of M59, with increasing probabilities (near 100%) within urban Detroit and closer to the MI/OH border. Heat indices will peak in the mid 90s outside of the cold front. The heat advisory has been further trimmed to reflect the locations that have high confidence to be impacted by the cooler air. Renewed isolated to scattered thunderstorm development will also be likely tomorrow afternoon and evening. Surface convergence across the multiple boundaries (northeast flow from Huron, west-northwest flow off of southern Lake Michigan, southwest flow from northern Indiana) will provide multiple chances for initiation. Wet microbursts with wind gusts up to 60 mph and highly localized flooding will again be the main concerns for any stronger thunderstorm development.

This pattern of above normal temperatures will continue to end the week. Friday will again have cooler temperatures along and in the vicinity of the lakes with the northeast flow in place along with renewed rain and shower chances in the afternoon. For Saturday, multiple shortwaves will ride along the periphery of the heat dome and will advect some of the hottest air across the western Midwest into the Great Lakes. This has the potential to support a boost back into the mid-90s for the southern portion of the cwa and will diminish the lake influence for the northern third as southwest flow returns. As of right now the increased stability looks to keep the greater portion of the cwa dry, but any slight modification of the shortwave path to the south with new model output would put us in the path of potential thunderstorms. Breakdown of this pattern looks to commence on Sunday once a prefrontal trough and eventual cold front swing over the state. Showers and storms will be likely along the prefrontal trough.


Hot and stable conditions across the waters maintain low wind and waves today outside of any thunderstorm activity. Timing and location will be highly uncertain, but the typical peak heating of the day into early evening hours will be favored. Some breakup in the pattern occurs Thursday as high pressure builds across Ontario which forces a cold front south through Lake Huron. This will flip winds around to the north but warm temperatures remain across region. A stronger cold front looks to be on track for the second half of the weekend however, and wind speeds then could reach or exceed 25 knots with waves building to around 4 feet. Small craft advisories may be needed.


A moist and unstable airmass will remain in place through the end of the week. Isolated to scattered thunderstorm development are expected across portions of SE MI this afternoon and evening. The most intense thunderstorms will have the potential to produce highly localized rainfall amounts of 1-2 inches in a 30-60 min period.
Thunderstorm training (repeated thunderstorms) can also provide the chance see highly localized totals of 1-2+ inches. Uncertainty in specifics of location and exact timing for any flooding precludes the issuance of an flood watches. Additional storms with highly localized flooding potential will again be possible on Thursday during the afternoon and evening.

MI...Heat Advisory until 10 PM EDT Thursday for MIZ068>070-075-076-082- 083.

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

Weather Reporting Stations
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Stations Dist Age Wind AirWater WavesinHgDewPt
SBLM4 - Saginaw Bay Light #1, MI 18 mi55 minNE 18G21 70°F 30.24
45163 32 mi55 minNE 14G16 67°F 1 ft30.30
GSLM4 - Gravelly Shoals Light MI 35 mi75 minNNE 15G16 67°F 30.27
TAWM4 - Tawas City, MI 52 mi75 minNNE 1.9G2.9 62°F 30.29

Wind History for Harbor Beach, MI
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Airport Reports
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AirportDistAgeWind ktVisSkyWeatherAirDewPtRHinHg
KHYX SAGINAW COUNTY H W BROWNE,MI 10 sm19 minNNE 0610 smMostly Cloudy72°F66°F83%30.25
KMBS MBS INTL,MI 11 sm61 minNE 0710 smClear73°F66°F78%30.27
KCFS TUSCOLA AREA,MI 24 sm19 minNNE 0410 smPartly Cloudy72°F70°F94%30.25
Link to 1 hour of 5 minute data for KHYX
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Wind History graph: HYX
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Tide / Current for
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Weather Map
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GEOS Local Image of GreatLakes   

Detroit, MI,

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