Marine Forecasts

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7 Day Forecast for Marine Location Near Village of Grosse Pointe Shores, MI

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Area Discussion for - Detroit/Pontiac, MI

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FXUS63 KDTX 091001 AFDDTX

Area Forecast Discussion National Weather Service Detroit/Pontiac MI 601 AM EDT Sun Aug 9 2020

AVIATION.

Most of SE MI will be dry today with some degree of diurnal cu developing this afternoon. The chance for showers/thunderstorms still resides mainly around mbS as the axis of deeper moisture and instability continues to build across Mid MI. Best chance will be around noon as a cell currently over Lake MI tracks eastward through the morning. Farther south we look to remain capped through the afternoon keeping the tafs clear of precip. Southwesterly flow will prevail for all sites today as the cold front remains locked up west of Lake MI.

For DTW . continued southwesterly flow with diurnal cu field developing today mostly at or above 5kft. Lake Erie lake breeze front may make an attempt to wash through late in the afternoon - flopping winds around to the southeast for a period of time. We then start looking ahead at the system coming through early Monday which will be the next chance of thunderstorms.

DTW THRESHOLD PROBABILITIES.

* Low for ceiling below 5000 ft today. * Medium for lake-breeze to shift winds from southwest to southeast after 20z this afternoon.

PREV DISCUSSION. Issued at 407 AM EDT Sun Aug 9 2020

DISCUSSION .

The return of mid summer heat and humidity is on schedule for today as early morning surface observations show mid to upper 60s dewpoint making eastward progress from the Midwest into lower MI. Expect this air mass to wash over the entire area as the day unfolds and as high temperatures make a run toward 90 this afternoon for heat index in the mid 90s. The increased humidity comes in with limited potential for thunderstorms with the best chance for activity actually occurring during the morning. Model analysis fields indicate a diffuse mid level theta-e ridge overhead in which elevated convection will percolate leading up to sunrise. A generous scattered coverage is possible mainly north of the I-69 corridor until about mid morning before dissipating as elevated instability fades. After that, the short wave ridge aloft reinforces mid level warm air and effectively caps surface based convection around the 800 mb level according to model soundings. It is possible that an isolated storm occurs around the Tri Cities to northern Thumb region either near the shoreline or moving in from higher terrain areas of northern lower MI. A low POP remains in the forecast for that area late afternoon through this evening.

Warm and humid conditions become firmly entrenched across SE MI tonight as light SW surface wind reinforces higher dewpoint from the central Plains and Midwest. This occurs under clear to partly cloudy sky through the night depending on the extent of cloud debris from daytime thunderstorms. The scenario for convection remains complex beginning with the ongoing central/northern Plains MCS and resulting MCV that is projected to move over the U.P. tonight. Activity tied to this wave remains well to our north but is followed by a new round of surface based convection along the northern Plains to upper Midwest cold front. These storms are shown to grow upscale enough for a chance of survival into Lower MI Monday morning and into SE MI by Monday afternoon. Larger scale support is limited to minor height falls shown in model data preceding the main short wave still over central Canada and the northern Plains. Mid chance POPs in the guidance package look reasonable for a weakening pattern of convective remnants.

Scattered remnant showers and cloud debris keep afternoon temperatures in check with highs in the mid to upper 80s accompanied by continued humid conditions. Boundary layer moisture stands ready to fuel another round of convection that organizes along the cold front moving into Lower MI Monday night. The front is driven into the central Great Lakes by the southern extent of the Canadian upper level trough. It provides substantial larger scale forcing that leads to a stronger low to mid level wind field and sharpening moisture axis ahead of the front. There is some concern about recovery of instability as a limiting factor for convective intensity but this should not have much affect on coverage which is worthy of likely POPs Monday night into Tuesday morning.

Assuming the strength of the upper level trough holds into Tuesday, then its passage should bring enough subsidence to push the cold front south of the Ohio border Tuesday afternoon. The post front air mass settles in with cooler and less humid conditions for the mid week period. The front itself remains active to our south and could brush the Ohio border region with some showers depending on the actual character of any waves in the zonal flow aloft. These carry low predictability for minimal POPs during late week and into next weekend.

MARINE .

Broad high pressure will continue slowly drifting eastward toward the Mid-Atlantic region today as return southwest flow continues to bring an increasingly warm and humid airmass across the region that will become firmly established today and Monday. Widely scattered showers and thunderstorms will be possible this morning associated with a pocket of elevated instability moving into northern Lower Michigan and possibly Saginaw Bay/portions of central Lake Huron. The better potential for showers and thunderstorms, however, will accompany the arrival of a cold front Monday. Ahead of the cold front, southwest winds will ramp up with gusts in nearshore waters likely approaching 20-25 knots. Drier weather and lighter, northerly flow behind the cold front passage will then prevail for the middle of next week.

DTX WATCHES/WARNINGS/ADVISORIES. MI . NONE. Lake Huron . NONE. Lake St Clair . NONE. Michigan waters of Lake Erie . NONE.

AVIATION . DRK DISCUSSION . BT MARINE . IRL

You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.

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Weather Reporting Stations

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Stations	Dist	Age	Wind	Air Temp	Water Temp	Waves	Pressure	DewPt
45147 - Lake St Clair	2 mi	42 min	SW 14 G 16		74°F	1 ft	1017.2 hPa (-0.1)
CLSM4 - St. Clair Shores, MI	11 mi	42 min	SW 6 G 9.9	71°F			1019.3 hPa
AGCM4	13 mi	54 min		71°F	74°F		1018.6 hPa
MBRM4 - 9014090 - Mouth of the Black River, MI	38 mi	54 min		71°F			1017.3 hPa
FTGM4 - 9014098 - Fort Gratiot, MI	40 mi	54 min		70°F			1016.9 hPa	59°F

Wind History for Fort Gratiot, MI

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Airport Reports

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Airport	Dist	Age	Wind kt	Visibility	Sky/Weather	Temp	DewPt	Humidity	Pressure
Selfridge Air National Guard Base, MI	14 mi	46 min	SW 5	10.00 mi	Fair	69°F	62°F	78%	1018.4 hPa
Coleman A Young Municipal Airport, MI	19 mi	49 min	SW 6	10.00 mi	Fair	70°F	59°F	68%	1018.6 hPa

Link to 5 minute data for KMTC

Wind History from MTC (wind in knots)

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Tide / Current Tables for

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Tide / Current Tables for

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Weather Map

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GEOS Local Image of    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East

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Wind Forecast for Detroit/Pontiac, MI (7,2,3,4)

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Ground Weather Radar Station Detroit, MI

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