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7 Day Forecast for Marine Location Near New Baltimore, MI

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Area Discussion for - Detroit/Pontiac, MI

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FXUS63 KDTX 011953 AFDDTX

Area Forecast Discussion National Weather Service Detroit/Pontiac MI 353 PM EDT Thu Oct 1 2020

DISCUSSION.

Mid afternoon radar trends indicate showers and thunderstorms burning quickly through available instability. Cellular coverage and the pulsy nature of stronger updrafts reflects the overall lower convective potential compared to yesterday. Slower storm motion as a function of the weaker wind profile has also played into the convective mode. Forcing from the upper level circulation and surface trough maintain activity having a gradually decreasing trend in coverage and intensity as surface based instability becomes exhausted by early evening.

The cold front helping to focus today's showers/storms moves through SE Michigan tonight. The colder air inbound post front takes low temperatures down into the mid and upper 30s while NW wind lingers at 5 to 10 knots through sunrise Friday. That wind speed is high enough to prevent frost development at interior locations where clouds have a chance of decreasing during the night. The typically colder regions of the Thumb are influenced by the additional warming effects of clouds and onshore wind direction off the warmer water of Lake Huron. The warming effect of the lake is also reflected in model soundings that show the boundary layer remaining well above freezing and capable of lake effect rain showers that linger through Friday morning. Inland locations experience dry weather but plenty of diurnal cumulus through Friday afternoon as high temperatures struggle to reach the lower and mid 50s.

Diffuse high pressure settles over lower Michigan Friday night while broadly cyclonic flow and cold air aloft remain in place. The wind and temperature pattern support model RH depictions of diurnal cumulus Friday afternoon lifting into meaningful coverage of mid level clouds Friday night. This is combined with thickening high clouds ahead of the next short wave to make the low temperature forecast and potential for frost difficult to evaluate. These cloud trends are definitely something to monitor before getting too aggressive with low temperatures and frost potential heading into Saturday morning.

Thickening high clouds occur ahead of the above mentioned short wave that continues approaching while surface high pressure departs eastward during Saturday. The system produces backing flow in the mid and upper levels that starts weak moisture transport during the day. Model plan view depictions of wind and theta-e suggest weak advection that may not be able to overcome dry air lingering in the low levels before evening. There is general agreement on the slower trend of saturation in QPF fields among today's mid range model solutions but it will be a close call. The upper level trough axis is still more over the Midwest than Great Lakes by Saturday night but is able to influence forcing with increased SW flow through the mid levels. The orientation of the mid level theta-e gradient also becomes more SW-NE while contracting through Sunday morning. This is a good sign of implied mid level Fgen downstream of the 500 mb trough to enhance the vertical motion response prior to arrival of the trough itself. The rapidly improved organization in these features is worthy of at least scattered to numerous coverage of showers late Saturday night through Sunday.

The short wave feature producing the wet weather to finish the weekend carries the larger scale trough axis eastward by Monday. The upper level ridge moving in from central Canada brings surface high pressure for improved weather and a gradual warming trend. Highs return back toward normal by Tuesday before the next front arrives for the mid week period.

MARINE.

Afternoon observations verify moderate north wind developing on the north end of Lake Huron as cold front settles through the central Great Lakes. Wind speed remains around 20kts or less during the night while the long fetch over Lake Huron leads to high waves around the Thumb shoreline. Small Craft Advisories remain in effect tonight and Friday for these conditions. The colder air mass settles over the Great Lakes and lasts through the weekend keeping conditions unsettled with the potential for rain showers and waterspouts in Lake Huron lingering into the weekend.

PREV DISCUSSION. Issued at 122 PM EDT Thu Oct 1 2020

AVIATION .

Similar afternoon compared to yesterday will unfold across the airspace as the region remains entrenched within a cool, cyclonic flow regime characterized by steep lapse rates, sufficient boundary layer moisture, and ample forcing aided by an approaching cold front boundary from the west. The result will be another afternoon into early evening of numerous showers and embedded thunderstorms, with thunderstorm coverage across the northern sites mainly before 21z, and the southern sites centered in the 19z-23z window. Small hail will continue to be a concern with any stronger convection, but a decreased wind field will lessen the gusty wind threat. Flying conditions will be variable ranging from low end VFR at times to low end MVFR in convection. Cold front looks to track through during the evening hours flipping westerly winds in the 10-15 knot range to the northwest at similar magnitudes, with fairly good push of dry air accompanying the front allowing for a decent clearing response in the wake of ending showers with loss of daytime heating. Exception may be for KPTK, KFNT, and KMBS, where a more northerly trajectory off Saginaw Bay may allow for MVFR stratocu to hang around through at least the first half of the night. Reinvigorated diurnal stratocu then redevelops to end the period during the day Friday.

For DTW . Thunderstorm confidence remains moderate, although timing is fairly high in the 19z-23z window. Trended a bit more optimistic with clearing with this issuance with surge of dry air in wake of cold front passage late evening into the overnight hours.

DTW THRESHOLD PROBABILITIES .

* Moderate in ceilings at or below 5000 feet this afternoon. Low tonight.

* Moderate in thunderstorms this afternoon into early this evening.

DTX WATCHES/WARNINGS/ADVISORIES.

MI . Lakeshore Flood Advisory from 10 PM this evening to 4 PM EDT Friday for MIZ049-055-063.

Lake Huron . Small Craft Advisory from 10 PM this evening to 4 PM EDT Friday for LHZ421-441>443.

Lake St Clair . NONE.

Michigan waters of Lake Erie . NONE.



DISCUSSION . BT MARINE . BT AVIATION . 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
AGCM4	10 mi	43 min		51°F	62°F		1013 hPa
45147 - Lake St Clair	12 mi	61 min	WNW 18 G 21			2 ft	1011.5 hPa (+1.0)
CLSM4 - St. Clair Shores, MI	13 mi	61 min	WNW 6 G 12	56°F			1013.5 hPa (+1.0)
MBRM4 - 9014090 - Mouth of the Black River, MI	30 mi	43 min		56°F			1011.5 hPa
FTGM4 - 9014098 - Fort Gratiot, MI	32 mi	43 min	WNW 5.1 G 8	53°F			1011.1 hPa	44°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	7 mi	65 min	NW 7	10.00 mi	Mostly Cloudy	53°F	50°F	90%	1013.2 hPa
Coleman A Young Municipal Airport, MI	20 mi	68 min	N 5	10.00 mi	A Few Clouds	57°F	44°F	62%	1013.2 hPa
St Clair County International Airport, MI	24 mi	66 min	W 8	10.00 mi	Light Rain	54°F	44°F	72%	1012.9 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.
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Other links: Northern Pacific     Contential US     Full GOES-East

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Ground Weather Radar Station Detroit, MI

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