Marine Forecasts

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7 Day Forecast for Marine Location Near St. Clair, MI

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Area Discussion for - Detroit/Pontiac, MI

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FXUS63 KDTX 182327 AFDDTX

Area Forecast Discussion National Weather Service Detroit/Pontiac MI 627 PM EST Sat Jan 18 2020

AVIATION.

A strong and cold westerly wind will govern conditions tonight. This environment will encourage the downstream flux of lake Michigan moisture, translating into a scattered to numerous coverage of light snow showers. Periodic bursts of heavier snow showers will be possible, particularly during the early portion of the night. Any such activity will lead to brief IFR level visibility restrictions, with potential for a quick accumulation. Outside of snow showers, prevailing MVFR conditions within an extensive low stratus canopy. Gusty westerly conditions will persist throughout the night, reaching 30 to 35 knots at times. A cold front advancing south across the area will provide a secondary focus for snow shower development on Sunday. Outgoing forecast highlights the most likely window during the daylight period to witness a period of accumulating snow and accompanying visibility restrictions. Winds becoming north-northwesterly and diminishing in the wake of this boundary.

For DTW . Favorable environment exists early tonight for periodic lake effect snow showers or flurries to track near DTW. The airport likely resides within the southern periphery of the main corridor of activity, casting some doubt as to the potential for heavier snow showers to directly impact the terminal. Will continue to highlight the most likely window for meaningful activity, centered 02z-05z. Westerly winds will continue to gust within the 30 to 35 knot range well into the night.

DTW THRESHOLD PROBABILITIES .

* High for ceilings under 5000 feet through Sunday.

* High in precipitation type as snow through Sunday.

* Moderate in exceeding crosswind threshold from 250-270 degrees tonight.

PREV DISCUSSION. Issued at 254 PM EST Sat Jan 18 2020

DISCUSSION .

A region of rain showers, mixed with some snow and sleet at times, now advancing across the forecast area is tied to the mid level trough axis associated with the upper low over western Upper Mi. This upper low will move east and become absorbed back into the mean flow, with the associated surface low tracking across north central Lower Mi and central Lake Huron this evening. The attendant surface cold front will traverse Se Mi shortly after forecast issuance time. Post frontal cold air advection will steepen the low level lapse rates, allowing better mixing of the strong wind fields aloft. Regional observations have shown wind gusts of 30 to 40 knots from Iowa into central Indiana, where post frontal downward momentum transport is stronger. The wind potential across Se Mi appears as though it will be more contingent on the growth of the mixed layer through cold air advection. With model soundings showing 40 knots at the top of the mixed layer, peak wind gusts tonight in the 30 to 40 MPH range (just below advisory) seem warranted.

Afternoon temps have risen well into the 30s ahead of the approaching cold front. Post frontal cold air advection will result in a steady drop in temps tonight, with temps falling into the upper 20s by late evening and low 20s/teens by daybreak Sunday. This of course will lead to the freezing of any standing water/slush on paved surfaces. The presence of deep wrap around moisture and cyclonic flow will support snow shower activity through the night, enhanced by the moisture flux off Lake Mi in westerly flow. A secondary mid level short wave impulse is forecast to rotate across Lower Mi late tonight/early Sun morning, which will support some enhancement to the snow shower activity. A secondary sfc cold front is forecast to move from north to south across the forecast area on Sunday (14Z to 22Z) in the wake of this mid level short wave. Enhanced boundary layer convergence, steep low level lapse rates and ample moisture (super saturated with respect to ice) within the convective cloud layer suggests a chance for some higher intensity snow showers affecting the area with this secondary cold front. The combined affects of the snow showers both tonight and Sunday will likely drop another inch or two of snow across the area. Even with the steepening of the daytime mixed layer, the cold airmass across the region on Sunday will hold daytime temps in the 20s with wind chill readings in the single digits and teens.

A much drier airmass will reside across Se Mi Sun night through early next week. There is reasonable agreement among the model solutions in showing a positive pv anomaly diving from the northern plains into the deep south Mon into Tuesday with enhanced mid level ridging expanding into the Great Lakes region, thus keeping weather conditions rather benign across the Great Lakes. With the polar low drifting north and a quasi zonal flow set to take shape across NOAM, a return of mild January weather looks in store for the end of the forecast period.

MARINE .

Deepening low pressure will track across central Lake Huron this evening. The low will drive much colder air across the lakes. Based on the track of the low, winds across central and northern Lake Huron will actually decrease this evening. Meanwhile, across the south half of the lake, winds will veer to the west southwest this evening with a few gusts exceeding gale force. North-northeast winds will develop on the north third of the lake as the low passes through this evening. A trailing cold front will then be forced south across the lake overnight into Sunday morning, with winds turning north-northwest in the wake of the front. The post frontal gradient will be weakening, so wind speeds/gusts will actually decrease slightly tonight into Sunday morning.

DTX WATCHES/WARNINGS/ADVISORIES. MI . Lakeshore Flood Warning until 10 PM EST this evening for MIZ063-070.

Lake Huron . Gale Warning until 4 AM EST Sunday for LHZ363-421-441>443-462>464.

Lake St Clair . Gale Warning until 7 AM EST Sunday for LCZ460.

Michigan waters of Lake Erie . Gale Warning until 7 AM EST Sunday for LEZ444.

Low Water Advisory until 1 PM EST Sunday for LEZ444.



AVIATION . MR DISCUSSION . SC MARINE . SC

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
MBRM4 - 9014090 - Mouth of the Black River, MI	11 mi	49 min		35°F			1000.9 hPa
FTGM4 - 9014098 - Fort Gratiot, MI	13 mi	49 min	W 19 G 29	36°F			1000.6 hPa	30°F
AGCM4	14 mi	49 min		36°F	35°F		1001.9 hPa
CLSM4 - St. Clair Shores, MI	32 mi	39 min	WSW 15	36°F			1003.7 hPa
PSCM4	42 mi	79 min	WSW 15 G 24	35°F			1016.9 hPa (-0.0)

Wind History for Fort Gratiot, MI

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SE9 G12

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SE10 G18

SE14 G20

SE12 G17

SE13 G19

S10 G13

SE18 G24

S14 G20

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S16 G21

S15 G23

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S17 G25

S13 G17

SW14 G21

SW10 G17

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1 day ago

NW14 G22

N12 G23

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SW3

W4 G8

NW6 G11

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W6 G16

NW10 G16

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NW7 G19

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NW6 G16

NW14 G20

NW10 G14

NW12 G22

NW11 G26

NW11 G22

NW15 G22

NW12 G24

NW8 G18

NW12 G17

NW12 G20

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Airport Reports

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Airport	Dist	Age	Wind kt	Visibility	Sky/Weather	Temp	DewPt	Humidity	Pressure
St Clair County International Airport, MI	8 mi	84 min	WSW 10 G 19	10.00 mi	Overcast	37°F	32°F	81%	1000.3 hPa
Selfridge Air National Guard Base, MI	24 mi	2.4 hrs	WSW 17 G 26	7.00 mi	Light Rain	39°F	38°F	100%	1000.7 hPa

Link to 5 minute data for KPHN

Wind History from PHN (wind in knots)

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E5

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E11 G16

SE9 G15

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SE9 G14

SE10 G17

SE12 G16

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SE9 G18

SE12 G19

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1 day ago

NW12 G20

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N11 G16

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SE3

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W9 G15

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W12 G17

W13 G17

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NW7

W8 G14

NW7

W9 G17

W9 G18

NW12 G16

NW15 G22

NW13 G19

W11 G22

W7

W9 G18

NW9 G14

NW11 G16

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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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Wind Forecast for Detroit/Pontiac, MI (19,4,5,8)

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Ground Weather Radar Station Detroit, MI

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