Marine Forecasts

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7 Day Forecast for Marine Location Near Harbor Beach, MI

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Area Discussion for - Detroit/Pontiac, MI

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FXUS63 KDTX 152031 AFDDTX

Area Forecast Discussion National Weather Service Detroit/Pontiac MI 331 PM EST Sun Dec 15 2019

DISCUSSION.

Healthy diurnal cloud and flurry response ongoing within the lake- enhanced moisture and instability plume across the central Lakes region this afternoon. With sunset, the lake clouds will slowly thin and dissipate this evening, while high and mid-level clouds spill overhead.

The first of two confluent waves - currently over the mid- Mississippi Valley - will slide to the south of the region tonight. This wave is responsible for the incoming upper-level cloud cover. The tropopause-level jet axis remains positioned to the south of the state - preventing the ribbon of low-level ascent from making a northward push overnight. Expect the light snow shield to remain well south - but some flurry activity may make it through the rather impressive dry layer centered on 3kft to the surface toward daybreak across the very far south.

The second more substantial wave - currently over the southwest CONUS - will quickly eject out over the southern Plains on Monday and follow within the confluent flow over the Ohio Valley. An axis of deformation in the 600-500mb layer will sweep across the southern half of the forecast area. However, the jet core remains south of the area with this wave as well - precluding much in the way of a northward advancement of the snow shield. A couple hours of light snow are possible near the border - otherwise, just a shield of mid- clouds with plenty of virga within the restricted region of mid- level forcing.

Attention turns to the northern stream with a sharpening upper wave sweeping southeast across Ontario late Tuesday and Wednesday. Trends have been slightly more amplified. Given a more amplified look of the incipient wave on GOES WV imagery - expect the wave to come in a bit stronger and slower in the next cycle or two as better remote sampling occurs. The associated low-level airmass is respectably cold - 850mb temps below -20C across the region. There should be a rather nice lake-effect response on Superior and Huron starting Tuesday night and continuing Wednesday. Lake Michigan will also get into the act to a lesser extent. The timing of the influx of cold air being overnight complicates the inland impacts as the convective response will be somewhat muted. That said, there is some signal in the model soundings to keep an eye on a ribbon of snow showers on the arctic front Tuesday night, if the front is able to kick-up enough boundary layer moisture. Highs on Wednesday will be locked in the low-mid 20s with wind chills in the single digits . Thursday looks only slightly warmer.

Most of the guidance suite, save the GFS, indicates longwave ridging quickly follows for the end of the week into next week. Temperatures will moderate and chances for precipitation will be rather meager.

MARINE.

Small Craft Advisory conditions have come to an end as winds decrease and elevated wave action pushes away from the nearshore zones. There will be a slight backing of the winds to the southwest into this evening and tomorrow as a high pressure slides into the western Great Lakes with short wave ridging. Winds will remain light into tomorrow while a system organizes across the TN/OH River Valleys tonight into Tuesday. Little impact to the Great Lakes other than chances for light snow showers across the southern lakes. Greater surge of arctic air with a polar low will arrive Tuesday night/Wednesday morning bringing possible northwest gales across Lake Huron. The cold air in combination with elevated winds will also bring potential for heavy freezing spray across Lake Huron as well. Increasing waves will also bring an additional round of Small Craft Advisories to the nearshore zones. Arctic surge does not stick around for long as high pressure with decreasing winds follows on Wednesday night.

PREV DISCUSSION. Issued at 1227 PM EST Sun Dec 15 2019

AVIATION .

Westerly flow off of Lake Michigan will continue to produce a healthy BKN cloud deck across all terminal sites through the afternoon, with mainly VFR cigs, although periods of MVFR cannot be ruled out across the Metro terminals north into KPTK as the last of the moisture responsible for this mornings snow showers move out of the area. Expecting all terminals to achieve VFR by the late afternoon as dry air builds in the low-levels and cloud depths rise from daytime heating. Loss of daytime heating and intrusion of low- low to mid-level dry air will aid in the loss of cloud cover late this evening and overnight, before a mid-level cloud deck moves overhead, from a storm system located across the Tennessee Valley. Expecting precipitation from the system to stay south of the terminals, mainly around the MI/OH border south.

For DTW . Light snow showers remain likely over the next couple of hours, through 19Z, before incoming dry air in the low-levels cuts off snow chances. Otherwise, expecting BKN cloud deck between 4-6 kft to hold during daylight hours before eroding tonight. A secondary chance of ceilings returning aob 5kft during the mid- morning hours, but confidence remains low at this time as some guidance suggests ceilings will hold above 5kft, tied to incoming moisture from southern storm system. Model trends continue to hold overnight snow chances south of the terminal.

DTW THRESHOLD PROBABILITIES .

* High for cigs below 5000 ft this afternoon, low this evening. Low/moderate again for Monday morning.

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

DISCUSSION . Mann MARINE . AA AVIATION . AM

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
HRBM4 - 9075014 - Harbor Beach, MI	1 mi	52 min	SSW 1.9 G 2.9	25°F	33°F		1019.4 hPa (+1.3)	19°F
KP58	15 mi	61 min	SW 2.9	27°F			1019.8 hPa	17°F
PSCM4	30 mi	52 min	SW 1.9 G 2.9	27°F			1037.6 hPa (+1.7)
GSLM4 - Gravelly Shoals Light MI	49 mi	72 min	WSW 8.9 G 13	27°F
TAWM4 - Tawas City, MI	51 mi	72 min	NW 4.1 G 6	26°F			1018.6 hPa

Wind History for Harbor Beach, MI

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W6 G10

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W10 G15

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S19 G28

S18 G24

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Airport Reports

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Airport	Dist	Age	Wind kt	Visibility	Sky/Weather	Temp	DewPt	Humidity	Pressure
Port Hope, MI	15 mi	61 min	SW 3	mi		27°F	17°F	66%	1019.8 hPa
Huron County Memorial Airport, MI	18 mi	56 min	N 0	10.00 mi	Fair	24°F	17°F	75%	1019 hPa

Link to 5 minute data for KP58

Wind History from P58 (wind in knots)

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W12 G19

W13 G21

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W15 G23

NW18 G26

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S15 G23

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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 (18,4,5,8)

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Ground Weather Radar Station Detroit, MI

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