Marine Forecasts

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7 Day Forecast for Marine Location Near Pinconning, MI

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Area Discussion for - Detroit/Pontiac, MI

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FXUS63 KDTX 151035 AFDDTX

Area Forecast Discussion National Weather Service Detroit/Pontiac MI 535 AM EST Sun Dec 15 2019

AVIATION.

Cold westerly flow coming off Lake Michigan will maintain mostly MVFR stratus this morning with scattered light snow showers and flurries around as well. Gradual low level drying and daytime heating will ease ceilings into VFR as stratus lingers into early this evening. Low clouds to be replaced by mid clouds tonight as a weather system tracks through the Ohio Valley. Light snow is expected to pass just south of the DTW/YIP terminals.

For DTW . A dusting of snow is possible to start the taf period, with another very low chance of light snow late tonight (not included in taf).

DTW THRESHOLD PROBABILITIES .

* High for cigs below 5000 ft today, then low. * High for ptype as snow.

PREV DISCUSSION. Issued at 245 AM EST Sun Dec 15 2019

DISCUSSION .

Cold frontal passage early this morning will bring a period of light snow shower activity to the area, enhanced to some degree by plume of low level moisture off Lake Michigan. This activity will settle south through the forecast area during the pre-dawn hours and then generally be limited to areas south of M-59 or so by 12z. Any lingering lake effect plumes within cold air advection will also orient northwest to southeast into the far southern portions of the forecast area. This will be minor snow shower activity given rather shallow low level inversion heights. Drier low level airmass with building surface ridge will also limit (and eventually end) this activity.

Main focus of this forecast will then turn to synoptic system(s) late tonight into Monday night. Model solutions generally remain progressive with the upper flow pattern as 150 knot sub-tropical jet arcs east/northeast into the eastern CONUS around shortwave now over the central plains and well in advance of a notable Pacific shortwave now progressing onshore over Oregon and northern California. The lead jet dwarfs energy digging in behind the Pacific system (which is on the order of 100 knots in terms of the jetlet speed). This further supports a progress track for this system

The trajectory of the lead jet would keep the right entrance region south of the forecast area and support a general model consensus of keeping all/most of snow from these shortwaves to the south of lower Michigan. This will certainly be the case for the lead shortwave as snow shield expands east into the Ohio Valley late today/tonight with little to no pivot north as the wave tracks into zonal and slight confluent upper level flow.

There remains some uncertainty with regard to the second more dynamic shortwave now over the western CONUS which will generally maintain its amplitude a bit better than the lead wave. Shortwave energy will also be pivoting around upper low positioned over the far north central portions of Canada and digging through central Canada (and eventually into the northern Great Lakes). The initial interaction of these streams will allow the upper pattern to buckle over the plains with an upper trough developing. Shortwave ridging downstream of this, while subtle, may be enough to coax entrance region of the subtropical jet closer to the forecast area as the southern wave approaches.

So far, the satellite representation (including a decent look from GOES-15 in this fairly data void satellite area) of the lead vorticity spokes pivoting around northern upper low suggest this energy may be digging a bit sharper southwest into the Northwest Territories. If the trend were to persist, a slightly deeper mean upper trough would result and the odds that some light deformation snow from the southern system would lift into southern parts of the forecast area would increase. Given this, will not abandon the idea of some light accumulating snow over far southern areas completely despite a definite consolidation of most model solutions in that direction.

That said, there is likely a rather hard limit to now far north the deformation can stray as the overall pattern, including the northern stream energy, remains very progressive and will tend to support better phasing of the southern/northern streams to the east of the region. So, feel comfortable leaving northern portions of the forecast area dry with increasing chances of light accumulating southward (and particularly closer to the Michigan and Ohio state line).

A colder pattern becomes established into the middle of the week once this southern shortwave passes and the northern vorticity digs through Ontario and allow for a brief intrusion of arctic air into the Great Lakes. The coldest day will be Wednesday when temperatures hold in the 20s throughout the day. The overall upper pattern does remain progressive though and this bubble of arctic air moderates as the northern upper low pivots into the Canadian maritime. A wavy zonal pattern then expands east over the CONUS in the wake of this system and brings moderated Pacific air back east through the CONUS and cuts off any further intrusion of arctic air for the remainder of this forecast period (and beyond). This will result in moderating temperatures back to around 40 for week's end.

MARINE .

A Gale Warning will remain in effect through the morning hours as marginal gales affect the northern half of Lake Huron. Increased northwest flow is also bringing hazardous boating conditions for small crafts impacting the Thumb nearshore zones with elevated wave action. These conditions will persist into the afternoon. Winds and waves begin to ease up throughout the afternoon today as the low pressure system lifts further off to the northeast and replaced by a weak high pressure moves into the northern Great Lakes. Winds remain light across the lakes on tomorrow into Tuesday while a low pressure system stays to the south across the Ohio River Valley, but brings chances for snow showers to the southern lakes on the northern fringe of the system. A more impactful surge of arctic air with a polar low pressure system will arrive late Tuesday into Wednesday.

DTX WATCHES/WARNINGS/ADVISORIES. MI . NONE. Lake Huron . Small Craft Advisory until 5 PM EST this afternoon for LHZ421-441- 442.

Gale Warning until noon EST today for LHZ361>363.

Lake St Clair . NONE. Michigan waters of Lake Erie . NONE.

AVIATION . SF DISCUSSION . DG MARINE . DG

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
SBLM4 - Saginaw Bay Light #1, MI	16 mi	80 min	NW 14 G 17	28°F			1012.2 hPa (+4.1)
GSLM4 - Gravelly Shoals Light MI	31 mi	40 min	W 15 G 19	25°F
TAWM4 - Tawas City, MI	46 mi	40 min	NW 6 G 12	23°F			1013.2 hPa

Wind History for Harbor Beach, MI

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NW3

N6

N9

NW11 G14

NW11 G15

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NW7

NW9 G13

W6 G12

W6 G10

W6 G12

W6 G13

W7 G10

W9

W11 G14

W9 G12

W10 G17

W11 G18

W10 G15

NW11 G19

NW10 G14

NW8 G11

NW12 G18

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1 day ago

S9

S8 G11

S8 G12

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S6 G9

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NW5 G8

NW5 G8

2 days ago

S10

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S11 G16

S11 G15

S15 G21

S18 G23

S19 G24

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S18 G22

S19 G28

S18 G24

S14 G19

S14 G17

S15 G19

S14 G18

S14 G19

S13 G17

SW11 G14

S10 G13

SW9 G12

S9 G12

S8

S9

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Airport Reports

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Airport	Dist	Age	Wind kt	Visibility	Sky/Weather	Temp	DewPt	Humidity	Pressure
Jack Barstow Airport, MI	15 mi	25 min	WNW 4	10.00 mi	Mostly Cloudy	28°F	19°F	72%	1014.2 hPa
MBS International Airport, MI	16 mi	27 min	WNW 11	10.00 mi	Overcast	28°F	17°F	63%	1015 hPa
Saginaw County H W Browne Airport, MI	23 mi	25 min	W 9	10.00 mi	Overcast	30°F	19°F	64%	1014.2 hPa

Link to 5 minute data for KIKW

Wind History from IKW (wind in knots)

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NW3

Calm

W5

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W4

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W8 G14

W8

W10 G15

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W10 G15

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1 day ago

Calm

S3

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2 days ago

SE7

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SE9 G14

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S11

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Calm

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S5

S10 G15

S10 G15

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S3

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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 (9,2,3,4)

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Ground Weather Radar Station Detroit, MI

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