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7 Day Forecast for Marine Location Near Harper Woods, MI

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Area Discussion for - Detroit/Pontiac, MI

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FXUS63 KDTX 082028 AFDDTX

Area Forecast Discussion National Weather Service Detroit/Pontiac MI 325 PM EST Sun Dec 8 2019

DISCUSSION.

A mild and wet start to the work week, with a good shot of cold air for the mid week period.

Narrow stream of moisture (850-700 mb Theta-E) tracking through southern Lower Michigan this afternoon with deep southwest flow ahead of a cold front tracking through the northern Great Lakes as upper level jet max advances through northeastern Ontario and into southern Quebec. Widespread rain likely not developing until late tonight.

Better push of low level moisture (6 C dew pt at 925 mb) into southeast Michigan on Monday as strong upper level wave currently tracking into Montana swings into the western Great Lakes Monday evening. Meanwhile, larger upper wave along the California coast will dive south-southeast, but a piece of upper level PV/energy breaks off and races through the Midwest on Monday, proving favorable ascent. However, better right exit region/moisture surge with the 150+ knot upper level jet looks to be tracking off into the Eastern Great Lakes, with the strengthening surface wave tracking close to the Straights. Weaker pressure fields over southeast Michigan, with sufficiently cold ground and low level moisture coming over the top to support low clouds/fog and rain through the day, but aggressive mid level dry slot arriving by midnight looks to shut off most of the precipitation as the good blast of cold air sweeps in, sending 850 mb temps into the negative mid teens for Tuesday. Still, with cold cyclonic flow, probably steep enough low level lapse rates with modest cape in the DGZ to generate scattered light snow shower/flurry activity, but limited cloud depths preventing more vigorous activity. Potentially a better chance of stronger snow shower activity on Wednesday as more robust upper level wave/cold pool swings through, sending 850 mb temps into the negative lower twenties/around 20 C. Brief support/extension to 700 mb as weak upper wave comes out of the Midwest. Still, extreme dry nature of the arctic airmass is sometimes too much to overcome, as PW Values drop at or below 0.1 inches. Will favor a burst of snow/scattered snow shower mention breaking off Lake Michigan as water temps still hovering around 40 degrees. Strong subsidence/surface anti-cyclone (1040+ mb) building in Wednesday night suggests skies clearing out with temps potentially dipping into the single numbers, even with little or no snow on ground. IF snow cover does materialize, zero or below in normally colder spots not out of the question, but invading high clouds toward sunrise appear likely.

Energetic pseudo zonal upper flow over the Conus on Friday makes for difficult Weekend forecast as flow appears to buckle east of the Mississippi River valley with potential storm system tracking through Central/Eastern Great Lakes Saturday night, per 00z Euro. 00z GFS displaced considerably farther to the East, as interaction/merging/phasing with the system tracking through the northern Gulf of Mexico will be the key, and the 00z Canadian illustrates little interaction/much better separation. However, the 12z GFS has trended toward the Euro, thus rain and snow remains in play, but the 12z Euro has now flipped toward the 00z GFS and is well to the east. Plenty of additional flip-flopping remains likely due to multiple upper level wave interactions in play.

MARINE.

Gale warnings and small craft advisories have been allowed to expire as wind gusts and associated wave heights continue to diminish through the evening hours, tied to a weakening pressure gradient. Attention will then turn to a developing low pressure system, set to travel northeast from the central Plains, eventually traveling through northern lower Michigan and Ontario/Quebec. Ahead of the low, surge of warmer air will allow widespread rain to develop across the Great Lakes starting late tonight, which will continue through Monday. Increased stability from the advancing warmer air will allow lighter winds to persist into Monday afternoon as the low settles over northern lower Michigan, with an uptick in wind speeds and gusts expected late Monday night into Tuesday morning given reduced stability from increasing cold air advection. Most locations look to stay below gales at this time, however, northern Lake Huron will have the chance to see low-end gales early Tuesday morning. Last, there is a high probability for snow squalls to travel across Lake Huron and potentially Lake St. Clair both Tuesday and Wednesday given the high instability across the Lakes. Freezing spray also remains possible across Lake Huron on Wednesday.

HYDROLOGY.

Rain developing late tonight and continuing through Monday. Mild air with high moisture content for this time of year fuels a cold front and low pressure system moving across the region. Local probability guidance suggests rainfall totals approach a half inch. Locally higher totals are possible in locations where heavier showers occur repeatedly but amounts under one inch. A transition to mixed rain and snow is possible if any precipitation lingers long enough after the cold front moves through Monday night and Tuesday morning. The expected rainfall tonight and Monday may lead to ponding of water in prone areas and small rises on area rivers.

PREV DISCUSSION. Issued at 1235 PM EST Sun Dec 8 2019

AVIATION .

MVFR stratus has shrouded most of southeast MI this afternoon and aviation conditions will continue to worsen through the TAF period as abundant low-level moisture continues to advect in on a gusty wind from the southwest. Areas of light rain develop this evening and tonight as low pressure strengthens over the midwest, then widespread rain moves through during the day Monday as the low tracks through northern MI. The milder and more humid air moving in today brings good potential for vsby reductions in fog tonight and possibly into tomorrow. IFR stratus develops this evening and persists through the period. Some LIFR ceilings will be possible late tonight, particularly around mbS, but will hold off on including in TAF for now until better observational evidence is presented upstream. Marginal LLWS will be most likely across the Detroit TAF sites for a few hours this evening /centered on 23-03z/, but slightly elevated winds at the surface should keep shear below 30 kt most of the time.

For DTW . MVFR cigs persist this afternoon with southwest winds gusting as high as 25 kt. Winds subside this evening as chances for light rain increase and ceilings lower to IFR in addition to the development of MVFR to possibly IFR fog. Moderate and more widespread rain moves in around 13z Monday, persisting into the early afternoon. Low confidence in LIFR conditions tonight.

DTW THRESHOLD PROBABILITIES .

* High confidence in cigs aob 5000 feet through tomorrow.

* Low confidence in cigs aob 200 feet late tonight.

DTX WATCHES/WARNINGS/ADVISORIES. MI . NONE. Lake Huron . Small Craft Advisory until 4 PM EST this afternoon for LHZ421-422- 441>443.

Gale Warning until 4 PM EST this afternoon for LHZ362-363.

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

DISCUSSION . SF MARINE . AM AVIATION . TF HYDROLOGY. sf

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
CLSM4 - St. Clair Shores, MI	7 mi	51 min	S 7 G 14	44°F			1013.9 hPa (-1.7)
AGCM4	28 mi	51 min		42°F	39°F		1013.3 hPa (-1.8)
THLO1 - Toledo Light No. 2 OH	42 mi	51 min	S 12 G 13	45°F
MBRM4 - 9014090 - Mouth of the Black River, MI	49 mi	57 min		42°F			1012.5 hPa

Wind History for Fort Gratiot, MI

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S9

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S8 G11

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S12 G16

S11 G15

S12 G16

S10 G18

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S11 G16

S11 G15

S11 G16

S10 G14

SW11 G19

SW13 G23

SW15 G22

SW16 G23

S9 G17

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1 day ago

NW13 G18

NW6 G11

NW10 G17

NW5 G11

NW5 G8

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NW5 G9

N4 G7

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SW4 G9

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NW4

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S7 G10

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SW6 G11

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SW7 G11

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NW15 G23

NW13 G19

NW13 G19

N12 G20

NW18 G26

NW11 G16

NW11 G18

NW9 G14

NW7 G18

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Airport Reports

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Airport	Dist	Age	Wind kt	Visibility	Sky/Weather	Temp	DewPt	Humidity	Pressure
Coleman A Young Municipal Airport, MI	2 mi	58 min	SSW 12 G 18	10.00 mi	Mostly Cloudy	45°F	37°F	74%	1013.8 hPa
Troy, Oakland/Troy Airport, MI	13 mi	55 min	SSW 10 G 15	10.00 mi	Overcast	45°F	39°F	81%	1013.2 hPa
Selfridge Air National Guard Base, MI	16 mi	1.9 hrs	S 10	10.00 mi	Overcast	42°F	38°F	87%	1014.1 hPa
Detroit, Detroit Metropolitan Wayne County Airport, MI	22 mi	58 min	S 11	7.00 mi	Overcast	46°F	37°F	73%	1013.8 hPa
Detroit/Grosse Ile, Grosse Ile Airport, MI	24 mi	56 min	S 7	10.00 mi	Partly Cloudy	41°F	37°F	86%	1013.5 hPa

Link to 5 minute data for KDET

Wind History from DET (wind in knots)

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N10 G18

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Calm

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2 days ago

Calm

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SE3

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NW11 G21

NW15 G26

N10 G26

N14 G24

N15 G24

N11 G20

N9

NW7 G17

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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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Wind Forecast for Detroit/Pontiac, MI (16,3,4,5)

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Ground Weather Radar Station Detroit, MI

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