Marine Weather and Tide Forecast for Ephraim, WI
 | Sunrise 7:15 AM Sunset 4:13 PM Moonrise 10:40 PM Moonset 12:20 PM |
Marine Forecasts
NOTE: Zones were updated 3/20/2025. If your report is out of date, please click Edit
LMZ541 Rock Island Passage To Sturgeon Bay Wi- 738 Pm Cst Tue Dec 9 2025
.small craft advisory in effect from midnight cst tonight through Wednesday afternoon - .
Tonight - SE wind 5 to 10 kts becoming ne 15 to 25 kts with gusts to around 30 kts after midnight. A chance of light snow. Waves 2 to 4 ft subsiding to 1 to 3 ft late in the evening, then building to 2 to 4 ft after midnight building to 4 to 7 ft late in the night.
Wednesday - N wind 15 to 25 kts with gusts to around 30 kts. A slight chance of light snow in the morning. Waves 4 to 7 ft subsiding to 3 to 5 ft in the afternoon.
Wednesday night - NW wind 15 to 25 kts with gusts to around 30 kts. Partly cloudy in the evening then becoming mostly cloudy. Waves 2 to 4 ft subsiding to 1 to 3 ft in the late evening and overnight.
Thursday - NW wind 10 to 20 kts backing W 5 to 10 kts in the afternoon. Partly Sunny. Waves 2 ft or less.
LMZ500
No data
No data
7 Day Forecast for Marine Location Near Ephraim, WI
NEW! Add second zone forecast
FXUS63 KGRB 100122 AFDGRB
Area Forecast Discussion National Weather Service Green Bay WI 722 PM CST Tue Dec 9 2025
New Information added to update section
UPDATE
Issued at 715 PM CST Tue Dec 9 2025
Lowered QPF/snowfall amounts across the far north, which necessitated cancelling the Winter Weather Advisories over Vilas, Forest and northern Marinette counties. Increased QPF/snowfall amounts over the Fox Valley/Kewaunee/Manitowoc areas (biggest changes were for the 06z-12z period), which resulted in an upgrade to a Winter Storm Warning. Also downgraded Lincoln County to an advisory, as snowfall totals were lowered to 2-4 inches.
Moderate snowfall had moved into central WI, where MFI was reporting 1/2sm vsbys. The heavier snowfall will fill in across the Fox Valley/lakeshore areas in the next hour or two, bringing hazardous travel conditions to the I-41 and I-43 corridors.
UPDATE Issued at 526 PM CST Tue Dec 9 2025
Strongly considering upgrading the advisory to a Winter Storm Warning in parts of the Fox Valley/lakeshore areas, with the highest likelihood in Outagamie, Winnebago, Calumet and Manitowoc counties, where probabilistic forecasts show a 50-80% chance of 6+ inches. Also considering downgrading Lincoln County to an advisory. Will also need to take a look at the far northern counties, where it's looking less likely for significant snow accumulations. Models have largely settled on the heaviest snow falling south of a line from Wausau to Manitowoc, with the highest snowfall rates (1+ inch/hour) occurring from this evening into the early overnight hours (02z-08z/Wed). Additional accumulations occur as the deformation zone pulls through the area late tonight into early Wednesday morning.
Will make final headline decisions within the next hour, and get updates out before the heavier snowfall rates move into the forecast area.
KEY MESSAGES
- Snow will overspread the region late this afternoon/evening, exiting by around sunrise Wednesday. Rates may reach or exceed 1 inch per hour across central into east-central Wisconsin this evening resulting in hazardous travel conditions.
- Much colder temperatures arrive for the end of the week. Bitter cold wind chills likely will be as low as 10 below to 30 below zero at times through the weekend.
- Periodic light snow chances will continue late this week into early next week with the highest chances on Friday (30-50%).
DISCUSSION
Issued at 226 PM CST Tue Dec 9 2025
Tonight-Wednesday: Snow Tonight, Gusty Winds Wednesday
GOES water vapor imagery early this afternoon shows the shortwave trough of interest across the northern plains. Snow has been occurring across parts of Minnesota within strong mid-level warm advection ahead of the 990 mb surface low. This snow will quickly advance south and east this evening/overnight with the low passing across southern Wisconsin.
Overall, high res guidance has trended a bit south, more in line with global (GEFS/ECMWF) ensembles, with the highest precipitation amounts forecast in a narrow stripe across central into east-central Wisconsin just north of the strong surface low. As a result, trimmed snow amounts across northern Wisconsin and replaced the Winter Storm Warning with and Advisory for a few counties.
Northern areas may need to even trend lower with amounts this evening. On the southern end, Waushara County was added to the warning with generally medium (40 to 60%) chances for 6" from central into east-central Wisconsin.
These systems are difficult to nail down the details for, with higher rates associated with stronger mesoscale forcing potentially impacting amounts. Trends across parts of the Fox Valley and lakeshore areas will need to watched this evening as some guidance extends an axis of localized amounts in the 6-7 inch range towards parts of the Fox Valley. Snow rates could exceed 1 inch per hour for a 2 to 4 hour window centered on this evening across central into east-central Wisconsin, resulting in difficult travel. Snow should be quickly waning by sunrise on Wednesday as the low pulls east.
Winds will pick up from the north late tonight and Wednesday as the low pulls east with some gusts in the 20 to 30 mph range. This likely will be insufficient to cause true blowing snow, but some drifting may occur.
Thursday-Tuesday: Colder, Light Snow at Times
Heading through the late week period, a cold northwest flow pattern will prevail across the Upper Midwest. A few embedded waves in the flow will bring some potential for light snow. Right now the highest snow chances are centered on Friday as the Arctic front slides through with probabilities for an inch of snow in the 30 to 60% range. However, additional shortwaves will dive southeast from the northern plains Thurs/Thurs Night, Saturday, and possibly early next week, so it's an active pattern.
The most significant impact will be the push of Arctic air for the weekend. EFI values for high/low temps drop below -0.8, indicating strong ensemble agreement for anomalous cold over the weekend. Highs may struggle to top the single digits over the weekend as low-level cold advection persists with the ridge axis passing west of the area. Cold weather headlines may be needed this weekend, although there is uncertainty with cloud trends, which may impact temps.
By early next week, progressive ridging spreading eastward will allow temps to rebound, but the spread increases considerably by early next week.
AVIATION
for 00Z TAF Issuance Issued at 526 PM CST Tue Dec 9 2025
Light snow was moving into central WI early this evening, slightly slower than previously thought. The steady snow will overspread all but far northern WI this evening, with moderate to heavy snow likely along and south of a line from Wausau to Manitowoc, where accumulations of 5 to 7 inches are expected. The heaviest snows will occur from this evening into the early overnight hours, though light to occasionally moderate snow will continue in association with the system deformation zone later tonight into early Wednesday. Flight conditions will mainly be in the IFR/LIFR categories, but localized VLIFR vsbys could accompany any pockets of heavy snow.
The snow tapers off late tonight into early Wednesday, but MVFR ceilings should persist through mid to late afternoon, when at least partial clearing is expected to arrive.
Easterly winds are expected into the early overnight, followed by increasing north winds late tonight into Wednesday. The northerly winds are expected to gust to 20 to 30 kts, locally to near 35 kts near Lake Michigan.
GRB WATCHES/WARNINGS/ADVISORIES
Winter Weather Advisory until 6 AM CST Wednesday for WIZ010- 018>021.
Winter Weather Advisory until 9 AM CST Wednesday for WIZ022-073- 074.
Winter Storm Warning until 6 AM CST Wednesday for WIZ030-031- 035>037-045.
Winter Storm Warning until 9 AM CST Wednesday for WIZ038>040- 048>050.
Area Forecast Discussion National Weather Service Green Bay WI 722 PM CST Tue Dec 9 2025
New Information added to update section
UPDATE
Issued at 715 PM CST Tue Dec 9 2025
Lowered QPF/snowfall amounts across the far north, which necessitated cancelling the Winter Weather Advisories over Vilas, Forest and northern Marinette counties. Increased QPF/snowfall amounts over the Fox Valley/Kewaunee/Manitowoc areas (biggest changes were for the 06z-12z period), which resulted in an upgrade to a Winter Storm Warning. Also downgraded Lincoln County to an advisory, as snowfall totals were lowered to 2-4 inches.
Moderate snowfall had moved into central WI, where MFI was reporting 1/2sm vsbys. The heavier snowfall will fill in across the Fox Valley/lakeshore areas in the next hour or two, bringing hazardous travel conditions to the I-41 and I-43 corridors.
UPDATE Issued at 526 PM CST Tue Dec 9 2025
Strongly considering upgrading the advisory to a Winter Storm Warning in parts of the Fox Valley/lakeshore areas, with the highest likelihood in Outagamie, Winnebago, Calumet and Manitowoc counties, where probabilistic forecasts show a 50-80% chance of 6+ inches. Also considering downgrading Lincoln County to an advisory. Will also need to take a look at the far northern counties, where it's looking less likely for significant snow accumulations. Models have largely settled on the heaviest snow falling south of a line from Wausau to Manitowoc, with the highest snowfall rates (1+ inch/hour) occurring from this evening into the early overnight hours (02z-08z/Wed). Additional accumulations occur as the deformation zone pulls through the area late tonight into early Wednesday morning.
Will make final headline decisions within the next hour, and get updates out before the heavier snowfall rates move into the forecast area.
KEY MESSAGES
- Snow will overspread the region late this afternoon/evening, exiting by around sunrise Wednesday. Rates may reach or exceed 1 inch per hour across central into east-central Wisconsin this evening resulting in hazardous travel conditions.
- Much colder temperatures arrive for the end of the week. Bitter cold wind chills likely will be as low as 10 below to 30 below zero at times through the weekend.
- Periodic light snow chances will continue late this week into early next week with the highest chances on Friday (30-50%).
DISCUSSION
Issued at 226 PM CST Tue Dec 9 2025
Tonight-Wednesday: Snow Tonight, Gusty Winds Wednesday
GOES water vapor imagery early this afternoon shows the shortwave trough of interest across the northern plains. Snow has been occurring across parts of Minnesota within strong mid-level warm advection ahead of the 990 mb surface low. This snow will quickly advance south and east this evening/overnight with the low passing across southern Wisconsin.
Overall, high res guidance has trended a bit south, more in line with global (GEFS/ECMWF) ensembles, with the highest precipitation amounts forecast in a narrow stripe across central into east-central Wisconsin just north of the strong surface low. As a result, trimmed snow amounts across northern Wisconsin and replaced the Winter Storm Warning with and Advisory for a few counties.
Northern areas may need to even trend lower with amounts this evening. On the southern end, Waushara County was added to the warning with generally medium (40 to 60%) chances for 6" from central into east-central Wisconsin.
These systems are difficult to nail down the details for, with higher rates associated with stronger mesoscale forcing potentially impacting amounts. Trends across parts of the Fox Valley and lakeshore areas will need to watched this evening as some guidance extends an axis of localized amounts in the 6-7 inch range towards parts of the Fox Valley. Snow rates could exceed 1 inch per hour for a 2 to 4 hour window centered on this evening across central into east-central Wisconsin, resulting in difficult travel. Snow should be quickly waning by sunrise on Wednesday as the low pulls east.
Winds will pick up from the north late tonight and Wednesday as the low pulls east with some gusts in the 20 to 30 mph range. This likely will be insufficient to cause true blowing snow, but some drifting may occur.
Thursday-Tuesday: Colder, Light Snow at Times
Heading through the late week period, a cold northwest flow pattern will prevail across the Upper Midwest. A few embedded waves in the flow will bring some potential for light snow. Right now the highest snow chances are centered on Friday as the Arctic front slides through with probabilities for an inch of snow in the 30 to 60% range. However, additional shortwaves will dive southeast from the northern plains Thurs/Thurs Night, Saturday, and possibly early next week, so it's an active pattern.
The most significant impact will be the push of Arctic air for the weekend. EFI values for high/low temps drop below -0.8, indicating strong ensemble agreement for anomalous cold over the weekend. Highs may struggle to top the single digits over the weekend as low-level cold advection persists with the ridge axis passing west of the area. Cold weather headlines may be needed this weekend, although there is uncertainty with cloud trends, which may impact temps.
By early next week, progressive ridging spreading eastward will allow temps to rebound, but the spread increases considerably by early next week.
AVIATION
for 00Z TAF Issuance Issued at 526 PM CST Tue Dec 9 2025
Light snow was moving into central WI early this evening, slightly slower than previously thought. The steady snow will overspread all but far northern WI this evening, with moderate to heavy snow likely along and south of a line from Wausau to Manitowoc, where accumulations of 5 to 7 inches are expected. The heaviest snows will occur from this evening into the early overnight hours, though light to occasionally moderate snow will continue in association with the system deformation zone later tonight into early Wednesday. Flight conditions will mainly be in the IFR/LIFR categories, but localized VLIFR vsbys could accompany any pockets of heavy snow.
The snow tapers off late tonight into early Wednesday, but MVFR ceilings should persist through mid to late afternoon, when at least partial clearing is expected to arrive.
Easterly winds are expected into the early overnight, followed by increasing north winds late tonight into Wednesday. The northerly winds are expected to gust to 20 to 30 kts, locally to near 35 kts near Lake Michigan.
GRB WATCHES/WARNINGS/ADVISORIES
Winter Weather Advisory until 6 AM CST Wednesday for WIZ010- 018>021.
Winter Weather Advisory until 9 AM CST Wednesday for WIZ022-073- 074.
Winter Storm Warning until 6 AM CST Wednesday for WIZ030-031- 035>037-045.
Winter Storm Warning until 9 AM CST Wednesday for WIZ038>040- 048>050.
| Stations | Dist | Age | Wind | Air | Water | Waves | inHg | DewPt |
| NPDW3 - Northport Pier at Death's Door WI | 14 mi | 116 min | S 2.9G | 22°F | ||||
| MN4 - 9087088 - Menominee, MI | 22 mi | 56 min | NNE 4.1G | 25°F | 36°F | 29.49 | 19°F |
Wind History for Menominee, MI
toggle option: (graph/table)
Link to 1 hour of 5 minute data for KMNM
Terminal Aerodrome Forecast (TAF) for KMNM
Wind History Graph: MNM
(wind in knots)
GEOS Local Image of great lakes
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