Marine Weather and Tide Forecast for Green Bay, WI

DISCUSSION
Issued at 402 AM CST Mon Dec 9 2024

Short Term
Today
Tonight...and Tuesday

Areas of dense fog and temperatures near freezing could make for hazardous travel in far northcentral Wisconsin early this morning.

Drier air will arrive today as the surface low over northeast Wisconsin moves slowly away. This should clear out the clouds over all but north central Wisconsin by afternoon. It will be another mild day, especially south of highway 29, where high temperatures should be in the low to mid 40s. A surface trough moving across north central Wisconsin during the late afternoon and evening hours could produce some snow and rain showers there. Snow accumulations should be less than a half inch.

Clouds are expected to return to the entire area tonight and Tuesday, with a chance of lake effect snow in Vilas county. Wind direction is not favorable for any significant accumulation until late Tuesday night and Wednesday. Lows tonight will be around five degrees above normal. Highs Tuesday will be near normal.

Long Term...Tuesday Night Through Sunday

Extended forecast concerns focus primarily on the arrival of cold air for the midweek period, which may be accompanied by some light snow for much of the region. The next chance for precipitation follows for the upcoming weekend.

Temperatures...
Upper troughing moves into the region Tuesday accompanied by an arctic airmass what will bring some much colder air into the region. Guidance has remained fairly consistent in bringing temperatures at the surface into the single digits below zero everywhere but the lakeshore. Combined with a tightening pressure gradient during the overnight period resulting in occasional gusts up to 15 to 20 mph, wind chill readings for the morning period headinto the -25 to -15 range. Confidence remains steady that cold weather headlines will be necessary for central and north- central Wisconsin as we approach the middle of the week.

The cold will not stick around too long fortunately. After a cold day in the single digits to low teens on Thursday, a steady warming is in the works for the end of the week with temperatures getting back into the 30s Saturday and Sunday.

Precipitation...
As the colder air arrives Tuesday into Wednesday, expect lake effect snow to kick up again, likely lasting well into the Thursday. Additionally, dynamics along the cold front itself along with the upper low tracking overhead will likely prove sufficient to bring a period of light snow through the region Wednesday afternoon. Accumulations will likely be under an inch for central to east-central Wisconsin but a quick inch or two will be possible for much of the northwoods and northern Door County. Winds during this time may reduce visibility at times with any snow. After the front passes, dry conditions will return everywhere but the lake effect snow region in the north, as a fairly low inversion will likely limit any additional snow making it too far into Wisconsin.

Finally, with overrunning warm air working its way back into the region by next weekend, another chance for precipitation will also make its way into the area as a southern stream system lifts into the area. Uncertainty on timing and track is too high to bring much details into this period at this time.

AVIATION
for 06Z TAF Issuance Issued at 1049 PM CST Sun Dec 8 2024

Low pressure will move across northern Wisconsin overnight into Monday morning, resulting in poor flying conditions. IFR/LIFR ceilings will surge south with the passage of the surface low, but should remain northwest of the Fox Valley. Patchy drizzle and areas of fog are also likely north of the surface low track over north- central WI that will lower visibilities to IFR/LIFR.

Once the surface low passes, flight conditions are expected to return to VFR for several hours from late morning through early afternoon except for north- central WI. Then MVFR clouds/visibilities and scattered rain and snow showers return from west to east after 21z Monday. Added a prob30 group for light rain/snow showers at AUW/CWA/RHI from 21-24z Monday.

GRB WATCHES/WARNINGS/ADVISORIES
None.