NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION. Privacy and Cookie policy

LMZ542 Sturgeon Bay To Two Rivers Wi-two Rivers To Sheboygan Wi- 925 Am Cst Wed Dec 6 2023
This afternoon..SW wind 10 to 20 kts. A chance of sprinkles. Waves 1 to 3 ft.
Tonight..SW wind 10 to 20 kts with a few gusts to around 25 kts. A chance of sprinkles in the evening. Waves 2 to 4 ft subsiding to 1 to 3 ft early in the morning.
Thursday..W wind 5 to 10 kts backing S in the afternoon. Partly cloudy in the morning then clearing. Waves 2 ft or less.
Thursday night..S wind 10 to 20 kts. Partly cloudy. Waves 1 to 3 ft building to 3 to 5 ft after midnight. A small craft advisory may be needed.

LMZ500
No data

FXUS63 KGRB 061111 AFDGRB

Area Forecast Discussion National Weather Service Green Bay WI 511 AM CST Wed Dec 6 2023

Updated aviation portion for 12Z TAF issuance

KEY MESSAGES

- Well above normal temps (10-20 degrees), but below records, are likely on Friday.

- Low probabilities (10-20%) of significant winter weather continue on Saturday and Saturday night over northeast and north-central Wisconsin.

DISCUSSION
Issued at 250 AM CST Wed Dec 6 2023

SHORT TERM
Today
Tonight...and Thursday

High pressure over the western Great Lakes will slide east today, allowing a warm front to lift north over the region. The warm front will turn winds from a west to northwest direction to a south to southwest direction by this afternoon. Despite the passage of a warm front, clouds are expected to remain across the region with very shallow mixing heights as the warm air advection will mainly be aloft. Therefore, highs are only expected to rise into the 30s this afternoon. There will be some weak isentropic lift associated with the warm front this afternoon; however, model soundings show quite a bit of dry air in the column. Given the dry air and weak lift only a few flurries or sprinkles are possible as the warm front lifts north today. Winds will increase behind the warm front this afternoon and this evening, with southwest winds gusting to 25 to 35 mph at times, particularly across east-central Wisconsin and the lakeshore.

Weak ridging will then slide through the western Great Lakes region tonight, which is expected to keep the area dry. The ridge will also cause winds across east-central Wisconsin and the lakeshore to ease throughout the overnight hours. Although there be some partial clearing at times tonight, surface winds should keep temperatures from plummeting too much across the area. Lows tonight are expected to range from the middle 20s across the north, with around 30 across east-central Wisconsin and the lakeshore.

The ridge will slide off to the east on Thursday, allowing surface winds to once again turn south to southeast throughout the day.
Despite southerly winds, model soundings once again show a steep low level inversion and shallow mixing height only to around 1000 kt AGL. Therefore, highs on Thursday will be a bit cooler than expected with a southerly wind as the warm air advection will once again mainly be aloft. Highs on Thursday are expected to mainly be in the lower to middle 40s.

LONG TERM...Thursday Night Through Tuesday

Thursday night through Friday night...Low pressure will be traveling northeast from North Dakota to northern Ontario during this time period. The airmass south of the low track will be very dry through Friday and therefore no precip is expected. Highs on Friday remain expected to range from 10 to 20 degrees above normal.

On Friday night, gulf moisture will be surging north and into the region ahead of a developing cyclone. Forecast soundings indicate the chance of drizzle or light showers increasing through the night as the gulf moisture arrives. Thermal profiles suggest most precip will consist of liquid, except for far north-central WI where temps will be close to freezing. Little to no accumulations are expected by 6 am Saturday.

Saturday through Tuesday...Model differences remain large regarding a strengthening cyclone forecast to cross the region Saturday into Sunday. In general, there has been a slight slowing trend of the deep trough over the central Plains on Saturday, while the surface low track has shifted to the northwest. The probabilities for greater than 0.25 precip has increased over northeast Wisconsin, while the probabilities for greater than 2 inches of snow has shifted west from northeast to north-central WI, which makes sense given the surface low trends.

With that said, however, the GFS seems to be an outlier compared to other operational/ensemble model systems. A positively tilted trough would argue for a more progressive, suppressed, and weaker cyclone passing across the upper midwest than the GFS depicts. This would favor more of an ECMWF/Canadian solution.

Given the large model spread and large run-to-run changes of the operational models, awfully difficult to get a handle on the potential for hazardous weather. The strong dynamics with this system would argue for low probabilities (20-30%) of significant snow accumulations in the Saturday to Saturday night time period.
Confidence is low where these hazards will occur however.

Colder air will filter into the region behind the system for early next week. Still indications of clipper energy moving through the region at some point early next week.

AVIATION
for 12Z TAF Issuance Issued at 511 AM CST Wed Dec 6 2023

A mix of VFR and MVFR cigs prevailed across the area early this morning as observations show the MVFR cigs across central and north-central WI slowly eroding. Meanwhile, VFR cigs were filling in across east-central and northeast Wisconsin where clouds had previously cleared. Overhead some mid to high level clouds were also noted moving over the TAF sites. Any lower clouds that clear out this morning should fill back in this afternoon, with bases expected to be mainly VFR in the afternoon. Low and mid clouds should then dissipate tonight, leaving only high clouds during the overnight hours.

Light west winds will turn southwest and increase this afternoon, with gusts of 15 to 25 kts, as high pressure gradually shifts eastward. In addition, a period of LLWS, with westerly winds to 40 kts, is expected late this afternoon into the evening. Winds will then die down late tonight as a ridge of high pressure moves back over the region.

GRB WATCHES/WARNINGS/ADVISORIES
None.

toggle option: (graph/table)

Full Color Weather Map

Link to Loop


Other links: GEOS-West     Contential US     Full GOES-East

Green Bay, WI,