Marine Weather and Tide Forecast for Sobieski, WI

DISCUSSION
Issued at 115 PM CST Sat Dec 7 2024

Short Term...Tonight and Sunday

Any lingering snow showers across the far north gradually came to an end late this morning, giving way to warming temperatures and decreasing low clouds. Increasing southwest flow then ushered in well-above average temperatures this afternoon (upper 30s to mid 40s), the mildest temperatures we've seen in some time. Gusts from 20 to 25 mph were observed along and east of the Fox Valley.

Tonight... Expect increasing low clouds to hold temperatures down in the upper 20s to low 30s across the forecast area overnight as a weak cold front stalls out over northern Wisconsin. Surface winds will gradually subside overnight through tomorrow morning, veering to west/northwest.

Mixed precip chances Sunday evening... Our next weathermaker arrives tomorrow evening in the form of a clipper system as an upper-level shortwave approaches from the northern Plains. Expect precip chances to arrive to central and north-central Wisconsin from the west tomorrow evening ahead of increasing warm air advection. Ptype looks to be tricky as CAMs present several different scenarios that could play out based on thermal profiles.
Model soundings across north-central Wisconsin show deep-layer saturation Sunday evening, with temperatures hovering near/slightly below zero. This solution would suggest the onset of frozen precip (snow) right off the bat. However, the NAM and RAP show a more pronounced warm nose in the low to mid levels with saturation in the lowest 3 to 5k ft, introducing the potential for liquid precip (freezing rain or drizzle) earlier on. Suspect that precip will start as snow across north-central Wisconsin tomorrow evening before warm air advection chases away colder air in the low levels. This being said, an abrupt switch to liquid precip looks to be in store later Sunday evening (more on this in the long-term). All in all, forecast confidence remains on the low end for ptype as any wobble of a degree or two in the thermal profile could paint a completely different picture. Opted to leave a rain/snow mix in the forecast for the time being.

Long Term...Sunday Night Through Saturday

Precipitation type on Sunday night remains a concern with a wintry mix possible over the north. Behind this system, another push of cold air settles across the region most of the week. Lake effect snow showers will return to northern WI and some areas will see sub zero wind chills Wednesday into Thursday. Upper level pattern buckles late this week into next weekend with sudden zonal flow taking over, leading to a warming trend, but there also may be another chance of precipitation as that occurs.

Precipitation...
PV anomaly/shortwave crashing ashore later today over British Columbia reaches northern plains with clipper low pressure system by Sunday evening. As that occurs, warm front will extend east of the low across the western Great Lakes. The low then crosses Lake Superior Monday into Monday evening while a cold front sweeps eastward across the Great Lakes. Warm air advection along south of edge of more widespread precip could result in a wintry mix of snow, freezing rain and rain Sunday night, especially into the early morning hours. There is uncertainty on how far south the widespread precip will extend into our northern counties and there is also a question of degree of warmth in the lowest 3-5kft. Both these factors result in a complicated and lower confidence ptype forecast. Where a wintry mix or mainly freezing drizzle occurs, untreated roads, sidewalks and parking lots could become slippery.
Winter weather advisory could be needed eventually, but it is not clear cut by any stretch. For now, will continue to mention this in the HWO.

Once the system shifts east, Monday looks mainly dry. Cold front shifting through on Monday night will start up a lake effect regime over northern WI as a sufficiently cold northwest flow regime develops across Lake Superior. Glace at forecast soundings point to low inversions under 5kft Tuesday through Thursday.
Normally that would result in light intensity lake effect, but most of that lake convective layer will be in the DGZ, so higher SLRs, fluffier snow. In addition, a shortwave working through Tuesday night into Wednesday interacting with an already primed lake effect setup could result in several inches of snow for Vilas County. That shortwave could also bring snow showers or flurries to most of the area on Wednesday, even away from the lake snow belts of northern WI. Adjusted pops to a floor of slight chance late Tuesday night into Wednesday and ramped them up to likely for snow belt of Vilas County.

The next chance of precipitation arrives next weekend. A lot of uncertainty though with this as the primary models (GFS, ECMWF, Canadian) are much more wrapped up with a low tracking across the region than their associated ensembles. If something closer to the stronger ideas ended up verifying, we would be dealing with widespread mixed precipitation and even the potential for accumulating snow at some point next weekend. Did not mention any freezing rain in forecast this far out, especially given the uncertainty how the system will play out.

Temperatures...
Roller coaster fits temperature trend this week. Temps start off mild with highs as warm as low to mid 40s on Monday, but then tumble with highs only reaching the teens to lower 20s Wednesday into Thursday. During this time, will see another round of sub zero wind chills, with lowest readings expected Wednesday night into Thursday morning. Highs become more seasonable chilly by Friday (20s north into the low 30s east-central), then rebound back above normal by next weekend. Though extent of that warm up will depend on strength and location of possible low pressure system.

AVIATION
for 18Z TAF Issuance Issued at 1144 AM CST Sat Dec 7 2024

MVFR cigs exited to the east mid-morning, leaving high clouds and VFR conditions in their wake. Expect high clouds to persist overnight, with opportunities for partial clearing across central Wisconsin. MVFR/IFR cigs then make a comeback early tomorrow morning as a weak cold front stalls out over northern Wisconsin, mainly affecting RHI.

Southwest winds began to ramp up late this morning, gusting from 20 to 25 mph at the eastern TAF sites. LLWS then becomes a concern at all TAF sites starting later this afternoon/evening as surface winds gradually subside and a 50 to 55 knot 850 mb jet builds in over eastern Wisconsin. LLWS then lifts from south to north mid-morning on Sunday.

GRB WATCHES/WARNINGS/ADVISORIES
None.