textproduct: Gaylord

KEY MESSAGES

-Ongoing lake effect snow will continue to impact the typical snowbelts of northern Michigan through Sunday morning.

-Very cold temperatures and wind chills expected through tonight with apparent temps well below zero.

-Mild weather returns later next week with highs above freezing Wednesday and Thursday.

SHORT TERM /THROUGH TONIGHT/

Issued at 307 AM EST Sat Dec 13 2025

Pattern Synopsis...Longwave midlevel troughing with a decent jet core (150-170+ kts) continues to stretch across the northern half of North America. cP and cA air from the north will plummet surface temperatures the next few days across the Great Lakes region. Open water and warm lake temperatures will continue lake effect snow through the short term, especially tonight as midlevel embedded shortwave troughing digs across the CWA.

Forecast Details...

Today...Post cold frontal condtions are the main focus on today's forecast as cold air advection draws cA into the region with gusts in the mid 20s and highs in the low to mid teens. Even with dry atmospheric midlevels today, ongoing lake effect snow supported with lake aggregate troughing will provide enough instability to accumulate several inches for localized parts of the CWA. WNW directional winds will favor classic snowbelts of northern Michigan, mainly west of I-75. All counties currently under advisories can only expect only a general 2-4" for most locations through 00Z tonight due to daytime heating over land creating a unstable environment and turning LES bands more cellular. However; better fetch, orographic lift, and stronger low level directional shear over the classic "big five" of northern lower (Charlevoix, Kalkaska, Otsego, Crawford, and Antrim) will see localized higher totals of 6- 8"+.

Northern parts of the UP will receive the highest QPF across the CWA as favorable fetch across lake superior delivers higher snowfall totals. Expect widespread amounts of 1-3" across the majority of eastern upper while areas near and north of M-28 has medium to high probabilities (40-70%) of 4-8" and localized amounts of over 10" near and north of Sault Ste. Marie

Tonight...Winds will decouple right after sunset for a few hours then start to veer, shifting snowbands and highest snow totals slightly southwest compared to today. By 12z Sunday, radar will appear to have returned to classic NNW milti-banded LES. Widespread additional amounts of 1-3" of 18:1 snowfall can be expected across most of the snowbelts while localized areas of Antrim and Kalkaska county of 2-4"+ by Sunday morning. Most widespread noticeable/impactful weather overnight will be the continued cold temperatures as overnight lows in the single digits.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 307 AM EST Sat Dec 13 2025

Sunday and Monday...Previously mentioned shortwave troughing will be positioned over eastern Lake Huron Sunday. Persistent breezy NW winds will continue the typical par-of-the-course lake effect snow. Dry low to mid level atmospheric conditions and weaker low level winds will lead to lower QPF totals. Most accumulations of roughly an inch or less is expected for the typical snow belts of northern lower and eastern upper. Another embedded shortwave develops lee of the Canadian Rockies and progresses to southern Ontario this Monday. Highest synoptic-driven snowfall favors the northern parts of the CWA with low to medium probabilities (30-50%) of a general 2-4" near and north of the bridge. Still too early to give a more definitive forecast, but another widespread round of snow with a quick shot of LES is expected this Monday through Monday night.

Tuesday and Wednesday...Longwave troughing pattern over the northern CONUS and Canada will begin to progress northward, raising midlevel heights across the Great Lakes region and creating more of a zonal flow pattern. This will support high pressure to build from the south and return some overdue mild and quiet weather. At the surface, little to no precip is expected while temperatures build above freezing with highs in the upper 30s to low 40s.

Thursday and Friday Outlook...Long range ensemble guidance depicts another trough digging across the midwest around the Thursday timeframe. Current trends show a lack of southerly moisture advection, hinting at low amounts of QPF. Most of the impacts and potential concern remains from warm air advection reintroducing multiple precipitation types. Most likely outcome will be rainfall Thursday then transitioning to light snowfall as soon as post frontal CAA moves into the CWA.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1133 AM EST Sat Dec 13 2025

Lake effect SHSN continue throughout the forecast period. Most of the heavier activity will continue to avoid much of the TAF sites, with the exception of MBL, which will continue to see instances of IFR CIGs throughout the afternoon. Most sites otherwise hold MVFR to VFR with occasional dips to IFR during any snow shower passages. Gusty WNW winds shift NNW to N through the night, with better chances of heavier snow showers at the TAF sites. This should carry into Sunday morning, perhaps tapering some as we head into the afternoon.

APX WATCHES/WARNINGS/ADVISORIES

MI...Winter Weather Advisory until 7 AM EST Sunday for MIZ016-017- 020>022-025>028-031-032-099. Winter Storm Warning until midnight EST tonight for MIZ086-087. MARINE...Small Craft Advisory until 1 PM EST Sunday for LHZ345>349. Small Craft Advisory until 11 AM EST Sunday for LMZ323-341-342- 344>346. Small Craft Advisory until 7 PM EST this evening for LSZ321- 322.