textproduct: Gaylord

KEY MESSAGES

- Yet another early spring mixed precipitation event for northern Michigan today.

- Colder air arrives Monday with a return to lake effect showers.

- Next round of precipitation arrives during the latter half of the week (more precip type issues??).

DISCUSSION

Issued at 311 AM EDT Sat Apr 4 2026

Pattern Synopsis/Forecast: Split flow across central North America...with a zonal northern branch across Canada and a southern branch short wave trough over the northern/central Plains. Flow consolidates over eastern Canada...with an upstream trough over the Pacific between Alaska and Hawaii with some small scale Rex blocking over Alaska which will have some downstream impacts for us next week. Short wave ridging was crossing the upper Lakes Friday evening with 100+m/12h height rises ahead of the Plains system. Return flow ahead of the short wave trough pulling deep layer moisture northward into the Midwest along with modestly steep mid level lapse rates (6- 7C/km). Tight low level thermal gradient across Wisconsin/Michigan this evening...850mb temperatures around +12C across southern Wisconsin/southern Lower... and below zero across the Lake Superior basin along a sharp deformation axis. 0200Z surface analysis shows a 1008mb surface low over far southern Iowa...tracking east-northeast toward a 2-3mb/3h pressure rise center to its northeast. Warm front extends east into central Illinois/Indiana/northern Ohio. 1035mb high west of James Bay providing northeast boundary layer flow into Michigan early this morning.

Plains short wave trough/compact low will be the initial feature of interest as it propagates across the upper Lakes tonight into the first part of Sunday. Small blocking high north of Alaska forecast to bridge with building ridge into western Canada...which will send some late season arctic air into Michigan for the first part of next week (it being April not January looking at 500mb heights around 540dam as opposed to sub-500dam winter cold air outbreak). Temperatures should moderate midweek accompanied by a short wave trough passage in the Thursday time frame.

System dynamics and surface tendency diagnostics suggest Iowa surface low will track probably a bit farther north/ west than Thursday's system; from the Wisconsin/Illinois border this morning...up Lake Michigan and into eastern Upper/eastern Lake Superior while occluding tonight. Colder cyclonic flow develops in its wake for the upper Lakes Easter Sunday...followed by a secondary short wave trough/reinforcing cold push for Monday associated with continental Arctic air mass trajectory. Looking at high pressure crossing the state Tuesday...then milder southerly winds for Wednesday ahead of next surface low which looks to push a cold front across Michigan around Thursday.

Primary Forecast Concerns:

Yet another early spring mixed precipitation event for northern Michigan today: Precipitation coverage has been expanding across Wisconsin toward Lake Michigan early this morning as strong low level moisture flux gets pulled up the warm frontal zone...helped by some right entrance region jet forcing with a 110kt jet streak across northeast Ontario...frontogenetic forcing as a result of the aforementioned deformation axis across northern Wisconsin/Upper Michigan...and elevated instability and resultant convection with 500-1000J/kg MUCAPE across southern Wisconsin/southern Lake Michigan. 0000Z APX sounding had a dry elevated warm nose around 6K feet deep above 850mb...so some room for evaporative cooling but warm advection definitely ongoing over southwest Lower. Still expecting precipitation to blossom across the forecast area during the pre-dawn hours with +3 sigma precipitable water anomalies getting drawn into northern Lower. Precipitation coverage should be widespread through midday...then with drier air impinging from the west things should taper off from west to east (drizzle/fog) though won't rule out some scattered showers trying to develop along the leading edge of the dry slot. As for precipitation type...the issue once again will be freezing rain with plenty of warm air aloft. As of 0700Z temperatures were mostly in the mid 30s with only KGLR/KMCD at 32F...with some initial glazing ongoing outside the window. Best chance for temperatures to drop to or a degree below 32F remains across eastern Upper and the higher terrain of northern Lower north of the M-72 corridor. Current thinking is temperatures across northern Lower should warm above freezing by midday (expecting to see 40s across northern Lower this afternoon with some 50+ highs along/south of M-72)...with parts of Chippewa county probably hanging on to near freezing temperatures into early afternoon. Do not see a need to make any changes to the ongoing northern Lower Winter Weather Advisories/eastern Upper Ice Storm Warning...now is just time to let things play out.

Colder air arrives Monday with a return to lake effect showers: Should be at a minimum some instabilty snow/rain showers for Easter Sunday; not sure why the NBM is so reticent to add PoPs to the forecast especially Sunday night with the passage of some decent looking short wave troughs (and Monday for that matter) so have taken matters into my own hands (I am going to miss the SREF PoPs once they go away in the near future). Cold front ushering in an early spring arctic air mass will drop into the state at some point Monday...if early enough could see temperatures falling into the 20s during the afternoon. 850mb temperatures dropping into the teens below zero will set up lake effect snow showers by Monday night and into Tuesday morning...just in case we were missing it.

Next round of precipitation arrives during the latter half of the week (more precip type issues??): Warm air returns Wednesday...but of course along with it will be another period of precipitation. As of now this event will involve another precipitation transitions but this time it looks like more just a snow to rain event with the driving surface low expected to be well to the north (avoiding boundary layer cold advection from the northeast and thus the freezing rain intermediary). Precipitation probabilities continue through the rest of the week but this is more likely due to model spread/uncertainty/hedging.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 644 AM EDT Sat Apr 4 2026

Occasional rain and freezing rain continue today, and cigs/vsbys will tend to worsen. FZRA will be seen at CIU into mid afternoon, PLN until near noon, before becoming rain. Lowest cigs/vsbys will likely be this afternoon/evening, near a passing cold front, with LIFR at times at most spots. Conditions improve to IFR and MVFR with time tonight.

Gusty se winds this morning. Gust sw, w, and nw winds late today and tonight. LLWS early today MBL/TVC.

APX WATCHES/WARNINGS/ADVISORIES

MI...Winter Weather Advisory until 2 PM EDT this afternoon for MIZ016>018-021>024-097>099. Winter Weather Advisory until 11 AM EDT this morning for MIZ027>030. Ice Storm Warning until 5 PM EDT this afternoon for MIZ086>088- 095-096. MARINE...Small Craft Advisory until 8 PM EDT Sunday for LHZ345>349. Small Craft Advisory until 8 PM EDT Sunday for LMZ323-341-342- 344>346. Small Craft Advisory until 8 PM EDT Sunday for LSZ321-322.