textproduct: Gaylord

KEY MESSAGES

- Early spring storm system to impact the Great Lakes Wednesday night/Thursday with myriad potential hazards.

- Another round of (wintry) precipitation for Saturday.

- Turning cooler for Easter Sunday.

DISCUSSION

Issued at 341 PM EDT Tue Mar 31 2026

Pattern Synopsis/Forecast: Zonal flow pattern starting to show signs of buckling a bit: split flow over the eastern Pacific with a compact upper low over the Gulf of Alaska and a positive tilt short wave trough west of California. Short wave trough crossing the southern Prairie provinces...with downstream troughing over Atlantic Canada. 130+kt northern branch jet streak across Ontario/Quebec... tight thermal gradient from northern Wisconsin/Upper Michigan northward with a low level thermal ridge extending from the central Plains into the Great Lakes. Already a broad area of 1+ inch precipitable water values across the eastern half of the CONUS. At the surface...strung out series of frontal waves along a stationary boundary extending from the lower Lakes west across southern Wisconsin/northern Iowa/southeast Nebraska. Broad high pressure over the western Atlantic feeding moisture from the Gulf northward into the frontal boundary with 50s dew points into southern Lower Michigan. On the opposite end of the spectrum cold high pressure extends across most of central/eastern Canada...broken up only by an inverted trough across Manitoba/Minnesota as a surface reflection of the passing short wave trough riding along the Canadian border.

This short wave will cross the upper Lakes tonight...while short wave trough west of California will get kicked east by digging Gulf of Alaska upper low. This trough expected to cross the central/ southern Plains Thursday...and through the Great Lakes Friday. This will be followed by the kicker low...expected to track from the Pacific Northwest/northern Great Basin Thursday...across the northern/central Plains Friday...and the upper Midwest/Great Lakes during the weekend. Potential for another reinforcing short wave trough in the Tuesday time frame.

Frontal boundary across southern Lower expected to remain there into tonight with a frontal wave or two rippling along it. High pressure to the north then nudges the front into the Ohio Valley with a reinforcing push of colder northeast boundary layer flow for Wednesday. Attention then turns to incipient lee cyclogenesis in the central/southern High Plains...the evolution of which will have big implications on Thursday/Friday weather impacts. Current trends suggest initial low will spin up over southeast Colorado late Wednesday...track toward MCI-OMA vicinity Thursday morning...then likely across the upper Lakes Friday (perhaps across eastern Upper). The northern extent of the storm track will be resisted by a 1036+mb high over northern Ontario/Quebec...which is actually quite anomalous for early April. The main concern is that this high gives way sufficiently to allow the low to propagate into the colder air. System dynamics and surface tendency QG diagnostics suggest a track across northern Michigan is quite reasonable provided the low level stability issues can be overcome. Another Colorado/western Kansas low is expected to spin up Thursday night...and follow a similar (perhaps slightly farther south) track across Lower Michigan Saturday. Colder northwest boundary layer winds set in for Easter Sunday.

Primary Forecast Concerns:

Early spring storm system to impact the Great Lakes Wednesday night/Thursday with myriad potential hazards: Impressive deep layer moisture surge expected to get pulled across east-west baroclinic zone Wednesday night into Thursday; precipitable water values across northern Lower ~1.25"/+3 sigma standardized anomaly. Precipitation shield will spread southwest to northeast across the forecast area probably starting close to midnight Thursday...as the moisture flux is worked on by isentropic ascent/increasing frontogenetic forcing/right jet entrance region forcing. Pronounced elevated warm nose also expected to develop up the warm frontal zone...and with easterly winds reinforcing a colder (and drier) boundary layer setting up a pretty good freezing rain scenario over a good part of northern Lower especially along/east of US-131. The exception may be the Tip of the Mitt counties where precipitation arrives late and more likely as the frozen type (snow/sleet) before transitioning to freezing rain. How impactful icing gets will depend on 1) If the entrenched sub-freezing surface air can be overcome during the day and 2) If there is a break in the precipitation ahead of the cold front passage (QPF reduction). Will trend the forecast such that higher terrain areas along with northeast Lower will remain at or below freezing through Thursday morning before warming above freezing during the afternoon. Cold frontal rain band (likely with convection) swings through the forecast area Thursday night likely followed by dry slotting.

Meanwhile across eastern Upper and the Straits region more likely that precipitation arrives as snow/sleet early Thursday morning... then with the warm nose lifting into the Upper Peninsula expect a transition to more of a freezing rain set up with surface temperatures likely to remain below freezing through the afternoon (am less confident about temperatures warming above freezing north of the bridge until perhaps Thursday evening but that is dependent on storm track). Winds will be gusty from the east as well...on the order of 30+mph. Not sure how readily this snow will blow around but it won't hurt the cause.

Forecast snow and ice totals don't quite reach what would be warning criteria. However will be issuing Winter Storm Watches for eastern Upper and far northern Lower for the following reasons: 1) Eastern Upper will likely see wintry precipitation through the day (frozen to freezing)...so a combination of cement mixer consistency snow and some ice on top of that will be impactful from a travel standpoint...along with gusty east winds. 2) The northern Lower counties are the ones that I'm most concerned about the cold air hanging on longer during the day Thursday and could be more problematic. 3) And my favorite: there is nothing wrong with going from a watch to a high-end advisory. Watches are not pre-warnings; we can go deeper with this if surface temperature trends become more problematic...or we can back out (I'm certain no one will be upset with only getting a minimal amount of icing given recent history). The proposed watch from WPC extended all the way down the US-131 and I-75 corridors into central Lower but didn't want to go that far given the assumption that it is more likely that freezing precip will be more transient farther south. Wanted to hit the areas that could be more problematic. Northern Lower watch will run from 0600Z- 2100Z Thursday...Eastern Upper from 0900Z Thursday-0000Z Friday.

Another round of (wintry) precipitation for Saturday: As mentioned above next system that arrives Saturday will take a similar track to Thursday's storm...which also brings up the potential for another round of a mix of precipitation types for Friday night into Saturday...again with the likelihood of a transition to all rain at some point Saturday (provided surface temperatures behaves mainly north of the Bridge).

Turning cooler for Easter Sunday: Brisk/cold northwest winds settle across the Great Lakes in the wake of Saturday's system...which will pull cold air back across the Great Lakes for Easter. Some wraparound moisture and/or some instability rain/snow showers also in the offing.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1256 PM EDT Tue Mar 31 2026

Showers and embedded thunderstorms will work across much of northern MI this afternoon into early evening with CIGs largely varying from IFR to MVFR. Best chances for any embedded storms will be across northern lower Michigan where a strong storm or two cannot be ruled out. Flight conditions are expected to improve back to MVFR area-wide later this evening/tonight with increasing probabilities for VFR during the day Wednesday.

APX WATCHES/WARNINGS/ADVISORIES

MI...Winter Storm Watch from late Wednesday night through Thursday afternoon for MIZ016>018-022>024-098-099. Winter Storm Watch from late Wednesday night through Thursday evening for MIZ086>088-095>097. MARINE...Small Craft Advisory until 8 PM EDT this evening for LHZ348.