textproduct: Gaylord

KEY MESSAGES

- Flooding concerns through at least midweek, particularly across eastern upper and far northern lower Michigan where snowpack meltoff may agitate already elevated water levels.

- Rain and thunder, heavy at times, to continue overspreading the region into the morning and lasting through tonight.

- Another round of showers and thunderstorms Monday night into Tuesday. Heavy rain possible again. Potential for severe thunderstorms later Monday night and again Tuesday.

- Above normal temperatures through the week, trending back below normal next weekend.

DISCUSSION

Issued at 228 AM EDT Sun Apr 12 2026

Pattern Synopsis:

Transition to an active pattern well underway across northern lower and eastern upper Michigan. Longwave troughing is settling into place across the western CONUS, with an amplifying ridge building across the eastern seaboard. Core of the ridge will generally be in the FL/GA vicinity, and resulting anticyclonic flow (SE to S flow over the Gulf) will allow for deep moisture advection to surge from the southern plains all the way to northern Michigan along an active southern stream jet. This setup will carry numerous Pacific borne shortwaves ejecting from the intermountain west and force them into the Great Lakes... bringing a prolonged period of warmer temperatures but at the cost of a very wet period of weather across the region.

Details:

Rest of Tonight - Today / Sunday

00z RAOB hinted at the transition to active weather despite sunny skies at launch time... well mixed dry layer in the low levels beneath a strengthening warm and moist intrusion aloft... and those distant clouds to the west have now overspread the region. Still quite a bit of dry air to fight through, but pockets of elevated instability have led to a few blossoming convective showers across the straits and south of M-55. Strengthening low level jet influence should continue to drive convective processes over Wisconsin and to the south, with minimal elevated instability to be had likely limiting any thunder potential to a few rumbles, largely favoring west of I-75 and eastern upper. Nonetheless, once the atmosphere saturates, anticipating a period of very efficient stratiform rainfall as precipitable water values swell to 1.00 - 1.25" (representing a 4 sigma anomaly to climatological norm) early this morning through the rest of today. With elevated instability poking into the region tomorrow, possible to see more thunderstorm activity across the region, though severe weather is not anticipated. Bigger story of course will be the rainfall with the ongoing erosion of our snowpack. Current trends keep rainfall over an inch to a more localized extent north of M-32 and into eastern upper thru this evening... whereas better convective elements look to permit rainfalls of 1.00 - 2.50" along / south of M-32.

This Evening - Monday Morning:

Concerns are mounting regarding the strengthening of the low level jet (LLJ) later this evening into tonight. This will drive another round of elevated instability across the region... but will likely split into two distinct impact areas: one in the Straits and one generally south of M-32. Stable layer at the surface should be somewhat disturbed across the rest of the area, which will likely only permit occasional rounds of stratiform rain. But in the two aforementioned areas, convection may be a bit more robust (with potential for echo training) for differing reasons.

Anticipating a zone of elevated instability to really get going this evening into early tonight across Lake Michigan, aided by very stable marine layer airmass beneath the overriding warm intrusion. This will allow for lapse rates to steepen considerably into the evening, and some Convective Allowing Models (CAMs) are hinting at convective initiation off Green Bay riding the prevailing flow into the Straits (including the Cheboygan River Basin). Worst case scenario from CAMs depicts instability of 600 to 1000 J/kg permitting repeated thunderstorm activity across this very sensitive region... with the ceiling for rainfall being an additional 1.00 - 2.50" of rain (which is believable if PWATs near 1.00" can hold as guidance depicts). Obviously still some time to sort this out, but this trend needs to be monitored closely as this amount of rainfall in such a short time may be extremely detrimental to the ongoing situation across the Cheboygan River Basin. Convection is fickle, and the location(s) of heaviest rainfall / greatest impacts are certainly subject to change.

Secondary area of convection also poses some question. A surface cold frontal boundary set to clear the region later overnight, LLJ processes may drive another area of convection that generally impacts an area along / south of a Manistee to Alpena line... perhaps confined to M-55 and south. Those favorable aforementioned parameters will be overhead in this corridor too... but this feature may be a touch more transient... so in this corridor, anticipating a ceiling of an additional 0.75 to 1.50 inches of rain through Monday morning.

We finally catch a break between waves by Monday... and with spring- like warmth building... highs in the Yoop 50 to 55, and 60 to 70 across northern lower. Peeks of sun likely build through the day.

This break will be short-lived... another wave is set to drive another round of convection over Wisconsin that will spread into the region Monday night through Tuesday. This particular feature will bring ample shear and instability to the region... moreso than the initial round of convection today, and will drive a severe thunderstorm threat too. Initial elevated nature of storms Monday night will limit hazards to hail and wind. Will have to see how well this airmass recovers into the day on Tuesday. A stationary front will dictate the difference between moist, unstable air to the south, and colder stable air to the north. Any daytime severe convection will likely lie south of this frontal boundary... which... if pattern recognition has anything to say about this... suggests the very southern edge of the CWA would pose the greatest risk for severe storms during the day Tuesday... likely moreso the farther downstate one goes in lower Michigan. Not to be lost in all of this... we will be staring down potential for another round of heavy rain from this feature... with an additional 1 to 2 inches of rainfall not entirely out of the question. For those wanting a break from this pattern, the news is bleak. Additional waves of precipitation are set to carry across the region through the rest of the week into next weekend. Certainly a wet start to Spring across the Northwoods.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 1123 PM EDT Sat Apr 11 2026

An increasingly lower cloud deck will spread from southwest to northeast across the area this morning. Transition to MVFR and potentially IFR cigs expected this morning, with these lower cigs continuing through the afternoon as well. Some gradual improvement expected this evening. Showers and areas of mist will accompany this lower cloud deck, with some brief periods of heavier showers possible. May also hear a rumble of thunder or two today, but nothing significant anticipated at this time. Light winds will become increasingly gusty out of the southeast and south today, becoming more southwest this evening. Despite these gusty winds, a very strong low level jet will produce widespread low level wind shear today into early this evening.

APX WATCHES/WARNINGS/ADVISORIES

MI...Flood Watch through Wednesday morning for MIZ016>018-086>088- 095-096. MARINE...Gale Watch from this afternoon through late tonight for LHZ345. Small Craft Advisory until 11 AM EDT Monday for LHZ346>349. Gale Watch from this afternoon through late tonight for LMZ323- 341-342-344>346. Small Craft Advisory until 11 AM EDT Monday for LSZ321-322.