textproduct: Gaylord

KEY MESSAGES

- Flooding concerns through the week as an active pattern consisting of numerous rain chances overlapped saturated soils and / or melting snowpack continues.

- A brief reprieve from rain through the day today with peeks of sun in the afternoon. Large temperature contrast with highs near 70 close to Saginaw Bay and in the 40s across parts of eastern upper.

- Another series of showers and thunderstorms tonight into Tuesday, and again Tuesday night. Downpours will accompany thunderstorms. Potential for severe thunderstorms later Monday night and again Tuesday night.

- Additional rounds of rain expected Wednesday into Thursday, and again Friday night into the weekend.

DISCUSSION

Issued at 238 AM EDT Mon Apr 13 2026

Pattern Synopsis:

Active pattern continues through the forecast period, with the setup remaining the same- longwave trough has established itself across the western CONUS, with ejecting Pacific waves riding southern stream flow from the southern Plains into the Great Lakes. Ridging anchored across the eastern seaboard continues to promote a deep moisture connection from the Gulf, which will allow for repeated rounds of rain / convection to impact northern Michigan through the week... which is only going to prolong the ongoing hydro / flooding situation ongoing across this region.

Details:

Our first big rain event from this pattern will continue to wind down as we head into the morning, with deeper saturation slowly shifting north and east with its attendant shortwave / mid-level mesolow. Most efficient rainfall will occur across a narrow corridor from roughly Cadillac to Alpena (up to an additional localized 0.50" of rainfall through the morning across the region). This corridor will be subject to additional flooding concerns (on top of the already ongoing hydrological situation) through much of the day tomorrow as streams undergo their hydrological responses. Rain should clear out by mid morning, with some peeks of sun building by later in the day. A frontal boundary stalled out across the region leads to temperature contrasts across the area... warm and humid (60s and 70s) south and 40s to near 50 in eastern upper for Monday.

The reprieve will be quite short lived as the next shortwave and low level jet (LLJ) intrusion draws in yet another moisture rich airmass to the region. Vigorous convection anticipated to develop over Minnesota and Wisconsin late this afternoon into the evening, with the stalled frontal boundary being the focus for the most intense activity. Plentiful instability and shear may be just enough to allow severe storms capable of producing large hail to materialize late this evening into tonight, on top of the heavy rain threat this will bring. The focus for severe storms and the heaviest rains likely favors areas south of M-32 at this juncture. In this area, it will be possible to observe an additional 1.50 to 3.00"+ of rainfall Monday night into Tuesday as echo training permits repeated downpours within an airmass constituted of PWATs exceeding 1.25. As such, will have to watch this area very closely... we already have dams with open gates on the Manistee (Tippy Dam) and Au Sable (Mio Dam) rivers... and most of these rivers are set to approach or have already exceeded their maximum heights as it is. Adding this rain on top of what is already occurring may create serious issues in areas that flood easily downstream of these dams in what looks to be the inevitable event that they will continue to release water. As far as the Cheboygan basin goes... additional rain is anticipated from this outburst there too... If current trends hold, most of that basin will endure 0.25 to 0.50 inches of rain... but the headwaters of the Sturgeon and Black River in Otsego and Montmorency counties may see a general 0.75 to 1.50"... all of which will quickly flow into the water-logged areas of the basin. Certainly a lot to monitor in the next 36 hours, with even more on the horizon.

Another wave is set to pass through Tuesday night along that stationary front, which will drive another vigorous convective response from the Quad Cities , IL / IA area north and east into Michigan. The northward extent of this response is in question... but in the event that the stalled front remains north enough to permit very warm surface temperatures in the southern portion of the CWA (drum up instability), we could be dealing with another outburst of heavy rain and severe thunderstorms over an area that doesn't need it. Perhaps another brief break in the action for Wednesday, but long term guidance wants to continue to initiate convection along that stalled frontal boundary Wednesday evening into Thursday with another LLJ intrusion. Should trend dry later Thursday into Friday... with more rain to follow on Saturday. With this, it should be stated that it will be entirely possible for us to be contending with hydro / flooding concerns over the next week, perhaps longer. This certainly could be a long stretch for northern Michigan.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 652 AM EDT Mon Apr 13 2026

Grungy out there this morning, with a mix of LIFR to MVFR conditions. Overnight rain is departing, though another round is expected tonight. Relatively little today. Cigs/vsbys will tend to improve thru the day today, with MVFR to VFR for the afternoon and early evening. Then SHRA return tonight with IFR/MVFR conditions returning. TS is mentioned for part of tonight at TVC/MBL.

Sw winds early will veer nw by afternoon. Winds become southerly again by late tonight.

APX WATCHES/WARNINGS/ADVISORIES

MI...Flood Watch through Wednesday morning for MIZ016>018-020>036- 041-042-086>088-095-096-099. MARINE...Small Craft Advisory until 11 AM EDT this morning for LHZ345>349. Small Craft Advisory until 11 AM EDT this morning for LMZ323- 341-342-344>346. Small Craft Advisory until 11 AM EDT this morning for LSZ321- 322.