textproduct: Gaylord

KEY MESSAGES

- A few showers and rumbles of thunder possible this afternoon and evening across the eastern U.P.

- Numerous showers and storms on Tuesday.

- Strong system with potentially heavy rainfall Wednesday night into Thursday.

- Cool temperatures persist into next week.

DISCUSSION

Issued at 1228 PM EDT Mon Jun 15 2026

Pattern Synopsis:

A closed mid/upper low will remain parked just south of Hudson Bay through most of this week with the jet draped across the northern CONUS. Shortwave troughing over the Ohio Valley will slide further east as more pronounced troughing digs into the Great Lakes Tuesday. Forcing provided aloft will support relatively weak pressure falls along an advancing cold front set to work across the area later Tuesday/Tuesday night. Ridging quickly slides overhead Wednesday ahead of a very impressive system for mid/late June barrels into the Great Lakes Wednesday night/Thursday. As discussed yesterday, heights from 700mb and below as well as MSLP are forecast to be deeper/lower than any values from the 1979-2009 Climate Forecast System Reanalysis (CFSR) climatology for a 3-week period centered on Thursday's date. Around 95 percent of all North American Ensemble Forecast System (NAEFS) members are forecasting these extreme values as well. This combination speaks to both how rare a cyclone near 990mb is for the Great Lakes heading into late June -- likely a once- in-several-decade system -- and that there is high confidence in a system of this magnitude materializing several days out.

Forecast Details:

A few showers and perhaps rumbles of thunder are possible later this afternoon and evening across the eastern U.P. and near the Straits. Otherwise, dry conditions are anticipated across the area through tonight. Rain chances quickly ramp up across the area on Tuesday, especially late Tuesday morning and afternoon as numerous showers/storms are anticipated. Pockets of several hundred J/kg MLCAPE will be possible between cells/more dense cloud cover during the afternoon, potentially support a few strong storms capable of producing gusty winds and hail. Overall, though, severe weather is not expected at this time. Localized areas that are targeted by multiple rounds of showers/storms Tuesday may see rainfall amounts around 0.5" or greater.

Rain chances end Tuesday night into Wednesday before focus quickly shifts to the aforementioned strong system set to track across the region late Wednesday into Thursday. While most potential higher-end impacts will likely focus south of the CWA, steady rainfall over a 12+ hour period could bring amounts in excess of 1" to portions of northern lower Michigan by Thursday morning. Gusty east winds will also be possible overnight Wednesday before switching to west/northwest winds behind the system on Thursday. Temperatures will also likely be noticeably cooler on Thursday as highs may struggle to warm into the low to mid 60s with lingering showers and cloud cover. Temperatures look to remain a few degrees below average for the bulk of the next 7 days as we head into late June.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1242 PM EDT Mon Jun 15 2026

VFR conditions persist through the issuance period. VCSH around KCIU mainly later this evening around 20z lasting until around 00z, noting a possible scattered shower or two wanting to pass over the terminal as showers skirt across eastern Upper. Chances for showers/storms redevelop with greater chances of precip. moving west to east through the day beginning around 12z across KTVC, KMBL, and KPLN, with greater chances for showers/storms across KAPN later in the afternoon/evening around 18Z. West winds turn southwest through the day with gusts 15-20 knots possible, becoming lighter and south- southwest tonight. Winds look to increase once again ~12z, especially KTVC and KMBL with redeveloping gusts 10-20 knots.

APX WATCHES/WARNINGS/ADVISORIES

MI...None. MARINE...None.