textproduct: Gaylord

KEY MESSAGES

- Times of light to moderate rain will linger through Monday.

- Medium to high confidence (75% chance) for widespread 0.5 to 1" of rain over northern lower by Monday evening with a swath of 1 to 2" near and south of M-72.

- Unsettled pattern continues chances for rain through the work week.

DISCUSSION

Issued at 127 AM EDT Sun Aug 30 2026

Current radar and satellite depict widespread stratiform rain with a band of moderate rain at the northern most tip of a LLJ reaching into northern MI. Surface rain guage reports show at most one to two tenths under this more moderate precipitation. Deep moisture is present over the western Great Lakes region, thanks to a plume of Pacific moisture streaming into the northern Plains over the Rockies and a more shallow and narrow Gulf tap moving over the central plains (towards WI). In the upper levels, a positively tilted upper trough over the Pac NW bottoms out over the SoCal coast. This feature has broken a larger upper ridge down and moved it over the central Rockies and plains. A focused jet over WY/MT has initiated a few lee side lows over the Dakotas (which has driven the shallow Gulf moisture transport towards the northern plains). As another lee side low spins over SD this morning, the surface warm front remains draped over southern MN and WI with a weak extent into the southern L.P. of MI. The warm sector aloft is reaching farther north, and hints of this is seen with blossoming showers over central MI (proven by the presence of elevated instability within the LLJ). The surface cyclone will weaken and drift to the east today. As temperatures south of the warm front rise this afternoon, a 10F degree temp gradient at the surface should set up between the northern and southern L.P. with the actual boundary resting somewhere near M-55. As elevated instability lingers and lower level convergence forms today, quasi- zonal flow aloft will track waves of showers and rain bands from west to east. Soundings depict warm rain processes with WCD of 15 kft possible.

As the moist airmass continues tonight, the LLJ will strengthen and refocus. By this time, the upper closed low will be slowly tracking across the international border (near MT). A stronger jet over MT/WY will help initiate another surface low over SD/MN. Guidance keeps this farther north than the previous, which should keep the LLJ pointed towards northern MI. Another band of moderate rain will track across northern MI late this evening. The main difference will be a more defined presence of the warm front draped over northern MI from west to east. A couple hundred J/kg of elevated instability will be present (especially farther west), however more moderate rain will have an easier time forming along the frontal boundary. Off and on light to moderate rain will continue into early Monday morning with pockets of more steady moderate rain due to training along the forcing mechanism (front). Low chances for thunder due to the lower instability present.

Shower chances will shift to the north during the day on Monday as the upper closed low lifts into CAN and drags a trailing cold front with it over the U.P. Drier conditions and a brief reduction in temperatures will be seen Tuesday. The warm sector quickly returns early Wednesday ahead of another system moving across the northern plains. This keeps temperatures above normal and rain chances in the forecast for the end of the work week.

Expected Rain Amounts: Widespread half of an inch to an inch is expected over northern lower by late Monday, with a swath of 1 to 2" along and south of M- 72. Locally higher amounts will be possible where moderate rain can train over this 36 hour window. There is moderate to high confidence (75%) in the bands of moderate rain producing 1 to 2" due to the deep moisture present and thus warm rain processes, as well as the forcing features (nose of the LLJ and along the warm frontal boundary). Most CAMs do not overlap these forcing features for long periods of time, however an outlier or two does (and the resulting rain amounts are very high). Those very high amounts are not a likely outcome due to the movement and shifts of the forcing features.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 658 AM EDT Sun Aug 30 2026

Periods of showers will continue thru the TAF period, especially for the northern lower MI sites. An isolated TSRA is possible, but the chance is too small to include in any of the TAFs at this time. CIU has had variable conditions early this morning, but we expect low-end MVFR to prevail there for much of today. PLN has recently lowered to MVFR, and should tend to stay there today. The other sites have stayed VFR, but TVC/APN should both become MVFR this morning. MBL largely stays VFR. Late tonight, fog/stratus should result in IFR conditions at CIU/PLN/APN.

Light se to s winds.

HYDROLOGY

Issued at 127 AM EDT Sun Aug 30 2026

Soils over NW lower and eastern upper are fairly dry, with 6 hr FFG of at least 3". Pockets of lower FFG exist in NE lower due to recent rains, specifically Alpena, Preque Isle, Ogemaw, and Iosco counties. The 6 hr FFGs are closer to 1.5" here. Due to this, some spots over the aformentioned counties could be more susceptible to run off and thus collection of water in low spots/hilly terrain along with, minor ponding on roadways, and quick rises in creeks. With the forecast in mind, the areas adjacent to Saginaw Bay are the most at risk for seeing these minor flooding impacts; as this is where the lower FFGs exists and higher rainfall amounts are expected (swath of 1-2"). Due to the more gradual nature of rain over 36 hours, flooding impacts are expected to remain minor. None of the forecasted river gauges show significant rises, including the HEFS probabilistic outlooks. The Manistee at Sherman is the only river gauge that shows a 5 to 10% chance of touching Action Stage, with the Rifle showing a 5 to 10% chance of approaching Action Stage.

APX WATCHES/WARNINGS/ADVISORIES

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