textproduct: Grand Rapids

KEY MESSAGES

- Increasing clouds tonight

- Strong/severe storms Tuesday night, freezing rain north

- Cooler with snow/rain midweek on

DISCUSSION

Issued at 235 PM EDT Mon Mar 9 2026

- Increasing clouds tonight

Satellite imagery shows mostly clear skies over southwest Lower, but changes are looming to the south. Latest visible loop shows an area of stratus over southern IL/IN moving north. MOS guidance and RH profiles indicates these low clouds will advect north across the cwa tonight. Drizzle is possible too given the omega seen in the cloud layer.

- Strong/severe storms Tuesday night, freezing rain north

Models remain in decent agreement regarding a potential severe weather event Tuesday night. Somewhat similar to a few days ago, a warm front will move north in response to strengthening low pressure over the Missouri Valley. This warm front will be the focal point to strong to severe storms Tuesday night across the cwa. Dynamics are fairly strong with bulk shear around 50 kts and SBCAPE 1500 j/kg along the I-94 corridor. The models are suggesting that the warm front won't get much farther than a Allegan to Lansing line. If that's the case, then the strongest storms would be in this surface based environment. RRFS-EMC and HREF guidance shows the strongest updraft helicity along the I-94 corridor. All modes of severe storms appear possible within the corridor: tornadoes, large hail and strong winds. North of that boundary, the storms will be elevated...suggesting that hail would be the main threat. MUCAPE climbs to around 2500 j/kg along the I-96/M-57 corridors. SPC has continued the slight risk along/south of I-96.

Timing wise, guidance points toward storm development commencing around 00z and continuing overnight.

The storms will move east of the cwa Wednesday morning once the low moves by and northwest winds advect colder air into the cwa.

Temperatures will be cold enough along the US-10 corridor east of Baldwin for some freezing rain to develop Tuesday night. Perhaps a few hundredths of an inch of ice are possible by Wednesday morning.

- Cooler with snow/rain midweek on

Colder air Wednesday will result in some light snow across the northern cwa; accumulations will be an inch or less.

A clipper system will move across the region Thursday night and Friday bringing mixed rain and snow and another system Saturday night and sunday will be stronger and colder and potentially bring some freezing rain, snow, and rain to the cwa; winter isn't done yet!

Highs will mainly be in the 40s from midweek through the weekend before falling into the 30s early next week.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 733 PM EDT Mon Mar 9 2026

We are starting off this forecast period with VFR conditions with just a few high clouds overhead. This will change quickly tonight with lower clouds and fog developing over the area from the south. This should start out at the I-94 terminals and KMKG as the better low level moisture comes in from the south, and from over Lake Michigan. We expect all sites to be IFR by 07z, and many sites could be flirting with VLIFR conditions for both ceilings and visibilities.

We will see a front drop through the terminals beginning around daybreak around KMKG and KGRR, and gradually later for southern terminals. This will switch the winds from the SW to NE. Conditions are expected to improve slightly with some diurnal heating on Tuesday afternoon. This means IFR instead of LIFR-VLIFR. A few rain showers will become possible after 22z. The heavier showers and storms will come after the end of this forecast period after 00z Wednesday.

HYDROLOGY

Issued at 235 PM EDT Mon Mar 9 2026

Another round of widespread rain is expected Tuesday night through Wednesday morning across the area. It's currently looking like the heaviest rain will fall along the I-94 corridor (1-1.5 inches, with locally more), with slightly lesser amounts along the I-96 corridor (0.5-1.0, with locally more), and incrementally less as you go north from there. With soils still quite wet, and rivers high, we're expecting a dual hydro threat from this next storm system. We very well could end up needing a few flood advisories, especially if storms track over any urban areas repeatedly. Meanwhile, for the 2nd half of the week, even 1.0 basin-averaged rain amounts will likely cause some minor river flooding, especially on some of the smaller rivers and streams like the Red Cedar at East Lansing, Maple River at Maple Rapids, and Portage River at Vicksburg. If the higher rain amounts occur, additional rivers will likely see minor flood conditions. Now is the time to prepare for renewed rising water levels, and have a plan to monitor and respond to river conditions.

GRR WATCHES/WARNINGS/ADVISORIES

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