textproduct: Grand Rapids

KEY MESSAGES

- Light rain possible today

- Cooler Thursday, lake shore rain/snow showers through Saturday

DISCUSSION

Issued at 206 PM EST Wed Nov 11 2026

- Light rain possible today/tonight

Water vapor imagery shows a short wave in western IL being nudged eastward by another short wave dropping south across northwest IA within a deepening upper trough. The IL short wave is producing light rain across the northern half of the cwa, with much more sparsely populated echos south of I-96. A wider radar view shows more showers/storms moving across northern IL. Model trends point toward the IL thunder remaining south of the cwa. All of the precipitation tonight will be light rain.

- Cooler Thursday, lake shore rain/snow showers through Saturday

The IA short wave will drag down colder air tomorrow as it pivots through the upper trough. H8 temperatures near +2c today will fall to -7c Thursday. The north flow that will be generated by the short wave will coupled with the cold advection will produce lake effect rain showers mostly over the lake, but clipping the lake shore too. While boundary layer air will be too warm for snow Thursday, that could change Thursday night as the temperature drops. If any snow does develop Thursday night, the lake shore north of Whitehall has the highest chance of seeing it. That area could potentially see a few tenths of an inch of snow. The bulk of the precipitation will be just west of the lake shore falling over the lake.

The upper trough will remain over the state through Saturday before beginning to lift northeastward. The colder air will remain too with h8 temps in the -6c to -8c range through the weekend. That will produce surface temperatures in the mid 40s for highs through Monday before the trough moves east and then ridging noses into the region. At that point highs will climb into the 50s early/mid week.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 657 PM EST Wed Nov 11 2026

Main change was to add detail to expected fuel alternate ceilings after 06Z. We carried VCSH rather extensively with episodic light rain being possible early tonight. Nonetheless, we estimate a 90 percent chance of VFR conditions prevailing at the terminals through 06Z.

Water vapor imagery shows a well defined vort max moving east across extreme southern Lake MI at this time. Broad mid-level deformation associated with this extends roughly from the Holland area to the Michigan thumb. Surface reports of light rain appear to be confined to along and east of US-127 associated with that broader deformation zone, however.

Over far southwest Lower MI, we are seeing respectable reflectivity aloft immediately downstream of the vort max, but no surface observations of rain. This may speak to a very dry sub-cloud layer in that vicinity, possibly being reinforced by northeasterly flow near the surface. Moistening is expected to occur overnight though, resulting in a gradual lowering of ceilings across the region overnight.

Some observation sites over far southwest Lower MI, including AZO/BTL, are rather gusty at the present time, but expect this to be short lived as the upper vort max passes east of the area.

GRR WATCHES/WARNINGS/ADVISORIES

MI...None. MARINE...Small Craft Advisory until 7 PM EST Friday for LMZ844>849.