textproduct: Grand Rapids

KEY MESSAGES

- Dry Through Tuesday Morning, Windy Sunday Afternoon

- Showers and Thunderstorms Tuesday, Strong to Severe Storms Possible

- Several Chances For Wintry Precipitation Through End Of The Week

DISCUSSION

Issued at 151 PM EDT Sun Mar 8 2026

- Dry Through Tuesday Morning, Windy Sunday Afternoon

High pressure and a zonal upper-level pattern dominate the forecast for the next 36 to 48 hours. Combined with a dry airmass across the region, partly to mostly sunny skies are expected today and Monday. An increased pressure gradient as a result of an Ontario Low and Southwest winds are likely to gust in the 40-45 mph range north of a Holland to Lansing line this afternoon, just shy of advisory criteria. Highs Monday will be in the 60s, with some areas Tuesday potentially seeing the low 70s.

- Showers and Thunderstorms Tuesday, Strong to Severe Storms Possible

The start of our active pattern arrives Tuesday with the arrival of a low pressure system into the upper Mississippi Valley. Southerly flow ahead of this system in conjunction with northeasterly flow associated with an Ontario High will set up a warm front across the area. There is a conditional risk of severe thunderstorms Tuesday Evening/Night dependent on where this front sets up.

The primary failure mode for severe weather (what would prevent severe storms from developing) is a lack of instability. Some CAM guidance suggests that morning showers could hold the front south, limiting our severe weather threat. If the warm front pushes north into the state, areas near and south of the front will have the potential to see severe storms. Given the very potent kinematic environment (0-3km shear in excess of 40 knots), and the potential for a nearby warm frontal boundary, any surface based storms could produce large hail, damaging winds, and tornadoes. However, given the potential failure mode noted before, it is unclear whether surface based instability will be present by the time storms develop. The best chance for severe weather is across our southwest forecast area, towards I-94 near west of I-69. The SPC currently has a marginal risk of severe thunderstorms as far north as I-96 accounting for both uncertainty in frontal placement, and the potential for elevated storms to produce hail just north of wherever the front sets up. This system will be closely monitored over the coming days as the latest forecast trends become clear. The forecast location of the front and extent of the warm sector are likely to shift over the coming days.

The other concern is heavy rainfall. Mean wind parallel to the warm frontal boundary suggests the potential for training storms. A scenario that is suggested in some of the experimental CAM guidance that extends to that timeframe. If training storms occur, isolated rainfall totals of 1.5-3 inches are possible.

- Several Chances For Wintry Precipitation Through End Of The Week

This system will see colder air filter in on the back side as a northern stream wave arrives Wednesday Morning. Most likely, this will occur as rain mixing with and potentially transitioning to snow before ending Thursday. A low chance (10%) of a wintry mix exists across the higher terrain areas of Central Lower Michigan as this transition occurs.

We then see another clipper arrive for the Thursday Night into Friday. The thermodynamic environment for snow is pretty marginal with 850mb temps near zero and surface temps shifting to either side of the freezing line. Going with a prevailing forecast of a rain/snow mix.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 751 PM EDT Sun Mar 8 2026

VFR is expected tonight and Monday with clouds mostly above 12,000 feet. 30 to 40 knots of LLWS between 2,000 feet and ground will likely be occurring throughout tonight until a little after sunrise Monday.

GRR WATCHES/WARNINGS/ADVISORIES

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