Severe threat increases as temperatures warm and storms develop

Posted at 5:40 PM, May 15, 2019
and last updated 2019-05-16 12:06:15-04

WEST MICHIGAN -- We've all been waiting for the warmer temperatures this time of year, but with the increased numbers come more heat and energy in the atmosphere and the threat of strong to severe thunderstorms. Thursday afternoon/evening/night pose a threat for strong to severe storms...and to a lesser degree on Friday. Our primary threats would be large hail and damaging straight line winds, but as a couple fronts approach, an isolated tornado can't be ruled out with a turning motion in the atmosphere.

Below is a snapshot from our forecast model valid for 6 P.M. Thursday. With the red line (warm front) over the area, we may begin to see some thunderstorms form in the late afternoon.

The next forecast model snapshot (below) is valid for 6 A.M. Friday. A cold front (blue line) is cutting through area. That too, may trigger showers and thunderstorms..perhaps more than what our model is showing. Some of these may also be strong to severe.

The last snapshot below is valid for 6 P.M. Friday. Note the chance of more showers on Friday north of these fronts.

The next two slides are from severe weather meteorologists at the Storm Prediction Center. The severe outlook below is valid for Thursday. The area in yellow is a SLIGHT RISK of severe weather just south/west of Grand Rapids on Thursday/Thursday night. The primary threats would be hail and wind, but an isolated tornado is also possible in those areas. To a lesser degree, the areas in green are in a MARGINAL RISK of severe weather for the same reasons.

Our last image below from the Storm Prediction Center is valid for Friday. Note that only a few counties shaded in green remain under a MARGINAL RISK for severe weather.

Brief, heavy downpours are possible with any of these storms and our rain and thunderstorm threat continues into and through the entire weekend until this system entirely departs. In the forecast model image above (for 6 P.M. Friday), the red line (or warm front) is expected to lift into the state on Saturday and Sunday. That means temperatures south of the front over the weekend (mainly from Grand Rapids southward) will likely be in the 75 to 80 degree range...despite the clouds and precipitation. Make sure to stay up on later forecasts as the Storm Prediction Outlooks and threat level may change, and the location/timing of these fronts may change and ultimately affect our high temperatures this weekend. Get the complete West Michigan forecast at