Slight risk today, storm spotter activation possible

Convective outlook map indicating Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Probability of damaging thunderstorm winds or wind gusts of 58 mph or higher within 25 miles of a point.

1:30 p.m. EDT update: The SPC issued an updated convective outlook at 12:25 p.m. EDT. The area outlines remain pretty much the same as they were in the earlier outlook. The 12:25 p.m. outlook contains the following language:

“Storms may increase in coverage and intensity this afternoon as lift is enhanced by existing outflow boundaries. Hail and damaging winds will be the primary hazards with these storms into this evening.”

Original post: There’s a slight risk of severe weather over the northern half of Indiana and Ohio and the southern half of Michigan between 9 a.m. EDT today and 8 a.m. EDT tomorrow. The main risk is damaging wind and hail but a tornado is possible. Casual weather observers should be alert for watches and warning through this afternoon and tonight. Make sure your weather alert radios work!

If you are interested in weather details, here’s a summary of relevant products from the National Weather Service (NWS):

At 8:47 a.m. EDT, the NWS Storm Prediction Center issued a Day One Convective Outlook that indicates a slight risk of severe weather over all of the county warning area (CWA) of the northern Indiana weather forecast office (WFO), including, of course, Fort Wayne. The outlook indicates a five percent risk of a tornado within 25 miles of any point in the risk area, a 15 percent risk of hail of one inch or greater diameter, and a 15 to 30 percent risk of thunderstorm winds or wind gusts of 50 knots (58 mph) or higher. As you can see in the map above, the area of enhanced (30 percent) wind damage risk includes Allen, DeKalb and Steuben Counties of Indiana and much of northwestern Ohio. The text of the outlook discusses the possibility of bands or small clusters of sustained storms and/or weak supercells with bowing segments capable of locally damaging wind and possibly a tornado.

At 4:59 a.m. EDT the Northern Indiana NWS WFO issued a Hazardous Weather Outlook that reads, “Scattered thunderstorms are expected across the area today and tonight. Locally heavy rainfall is possible during this period. Also, some of the storms may be severe with large hail and damaging winds this afternoon and this evening. The outlook also indicates that spotter activation might be needed this afternoon and this evening.

In an Area Forecast Discussion issued at 6:43 a.m. EDT, the northern Indiana WFO wrote, “A warm front over northern portions of Illinois Indiana and Ohio early this morning will lift north into Wisconsin and Michigan today. Thunderstorms are expected in the vicinity of the front.”

The discussion also indicates that a shortwave impulse is forecast to move across the WFO’s CWA this afternoon through an air mass that will be moderately unstable by that time. The combination of 30 to 40 knot 0 to 6 kilometer shear and moderate instability suggests that some of the storms could be severe. In addition, another shortwave impulse tonight could combine with some lingering instability and convective outflow boundaries, resulting in thunderstorms again tonight. The best chances for those storms will be in the northern portion of the CWA, closer to the warm front.