Slight risk of severe weather for most of Indiana, parts of nearby states

1300Z Day 1 wind probability map
Probability of damaging straight-line thunderstorm winds of 58 mph or greater within 25 miles of a point between 9 a.m. today and 8 a.m. tomorrow. Red shaded area: 30 percent. Yellow: 15 percent. Brown 5 percent. Highlighted counties: NWS northern Indiana office county warning area. Source: SPC “Day 1 Convective Outlook” issued at 8:56 a.m. EDT.
1300Z Day 1 tornado map
Probability of a tornado within 25 miles of a point between 9 a.m. EDT today and 8 a.m. EDT tomorrow. Green shaded area: 2 percent. Unshaded area: 2 percent. Highlighted counties, NWS northern Indiana office county warning area. Source: SPC “Day 1 Convective Outlook” issued at 8:56 a.m. EDT.

Nearly the entire state of Indiana has a slight risk of severe weather between 9 a.m. EDT today and 8 a.m. EDT tomorrow, according to the “Day 1 Convective Outlook” that the National Weather Service (NWS) Storm Prediction Center issued at 8:56 a.m. EDT today. The slight risk area also includes about half of the 37-county warning area of the northern Indiana NWS office and all of IMO SKYWARN quadrant two.

The primary threat is damaging straight-line thunderstorm winds or gusts of 58 mph or stronger, although an isolated tornado cannot be ruled out. As you can see on the maps at right, the probability of damaging straight-line winds in northeastern Indiana is 15 percent, which is about 7.5 times the average probability for this time of year (2 percent). The probability of a tornado is 2 percent, which is about 20 times the average probability for this time of year (0.1 percent).

The severe weather risk is conditional, because it depends largely on sunshine. If cloud cover remains heavy all day, the threat of severe weather will be much lower than if the area sees sunshine. This is because the sun’s heating of the earth’s surface would increase atmospheric instability.

SKYWARN storm spotter activation might be needed this afternoon and early this evening, according to a “Hazardous Weather Outlook” issued by the northern Indiana NWS office at 5:27 a.m. EDT.

Residents of the slight risk area should be sure they have a reliable way to be aware of any watches or warnings the NWS might issue today, such as a weather alert radio. You can also keep up to date on weather developments by subscribing to this blog, following the northern Indiana NWS office on Twitter (@NWSIWX) and/or liking the northern Indiana NWS office on Facebook.

If you think others would benefit from the information in this post, used one of the sharing links below to share it. Add comments and/or questions with the comment link that up at the top, right below the post title.

Leave a Reply

Your email address will not be published. Required fields are marked *