Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. (More Info)

The risk of severe weather in Indiana and surrounded areas has increased and expanded, according to the Day 1 Convective Outlook that the National Weather Service (NWS) Storm Prediction Center (SPC) issued at 8:52 a.m. EDT. The SPC increased the slight risk area from the northern half of Indiana to the northern two thirds of the state. It also broadly increased the slight risk area to the east.

In addition, and perhaps more significant to readers of this blog, the probabilities of severe wind and hail in northern Indiana doubled from the previous outlook. Throughout the area covered by the Northern Indiana NWS office (see map at right), the probability of damaging thunderstorm winds or wind gusts of 50 knots (58 mph) or higher within 25 miles of a point is now 30 percent. In the same area, the SPC also forecasts a 30 percent probability of one inch diameter hail or larger within 25 miles of a point.

This morning, Warning Coordination Meteorologist Michael Lewis of the northern Indiana NWS office provided the following information via email to SKYWARN storm spotters:

Today:

Threat: Severe Winds > 58 MPH with Isolated damaging winds > 70 mph and torrential rainfall.

Timing: Isolated storms from mid-day through early afternoon. Redevelopment into more linear during the late afternoon into the evening. Location: Early this morning along and north or US-30. Development along and south of US-24 around mid-day. Development west of IN-9 later this afternoon with rapid eastward expansion.

Wednesday:

Threat: Straight Line Winds. Widespread damaging winds possible > 70 mph, hail > 1″ diameter, and torrential rainfall.

Timing: Squall line development early afternoon, rapidly building and accelerating across Indiana through early evening.

Location: Early this morning along and north or US-30. Development along and south of US-24 around mid-day. Development west of IN-9 later this afternoon with rapid eastward expansion.

Northern Indiana (NWS office) will be monitoring:

• Emergency Managers and Media Partners
• Social Media – (Facebook / Twitter)
• Amateur Radio
• e-mail (w-iwx.webmaster@noaa.gov)