The Storm Prediction Center has issued Severe Thunderstorm Watch number 236 in effect until 2 a.m. EDT.

The Storm Prediction Center issued a mesoscale discussion at 9:20 p.m. EDT that indicates a weather watch might be needed within the following hour or two. The mesoscale discssion indicates an increasing risk for severe wind gusts across parts of northern Indiana, southern Michigan and northwestern Ohio between 9:20 p.m. and 1 a.m.

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.

Click the image for a full-size version.

Update: The convective outlook issued at 9:05 p.m. EDT indicates that there is no longer any risk of severe weather in Indiana or Ohio.

Once again today, the Storm Prediction Center (SPC) has determined that a slight risk of severe weather exists in a large part of Indiana. According to the Day One Convective Outlook the SPC issued at 8:44 a.m. EDT, a slight risk exists in the eastern half of Indiana and all of Ohio from 9 a.m. EDT today until 8 a.m. EDT tomorrow, May 23. This includes all of IMO SKYWARN quadrants one and two. The outlook forecasts isolated thunderstorms this afternoon, with the primary risk being wind and hail damage (15 percent probability of either). Things look a bit more intense in eastern Ohio and parts of Pennsylvania and New York, where the probability of damaging winds and hail is 30 percent.

The northern Indiana national weather service weather forecast office issues a Hazardous Weather Outlook (HWO) at 5:01 a.m .EDT in which wrote that thunderstorms are likely, mainly this afternoon. The HWO also indicates that a few storms could be severe with large hail and damaging winds, mainly east of U.S. 31. The HWO indicates that the office does not expect to activate storm spotters today.

It will be interesting to see what the SPC has to say in their updated convective outlook at around 12:30 p.m. EDT.

Yellow indicates a slight risk of severe weather until 8 a.m. EDT May 22. Green indicates non-severe thunderstorms. Source: SPC 2000Z Day 1 Convective Outlook.

The Day 1 Convective Outlook the Storm Prediction Center issued at 3:58 p.m. EDT indicates no risk of severe weather for most of Indiana. Some counties near Fort Wayne continue to have a slight risk until 8 a.m. tomorrow. These include all of the following Indiana counties: LaGrange, Steuben, DeKalb, Allen and Adams. Also, portions of Noble, Whitley, Huntington, Wells and Jay. All of the following Ohio counties also have a slight risk: Paulding, Putnam, Van Wert and Allen. Other counties farther from the Fort Wayne area are also affected.

A recent forecast discussion from the northern Indiana weather forecast office indicates that storm development yet today is very unlikely. Showers and thunderstorms are much more likely during the early hours of tomorrow. The weather forecast office has not updated its Hazardous Weather Outlook since 6 a.m. today, when it wrote that storm spotter activation is not expected.

Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point, 9 a.m. EDT May 21 through 8 a.m. EDT May 22

 Almost all of Indiana has a slight risk of severe weather between now and 8 a.m. EDT tomorrow, according to the latest Day 1 Convective Outlook from the National Weather Service (NWS) Storm Prediction Center. The slight risk area includes at least part of every county covered by the northern Indiana NWS weather forecast office. The outlook indicates, however, uncertainty as to whether storms will be able to develop today in air made more stable by last night’s thunderstorms in the middle Mississippi Valley. The biggest concern in Indiana is straight-line wind. In Indiana, the outlook forecasts a 15 percent chance of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. The hail probability is only five percent in most of Indiana and the tornado probability is only two percent.

The Hazardous Weather Outlook that the northern Indiana weather forecast office issued early this morning indicates a slight chance of thunderstorms today and then a chance for thunderstorms tonight. The outlook indicates that an isolated storm tonight might become severe. It indicates that meteorologists do not anticipate a need for storm spotter activation.

As with yesterday, I advise checking the convective outlook as SPC updates it throughout the day and remain aware of any watches or warnings that the NWS issues.

According to the National Weather Service (NWS) Storm Prediction Center (SPC), almost all of Indiana and certainly all of the counties covered by the northern Indiana National Weather Service office have a slight risk of severe weather today. The Day 1 Convective Outlook that SPC issued at 8:17 a.m. EDT indicates that “multiple lines/clusters of thunderstorms will affect this region, with a few supercells possible. Hail and damaging winds are the main threats, but isolated tornadoes cannot be ruled out.”

The Northern Indiana weather forecast office, however, seemed less impressed when it issued its Hazardous Weather Outlook at 4:45 a.m. EDT. It reads, “Spotter activation is not expected at this time.”

The next convective outlook from SPC is due at 12:30 p.m. EDT. Keep an eye out for possible watches and warnings today, especially of the severe thunderstorm variety. And remember what June 29 taught us: severe thunderstorms can be very destructive!

The Storm Prediction Center issued a new Day One Convective Outlook at 4 p.m. EDT. It shrinks the area of Indiana for which there is a slight risk of severe weather. The slight risk area no longer includes any of IMO SKYWARN quadrant two. In fact, a small part of White County in quadrant three is the only part of the NWS northern Indiana office’s coverage area that still has a slight risk. The risk for the Fort Wayne area was always marginal at best today.