The infographic above shows the thinking of the northern Indiana office of the National Weather Service (NWS) as of midday Friday, Nov. 15, regarding the threats for severe weather Sunday. The information applies to all 37 Indiana, Michigan and Ohio counties covered by the northern Indiana office.

First severe storms could be seen as early as 10 am.
Severe threat will diminish after 8pm once the cold front moves through.

A line of thunderstorms will form along the cold front with a high risk for damaging winds
Tornadic circulations are possible along this line. There is a slight risk for low-topped supercell development ahead of this line with a risk of damaging winds and tornadoes

While there is still some uncertainty regarding the extent of the severe weather potential in our forecast area, there is increasing confidence that portions of the forecast area will see severe weather on Sunday. The tornadic threat is still quite uncertain, although there is at least a slight chance for a significant tornadic event.

Watch this blog, the NWS office’s Facebook page and/or the NWS office’s Twitter feed for updates as the weather system approaches.

The entire states of Indiana and Ohio, plus the southern half of lower Michigan are at slight risk of severe weather between 8 a.m. EST Sunday, Nov. 17 and 8 a.m. EST Monday, Nov. 18, according to a Day 3 Convective Outlook that the National Weather Service (NWS) Storm Prediction Center (SPC) issued at 3:30 a.m. EST today.

Forecasters say a deepening low pressure system will move northeastward from the upper Mississippi Valley into the Great Lakes region Sunday afternoon. A cold front will trail from the low, while a warm front lifts northward through the Ohio Valley and Great Lakes region.

The potential exists for storms ahead of the fronts to develop into supercells, but the extent of any tornado threat will depend on how much the atmosphere is able to destabilize, according to the convective outlook. And ongoing showers and cloud cover might limit that destabilization. Nonetheless, other storms will likely evolve into lines along the cold front and present a threat for widespread damaging straight-line wind.

SKYWARN storm spotters and others who are concerned about severe weather should be prepared to be aware of any storm watches or warnings that the NWS might issue Sunday. Our next look at the potential for severe weather will come with the SPC’s Day 2 Convective Outlook that’s due early Saturday morning.

The tornado siren test that normally happens throughout Allen County, Indiana at noon on the first Wednesday of every month did not happen today. The Allen County Department of Homeland Security (DHS) notified the Allen County Amateur Radio Emergency Service (ARES) this morning that the county would not test sirens today.

ARES Emergency Coordinator Jim Moehring, KB9WWM, did not indicate in an email message why DHS canceled the test. The department, has, however, canceled tests in the past when the weather was rainy, out of fear that citizens might confuse the test with an actual tornado warning.

The National Weather Service activates weather alert radios every Wednesday morning for a weekly test and postpones the weekly test if there is a threat of severe weather on Wednesday. The NWS conducted its weekly test this morning, as usual.

As you can see in the NWS infographic above, the line of strong storms about which forecasters are concerned is not forecast to arrive in the Fort Wayne area at around 10 p.m. EDT, well after official trick-or-treat hours.

The mayor and police chief of the City of Fort Wayne issued a statement this morning that official trick-or-treating hours in the city will remain 6 p.m. to 8 p.m. EDT this evening, despite the risk of severe weather today.

The statement reads, in part, “Though we received some inquiries into the rescheduling of Trick-or-Treating due to the weather forecast, it was decided that because of several area events already scheduled for Friday evening, the move would create a burden for many families.”

Read the entire statement.