Weather alerts in Indiana, 2017
3,075 weather alerts in 2017, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered any part of the state, so the counties below add up to more than the state.
Weather alerts by county
Each county as a circle sized by its count in 2017. Tap one for its archive.
- Alerts
- 3,075
- Warnings
- 1,306
- Watches
- 133
- Advisories
- 511
- Busiest month
- July578 alerts
- Busiest day
- March 1, 2017118 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
17 of 77 tornado warnings covering Indiana in 2017 had a tornado report inside them; 26 of 42 tornado reports fell inside a warning, on average 10 minutes after it went out.
Indiana, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 77 | 17 | 78% | 42 | 62% | 10 min |
| Severe thunderstorm warnings | 465 | 217 | 53% | 615 | 67% | 17 min |
| Flash flood warnings | 70 | 35 | 50% | 81 | 90% | 109 min |
Each office's whole area, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Northern Indiana: tornado warnings | 26 | 6 | 77% | 17 | 71% | 10 min |
| NWS Northern Indiana: severe thunderstorm warnings | 126 | 61 | 52% | 263 | 56% | 17 min |
| NWS Northern Indiana: flash flood warnings | 9 | 3 | 67% | 12 | 75% | 103 min |
| NWS Chicago, IL: tornado warnings | 14 | 6 | 57% | 17 | 76% | 17 min |
| NWS Chicago, IL: severe thunderstorm warnings | 158 | 76 | 52% | 310 | 72% | 21 min |
| NWS Chicago, IL: flash flood warnings | 12 | 6 | 50% | 27 | 81% | 129 min |
| NWS Louisville, KY: tornado warnings | 32 | 7 | 78% | 38 | 29% | 8 min |
| NWS Louisville, KY: severe thunderstorm warnings | 304 | 142 | 53% | 444 | 72% | 16 min |
| NWS Louisville, KY: flash flood warnings | 31 | 24 | 23% | 66 | 89% | 85 min |
| NWS Paducah, KY: tornado warnings | 46 | 12 | 74% | 45 | 58% | 20 min |
| NWS Paducah, KY: severe thunderstorm warnings | 223 | 108 | 52% | 306 | 70% | 18 min |
| NWS Paducah, KY: flash flood warnings | 49 | 20 | 59% | 58 | 83% | 145 min |
| NWS Lincoln, IL: tornado warnings | 23 | 3 | 87% | 21 | 29% | 11 min |
| NWS Lincoln, IL: severe thunderstorm warnings | 168 | 92 | 45% | 378 | 75% | 19 min |
| NWS Lincoln, IL: flash flood warnings | 31 | 10 | 68% | 26 | 81% | 142 min |
| NWS Wilmington, OH: tornado warnings | 34 | 12 | 65% | 24 | 54% | 11 min |
| NWS Wilmington, OH: severe thunderstorm warnings | 253 | 140 | 45% | 507 | 68% | 21 min |
| NWS Wilmington, OH: flash flood warnings | 97 | 65 | 33% | 204 | 92% | 103 min |
| NWS Indianapolis, IN: tornado warnings | 29 | 4 | 86% | 11 | 45% | 8 min |
| NWS Indianapolis, IN: severe thunderstorm warnings | 171 | 82 | 52% | 261 | 71% | 19 min |
| NWS Indianapolis, IN: flash flood warnings | 27 | 9 | 67% | 12 | 75% | 110 min |
An office's figures cover every county it serves, including across state lines.
Verified by the Iowa Environmental Mesonet's Cow, which matches each storm-based warning with the local storm reports inside its polygon while it was in force, within 15 km of its edge: a tornado warning counts as verified on a tornado report, a severe thunderstorm warning on hail of 1 inch or more, a gust of 58 mph or more, or wind damage, a flash flood warning on a flash flood report. The false alarm ratio is the share of warnings with no such report; "inside a warning" is the probability of detection, the share of reports that fell inside one; lead time runs from the warning's issue to each report inside it, counting zero for a report that came first. A warning with no report is not proof nothing happened: reports come from spotters, the public and damage surveys, and are thin where few people live.
The alerts
3,075 alerts are too many to list on one page. Narrow it to a product above, to a month in the chart, or to a county.
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Marion County183
- Allen County178
- Wabash County177
- Parke County171
- Miami County168
- Tippecanoe County167
- Dearborn County162
- Hamilton County161
- Cass County160
- Vermillion County159
- Wells County159
- Knox County155
- Huntington County154
- Ripley County153
- Fountain County153
- Wayne County153
- Franklin County152
- Washington County151
- Madison County150
- Lake County148
- Union County148
- Gibson County146
- Crawford County144
- Harrison County144
- Delaware County144
- Morgan County144
- Clinton County143
- White County143
- Ohio County140
- Boone County140
- Carroll County140
- Howard County139
- Whitley County139
- Clark County138
- Newton County137
- Montgomery County137
- Warren County137
- Marshall County137
- Fayette County136
- Porter County135
52 more counties
- Switzerland County134
- Hendricks County133
- Adams County133
- Starke County133
- Tipton County132
- Fulton County132
- Perry County131
- Grant County131
- Owen County130
- Hancock County129
- Jackson County129
- Johnson County129
- Shelby County129
- Vigo County128
- Henry County127
- Benton County126
- Jasper County126
- Posey County123
- Orange County123
- Daviess County123
- Pulaski County123
- Kosciusko County123
- Pike County122
- Lawrence County121
- Rush County121
- DeKalb County120
- Jefferson County120
- Dubois County119
- Floyd County119
- Monroe County119
- Putnam County119
- Sullivan County119
- Blackford County117
- Bartholomew County116
- Greene County116
- Jennings County114
- Clay County113
- Warrick County112
- Randolph County112
- Jay County112
- Elkhart County110
- Vanderburgh County108
- Noble County108
- Scott County106
- Spencer County104
- Brown County104
- Decatur County103
- LaGrange County97
- Martin County96
- Steuben County94
- Saint Joseph County93
- LaPorte County86
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20162018
Sources
National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Warning verification from the Mesonet's Cow. Rebuilt daily.