Alert archive / Indiana

Weather alerts in Indiana, 2021

2,309 weather alerts in 2021, 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 2021. Tap one for its archive.

Alerts
2,309
Warnings
817
Watches
108
Advisories
530
Busiest month
June520 alerts
Busiest day
June 19, 2021100 alerts

Over time

By month

Warning verification

How often warnings here had a storm report inside them, and how much warning the reports had.

6 of 34 tornado warnings covering Indiana in 2021 had a tornado report inside them; 6 of 22 tornado reports fell inside a warning, on average 6 minutes after it went out.

Indiana, 2021

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings34682%2227%6 min
Severe thunderstorm warnings29017440%53268%19 min
Flash flood warnings563341%6881%74 min

Each office's whole area, 2021

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Louisville, KY: tornado warnings311455%5381%19 min
NWS Louisville, KY: severe thunderstorm warnings1115451%19052%11 min
NWS Louisville, KY: flash flood warnings603935%9579%91 min
NWS Chicago, IL: tornado warnings411271%2556%16 min
NWS Chicago, IL: severe thunderstorm warnings1167535%39887%31 min
NWS Chicago, IL: flash flood warnings11736%2796%106 min
NWS Paducah, KY: tornado warnings511669%3352%19 min
NWS Paducah, KY: severe thunderstorm warnings1234266%14449%17 min
NWS Paducah, KY: flash flood warnings652955%5283%97 min
NWS Wilmington, OH: tornado warnings17665%1540%10 min
NWS Wilmington, OH: severe thunderstorm warnings1268533%27664%19 min
NWS Wilmington, OH: flash flood warnings332039%3586%77 min
NWS Lincoln, IL: tornado warnings541572%4751%17 min
NWS Lincoln, IL: severe thunderstorm warnings1304962%21354%22 min
NWS Lincoln, IL: flash flood warnings371462%3284%93 min
NWS Indianapolis, IN: tornado warnings11282%450%8 min
NWS Indianapolis, IN: severe thunderstorm warnings1056538%20773%17 min
NWS Indianapolis, IN: flash flood warnings271448%2378%102 min
NWS Northern Indiana: tornado warnings14193%911%3 min
NWS Northern Indiana: severe thunderstorm warnings1287740%37758%19 min
NWS Northern Indiana: flash flood warnings6350%2584%59 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

2,309 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.

52 more counties

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordThe radar archive20202022

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.