Weather alerts in Louisiana, 2013
2,264 weather alerts in 2013, 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 2013. Tap one for its archive.
- Alerts
- 2,264
- Warnings
- 1,199
- Watches
- 92
- Advisories
- 477
- Busiest month
- January359 alerts
- Busiest day
- February 25, 2013114 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
16 of 107 tornado warnings covering Louisiana in 2013 had a tornado report inside them; 21 of 42 tornado reports fell inside a warning, on average 11 minutes after it went out.
Louisiana, 2013
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 107 | 16 | 85% | 42 | 50% | 11 min |
| Severe thunderstorm warnings | 358 | 164 | 54% | 412 | 76% | 23 min |
| Flash flood warnings | 82 | 38 | 54% | 84 | 71% | 93 min |
Each office's whole area, 2013
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Shreveport, LA: tornado warnings | 47 | 12 | 74% | 31 | 74% | 14 min |
| NWS Shreveport, LA: severe thunderstorm warnings | 225 | 130 | 42% | 370 | 79% | 23 min |
| NWS Shreveport, LA: flash flood warnings | 16 | 7 | 56% | 43 | 40% | 89 min |
| NWS Jackson, MS: tornado warnings | 80 | 23 | 71% | 57 | 81% | 18 min |
| NWS Jackson, MS: severe thunderstorm warnings | 420 | 241 | 43% | 560 | 83% | 25 min |
| NWS Jackson, MS: flash flood warnings | 146 | 75 | 49% | 140 | 92% | 74 min |
| NWS Lake Charles, LA: tornado warnings | 21 | 4 | 81% | 14 | 43% | 13 min |
| NWS Lake Charles, LA: severe thunderstorm warnings | 93 | 28 | 70% | 84 | 54% | 22 min |
| NWS Lake Charles, LA: flash flood warnings | 32 | 19 | 41% | 49 | 78% | 112 min |
| NWS New Orleans, LA: tornado warnings | 54 | 2 | 96% | 14 | 14% | 10 min |
| NWS New Orleans, LA: severe thunderstorm warnings | 127 | 33 | 74% | 100 | 73% | 18 min |
| NWS New Orleans, LA: flash flood warnings | 36 | 13 | 64% | 29 | 93% | 64 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
2,264 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.
- Saint Landry Parish164
- Beauregard Parish154
- Morehouse Parish152
- Saint Martin Parish148
- Allen Parish147
- Avoyelles Parish146
- Bienville Parish144
- Evangeline Parish143
- Caddo Parish143
- Bossier Parish142
- Jackson Parish142
- Franklin Parish142
- Rapides Parish139
- Madison Parish137
- Tensas Parish137
- Ouachita Parish136
- Union Parish136
- West Carroll Parish136
- Concordia Parish136
- East Carroll Parish134
- Lafayette Parish133
- De Soto Parish133
- Richland Parish133
- Lincoln Parish131
- Webster Parish130
- Claiborne Parish129
- Vernon Parish127
- Red River Parish126
- Cameron Parish123
- Calcasieu Parish121
- Natchitoches Parish121
- Winn Parish121
- Caldwell Parish120
- Tangipahoa Parish117
- Saint John the Baptist Parish116
- Catahoula Parish113
- Washington Parish112
- Sabine Parish110
- Saint Tammany Parish110
- Grant Parish109
24 more counties
- LaSalle Parish105
- Saint Bernard Parish102
- East Baton Rouge Parish99
- Saint James Parish99
- Saint Helena Parish94
- Livingston Parish91
- Assumption Parish88
- Acadia Parish87
- Jefferson Davis Parish85
- Iberville Parish84
- West Feliciana Parish84
- East Feliciana Parish80
- West Baton Rouge Parish79
- Pointe Coupee Parish77
- St. Mary Parish77
- Vermilion Parish76
- Ascension Parish76
- Lafourche Parish75
- Jefferson Parish71
- Iberia Parish58
- Orleans Parish56
- Plaquemines Parish56
- Saint Charles Parish56
- Terrebonne Parish53
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20122014
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.