Alert archive / Louisiana / Flash Flood Warnings

Flash Flood Warnings in Louisiana, 2011

57 flash flood warnings in 2011. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of flash flood warnings reaches back to 1986.

Flash Flood Warnings by county

Each county as a circle sized by its count in 2011. Tap one for its archive.

Flash Flood Warnings
57
Busiest month
March19 flash flood warnings
Busiest day
March 9, 201113 flash flood warnings

Over time

By month

Warning verification

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

30 of 57 flash flood warnings covering Louisiana in 2011 had a flash flood report inside them; 46 of 62 flash flood reports fell inside a warning, on average 61 minutes after it went out.

Louisiana, 2011

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Flash flood warnings573047%6274%61 min

Each office's whole area, 2011

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Jackson, MS: flash flood warnings1649940%20593%110 min
NWS Shreveport, LA: flash flood warnings13931%2997%97 min
NWS Lake Charles, LA: flash flood warnings8450%978%32 min
NWS New Orleans, LA: flash flood warnings351266%3259%34 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

Every alert, in the order issued. Times are local, Central Time. Each opens its own page with the text, the map, the radar and the sounding.

IssuedProductOfficeCountiesLasted
Dec 31, 9:02 PM CSTFlash Flood WarningJANEast Carroll, Morehouse, Richland, West Carroll3 hr
Mar 4, 7:31 PM CSTFlash Flood WarningLIXSaint Tammany, Tangipahoa3 hr
Mar 4, 9:00 PM CSTFlash Flood WarningLIXSaint Tammany80 min
Mar 8, 4:27 PM CSTFlash Flood WarningLIXSaint Helena, Tangipahoa, Washington3 hr
Mar 8, 7:41 PM CSTFlash Flood WarningLCHAvoyelles, Rapides3 hr
Mar 8, 10:28 PM CSTFlash Flood WarningLCHRapides, Vernon3 hr
Mar 8, 11:10 PM CSTFlash Flood WarningSHVGrant, LaSalle4 hr
Mar 8, 11:30 PM CSTFlash Flood WarningJANCatahoula3 hr
Mar 8, 11:48 PM CSTFlash Flood WarningJANFranklin, Madison, Tensas3 hr
Mar 9, 12:28 AM CSTFlash Flood WarningJANCatahoula, Concordia3 hr
Mar 9, 1:32 AM CSTFlash Flood WarningLCHRapides, Vernon3 hr
Mar 9, 2:34 AM CSTFlash Flood WarningJANCatahoula116 min
Mar 9, 2:47 AM CSTFlash Flood WarningJANTensas118 min
Mar 9, 3:24 AM CSTFlash Flood WarningJANCatahoula, Concordia2 hr
Mar 9, 4:53 AM CSTFlash Flood WarningLIXLivingston, Tangipahoa3 hr
Mar 9, 6:52 AM CSTFlash Flood WarningLIXSaint Tammany113 min
Mar 9, 7:06 AM CSTFlash Flood WarningLIXJefferson, Orleans, Plaquemines, Saint Bernard5 hr
Mar 29, 7:05 PM CDTFlash Flood WarningLIXJefferson, Orleans, Plaquemines, Saint Bernard, Saint Charles3 hr
Mar 29, 10:07 PM CDTFlash Flood WarningJANFranklin, Madison, Tensas113 min
Mar 29, 10:23 PM CDTFlash Flood WarningJANMadison, Tensas2 hr
Apr 26, 11:27 PM CDTFlash Flood WarningJANEast Carroll, Madison, Morehouse, Richland, West Carroll2 hr
Apr 26, 11:31 PM CDTFlash Flood WarningSHVJackson, Lincoln, Ouachita4 hr
Apr 27, 12:34 AM CDTFlash Flood WarningJANFranklin, Madison, Richland116 min
Apr 27, 1:21 AM CDTFlash Flood WarningJANEast Carroll, Franklin, Madison, Morehouse, Richland, West Carroll114 min
Apr 27, 2:20 AM CDTFlash Flood WarningJANCatahoula, Concordia, Franklin, Madison, Richland, Tensas115 min
Apr 27, 3:27 AM CDTFlash Flood WarningSHVJackson, Ouachita6 hr
May 13, 11:16 AM CDTFlash Flood WarningJANMadison, Tensas119 min
May 13, 7:10 PM CDTFlash Flood WarningLIXPointe Coupee, West Feliciana3 hr
Jun 6, 2:21 PM CDTFlash Flood WarningLIXJefferson, Orleans3 hr
Jun 7, 2:39 PM CDTFlash Flood WarningLIXOrleans111 min
Jun 21, 10:46 AM CDTFlash Flood WarningSHVBienville, Jackson, Lincoln, Ouachita, Union3 hr
Jun 21, 11:32 AM CDTFlash Flood WarningJANMorehouse, Richland118 min
Jul 18, 6:46 AM CDTFlash Flood WarningLIXJefferson, Orleans, Plaquemines, Saint Bernard3 hr
Jul 18, 9:16 AM CDTFlash Flood WarningLIXAssumption, Lafourche, Terrebonne3 hr
Jul 21, 3:01 PM CDTFlash Flood WarningLIXJefferson, Plaquemines, Saint Charles48 min
Jul 25, 11:41 AM CDTFlash Flood WarningLIXSaint Tammany2 hr
Jul 26, 9:54 AM CDTFlash Flood WarningLCHSaint Martin2 hr
Jul 26, 12:04 PM CDTFlash Flood WarningLCHLafayette, Saint Landry, Saint Martin91 min
Jul 27, 2:54 PM CDTFlash Flood WarningLIXJefferson3 hr
Jul 28, 2:03 PM CDTFlash Flood WarningLIXJefferson3 hr
Aug 21, 3:42 PM CDTFlash Flood WarningJANMorehouse59 min
Sep 3, 7:23 AM CDTFlash Flood WarningLIXSaint Tammany3 hr
Sep 3, 8:03 AM CDTFlash Flood WarningLIXEast Baton Rouge, Livingston, Saint Helena, Tangipahoa6 hr
Sep 3, 3:57 PM CDTFlash Flood WarningLIXJefferson, Orleans, Plaquemines3 hr
Sep 3, 6:04 PM CDTFlash Flood WarningLCHAcadia, Jefferson Davis, Lafayette, Vermilion6 hr
Sep 4, 8:05 AM CDTFlash Flood WarningLIXAssumption, Lafourche, Terrebonne4 hr
Sep 4, 11:15 AM CDTFlash Flood WarningLIXPlaquemines3 hr
Sep 4, 5:27 PM CDTFlash Flood WarningLIXPointe Coupee, West Feliciana3 hr
Sep 4, 5:58 PM CDTFlash Flood WarningJANCatahoula, Concordia4 hr
Sep 4, 9:20 PM CDTFlash Flood WarningJANEast Carroll3 hr
Sep 5, 3:30 AM CDTFlash Flood WarningLIXWest Feliciana3 hr
Sep 25, 10:31 PM CDTFlash Flood WarningJANEast Carroll, Morehouse, West Carroll119 min
Sep 27, 6:18 AM CDTFlash Flood WarningJANEast Carroll, Morehouse, West Carroll4 hr
Sep 28, 8:26 PM CDTFlash Flood WarningLIXIberville, Pointe Coupee2 hr
Dec 20, 6:28 AM CSTFlash Flood WarningLCHBeauregard, Rapides, Vernon3 hr
Dec 22, 5:16 AM CSTFlash Flood WarningJANEast Carroll, Morehouse, Richland, West Carroll3 hr
Dec 26, 6:41 AM CSTFlash Flood WarningLIXEast Feliciana, West Feliciana6 hr

By county

Every county with at least one alert. A county page lists each alert that covered it.

4 more counties

The busiest days

Days with the most alerts issued, by UTC date.

  1. March 9, 201113flash flood warnings
  2. April 27, 20116flash flood warnings
  3. September 3, 20114flash flood warnings
  4. September 4, 20114flash flood warnings
  5. March 30, 20113flash flood warnings
  6. March 5, 20112flash flood warnings
  7. June 21, 20112flash flood warnings
  8. July 18, 20112flash flood warnings
  9. July 26, 20112flash flood warnings
  10. September 5, 20112flash flood warnings
  11. January 1, 20111flash flood warnings
  12. March 8, 20111flash flood warnings

Nearby

Alerts in force nowTornadoes on recordThe radar archive20102012

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.