Flash Flood Warnings in Montana, 2013

By month

17 of 70 flash flood warnings covering Montana in 2013 had a flash flood report inside them; 22 of 46 flash flood reports fell inside a warning, on average 51 minutes after it went out.

Montana, 2013

Each office's whole area, 2013

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.

• Musselshell County16
• Powder River County8
• Valley County8
• Big Horn County8
• Rosebud County7
• Phillips County7
• Yellowstone County5
• Custer County4
• Treasure County4
• Lewis and Clark County4
• McCone County3
• Carter County3
• Petroleum County3
• Carbon County3
• Teton County2
• Dawson County2
• Daniels County2
• Roosevelt County1
• Golden Valley County1
• Blaine County1
• Broadwater County1
• Jefferson County1
• Pondera County1
• Toole County1
• Fallon County1
• Garfield County1
• Sweet Grass County1
• Richland County1

1. June 11, 20136flash flood warnings
2. August 13, 20136flash flood warnings
3. May 26, 20135flash flood warnings
4. June 14, 20135flash flood warnings
5. June 25, 20135flash flood warnings
6. June 19, 20134flash flood warnings
7. September 7, 20134flash flood warnings
8. June 12, 20133flash flood warnings
9. June 20, 20133flash flood warnings
10. June 22, 20133flash flood warnings
11. July 4, 20133flash flood warnings
12. September 8, 20133flash flood warnings

Alerts in force nowTornadoes on recordThe radar archive20122014

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.