Flash Flood Warnings in Montana, 2010

By month

3 of 24 flash flood warnings covering Montana in 2010 had a flash flood report inside them; 3 of 14 flash flood reports fell inside a warning, on average 122 minutes after it went out.

Montana, 2010

Each office's whole area, 2010

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.

• Carter County6
• Big Horn County3
• Yellowstone County3
• Powder River County2
• Carbon County2
• Granite County2
• Custer County1
• Rosebud County1
• Dawson County1
• Prairie County1
• Wibaux County1
• Fallon County1
• Silver Bow County1
• Cascade County1
• Judith Basin County1
• Valley County1
• Lake County1
• Sanders County1
• Sweet Grass County1
• Teton County1

1. June 20, 20103flash flood warnings
2. June 21, 20103flash flood warnings
3. June 22, 20103flash flood warnings
4. June 10, 20102flash flood warnings
5. June 17, 20102flash flood warnings
6. August 6, 20102flash flood warnings
7. August 9, 20102flash flood warnings
8. May 27, 20101flash flood warnings
9. May 29, 20101flash flood warnings
10. June 16, 20101flash flood warnings
11. June 25, 20101flash flood warnings
12. July 29, 20101flash flood warnings

Alerts in force nowTornadoes on recordThe radar archive20092011

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.