Alert archive / Colorado / Weld County / Tornado Warnings

Tornado Warnings in Weld County, Colorado, 2010

26 tornado warnings in 2010. An alert counts here when it covered this county. The archive of tornado warnings reaches back to 1986.

Weld County and its neighbors

Each county as a circle sized by its count in 2010. Tap one for its archive.

Tornado Warnings
26
Busiest month
May16 tornado warnings
Busiest day
June 11, 20107 tornado warnings

Over time

By month

Warning verification

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

5 of 26 tornado warnings covering Weld County in 2010 had a tornado report inside them; 5 of 7 tornado reports fell inside a warning, on average 9 minutes after it went out.

Weld County, 2010

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings26581%771%9 min

Each office's whole area, 2010

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Denver/Boulder, CO: tornado warnings802174%3669%14 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, Mountain Time. Each opens its own page with the text, the map, the radar and the sounding.

IssuedProductOfficeLasted
May 15, 1:56 PM MDTTornado WarningBOU18 min
May 15, 2:00 PM MDTTornado WarningBOU30 min
May 15, 2:00 PM MDTTornado WarningBOU30 min
May 15, 2:28 PM MDTTornado WarningBOU47 min
May 18, 3:36 PM MDTTornado WarningBOU24 min
May 18, 3:51 PM MDTTornado WarningBOU39 min
May 18, 5:18 PM MDTTornado WarningBOU27 min
May 18, 5:28 PM MDTTornado WarningBOU36 min
May 18, 5:46 PM MDTTornado WarningBOU44 min
May 18, 6:19 PM MDTTornado WarningBOU41 min
May 18, 6:37 PM MDTTornado WarningBOU38 min
May 18, 8:19 PM MDTTornado WarningBOU21 min
May 26, 2:06 PM MDTTornado WarningBOU39 min
May 26, 3:11 PM MDTTornado WarningBOU49 min
May 26, 3:12 PM MDTTornado WarningBOU33 min
May 26, 4:17 PM MDTTornado WarningBOU43 min
Jun 6, 5:43 PM MDTTornado WarningBOU32 min
Jun 10, 5:40 PM MDTTornado WarningBOU50 min
Jun 10, 6:11 PM MDTTornado WarningBOU34 min
Jun 11, 3:51 PM MDTTornado WarningBOU39 min
Jun 11, 4:22 PM MDTTornado WarningBOU38 min
Jun 11, 4:42 PM MDTTornado WarningBOU48 min
Jun 11, 4:59 PM MDTTornado WarningBOU46 min
Jun 11, 5:28 PM MDTTornado WarningBOU47 min
Jun 11, 5:40 PM MDTTornado WarningBOU35 min
Aug 16, 4:25 PM MDTTornado WarningBOU29 min

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20092011

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.