Alert archive / Colorado / Grand County

Weather alerts in Grand County, Colorado, 2013

59 weather alerts in 2013, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Grand County and its neighbors

Each county as a circle sized by its count in 2013. Tap one for its archive.

Alerts
59
Warnings
18
Watches
10
Advisories
29
Busiest month
April16 alerts
Busiest day
March 8, 20132 alerts

Over time

By month

Warning verification

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

Grand County, 2013

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings10100%0
Flash flood warnings00

Each office's whole area, 2013

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Denver/Boulder, CO: tornado warnings61985%1675%18 min
NWS Denver/Boulder, CO: severe thunderstorm warnings2276571%17361%18 min
NWS Denver/Boulder, CO: flash flood warnings851978%5082%148 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
Jan 10, 5:02 AM MSTWinter Weather AdvisoryBOU35 hr
Jan 27, 2:47 PM MSTWinter Weather AdvisoryBOU27 hr
Jan 28, 3:37 AM MSTWinter Storm WatchBOU24 hr
Jan 29, 3:10 AM MSTWinter Storm WarningBOU60 hr
Feb 8, 3:18 PM MSTWinter Weather AdvisoryBOU38 hr
Feb 20, 4:17 AM MSTWinter Weather AdvisoryBOU30 hr
Feb 23, 3:41 PM MSTWinter Weather AdvisoryBOU25 hr
Mar 3, 4:11 AM MSTWinter Weather AdvisoryBOU32 hr
Mar 7, 4:21 AM MSTWinter Storm WatchBOU24 hr
Mar 8, 4:14 AM MSTWinter Storm WarningBOU37 hr
Mar 8, 4:14 AM MSTWinter Weather AdvisoryBOU43 hr
Mar 16, 3:38 PM MDTWinter Weather AdvisoryBOU26 hr
Mar 22, 4:28 PM MDTWinter Weather AdvisoryBOU26 hr
Apr 7, 4:15 AM MDTWinter Storm WatchBOU36 hr
Apr 8, 11:19 AM MDTWinter Storm WarningBOU27 hr
Apr 8, 4:26 PM MDTWinter Weather AdvisoryBOU35 hr
Apr 11, 3:32 AM MDTWinter Weather AdvisoryBOU14 hr
Apr 12, 3:55 PM MDTWinter Weather AdvisoryBOU43 hr
Apr 14, 5:15 AM MDTWinter Storm WatchBOU26 hr
Apr 15, 4:51 AM MDTWinter Storm WarningBOU23 hr
Apr 15, 4:51 AM MDTWinter Weather AdvisoryBOU23 hr
Apr 16, 5:44 AM MDTWinter Storm WarningBOU38 hr
Apr 16, 3:52 PM MDTWinter Weather AdvisoryBOU35 hr
Apr 21, 2:55 PM MDTWinter Storm WatchBOU15 hr
Apr 22, 5:46 AM MDTWinter Weather AdvisoryBOU27 hr
Apr 22, 9:20 AM MDTWinter Storm WarningBOU20 hr
Apr 29, 3:05 PM MDTWinter Storm WatchBOU21 hr
Apr 30, 4:05 AM MDTWinter Storm WarningBOU40 hr
Apr 30, 12:12 PM MDTWinter Weather AdvisoryBOU39 hr
May 8, 3:55 AM MDTWinter Weather AdvisoryBOU36 hr
May 19, 3:42 PM MDTWinter Weather AdvisoryBOU18 hr
Jun 12, 1:52 PM MDTRed Flag WarningBOU31 hr
Jun 16, 5:21 PM MDTSpecial Weather StatementBOU24 min
Jun 19, 3:55 AM MDTRed Flag WarningBOU16 hr
Jun 19, 2:12 PM MDTRed Flag WarningBOU30 hr
Jun 21, 5:04 AM MDTRed Flag WarningBOU15 hr
Jun 21, 3:35 PM MDTRed Flag WarningBOU28 hr
Jun 23, 3:05 PM MDTFire Weather WatchBOU14 hr
Jun 24, 5:01 AM MDTRed Flag WarningBOU15 hr
Jun 30, 3:52 PM MDTSevere Thunderstorm WarningBOU38 min
Jul 17, 2:50 PM MDTAreal Flood AdvisoryBOU3 hr
Aug 23, 4:11 PM MDTMesoscale DiscussionSPC2 hr
Aug 28, 3:20 PM MDTAreal Flood AdvisoryBOU3 hr
Sep 14, 4:30 AM MDTFlash Flood WatchBOU40 hr
Oct 2, 4:01 AM MDTWinter Storm WatchBOU35 hr
Oct 3, 3:54 AM MDTWinter Storm WarningBOU38 hr
Oct 3, 3:14 PM MDTWinter Weather AdvisoryBOU27 hr
Oct 10, 3:42 AM MDTWinter Weather AdvisoryBOU32 hr
Oct 13, 4:56 AM MDTWinter Weather AdvisoryBOU37 hr
Oct 16, 3:42 PM MDTWinter Weather AdvisoryBOU41 hr
Nov 4, 3:50 AM MSTWinter Weather AdvisoryBOU31 hr
Nov 15, 3:46 PM MSTWinter Storm WarningBOU43 hr
Nov 15, 3:46 PM MSTWinter Weather AdvisoryBOU43 hr
Dec 1, 2:26 PM MSTHigh Wind WarningBOU28 hr
Dec 2, 4:16 AM MSTWinter Storm WatchBOU11 hr
Dec 2, 4:16 AM MSTWinter Storm WarningBOU59 hr
Dec 4, 11:49 AM MSTWinter Weather AdvisoryBOU3 hr
Dec 21, 3:26 AM MSTWinter Weather AdvisoryBOU12 hr
Dec 22, 2:37 PM MSTWinter Weather AdvisoryBOU20 hr

By product

Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe 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.