Alert archive / Montana / Dawson County

Weather alerts in Dawson County, Montana, 2009

120 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Dawson County and its neighbors

Each county as a circle sized by its count in 2009. Tap one for its archive.

Alerts
120
Warnings
55
Watches
20
Advisories
23
Busiest month
July30 alerts
Busiest day
September 14, 20099 alerts

Over time

By month

Warning verification

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

1 of 5 tornado warnings covering Dawson County in 2009 had a tornado report inside them; 1 of 2 tornado reports fell inside a warning, on average 29 minutes after it went out.

Dawson County, 2009

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings5180%250%29 min
Severe thunderstorm warnings332039%1872%33 min
Flash flood warnings20100%0

Each office's whole area, 2009

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Glasgow, MT: tornado warnings18289%743%13 min
NWS Glasgow, MT: severe thunderstorm warnings1055845%15768%27 min
NWS Glasgow, MT: flash flood warnings40100%0

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 1, 9:24 PM MSTWinter Weather AdvisoryGGW37 hr
Jan 2, 3:24 PM MSTWind Chill AdvisoryGGW5 hr
Jan 3, 3:55 AM MSTWind Chill AdvisoryGGW15 hr
Jan 6, 3:03 PM MSTWinter Weather AdvisoryGGW24 hr
Jan 7, 3:48 AM MSTWinter Storm WatchGGW24 hr
Jan 8, 3:18 AM MSTFreezing Rain AdvisoryGGW7 hr
Jan 8, 10:28 AM MSTIce Storm WarningGGW11 hr
Jan 8, 3:04 PM MSTWinter Weather AdvisoryGGW20 hr
Jan 10, 2:45 PM MSTHigh Wind WatchGGW24 hr
Jan 11, 3:01 PM MSTHigh Wind WarningGGW19 hr
Jan 13, 2:50 PM MSTWind Chill AdvisoryGGW13 hr
Jan 13, 5:41 PM MSTHigh Wind WarningGGW3 hr
Jan 31, 4:02 AM MSTHigh Wind WarningGGW8 hr
Feb 23, 2:57 PM MSTFreezing Rain AdvisoryGGW19 hr
Feb 24, 4:55 AM MSTMesoscale DiscussionSPC5 hr
Feb 25, 3:22 AM MSTWinter Weather AdvisoryGGW56 hr
Mar 8, 12:53 PM MDTWinter Weather AdvisoryGGW9 hr
Mar 9, 3:10 AM MDTWind Chill AdvisoryGGW31 hr
Mar 27, 3:10 PM MDTWinter Storm WatchGGW24 hr
Mar 28, 3:16 PM MDTWinter Storm WarningGGW37 hr
Mar 28, 3:16 PM MDTWinter Weather AdvisoryGGW37 hr
Mar 29, 2:40 AM MDTBlizzard WarningGGW33 hr
Apr 22, 8:05 AM MDTRed Flag WarningGGW12 hr
May 10, 12:21 PM MDTSevere Thunderstorm WarningGGW9 min
May 10, 12:42 PM MDTSevere Thunderstorm WarningGGW33 min
Jun 22, 12:29 PM MDTMesoscale DiscussionSPC2 hr
Jun 24, 12:46 PM MDTMesoscale DiscussionSPC119 min
Jun 25, 3:50 AM MDTRed Flag WarningGGW17 hr
Jun 30, 2:52 PM MDTMesoscale DiscussionSPC83 min
Jun 30, 3:19 PM MDTSevere Thunderstorm WatchSPC7 hr
Jun 30, 3:56 PM MDTSevere Thunderstorm WarningGGW64 min
Jun 30, 4:14 PM MDTSevere Thunderstorm WarningGGW46 min
Jun 30, 4:52 PM MDTTornado WarningGGW38 min
Jun 30, 5:27 PM MDTTornado WarningGGW33 min
Jul 2, 11:41 AM MDTSevere Thunderstorm WatchSPC7 hr
Jul 2, 6:29 PM MDTMesoscale DiscussionSPC61 min
Jul 3, 9:18 PM MDTMesoscale DiscussionSPC57 min
Jul 5, 3:48 PM MDTMesoscale DiscussionSPC57 min
Jul 5, 4:43 PM MDTSevere Thunderstorm WarningGGW62 min
Jul 5, 5:43 PM MDTSevere Thunderstorm WarningGGW62 min
Jul 5, 6:33 PM MDTSevere Thunderstorm WarningGGW57 min
Jul 5, 7:00 PM MDTSevere Thunderstorm WarningGGW60 min
Jul 5, 7:10 PM MDTTornado WarningGGW65 min
Jul 5, 7:37 PM MDTSevere Thunderstorm WarningGGW53 min
Jul 6, 6:23 PM MDTMesoscale DiscussionSPC67 min
Jul 6, 7:23 PM MDTSevere Thunderstorm WatchSPC5 hr
Jul 6, 9:36 PM MDTSevere Thunderstorm WarningGGW54 min
Jul 6, 10:16 PM MDTTornado WarningGGW29 min
Jul 6, 10:28 PM MDTSevere Thunderstorm WarningGGW47 min
Jul 6, 10:30 PM MDTMesoscale DiscussionSPC60 min
Jul 6, 10:43 PM MDTTornado WarningGGW21 min
Jul 6, 11:15 PM MDTSevere Thunderstorm WarningGGW44 min
Jul 8, 7:55 AM MDTSpecial Weather StatementGGW50 min
Jul 8, 10:28 AM MDTFlash Flood WatchGGW9 hr
Jul 8, 10:38 AM MDTMesoscale DiscussionSPC97 min
Jul 8, 10:41 AM MDTSevere Thunderstorm WarningGGW64 min
Jul 8, 1:02 PM MDTMesoscale DiscussionSPC88 min
Jul 8, 2:20 PM MDTTornado WatchSPC8 hr
Jul 8, 5:46 PM MDTMesoscale DiscussionSPC89 min
Jul 8, 6:39 PM MDTSevere Thunderstorm WarningGGW29 min
Jul 13, 5:05 PM MDTMesoscale DiscussionSPC55 min
Jul 13, 6:11 PM MDTSevere Thunderstorm WatchSPC4 hr
Jul 22, 2:52 PM MDTFire Weather WatchGGW13 hr
Jul 23, 3:57 AM MDTRed Flag WarningGGW17 hr
Aug 7, 8:46 PM MDTSevere Thunderstorm WarningGGW37 min
Aug 7, 10:36 PM MDTFlash Flood WarningGGW4 hr
Aug 12, 9:03 PM MDTSpecial Weather StatementGGW57 min
Aug 13, 10:51 PM MDTSevere Thunderstorm WarningGGW54 min
Aug 13, 11:47 PM MDTSevere Thunderstorm WarningGGW58 min
Aug 14, 2:32 AM MDTSevere Thunderstorm WarningGGW28 min
Aug 14, 5:10 PM MDTMesoscale DiscussionSPC65 min
Aug 14, 8:00 PM MDTSevere Thunderstorm WatchSPC6 hr
Aug 14, 9:44 PM MDTSevere Thunderstorm WarningGGW61 min
Aug 14, 10:44 PM MDTSevere Thunderstorm WarningGGW61 min
Aug 14, 10:46 PM MDTSevere Thunderstorm WarningGGW49 min
Aug 14, 10:47 PM MDTMesoscale DiscussionSPC58 min
Aug 14, 11:46 PM MDTSevere Thunderstorm WarningGGW59 min
Aug 15, 1:28 AM MDTAreal Flood AdvisoryGGW3 hr
Aug 15, 1:31 AM MDTMesoscale DiscussionSPC89 min
Aug 23, 7:02 PM MDTMesoscale DiscussionSPC88 min
Aug 23, 7:55 PM MDTTornado WatchSPC5 hr
Aug 23, 8:02 PM MDTSevere Thunderstorm WarningGGW58 min
Aug 23, 8:59 PM MDTSevere Thunderstorm WarningGGW61 min
Aug 23, 9:34 PM MDTSevere Thunderstorm WarningGGW56 min
Aug 23, 10:17 PM MDTFlash Flood WarningGGW3 hr
Aug 23, 10:32 PM MDTSevere Thunderstorm WarningGGW41 min
Sep 5, 3:36 AM MDTFire Weather WatchGGW24 hr
Sep 6, 3:52 AM MDTRed Flag WarningGGW18 hr
Sep 8, 2:44 PM MDTRed Flag WarningGGW28 hr
Sep 13, 1:44 PM MDTMesoscale DiscussionSPC61 min
Sep 13, 2:35 PM MDTSevere Thunderstorm WatchSPC7 hr
Sep 13, 6:12 PM MDTSevere Thunderstorm WarningGGW63 min
Sep 13, 6:29 PM MDTMesoscale DiscussionSPC91 min
Sep 13, 7:04 PM MDTSevere Thunderstorm WarningGGW56 min
Sep 13, 7:08 PM MDTSevere Thunderstorm WarningGGW52 min
Sep 13, 7:52 PM MDTSevere Thunderstorm WarningGGW37 min
Sep 13, 7:58 PM MDTSevere Thunderstorm WarningGGW62 min
Sep 13, 8:53 PM MDTSevere Thunderstorm WarningGGW67 min
Sep 13, 9:20 PM MDTSevere Thunderstorm WarningGGW55 min
Sep 13, 9:52 PM MDTMesoscale DiscussionSPC53 min
Sep 18, 4:05 AM MDTFire Weather WatchGGW23 hr
Sep 19, 3:31 AM MDTRed Flag WarningGGW20 hr
Sep 24, 8:05 PM MDTFire Weather WatchGGW19 hr
Sep 25, 3:00 PM MDTRed Flag WarningGGW30 hr
Sep 27, 3:46 AM MDTRed Flag WarningGGW17 hr
Sep 29, 4:06 AM MDTRed Flag WarningGGW16 hr
Oct 3, 2:54 PM MDTWinter Storm WatchGGW24 hr
Oct 4, 2:48 PM MDTWinter Weather AdvisoryGGW36 hr
Oct 13, 2:53 PM MDTFreezing Rain AdvisoryGGW21 hr
Dec 9, 2:55 PM MSTWind Chill AdvisoryGGW18 hr
Dec 11, 3:06 PM MSTWinter Storm WatchGGW13 hr
Dec 12, 4:19 AM MSTWinter Weather AdvisoryGGW37 hr
Dec 14, 4:25 PM MSTWind Chill AdvisoryGGW12 hr
Dec 20, 7:52 AM MSTDense Fog AdvisoryGGW13 hr
Dec 20, 3:51 PM MSTWinter Weather AdvisoryGGW22 hr
Dec 22, 3:44 AM MSTWinter Storm WatchGGW23 hr
Dec 22, 3:05 PM MSTBlizzard WatchGGW12 hr
Dec 23, 3:01 AM MSTWinter Weather AdvisoryGGW17 hr
Dec 23, 3:14 PM MSTWind Chill AdvisoryGGW68 hr
Dec 24, 3:22 PM MSTWinter Weather AdvisoryGGW49 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 archive20082010

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.