Alert archive / North Dakota / Williams County

Weather alerts in Williams County, North Dakota, 2018

137 weather alerts in 2018, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Williams County and its neighbors

Each county as a circle sized by its count in 2018. Tap one for its archive.

Alerts
137
Warnings
38
Watches
16
Advisories
49
Busiest month
July29 alerts
Busiest day
July 10, 201810 alerts

Over time

By month

Warning verification

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

Williams County, 2018

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings231726%2396%33 min
Flash flood warnings00

Each office's whole area, 2018

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Bismarck, ND: tornado warnings24579%2264%9 min
NWS Bismarck, ND: severe thunderstorm warnings27516440%31590%28 min
NWS Bismarck, ND: flash flood warnings7443%771%119 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, Central Time. Each opens its own page with the text, the map, the radar and the sounding.

IssuedProductOfficeLasted
Jan 1, 11:59 AM CSTWind Chill AdvisoryBIS22 hr
Jan 9, 4:10 AM CSTWinter Weather AdvisoryBIS53 hr
Jan 11, 12:01 AM CSTWind Chill AdvisoryBIS60 hr
Jan 12, 3:24 AM CSTWind Chill WarningBIS32 hr
Jan 14, 2:42 AM CSTWind Chill AdvisoryBIS57 hr
Jan 18, 2:10 PM CSTWinter Weather AdvisoryBIS18 hr
Jan 29, 2:26 PM CSTWind AdvisoryBIS29 hr
Jan 31, 2:34 PM CSTWind Chill AdvisoryBIS21 hr
Feb 3, 3:18 AM CSTWind Chill AdvisoryBIS33 hr
Feb 3, 9:09 PM CSTWind Chill AdvisoryBIS15 hr
Feb 4, 3:03 PM CSTWind Chill AdvisoryBIS20 hr
Feb 5, 3:52 AM CSTWind Chill AdvisoryBIS29 hr
Feb 6, 2:05 PM CSTWind Chill AdvisoryBIS19 hr
Feb 8, 2:45 PM CSTWind Chill AdvisoryBIS21 hr
Feb 9, 2:59 PM CSTWind Chill AdvisoryBIS21 hr
Feb 11, 3:43 PM CSTWind Chill AdvisoryBIS20 hr
Feb 17, 2:39 PM CSTWinter Weather AdvisoryBIS21 hr
Feb 20, 3:07 PM CSTWind Chill AdvisoryBIS19 hr
Mar 2, 4:22 AM CSTWinter Storm WatchBIS59 hr
Mar 3, 3:41 PM CSTDense Fog AdvisoryBIS20 hr
Mar 3, 4:07 PM CSTWinter Storm WarningBIS65 hr
Mar 4, 3:00 PM CSTSpecial Weather StatementBIS45 min
Mar 4, 3:47 PM CSTMesoscale DiscussionSPC3 hr
Mar 6, 3:11 AM CSTWinter Weather AdvisoryBIS6 hr
Mar 12, 11:57 PM CDTDense Fog AdvisoryBIS10 hr
Mar 14, 6:40 AM CDTDense Fog AdvisoryBIS5 hr
Mar 22, 12:23 AM CDTDense Fog AdvisoryBIS14 hr
Mar 22, 3:51 AM CDTWinter Storm WarningBIS43 hr
Mar 22, 3:51 AM CDTWinter Weather AdvisoryBIS55 hr
Mar 23, 2:45 PM CDTRiver Flood WatchBIS24 hr
Mar 24, 1:03 AM CDTDense Fog AdvisoryBIS10 hr
Mar 24, 1:30 PM CDTRiver Flood WarningBIS4 days
Mar 26, 6:00 AM CDTDense Fog AdvisoryBIS7 hr
Mar 29, 4:08 AM CDTWinter Storm WatchBIS24 hr
Mar 29, 10:08 AM CDTRiver Flood WarningBIS8 days
Mar 30, 4:01 AM CDTWinter Storm WarningBIS24 hr
Mar 30, 3:03 PM CDTMesoscale DiscussionSPC5 hr
Mar 30, 9:40 PM CDTWind Chill AdvisoryBIS13 hr
Apr 6, 3:18 PM CDTWinter Weather AdvisoryBIS52 hr
Apr 19, 6:46 AM CDTDense Fog AdvisoryBIS4 hr
Apr 19, 9:13 AM CDTRiver Flood WarningBIS10 hr
Apr 20, 8:28 AM CDTRiver Flood WarningBIS12 hr
Apr 21, 7:04 AM CDTRiver Flood WarningBIS33 hr
Apr 26, 9:15 AM CDTRed Flag WarningBIS10 hr
Apr 28, 3:40 AM CDTRed Flag WarningBIS17 hr
Apr 29, 10:33 PM CDTSpecial Weather StatementBIS27 min
May 9, 2:41 PM CDTRiver Flood WarningBIS83 days
May 16, 11:58 PM CDTSpecial Weather StatementBIS47 min
May 17, 12:17 AM CDTSpecial Weather StatementBIS43 min
May 17, 1:55 AM CDTSpecial Weather StatementBIS50 min
May 18, 2:29 PM CDTFrost AdvisoryBIS19 hr
May 23, 11:09 PM CDTSpecial Weather StatementBIS66 min
May 27, 12:11 AM CDTSpecial Weather StatementBIS34 min
May 30, 10:02 PM CDTSevere Thunderstorm WarningBIS58 min
May 30, 11:07 PM CDTSpecial Weather StatementBIS38 min
Jun 1, 2:13 PM CDTMesoscale DiscussionSPC2 hr
Jun 1, 3:30 PM CDTTornado WatchSPC6 hr
Jun 1, 5:25 PM CDTSevere Thunderstorm WarningBIS35 min
Jun 1, 5:29 PM CDTSevere Thunderstorm WarningBIS61 min
Jun 1, 6:02 PM CDTMesoscale DiscussionSPC88 min
Jun 2, 3:10 AM CDTWind AdvisoryBIS18 hr
Jun 5, 12:00 AM CDTSpecial Weather StatementBIS45 min
Jun 7, 7:09 PM CDTSevere Thunderstorm WatchSPC7 hr
Jun 7, 10:04 PM CDTMesoscale DiscussionSPC86 min
Jun 10, 3:37 PM CDTSevere Thunderstorm WatchSPC7 hr
Jun 14, 10:56 AM CDTSevere Thunderstorm WarningBIS49 min
Jun 14, 11:44 AM CDTSevere Thunderstorm WarningBIS46 min
Jun 14, 12:28 PM CDTSevere Thunderstorm WarningBIS47 min
Jun 14, 2:54 PM CDTMesoscale DiscussionSPC96 min
Jun 14, 3:40 PM CDTTornado WatchSPC7 hr
Jun 14, 6:41 PM CDTMesoscale DiscussionSPC94 min
Jun 23, 2:07 PM CDTSpecial Weather StatementBIS38 min
Jun 23, 2:53 PM CDTSpecial Weather StatementBIS22 min
Jun 28, 2:01 PM CDTFlash Flood WatchBIS14 hr
Jun 28, 3:16 PM CDTTornado WatchSPC8 hr
Jun 28, 5:04 PM CDTSevere Thunderstorm WarningBIS23 min
Jun 28, 6:59 PM CDTMesoscale DiscussionSPC91 min
Jun 28, 8:47 PM CDTSevere Thunderstorm WarningBIS58 min
Jun 28, 9:06 PM CDTMesoscale DiscussionSPC84 min
Jun 28, 9:46 PM CDTSevere Thunderstorm WarningBIS59 min
Jun 28, 10:21 PM CDTMesoscale DiscussionSPC84 min
Jun 28, 10:41 PM CDTSevere Thunderstorm WarningBIS64 min
Jul 3, 9:13 PM CDTMesoscale DiscussionSPC2 hr
Jul 3, 9:39 PM CDTSevere Thunderstorm WatchSPC6 hr
Jul 3, 11:52 PM CDTSpecial Weather StatementBIS53 min
Jul 4, 12:42 AM CDTSpecial Weather StatementBIS48 min
Jul 9, 5:48 PM CDTMesoscale DiscussionSPC117 min
Jul 9, 7:01 PM CDTSevere Thunderstorm WatchSPC8 hr
Jul 9, 7:30 PM CDTSpecial Weather StatementBIS45 min
Jul 9, 8:38 PM CDTSevere Thunderstorm WarningBIS67 min
Jul 9, 8:59 PM CDTMesoscale DiscussionSPC91 min
Jul 9, 9:42 PM CDTSevere Thunderstorm WarningBIS63 min
Jul 9, 10:04 PM CDTSevere Thunderstorm WarningBIS56 min
Jul 9, 10:24 PM CDTMesoscale DiscussionSPC96 min
Jul 9, 10:41 PM CDTSevere Thunderstorm WarningBIS64 min
Jul 9, 11:42 PM CDTSevere Thunderstorm WarningBIS63 min
Jul 10, 12:18 AM CDTAreal Flood AdvisoryBIS3 hr
Jul 10, 7:32 PM CDTMesoscale DiscussionSPC118 min
Jul 10, 8:50 PM CDTSevere Thunderstorm WatchSPC5 hr
Jul 10, 9:19 PM CDTSevere Thunderstorm WarningBIS56 min
Jul 10, 10:09 PM CDTSevere Thunderstorm WarningBIS66 min
Jul 18, 2:21 PM CDTSevere Thunderstorm WarningBIS54 min
Jul 18, 2:44 PM CDTSevere Thunderstorm WarningBIS31 min
Jul 21, 12:53 PM CDTMesoscale DiscussionSPC3 hr
Jul 21, 3:24 PM CDTSpecial Weather StatementBIS36 min
Jul 21, 3:37 PM CDTSevere Thunderstorm WarningBIS27 min
Jul 21, 4:55 PM CDTSevere Thunderstorm WarningBIS65 min
Jul 21, 5:11 PM CDTSevere Thunderstorm WatchSPC7 hr
Jul 21, 5:56 PM CDTSevere Thunderstorm WarningBIS64 min
Jul 21, 6:18 PM CDTMesoscale DiscussionSPC87 min
Jul 21, 6:56 PM CDTSevere Thunderstorm WarningBIS64 min
Aug 10, 3:26 PM CDTFire Weather WatchBIS23 hr
Aug 11, 2:18 PM CDTRed Flag WarningBIS31 hr
Aug 12, 3:13 AM CDTHeat AdvisoryBIS16 hr
Aug 26, 3:52 PM CDTMesoscale DiscussionSPC113 min
Sep 3, 5:00 PM CDTMesoscale DiscussionSPC90 min
Sep 3, 5:44 PM CDTSevere Thunderstorm WatchSPC6 hr
Sep 4, 2:50 PM CDTFrost AdvisoryBIS18 hr
Sep 20, 2:32 PM CDTFrost AdvisoryBIS18 hr
Sep 25, 2:06 PM CDTFrost AdvisoryBIS18 hr
Sep 27, 2:55 AM CDTFreeze WatchBIS12 hr
Sep 27, 2:31 PM CDTFreeze WarningBIS19 hr
Sep 28, 3:09 PM CDTFreeze WarningBIS18 hr
Oct 2, 8:51 PM CDTDense Fog AdvisoryBIS5 hr
Oct 4, 3:20 AM CDTWinter Weather AdvisoryBIS39 hr
Nov 1, 3:10 PM CDTWinter Weather AdvisoryBIS42 hr
Nov 5, 9:17 PM CSTWind AdvisoryBIS21 hr
Nov 15, 3:01 PM CSTWinter Weather AdvisoryBIS29 hr
Nov 20, 8:52 PM CSTDense Fog AdvisoryBIS14 hr
Nov 21, 2:04 PM CSTDense Fog AdvisoryBIS22 hr
Nov 27, 3:13 AM CSTWinter Weather AdvisoryBIS45 hr
Nov 29, 3:36 AM CSTDense Fog AdvisoryBIS9 hr
Nov 29, 6:31 PM CSTDense Fog AdvisoryBIS20 hr
Nov 30, 4:07 AM CSTWinter Weather AdvisoryBIS38 hr
Nov 30, 2:56 PM CSTDense Fog AdvisoryBIS43 hr
Dec 1, 2:59 PM CSTDense Fog AdvisoryBIS19 hr
Dec 30, 2:58 PM CSTWind Chill AdvisoryBIS43 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 archive20172019

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.