Alert archive / California / Sonoma County

Weather alerts in Sonoma County, California, 2012

56 weather alerts in 2012, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Sonoma County and its neighbors

Each county as a circle sized by its count in 2012. Tap one for its archive.

Alerts
56
Warnings
14
Watches
7
Advisories
35
Busiest month
December16 alerts
Busiest day
December 2, 20125 alerts

Over time

By month

Warning verification

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

Sonoma County, 2012

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings00
Flash flood warnings70100%20%

Each office's whole area, 2012

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS San Francisco Bay Area, CA: severe thunderstorm warnings30100%10%
NWS San Francisco Bay Area, CA: flash flood warnings17382%1020%69 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, Pacific Time. Each opens its own page with the text, the map, the radar and the sounding.

IssuedProductOfficeLasted
Jan 3, 6:03 AM PSTDense Fog AdvisoryMTR4 hr
Jan 5, 2:40 AM PSTHigh Surf AdvisoryMTR39 hr
Jan 15, 8:08 PM PSTFreeze WatchMTR7 hr
Jan 16, 3:19 AM PSTFreeze WarningMTR29 hr
Jan 20, 10:14 AM PSTHigh Surf AdvisoryMTR48 hr
Jan 22, 2:33 AM PSTWind AdvisoryMTR27 hr
Jan 26, 5:04 AM PSTHigh Surf AdvisoryMTR10 hr
Jan 26, 3:16 PM PSTHigh Surf AdvisoryMTR3 hr
Feb 5, 1:55 PM PSTHigh Wind WatchMTR13 hr
Feb 6, 2:53 AM PSTWind AdvisoryMTR31 hr
Feb 7, 1:52 PM PSTHigh Surf AdvisoryMTR25 hr
Feb 8, 5:06 AM PSTDense Fog AdvisoryMTR4 hr
Feb 12, 4:29 AM PSTDense Fog AdvisoryMTR7 hr
Feb 13, 9:13 AM PSTHigh Surf AdvisoryMTR30 hr
Feb 29, 4:54 AM PSTHigh Surf AdvisoryMTR28 hr
Mar 5, 2:35 AM PSTWind AdvisoryMTR44 hr
Mar 7, 5:00 PM PSTFreeze WarningMTR15 hr
Mar 17, 2:58 AM PDTHigh Surf AdvisoryMTR41 hr
Mar 30, 3:01 AM PDTHigh Surf AdvisoryMTR35 hr
Mar 31, 2:30 PM PDTHigh Surf WarningMTR25 hr
Apr 1, 3:06 PM PDTHigh Surf AdvisoryMTR17 hr
Apr 4, 3:20 AM PDTFrost AdvisoryMTR24 hr
Apr 5, 8:17 PM PDTFrost AdvisoryMTR12 hr
Sep 5, 10:46 AM PDTRed Flag WarningMTR16 hr
Sep 28, 10:57 AM PDTExcessive Heat WatchMTR40 hr
Oct 29, 3:16 AM PDTDense Fog AdvisoryMTR5 hr
Oct 29, 1:20 PM PDTDense Fog AdvisoryMTR20 hr
Nov 9, 6:42 PM PSTFrost AdvisoryMTR13 hr
Nov 10, 10:13 AM PSTFrost AdvisoryMTR22 hr
Nov 25, 5:35 AM PSTDense Fog AdvisoryMTR3 hr
Nov 26, 3:52 AM PSTDense Fog AdvisoryMTR5 hr
Nov 27, 3:39 AM PSTWind AdvisoryMTR34 hr
Nov 27, 1:53 PM PSTHigh Wind WarningMTR21 hr
Nov 28, 2:14 PM PSTHigh Surf AdvisoryMTR67 hr
Nov 29, 11:22 AM PSTFlash Flood WatchMTR3 days
Nov 29, 11:23 AM PSTWind AdvisoryMTR27 hr
Nov 30, 4:16 AM PSTFlash Flood WarningMTR119 min
Nov 30, 6:22 AM PSTFlash Flood WarningMTR3 hr
Nov 30, 9:02 AM PSTAreal Flood AdvisoryMTR118 min
Nov 30, 11:03 AM PSTRiver Flood WatchMTR26 days
Nov 30, 10:32 PM PSTRiver Flood WarningMTR3 days
Dec 1, 10:23 AM PSTWind AdvisoryMTR26 hr
Dec 1, 4:44 PM PSTRiver Flood WatchMTR6 days
Dec 2, 6:35 AM PSTFlash Flood WarningMTR85 min
Dec 2, 6:54 AM PSTAreal Flood AdvisoryMTR3 hr
Dec 2, 7:41 AM PSTFlash Flood WarningMTR64 min
Dec 2, 8:47 AM PSTFlash Flood WarningMTR88 min
Dec 18, 3:04 AM PSTFreeze WarningMTR29 hr
Dec 19, 6:09 PM PSTWind AdvisoryMTR40 hr
Dec 21, 2:51 AM PSTHigh Surf AdvisoryMTR35 hr
Dec 21, 2:15 PM PSTAreal Flood AdvisoryMTR3 hr
Dec 22, 1:41 PM PSTWind AdvisoryMTR24 hr
Dec 23, 8:55 AM PSTFlash Flood WarningMTR4 hr
Dec 23, 9:31 AM PSTFlash Flood WatchMTR5 hr
Dec 23, 1:41 PM PSTFlash Flood WarningMTR3 hr
Dec 27, 12:39 PM PSTHigh Surf AdvisoryMTR57 hr

By product

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

ProductAlerts
Flooding
Flash Flood Warning7
River Flood Warning1
Flash Flood Watch2
River Flood Watch2
Areal Flood Advisory3
Heat
Excessive Heat Watch1
Cold
Freeze Warning3
Freeze Watch1
Frost Advisory4
Wind and dust
High Wind Warning1
High Wind Watch1
Wind Advisory8
Fire
Red Flag Warning1
Fog and smoke
Dense Fog Advisory7
Coast and beach
High Surf Warning1
High Surf Advisory13

The busiest days

Days with the most alerts issued, by UTC date.

  1. December 2, 20125alerts
  2. November 30, 20124alerts
  3. December 23, 20123alerts
  4. January 16, 20122alerts
  5. January 26, 20122alerts
  6. October 29, 20122alerts
  7. November 10, 20122alerts
  8. November 27, 20122alerts
  9. November 29, 20122alerts
  10. December 1, 20122alerts

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20112013

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.