Alert archive / Maryland

Weather alerts in Somerset County, Maryland

2,890 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Somerset County and its neighbors

Each county as a circle sized by its count since 1986. Tap one for its archive.

Alerts
2,890
Warnings
510
Watches
433
Advisories
734
Busiest year
2019166 alerts
Average year
76over 38 years on file

Over time

By year

Before late 2005 the archive holds only tornado, severe thunderstorm, flash flood and marine warnings, and from 1997 SPC's watches, so the jump that year is the archive widening, not the weather.

By month of the year

Warning verification

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

From 2008 to 2025, 0% of tornado reports in Somerset County fell inside a tornado warning, and 83% of the tornado warnings had no report inside them.

Tornado warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
200910100%0
201310100%0
201410100%0
20154175%0
201620100%0
201920100%0
20204250%0
202110100%0
202210100%20%
202310100%0

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
200822959%9100%30 min
200910550%6100%35 min
20109722%3100%23 min
20116433%540%14 min
20129633%1100%50 min
20137614%4100%10 min
20145260%0
20156350%475%38 min
20169633%850%10 min
20175180%0
20184250%250%12 min
2019201620%8100%22 min
20208538%2100%6 min
202111373%0
2022151127%5100%18 min
2023181139%4100%26 min
20247443%2100%32 min
202513838%1283%24 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2009110%0
2011110%0
20122150%0
2016110%2100%140 min
20182150%2100%63 min
2020330%3100%55 min
20232150%0
2024220%0
20252150%2100%78 min

Years from 2008, the first full year of storm-based warnings. The year still running is on its own page.

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.

By product

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

The latest warnings

The most recent on file, newest first.

IssuedProductOfficeLasted
Sep 22, 2:57 PM EDTCoastal Flood WarningAKQ5 days
Sep 4, 2:18 AM EDTSevere Thunderstorm WarningAKQ27 min
Sep 2, 2:42 PM EDTSevere Thunderstorm WarningAKQ48 min
Aug 28, 12:28 PM EDTFlash Flood WarningAKQ98 min
Aug 20, 8:56 PM EDTFlash Flood WarningAKQ115 min
Jul 28, 8:42 PM EDTSevere Thunderstorm WarningAKQ47 min
Jul 27, 3:01 PM EDTSevere Thunderstorm WarningAKQ21 min
Jul 27, 2:32 PM EDTSevere Thunderstorm WarningAKQ31 min
Jul 22, 6:32 PM EDTSevere Thunderstorm WarningAKQ58 min
Jul 22, 1:27 AM EDTFlash Flood WarningAKQ4 hr
Jul 22, 12:29 AM EDTFlash Flood WarningAKQ4 hr
Jul 22, 12:18 AM EDTSevere Thunderstorm WarningAKQ57 min

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive

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.