Alert archive / New York

Weather alerts in Westchester County, New York

4,745 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Westchester County and its neighbors

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

Alerts
4,745
Warnings
1,112
Watches
595
Advisories
1,615
Busiest year
2011305 alerts
Average year
122over 39 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, 100% of tornado reports in Westchester County fell inside a tornado warning issued on average 3 minutes before, and 90% of the tornado warnings had no report inside them.

Tornado warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
200820100%0
200910100%0
201140100%0
201230100%0
2018220%2100%3 min
202030100%0
202150100%0

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008271737%1688%20 min
2009261638%25100%26 min
2010231822%1457%31 min
2011332330%2677%19 min
2012261831%771%35 min
2013161225%9100%18 min
2014191332%4100%11 min
20157529%560%8 min
2016181233%475%13 min
2017131115%2100%10 min
2018161319%3263%17 min
2019181517%771%29 min
2020262119%1493%25 min
2021241825%989%35 min
202214936%2040%28 min
2023181422%1688%17 min
2024282221%4381%20 min
2025131023%1060%26 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008161319%2085%89 min
20097443%580%26 min
2010110%0
20119722%978%25 min
20126517%2100%5 min
201311109%1191%114 min
20149722%1090%58 min
2015330%0
2016110%0
20174250%540%92 min
20186517%813%74 min
2019440%757%75 min
20204175%20%
202112120%3583%115 min
20224250%956%44 min
202318180%4088%123 min
20248538%1100%87 min
20257614%14100%130 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 25, 5:27 AM EDTCoastal Flood WarningOKX58 hr
Sep 13, 9:06 AM EDTFlash Flood WarningOKX3 hr
Sep 13, 7:23 AM EDTFlash Flood WarningOKX4 hr
Aug 27, 2:37 PM EDTSevere Thunderstorm WarningOKX38 min
Aug 27, 11:09 AM EDTSevere Thunderstorm WarningOKX51 min
Aug 23, 7:21 AM EDTFlash Flood WarningOKX71 min
Aug 13, 12:27 AM EDTSevere Thunderstorm WarningOKX48 min
Aug 7, 6:47 PM EDTFlash Flood WarningOKX3 hr
Aug 7, 6:24 PM EDTSevere Thunderstorm WarningOKX51 min
Aug 7, 5:57 PM EDTSevere Thunderstorm WarningOKX48 min
Aug 7, 5:54 PM EDTFlash Flood WarningOKX2 hr
Aug 7, 5:50 PM EDTFlash Flood Warning Considerable damage threatOKX3 hr

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.