Alert archive / New York / Broome County

Flash Flood Warnings in Broome County, New York

169 flash flood warnings since 1986. An alert counts here when it covered this county. The archive of flash flood warnings reaches back to 1986.

Broome County and its neighbors

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

Flash Flood Warnings
169
Busiest year
201118 flash flood warnings
Average year
6over 30 years on file

Over time

By year

Before October 2007 these were issued for whole counties, and a storm crossing three counties was often three warnings; since then one polygon follows the storm. The count changed with the practice, not only with the weather.

Warning verification

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

From 2008 to 2025, 90% of flash flood reports in Broome County fell inside a flash flood warning issued on average 127 minutes before, and 38% of the flash flood warnings had no report inside them.

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008220%475%34 min
20094325%4100%55 min
20106267%9100%124 min
2011181328%2896%224 min
20137614%1080%133 min
20145260%367%145 min
20156267%2100%176 min
20178625%1191%72 min
201811827%2075%84 min
20192150%0
20209456%475%52 min
202110640%2095%101 min
20237443%475%70 min
202411827%22100%127 min
20256350%4100%90 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.

The latest flash flood warnings

The most recent on file, newest first.

IssuedProductOfficeLasted
Aug 2, 10:54 PM EDTFlash Flood WarningBGM2 hr
Aug 2, 8:30 PM EDTFlash Flood WarningBGM5 hr
Jul 29, 6:16 PM EDTFlash Flood WarningBGM3 hr
Mar 31, 6:37 PM EDTFlash Flood WarningBGM96 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.