Three Types Of Flood Warnings: What's The Difference? - WHSV

(WHSV) - Since its the middle of summer where thunderstorms and heavy rain commonly happen, its a good time to look at what each type of flood warning means.

Areal Flood Warning

Areal flood warnings are going to be issued for usually a larger area. This time of warning is issued when flooding may happen more gradual from rainfall that may last several hours or is more persistent.

This is when water rises and potentially over low lying areas, some roads and when smaller creeks and streams rise more gradually. In our area low water bridges also tend to get covered with water from rain that may last several hours. This type of flooding happens more over time, as opposed to flash flooding which happens rapidly. Areal flooding can still be dangerous and destructive as it can cover roads and damage property.

River Flood Warning

River flood warnings are issued when a river is predicted to at least reach flood stage. In this instance, it typically takes several rounds of heavy rain over a few days or even numerous thunderstorms. It can also happen when streams and rivers flow into another river and a more heavier, prolonged rain is present. River flood warnings can last for extended amounts of time as it can take a while for a river to flood or to recede after flooding.

Rivers continue to rise even after the rain stops. If the river is in a significant flood stage, it can cause major damage to low lying areas as rivers flood into these areas.

Flash Flood Warning

Flash flooding occurs when a large amount of rain comes down in a very short time period. Water has to find a place to go in these situations and danger can escalate quickly under these circumstances. Flash flooding can happen anywhere and it can happen quickly. Sometimes thunderstorms can drop 1-3″ of rain in an hour or less and that would be an example of flash flooding.

A perfect example of serious flash flooding was back in August 2020 when heavy rain flooded Staunton. In that situation, a thunderstorm with tremendously heavy rain stalled out over the city of Staunton and led to 2-7″ of rain in less than 6 hours.

Flash flooding is extremely dangerous and can turn deadly fast. Water can rise very quickly and the power of rushing water shouldn’t be underestimated.

If flash flooding is significant enough, a “Flash Flood Emergency” may be issued. With a flash flood emergency, flash flooding is extreme, deadly, and can cause catastrophic damage. These emergencies are rarely issued.

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