EUGENE, Ore. – April 29 to May 3 is Severe Weather Awareness week in Oregon. Monday’s focus is the threat of flash flooding and flooding.
Flash flooding occurs as a result of heavy rains in a short period of time, ice jams, snowmelt or a dam failure; a stream or river can rise in just a few minutes. Thunderstorms can cause flash floods when the rain falls faster than the rate it’s carried away by drainage channels. Flash floods are most common in the spring and summer, but can happen in the winter during rapid snowmelt.
Flooding occurs as a result of heavy rain over a few days. The flooding may take around a day to develop, but can last for several days; it’s more commonly a problem during the wet season, November through March.
The National Weather Service issues a variety of advisories to prepare Oregonians for possible dangerous conditions.
A Flash Flood Warning advises that flash flooding has been reported and those within the warning area should evacuate immediately to higher ground.
A Flash Flood Watch advises that flash flooding is possible and those within the watch area should be ready to evacuate quickly.
An Urban and Small Stream Flood Advisory states that flooding of small streams is not expected to produce a flash flood situation.
The NWS offers some tips to stay safe when flooding is observed:
1. Do not camp or park a vehicle along streams, during threatening conditions.
2. Be aware of river water levels and be prepared to take action to move to higher ground if river levels rise.
3. Do not enter areas that are already flooded.
4. Do not try to cross a flowing stream on foot when the water is at or above knee height.
5. Be aware of erosion from swift running water, which can cause the river bank to collapse.
6. Never let your children play around high water, storm drains, viaducts or arroyos.
7. Never attempt to drive over a flooded roadway. “Turn Around, Don’t Drown”.