Portland is preparing for a major weather event as an atmospheric river is set to bring heavy rain and the potential for flooding to the region this weekend. According to local weather experts, two inches of rain or more are expected to fall in Portland from Saturday, February 22 to Monday, February 24, with coastal areas seeing even higher totals. The atmospheric river will bring sustained rain, increased runoff, and the possibility of dangerous flooding in low-lying areas.
This phenomenon, which has been increasing in frequency, is the result of a narrow corridor of moisture in the atmosphere that funnels heavy rainfall into a concentrated area. These events are notorious for causing flash floods, disruptions to daily life, and dangerous travel conditions.
What Is an Atmospheric River?
An atmospheric river is a large, concentrated band of moisture flowing through the atmosphere, which can carry as much water as a flood. These rivers of moisture often cause intense rainfall and severe flooding, especially when they hit mountainous areas. The moisture then cascades down into the valleys and lowlands, causing significant rainfall over extended periods.
Portland is familiar with the effects of atmospheric rivers, but this particular one is forecasted to be especially powerful, bringing heavy rainfall and high snow levels, which will likely lead to rising water levels along streams and rivers in the area.
What to Expect in Portland This Weekend
- Friday, February 21: The atmospheric river will begin pushing rain into Portland by the afternoon, with steady rainfall expected through the evening. The high will be 50°F (10°C), but the heavy rain will make it feel colder.
- Saturday, February 22: Expect heavy rainfall starting early in the morning, with totals reaching 1–2 inches in some parts of the city. Highs will hover around 55°F (13°C), and lows will stay near 45°F (7°C).
- Sunday, February 23: The rain continues, though it will become more intermittent by the afternoon. Expect another 1–2 inches of rain. The high will be 58°F (14°C), with overnight lows of 47°F (8°C).
- Monday, February 24: The rain will begin to taper off, but flooding risks will still be high. Highs will reach 50°F (10°C) before the weather clears up for the next few days.
- Tuesday, February 25: Expect a brief break in the rain with some cloud cover. Highs will remain mild around 54°F (12°C).
What Does This Mean for Portland?
Portland is no stranger to rainfall, but an atmospheric river of this magnitude could cause some serious problems. Experts are predicting rising water levels and possible flooding in areas near rivers, creeks, and low-lying areas. Several local schools and businesses have already started preparing for closures, and the city is urging residents to stay off the roads during peak rainfall.
The snow levels in the nearby mountains are also expected to rise to around 7,000 feet, which will bring rain to areas that typically see snow in winter. This increased runoff can further increase the risk of mudslides and flooding in both urban and rural areas.
In preparation for this storm, the city has opened up emergency shelters for those without power or heat and advised residents to clear their gutters and secure loose outdoor items.
Safety Tips for Portland Residents
- Avoid travel during the heaviest rain. If you must travel, be prepared for flooded roads, especially in low-lying areas and near rivers. Avoid driving through flooded intersections or areas with standing water.
- Monitor flood alerts. Keep an eye on the National Weather Service and local news for the latest warnings about flooding in your area.
- Stay indoors during the worst of the storm. Flash flooding can happen quickly, and it’s safest to remain inside until the worst of the storm passes.
- Check on vulnerable neighbors. The elderly and those without proper heating are especially at risk during heavy rains. Make sure they have everything they need.
- Secure valuables. If you live in an area that’s prone to flooding, move valuable items to higher ground or place them in sealed plastic containers to prevent water damage.
When Will This Storm End?
The storm is expected to start easing on Monday, February 24, but rain will likely continue intermittently until Tuesday, February 25. After that, the city will see clearing skies and a return to drier weather, with temperatures remaining mild for the rest of the week.
Residents are encouraged to stay vigilant and prepared, as the atmospheric river could have far-reaching effects on travel, local flooding, and utilities.
