Severe weather alert activated Monday as a Pineapple Express slams West Coast

Updated: 10:08 AM PST – Flood Watch in effect from February 23, 10:00 PM PST until February 25, 10:00 PM PST

Roseburg, Ore., — FLOOD WATCH IN EFFECT FROM THIS EVENING THROUGH WEDNESDAY
EVENING.

• WHAT…Flooding caused by excessive rainfall and snowmelt is possible.
• WHERE…Coos, Curry, Josephine, Jackson, western and central Douglas, and western Siskiyou counties, including all small drainages, creeks, and streams, especially those where melting snow may contribute to high run off.
• WHEN…From this evening through Wednesday evening.
• IMPACTS…Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Creeks and streams may rise out of their banks. Flooding may occur in poor drainage and urban areas.
• ADDITIONAL DETAILS…
• Heavy rain is expected today through Tuesday, and with high snow levels, snow melt from any residual snowpack in the hills and mountains may contribute to excessive run off, leading to rapid rises on area creeks and streams.
• http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS…

You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop.

Roseburg, Ore., — Heavy rain possible in Coos, Curry, Douglas, Jackson, and Josephine counties in Oregon, and Siskiyou County in California Monday afternoon through Tuesday.

A warm sourced atmospheric river, commonly referred to as a Pineapple Express, will likely bring periods of moderate to heavy rainfall Monday afternoon through Tuesday. Current rainfall forecasts show widespread amounts of 2 to 4 inches along the coast with locally up to 6 inches in the favored coast ranges of Curry County. Up to an inch of rain is expected for many of the inland West Side valleys, with 1 to 3 inches along the Cascades and mountains and south slopes of Siskiyou County, and between a quarter of an inch and an inch across the East Side.

Compounding the hydrological concerns, the warm rain is expected with snow levels well above 7000 feet, which will result in snowmelt and therefore higher than expected runoff in area watersheds.

Small streams and creeks are likely to rise rapidly during this event with nuisance flooding and ponding of water on roadways during periods of heavy rain. Significant rises on main stem rivers and flashier creeks are also expected. Given that rivers are still running fairly low for this time of year, river flooding potential
is a bit lower than usual, but there is at least a low probability of some flooding, especially in the Coquille Basin, and along the more flashier streams such as Deer Creek in Roseburg and Little Butte Creek in Eagle Point.

While the exact scenario for the heavy rainfall and potential flooding remains uncertain, we will continue to monitor the forecasts and update accordingly. Flood Watches may be issued by the national Weather Service if this situation worsens.