The National Weather Service office in Portland has issued a Red Flag Warning for high fire potential in eastern Multnomah County, Clackamas County, Marion County, Linn County and eastern Lane County. The warning is in effect from midnight Tuesday until 11:59 Thursday night.
The next thermal trough entering Oregon is expected to develop over southern Oregon Tuesday night and move north through Wednesday into the foothills of the Cascades. Wind gusts of up to 25 mph are predicted – with some gusts anticipated to reach 35 mph near Mt. Hood.
The thermal trough is expected to stress all three points of the ‘wildfire triangle’ – very high temperatures, very low humidity and wind gusts; some thunderstorm activity is expected to generate dry lightning as well, increasing the potential for wildfire growth throughout the region.
The National Weather Service issues Red Flag Warnings & Fire Weather Watches to alert fire agencies of the onset, or possible onset, of critical weather and dry conditions that could lead to rapid or dramatic increases in wildfire activity. During these times extreme caution is urged by all residents, because a simple spark can cause a major wildfire.
A Red Flag Warning is the highest fire forecast warning issued by the National Weather Service to warn of conditions that are ideal for wildland fire ignition and propagation. When humidity is very low, wildland fuels are extremely dry and when high winds are accompanied with multiple lightning strikes, the Red Flag Warning becomes a critical statement for firefighting agencies, which often alter their staffing and equipment resources dramatically to accommodate the forecast risk.
To the public, a Red Flag Warning means high fire danger with increased probability of a quickly spreading vegetation fire in the area within 24 hours.
Kevin Weeks
Oregon Department of Forestry