Weather Alert in Oregon
Red Flag Warning issued August 27 at 9:16AM PDT until August 27 at 9:00PM PDT by NWS Portland OR
AREAS AFFECTED: Northern Willamette National Forest; Southern Willamette National Forest
DESCRIPTION: ...RED FLAG WARNING IN EFFECT THROUGH THIS EVENING FOR DRY AND UNSTABLE CONDITIONS, AND THUNDERSTORMS... .Low pressure in the area is increasing instability and producing thunderstorms within the area. Instability will be highest within the Lane and Linn County Cascades. High probability for pyrocumulus development. Outflow winds from thunderstorms may cause rapid fire spread. * AFFECTED AREA...In Oregon, Fire Weather Zone 689 Northern Willamette National Forest and Fire Weather Zone 690 Southern Willamette National Forest. * THUNDERSTORMS...Isolated to scattered thunderstorms. 20-30% chance of thunderstorms today. 5-10% chance for wetting rains with passing thunderstorms. * UNSTABLE...High instability with elevated mixing heights may promote pyroconvective activity. * OUTFLOW WINDS...Instantaneous gusts as high as 40 mph. Gusts at these speeds can be observed tens of miles away from the core of the thunderstorm. * IMPACTS...Conditions may be favorable for rapid fire spread which may threaten life and property. Thunderstorm outflow winds may result in unanticipated erratic fire spread. High instability may result in fire growth. Frequent lightning and critically dry fuels may result in fire starts.
INSTRUCTION: A Red Flag Warning means that critical fire weather conditions are either occurring now, or will shortly. A combination of the above conditions can contribute to extreme fire behavior.
Want more detail? Get the Complete 7 Day and Night Detailed Forecast!
Current U.S. National Radar--Current
The Current National Weather Radar is shown below with a UTC Time (subtract 5 hours from UTC to get Eastern Time).
National Weather Forecast--Current
The Current National Weather Forecast and National Weather Map are shown below.
National Weather Forecast for Tomorrow
Tomorrow National Weather Forecast and Tomorrow National Weather Map are show below.
North America Water Vapor (Moisture)
This map shows recent moisture content over North America. Bright and colored areas show high moisture (ie, clouds); brown indicates very little moisture present; black indicates no moisture.
Weather Topic: What are Nimbostratus Clouds?
Home - Education - Cloud Types - Nimbostratus Clouds
Next Topic: Precipitation
A nimbostratus cloud is similar to a stratus cloud in its formless,
smooth appearance. However, a nimbostratus cloud is darker than a stratus cloud,
because it is thicker.
Unlike a stratus cloud, a nimbostratus cloud typically brings with it the threat
of moderate to heavy precipitation. In some cases, the precipitation may evaporate
before reaching the ground, a phenomenon known as virga.
Next Topic: Precipitation
Weather Topic: What is Rain?
Home - Education - Precipitation - Rain
Next Topic: Shelf Clouds
Precipitation in the form of water droplets is called rain.
Rain generally has a tendency to fall with less intensity over a greater period
of time, and when rainfall is more severe it is usually less sustained.
Rain is the most common form of precipitation and happens with greater frequency
depending on the season and regional influences. Cities have been shown to have
an observable effect on rainfall, due to an effect called the urban heat island.
Compared to upwind, monthly rainfall between twenty and forty miles downwind of
cities is 30% greater.
Next Topic: Shelf Clouds
Current conditions powered by WeatherAPI.com
