A surge of deep monsoonal moisture combined with a slow-moving
upper trough will bring periods of heavy showers and thunderstorms
across the region. This airmass contains anomalously high moisture
content, supporting the potential for excessive rainfall. Flash
flooding will be possible, especially in steep terrain, narrow
canyons, and near recent burn scars where soils are less able to
absorb rainfall. The greatest risk will be Tuesday afternoon through
Wednesday evening as repeated rounds of storms move through.
* WHAT...Flash flooding caused by excessive rainfall continues to be
possible.
* WHERE...Portions of Idaho, including the following areas, Boise
Mountains, Camas Prairie, Lower Treasure Valley, Owyhee Mountains,
Southern Twin Falls County, Southwest Highlands, Upper Treasure
Valley, Upper Weiser River, West Central Mountains and Western
Magic Valley and Oregon, including the following areas, Baker
County, Malheur County and Oregon Lower Treasure Valley.
* WHEN...Through Wednesday evening.
* IMPACTS...Heavy rainfall could trigger flash flooding or debris
flows, especially in and near recent wildfire burn scars.
* ADDITIONAL DETAILS...
- https://www.weather.gov/safety/flood
A surge of deep monsoonal moisture combined with a slow-moving
upper trough will bring periods of heavy showers and thunderstorms
across the region. This airmass contains anomalously high moisture
content, supporting the potential for excessive rainfall. Flash
flooding will be possible, especially in steep terrain, narrow
canyons, and near recent burn scars where soils are less able to
absorb rainfall. The greatest risk will be Tuesday afternoon through
Wednesday evening as repeated rounds of storms move through.
* WHAT...Flash flooding caused by excessive rainfall continues to be
possible.
* WHERE...A portion of southeast Oregon, including the following
county, Harney County.
* WHEN...Through late tonight.
* IMPACTS...Heavy rainfall could trigger flash flooding or debris
flows, especially in and near recent wildfire burn scars.
* ADDITIONAL DETAILS...
- https://www.weather.gov/safety/flood
* 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. Around a
25% chance of thunderstorms. 10-20% chance of wetting rains in
passing storms.
* DRY AND UNSTABLE...Unstable conditions 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.
...A very unstable environment with dry conditions at the surface
will create weather weather conditions that could promote rapid
fire spread. Around a 25% chance of thunderstorms in the area
which could produce lightning and gusty outflow winds as high as
40 mph...
* 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. Around a
25% chance of thunderstorms. 10-20% chance of wetting rains in
passing storms.
* DRY AND UNSTABLE...Unstable conditions 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.
...RED FLAG WARNING IN EFFECT FROM 1 PM TO 9 PM PDT TUESDAY FOR
ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE WEATHER ZONES 280, 281,
282, 284, 285, 617, 620, 621, 622, 623, 624, AND 625...
* IMPACTS...Abundant lightning on dry fuels resulting in the
potential for numerous new fire starts.
* AFFECTED AREA...In California, all of Fire weather zones 280,
281, 282, 284, and 285, and in Oregon, all of Fire weather
zones 617, 620, 621, 622, 623, 624, and 625.
* THUNDERSTORMS...Scattered thunderstorms with abundant
lightning expected. Storms are likely to be wet, but lightning
strikes outside of precipitation cores are possible, and may
cause many new fire starts. Isolated overnight and early
morning storms are possible east of the Cascades, but
confidence is low.
* OUTFLOW WINDS...Gusts of 35 to 50 mph could travel outward up
to 25 miles from thunderstorm cores.
* DETAILED URL...View the hazard area in detail at
https://www.wrh.noaa.gov/map/?wfo=mfr
The National Weather Service in Portland has issued a Red Flag
Warning for thunderstorms and high instability, which is in
effect from 9 AM to 9 PM PDT Tuesday.
* AFFECTED AREA...In Oregon, Fire Weather Zone 689 Northern
Willamette National Forest and Fire Weather Zone 690 Southern
Willamette National Forest.
* THUNDERSTORMS...Scattered thunderstorms with critically dry
fuels.
* OUTFLOW WINDS...Gusts up to 40 mph may travel outward up to 25
miles from thunderstorm cores.
* IMPACTS...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.
* WHAT...Hot conditions with temperatures up to 96 degrees. This
will pose moderate to major risk of heat-related illness.
* WHERE...Foothills of the Blue Mountains of Oregon and Washington,
Simcoe Highlands, and Lower Slopes of the Eastern Washington
Cascades Crest.
* WHEN...Until 9 PM PDT Tuesday.
* IMPACTS...Hot temperatures may cause heat illnesses. Heat will
significantly increase the risk of heat-related illnesses for
those who are sensitive to heat, especially those without
effective cooling or adequate hydration.
* ADDITIONAL DETAILS...Lingering cloud cover from thunderstorms in
southern Oregon may result in lower than forecast afternoon
temperatures or higher than forecast overnight low temperatures.
* WHAT...Dangerously hot conditions with temperatures up to 95 to
100 degrees expected. This will pose a major risk of heat-related
illness.
* WHERE...Eastern Columbia River Gorge of Oregon and Washington,
Lower Columbia Basin of Oregon and Washington, Kittitas Valley,
and Yakima Valley.
* WHEN...Until 9 PM PDT Tuesday.
* IMPACTS...Heat related illnesses increase significantly during
extreme heat events. Extreme heat will significantly increase the
risk of heat-related illnesses for much of the population,
especially those who are heat sensitive and those without
effective cooling or adequate hydration.
* ADDITIONAL DETAILS...Lingering cloud cover from thunderstorms in
southern Oregon may result in lower than forecast afternoon
temperatures or higher than forecast overnight low temperatures.
At 430 PM PDT, Doppler radar was tracking a strong thunderstorm 7
miles southwest of Elderberry Flat Campground, or 11 miles northeast
of Grants Pass, moving south at 5 mph.
HAZARD...Winds in excess of 30 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible. Heavy rain is possible, and may result in some
localized high water.
This storm will remain over mainly rural areas of west central
Jackson and northeastern Josephine Counties.
At 428 PM PDT, Doppler radar was tracking a strong thunderstorm 7
miles east of Warner Wetlands, or 38 miles northeast of Lakeview,
moving north at 5 mph.
HAZARD...Winds in excess of 40 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible. Heavy rain is possible over the Hart Mountain
wildfire burn scar, which may result in localized debris
flows.
This storm will remain over mainly rural areas of east central Lake
County, including portions of the Hart Mountain Antelope Refuge.
* WHAT...Dangerously hot conditions with temperatures up to 96 to
100 degrees expected. This will pose a major risk of heat-related
illness.
* WHERE...Eastern Columbia River Gorge of Oregon and Washington,
Lower Columbia Basin of Oregon and Washington, Kittitas Valley,
and Yakima Valley.
* WHEN...Until 9 PM PDT Tuesday.
* IMPACTS...Heat related illnesses increase significantly during
extreme heat events. Extreme heat will significantly increase the
risk of heat-related illnesses for much of the population,
especially those who are heat sensitive and those without
effective cooling or adequate hydration.
* WHAT...Hot conditions with temperatures up to 96 degrees. This
will pose moderate to major risk of heat-related illness.
* WHERE...Foothills of the Blue Mountains of Oregon and Washington,
Simcoe Highlands, and Lower Slopes of the Eastern Washington
Cascades Crest.
* WHEN...Until 9 PM PDT Tuesday.
* IMPACTS...Hot temperatures may cause heat illnesses. Heat will
significantly increase the risk of heat-related illnesses for
those who are sensitive to heat, especially those without
effective cooling or adequate hydration.
The National Weather Service in Medford has issued a Red Flag
Warning, which is in effect from 1 PM to 9 PM PDT Tuesday.
* IMPACTS...Abundant lightning on dry fuels resulting in the
potential for numerous new fire starts.
* AFFECTED AREA...In California, all of Fire weather zones 280,
281, 282, 284, and 285, and in Oregon, all of Fire weather
zones 617, 620, 621, 622, 623, 624, and 625.
* THUNDERSTORMS...Scattered thunderstorms with abundant lightning
expected. Storms are likely to be wet, but lightning strikes
outside of precipitation cores are possible, and may cause many
new fire starts. Isolated overnight and early morning storms are
possible east of the Cascades, but confidence is low.
* OUTFLOW WINDS...Gusts of 35 to 50 mph could travel outward up
to 25 miles from thunderstorm cores.
* DETAILED URL...View the hazard area in detail at
https://www.wrh.noaa.gov/map/?wfo=mfr
The National Weather Service in Medford has issued a Red Flag
Warning, which is in effect from 1 PM to 9 PM PDT Tuesday.
* IMPACTS...Abundant lightning on dry fuels resulting in the
potential for numerous new fire starts.
* AFFECTED AREA...In California, all of Fire weather zones 280,
281, 282, 284, and 285, and in Oregon, all of Fire weather
zones 617, 620, 621, 622, 623, 624, and 625.
* THUNDERSTORMS...Scattered thunderstorms with abundant lightning
expected. Storms are likely to be wet, but lightning strikes
outside of precipitation cores are possible, and may cause many
new fire starts. Isolated overnight and early morning storms are
possible east of the Cascades, but confidence is low.
* OUTFLOW WINDS...Gusts of 35 to 50 mph could travel outward up
to 25 miles from thunderstorm cores.
* DETAILED URL...View the hazard area in detail at
https://www.wrh.noaa.gov/map/?wfo=mfr
...HOT, DRY, AND UNSTABLE CONDITIONS EXPECTED IN CENTRAL OREGON
THROUGH THIS EVENING...
.Hot conditions, combined with low relative humidities and an
unstable air mass, have the potential to create significant,
plume-dominated fire growth in the area surrounding the Flat
Fire.
* AFFECTED AREA...Fire Weather Zones 700 Central Mountains of
Oregon and 704 Northern Deschutes National Forest.
* TIMING...Until 9 PM PDT this evening.
* MIXING HEIGHT...As high as 8,000 ft AGL Today and 11,500 ft
AGL Monday.
* RELATIVE HUMIDITY...As low as 23 percent.
* IMPACTS...Any fire that develops will catch and spread
quickly. Outdoor burning is not recommended.
* AFFECTED AREA...In Oregon, Fire Weather Zone 687 Central
Oregon Cascade Foothills, Fire Weather Zone 689 Northern
Willamette National Forest and Fire Weather Zone 690 Southern
Willamette National Forest.
* THUNDERSTORMS...Scattered thunderstorms with critically dry
fuels.
* OUTFLOW WINDS...Gusts up to 40 mph may travel outward up to 25
miles from thunderstorm cores.
* IMPACTS...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.
* WHAT...Dangerously hot conditions with high temperatures of 90-97F
and overnight low temperatures of 60-70F expected.
* WHERE...Greater Portland/Vancouver Metro, Western and Central
Columbia River Gorge, the Corbett area and the Hood River Valley,
Central and Southern Willamette Valley, Foothills of the Northern
and Central Oregon Cascades, Lower Columbia River and Cowlitz
River Valleys, and South Washington Cascade Foothills.
* WHEN...Until 11 PM PDT Tuesday.
* IMPACTS...Heat related illnesses increase significantly during
extreme heat events, especially for those spending time outdoors
or without access to adequate cooling.
* ADDITIONAL DETAILS...The warmest overnight lows are expected to
occur in the Columbia River Gorge and in urban areas from Salem
northward.
* WHAT...Hot conditions with high temperatures of 85 to 92 degrees
and overnight low temperatures of 60-68F possible.
* WHERE...South Washington Cascades and the Northern and Central
Cascades of Oregon, North and Central Coast Range Valleys of
Oregon, and Willapa and Wahkiakum Lowlands.
* WHEN...Until 5 AM PDT Tuesday.
* IMPACTS...Heat related illnesses increase significantly during
extreme heat events, especially for those spending time outdoors
or without access to adequate cooling.
The Oregon Department of Environmental Quality and the Lane Regional
Air Protection Agency have continued an Air Quality Advisory, which
is IN EFFECT UNTIL 10 PM PDT THIS EVENING.
An Air Quality Advisory for Ozone remains in effect. High levels of
ozone in the lower atmosphere in the region combined with forecasted
conditions will cause air quality to reach unhealthy levels at times
through this evening.
Pollutants in smoke can cause burning eyes, runny nose, aggravate
heart and lung diseases, and aggravate other serious health
problems. Limit outdoor activities and keep children indoors if it
is smoky. Please follow medical advice if you have a heart or lung
condition.
More information about air quality can be found at:
www.orcaa.org
www.swcleanair.gov
www.oregon.gov/DEQ
www.lrapa.org
