* WHAT...Heavy snow expected. Total snow accumulations between 12
and 24 inches above 5000 feet, with up to 30 inches possible over
the highest peaks and ridgetops. Winds gusting as high as 50 mph.
* WHERE...The southern Oregon Cascades and Siskiyou Mountains. This
includes Highways 138 and 230 near Diamond Lake, Highway 62 near
Crater Lake, Highway 140 near Lake of the Woods and Highway 58 at
Willamette Pass and the Mt Ashland Ski Road up to the resort.
* WHEN...From 1 AM Friday to 10 AM PST Saturday.
* IMPACTS...Visibilities may drop below 1/4 mile due to falling and
blowing snow. The strong winds and weight of snow on tree limbs
may down power lines and could cause sporadic power outages.
* ADDITIONAL DETAILS...Snowfall rates from 10 am to 4 pm PST Friday
and from 10 pm Friday to 4 am PST Saturday could reach 1 inch per
hour at times.
* WHAT...Poor air quality will continue. This is due to an inversion
and stagnant air conditions near the surface that will continue to
trap pollutants.
* WHERE...Lake County and eastern Klamath County, South Central
Oregon Coast, Curry County Coast, Central Douglas County, Eastern
Curry County and Josephine County, Jackson County, and Klamath
Basin.
* WHEN...Until noon PST today.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems.
* WHAT...Heavy snow possible. Total snow accumulations of 8 to 18
inches possible, heaviest above 3000 feet. Winds could gust as
high as 40 mph.
* WHERE...Upper Slopes of the Eastern Washington Cascades Crest.
* WHEN...From Thursday evening through Saturday afternoon.
* IMPACTS...Heavy snowfall and very low visibility will create
extremely dangerous driving conditions.
* ADDITIONAL DETAILS...Snow levels will start around 2500-3500 feet
Thursday night before rising to 4000-4500 feet Friday afternoon.
Snow levels will then lower to 1500-2000 feet Friday night.
Precipitation will begin as snow for Snoqualmie Pass, before
transitioning to rain Friday afternoon. Rain will then transition
to snow again at Snoqualmie Pass Friday night.
* WHAT...Heavy snow possible. Total snow accumulations of 6 to 12
inches possible, heaviest above 4000-4500 feet. Winds could gust
as high as 40 mph.
* WHERE...East Slopes of the Oregon Cascades.
* WHEN...From Thursday evening through Saturday afternoon.
* IMPACTS...Significant snowfall with periods of heavy snowfall
rates will combine with low visibility to create very difficult
driving conditions.
* ADDITIONAL DETAILS...Snow levels will rise from around 4000 feet
Thursday night to around 5000 feet Friday afternoon. Snow levels
will then lower to around 3000 feet or less Friday night.
* WHAT...Poor air quality will continue. This is due to an inversion
and stagnant air conditions near the surface that will continue to
trap pollutants.
* WHERE...Lake County and eastern Klamath County, South Central
Oregon Coast, Curry County Coast, Central Douglas County, Eastern
Curry County and Josephine County, Jackson County, and Klamath
Basin.
* WHEN...Until noon PST Thursday.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems.
* WHAT...Heavy snow possible. Total snow accumulations between 18
and 30 inches possible.
* WHERE...Stevens Pass.
* WHEN...From Thursday evening through Saturday afternoon.
* IMPACTS...Motorists should be prepared for winter driving
conditions with accumulations up to an inch per hour Friday
morning through Friday evening.
* ADDITIONAL DETAILS...This will be the heaviest snowfall for
Stevens Pass in a couple of weeks.
* WHAT...Heavy snow possible. Total snow accumulations between 3 to
8 inches in the valleys and 1 to 2 feet in the mountains.
* WHERE...Priest River, Northport, Ione, Clark Fork, Deer Park,
Eastport, Flowery Trail Road, Fruitland, Tiger, Newport,
Schweitzer Mountain Road, Athol, Metaline, Orin-Rice Road,
Metaline Falls, Bonners Ferry, Sandpoint, Springdale-Hunters Road,
Kettle Falls, Colville, and Chewelah.
* WHEN...From late Thursday night through Saturday afternoon.
* IMPACTS...This will likely be the first widespread snow event in a
couple of weeks for north Idaho and northeast Washington.
* ADDITIONAL DETAILS...Lowland snow accumulations have the potential
to be widely variable with some locations in southern parts of
Stevens and Pend Orielle counties receiving a couple inches of wet
snow while lowland spots in the northern parts of the county have
the chance for 8 inches or more.
* WHAT...Heavy snow possible at or above elevations greater than
3000 ft. Total snow accumulations between 12 and 30 inches
possible.
* WHERE...West Slopes North Cascades and Passes, West Slopes North
Central Cascades and Passes, and West Slopes South Central
Cascades and Passes.
* WHEN...From Thursday evening through Saturday afternoon.
* IMPACTS...Travel could be very difficult.
* ADDITIONAL DETAILS...Snow levels will start around 2500-3500 feet
Thursday night before rising to 4000 feet Friday afternoon. Snow
levels will then lower to near 2000 feet Friday night.
Precipitation will begin as snow for Snoqualmie Pass, before
transitioning to rain Friday afternoon. Rain will then transition
to snow again at Snoqualmie Pass and increase in intensity Friday
night.
* WHAT...Heavy snow possible above 3000 feet. Total snow
accumulations between 6 and 12 inches, and up to 15 inches above
5000 ft. Winds could gust as high as 40 mph.
* WHERE...South Washington Cascades and the Northern and Central
Cascades of Oregon.
* WHEN...From Thursday evening through Saturday afternoon.
* IMPACTS...Roads, and especially bridges and overpasses, will
likely become slick and hazardous.
* ADDITIONAL DETAILS...Snow levels will start around 4000-5000 ft
Thursday evening into Friday, before lowering to 3000-3500 ft
Friday night.
* WHAT...Heavy snow possible above 3000 feet. Total snow
accumulations between 6 and 12 inches, and up to 15 inches above
5000 ft. Winds could gust as high as 40 mph.
* WHERE...South Washington Cascades and the Northern and Central
Cascades of Oregon.
* WHEN...From Thursday evening through Saturday afternoon.
* IMPACTS...Roads, and especially bridges and overpasses, will
likely become slick and hazardous.
* ADDITIONAL DETAILS...Snow levels will start around 4000-5000 ft
Thursday evening into Friday, before lowering to 3000-3500 ft
Friday night.
* WHAT...An extended period of stagnant air, with light winds and
little vertical mixing. This is due to an inversion near the
surface that will continue to trap pollutants.
* WHERE...Portions of south central, southwest, and west central
Idaho and northeast and southeast Oregon.
* WHEN...Until 5 AM MST /4 AM PST/ Friday.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems.
* WHAT...Stagnant air conditions will have potential to trap
pollutants near the ground.
* WHERE...Portions of North Idaho and Central, North Central, and
Northeast Washington including Spokane, Coeur d'Alene, Kellogg,
Bonners Ferry, Sandpoint, Metaline, Deer Park, Colville, Republic,
Omak, Winchester, Lake Chelan, Wenatchee, Leavenworth, and
Waterville.
* WHEN...Until 4 AM PST Friday.
* IMPACTS...Periods of air stagnation can lead to the buildup of
pollutants near the surface.
* WHAT...Stagnant conditions will have potential to trap pollutants
near the ground with deteriorated air quality.
* WHERE...Clarkston, Lewiston, Peck, Kamiah, Winchester, Alpowa
Summit, Soldiers Meadow Road, Nezperce, Pomeroy, Gifford,
Craigmont, Lapwai, Lewiston Grade, and Culdesac.
* WHEN...Until 4 AM PST Friday.
* IMPACTS...Periods of air stagnation can lead to the buildup of
pollutants near the surface.
* WHAT...An extended period of stagnant air, with light winds and
little vertical mixing. This is due to an inversion near the
surface that will continue to trap pollutants.
* WHERE...Portions of south central, southwest, and west central
Idaho and northeast and southeast Oregon.
* WHEN...Until 9 AM MST /8 AM PST/ Friday.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems.
* WHAT...Very cold temperatures as low as 24.
* WHERE...Central and Southern Willamette Valley, Tualatin Valley,
and North Clark County Lowlands.
* WHEN...Until 10 AM PST this morning.
* IMPACTS...Hypothermia can occur with prolonged exposure to these
temperatures.
* WHAT...Very cold temperatures as low as 24.
* WHERE...Central and Southern Willamette Valley, Tualatin Valley,
and North Clark County Lowlands.
* WHEN...Until 10 AM PST this morning.
* IMPACTS...Hypothermia can occur with prolonged exposure to these
temperatures.
* WHAT...Snow expected. Total snow accumulations between 12 and 24
inches above 5000 feet, with up to 30 inches possible over the
highest peaks and ridgetops. Winds gusting as high as 50 mph.
* WHERE...The southern Oregon Cascades and Siskiyou Mountains. This
includes Highways 138 and 230 near Diamond Lake, Highway 62 near
Crater Lake, and Highway 58 at Willamette Pass.
* WHEN...From 4 AM Friday to 10 PM PST Saturday.
* IMPACTS...Travel could be very difficult. The hazardous conditions
could impact the Friday morning and evening commutes as well as
weekend travel. Gusty winds could bring down tree branches as well
as cause areas of blowing snow and limited visibility.
* WHAT...For the Air Stagnation Advisory, a strong inversion and
stagnant air conditions near the surface will trap pollutants
possibly leading to poor air quality. For the Freeze Warning,
sub-freezing temperatures as low as 30 expected.
* WHERE...For the Air Stagnation Advisory, mainly areas inland from
the immediate coast. For the Freeze Warning this morning, mainly
the beaches from Port Orford to Reedsport, including North Bend
and Coos Bay.
* WHEN...For the Air Stagnation Advisory, until noon PST Thursday.
For the Freeze Warning, until 9 AM PST this morning.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems. Frost and freeze conditions could kill
crops, other sensitive vegetation and possibly damage unprotected
outdoor plumbing.
* WHAT...A strong inversion and stagnant air conditions near the
surface will trap pollutants possibly leading to poor air quality.
* WHERE...Valleys of Lake County and eastern Klamath County, Curry
County Coast, Central Douglas County, Eastern Curry County and
Josephine County, Jackson County, and Klamath Basin.
* WHEN...Until noon PST Thursday.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems.