* 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 in valleys.
* WHERE...Portions of south central, southwest, and west central
Idaho and northeast and southeast Oregon.
* WHEN...Until 5 PM MST /4 PM PST/ this afternoon.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems.
A thin layer of below freezing temperatures is trapped in the
Hood River Valley this morning as light rainfall begins to
increase across the region. Patchy freezing rain has been reported
by the cites of Parkdale, Glenwood, and Odell. Temperatures will
be slow to warm heading into the midday hours allowing light
freezing rain to continue until 1200-1300 PST. Light ice
accumulations of 0.02-0.06 inches this morning may impact travel
and make surfaces slick. Slippery road conditions are difficult to
see and can catch driver off guard, increasing the risk of car
accidents; use caution.
* 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 in valleys.
* WHERE...Portions of south central, southwest, and west central
Idaho and northeast and southeast Oregon.
* WHEN...Until 5 PM MST /4 PM PST/ this afternoon.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems.
* WHAT...For the Air Stagnation Advisory in valleys, 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. For the Dense Fog Advisory,
visibility less than one mile in dense fog.
* WHERE...Lower Treasure Valley Zones, and Upper Weiser River.
* WHEN...For the Air Stagnation Advisory, until 5 PM MST this
afternoon. For the Dense Fog Advisory, until 11 AM MST this
morning.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems. Low visibility could make driving conditions
hazardous.
* WHAT...For the Air Stagnation Advisory in valleys, 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. For the Dense Fog Advisory,
visibility less than one mile in dense fog.
* WHERE...Lower Treasure Valley Zones, and Upper Weiser River.
* WHEN...For the Air Stagnation Advisory, until 5 PM MST this
afternoon. For the Dense Fog Advisory, until 11 AM MST this
morning.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems. Low visibility could make driving conditions
hazardous.
* WHAT...Snow expected. Total snow accumulations of 5 to 9 inches.
Winds gusting as high as 40 mph.
* WHERE...In Oregon, Northern Blue Mountains of Oregon. In
Washington, Northwest Blue Mountains.
* WHEN...From 4 PM this afternoon to 4 PM PST Sunday.
* IMPACTS...Periods of moderate and heavy snow will cause low
visibilities to create difficult driving conditions.
* WHAT...South winds 25 to 35 mph with gusts 45 to 50 mph expected
for Ladd and Pyles Canyons.
* WHERE...Grande Ronde Valley.
* WHEN...Until 4 PM PST this afternoon.
* IMPACTS...Gusty winds will blow around unsecured objects. Tree
limbs could be blown down and a few power outages may result.
* WHAT...Visibility 1/2 mile or less in freezing fog.
* WHERE...Foothills of the Northern Blue Mountains of Oregon.
* WHEN...Until 11 AM PST this morning.
* IMPACTS...Low visibility could make driving conditions hazardous.
* ADDITIONAL DETAILS...Areas of dense fog, especially along
Interstate 84 around Pendleton, could make for hazardous driving
conditions. Additionally, below freezing temperatures may create
slick spots on roadways.
* WHAT...Visibility less than a quarter mile in freezing fog.
* WHERE...North Central Oregon.
* WHEN...Until 11 AM PST this morning.
* IMPACTS...Low visibility could make driving conditions hazardous.
* 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 in valleys.
* WHERE...Portions of south central, southwest, and west central
Idaho and northeast and southeast Oregon.
* WHEN...Until 5 PM MST /4 PM PST/ this afternoon.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems.
* WHAT...For the Air Stagnation Advisory in valleys, 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. For the Dense Fog Advisory,
visibility less than one mile in dense fog.
* WHERE...Portions of southwest and west central Idaho and southeast
Oregon.
* WHEN...For the Air Stagnation Advisory, until 5 PM MST this
afternoon. For the Dense Fog Advisory, until 11 AM MST this
morning.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems. Low visibility could make driving conditions
hazardous.
* WHAT...For the Air Stagnation Advisory in valleys, 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. For the Dense Fog Advisory,
visibility less than one mile in dense fog.
* WHERE...Portions of southwest and west central Idaho and southeast
Oregon.
* WHEN...For the Air Stagnation Advisory, until 5 PM MST this
afternoon. For the Dense Fog Advisory, until 11 AM MST this
morning.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems. Low visibility could make driving conditions
hazardous.
* WHAT...Mixed precipitation expected. Total snow accumulations up
to one inch. Freezing rain possible which may cause slick roads.
Ice accumulations under 0.10 inch.
* WHERE...Lower Treasure Valley Zones, and Malheur County.
* WHEN...From 5 PM MST /4 PM PST/ this afternoon to 5 AM MST /4 AM
PST/ Sunday.
* IMPACTS...Roads, and especially bridges and overpasses, will
likely become slick and hazardous. Plan on slippery road
conditions.
* WHAT...For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog. For the Air Stagnation Advisory, light winds
and limited air movement will lead to a period of stagnant air
conditions. This scenario could result in the build up of air
pollutants over time.
* WHERE...South Willamette Valley.
* WHEN...For the Dense Fog Advisory, until 9 AM PST Saturday. For
the Air Stagnation Advisory, until 4 AM PST Saturday.
* IMPACTS...Deteriorating air quality may cause issues for people
with respiratory problems. Low visibility could make driving
conditions hazardous.
* WHAT...For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog. For the Air Stagnation Advisory, light winds
and limited air movement will lead to a period of stagnant air
conditions. This scenario could result in the build up of air
pollutants over time.
* WHERE...South Willamette Valley.
* WHEN...For the Dense Fog Advisory, until 9 AM PST Saturday. For
the Air Stagnation Advisory, until 4 AM PST Saturday.
* IMPACTS...Deteriorating air quality may cause issues for people
with respiratory problems. Low visibility could make driving
conditions hazardous.
* WHAT...Light winds and limited air movement will lead to a period
of stagnant air conditions. This scenario could result in the
build up of air pollutants over time.
* WHERE...Foothills of the Northern and Central Oregon Cascades,
North and Central Coast Range Valleys of Oregon, Lower Columbia
River and Cowlitz River Valleys, Central Willamette Valley,
Tualatin Valley, Outer Southeast Portland Metro, Willapa and
Wahkiakum Lowlands, North Clark County Lowlands, and South
Washington Cascade Foothills.
* WHEN...Until 4 AM PST Saturday.
* IMPACTS...Deteriorating air quality may cause issues for people
with respiratory problems.
* WHAT...Snow expected above 3000 feet. Total snow accumulations 6
to 10 inches. Winds gusting as high as 40 mph.
* WHERE...In Oregon, North Oregon Cascades. In Washington, South
Washington Cascades.
* WHEN...From 4 PM Saturday to 4 PM PST Sunday.
* IMPACTS...Travel could be very difficult.
* ADDITIONAL DETAILS...Snow levels start off high Saturday morning
at over 9000 ft before lowering to around 5000 ft Saturday
afternoon and then down to 3000 ft Saturday night. Snow levels
will then remain around 3000 ft through Sunday night. The period
of heaviest snowfall is expected to occur late Saturday night
through Sunday morning.
...LIGHT FREEZING RAIN, MOUNTAIN SNOW EXPECTED THIS WEEKEND...
.A system moving across our region will bring areas of rain and some
light freezing rain to portions of the lower slopes of the eastern
Washington Cascades as well as the Kittitas Valley on Saturday. Then
on Sunday, areas of moderate snowfall will begin to fall across the
Washington Cascades as well as the northern Blue Mountains of both
Washington and Oregon.
* WHAT...Snow expected. Total snow accumulations of 5 to 9 inches.
Winds gusting as high as 40 mph.
* WHERE...In Oregon, Northern Blue Mountains of Oregon. In
Washington, Northwest Blue Mountains.
* WHEN...From 4 PM Saturday to 4 PM PST Sunday.
* IMPACTS...Periods of moderate and heavy snow will combine with low
visibilities to create difficult driving conditions.
* WHAT...For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog. For the Air Stagnation Advisory, light winds
and limited air movement will lead to a period of stagnant air
conditions. This scenario could result in the build up of air
pollutants over time.
* WHERE...South Willamette Valley.
* WHEN...For the Dense Fog Advisory, until 9 AM PST Sunday. For the
Air Stagnation Advisory, until 4 AM PST Saturday.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems. Low visibility could make driving conditions
hazardous.
* ADDITIONAL DETAILS...Fog will gradually thin Saturday morning,
with improving visibility after 8 am.
* WHAT...For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog. For the Air Stagnation Advisory, light winds
and limited air movement will lead to a period of stagnant air
conditions. This scenario could result in the build up of air
pollutants over time.
* WHERE...South Willamette Valley.
* WHEN...For the Dense Fog Advisory, until 9 AM PST Sunday. For the
Air Stagnation Advisory, until 4 AM PST Saturday.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems. Low visibility could make driving conditions
hazardous.
* ADDITIONAL DETAILS...Fog will gradually thin Saturday morning,
with improving visibility after 8 am.
