* WHAT...Visibility less than a quarter mile in freezing fog.
* WHERE...North Central Oregon.
* WHEN...Until 11 AM PST Saturday.
* IMPACTS...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...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. For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog.
* WHERE...South Willamette Valley.
* WHEN...For the Dense Fog Advisory, until 1 PM PST this afternoon.
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. With temperatures at or just below freezing, fog
droplets may freeze on contact with surfaces, with slick spots on
roadways possible early Friday morning.
* ADDITIONAL DETAILS...Fog will reform and increase across the south
Willamette Valley this evening. Overall, temperatures will hold at
or just above freezing overnight. But, a few spots will drop back
below freezing. As such, motorists should be prepared for
potentially icy or slick spots, especially on less-traveled rural
roadways and bridges.
* WHAT...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. For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog.
* WHERE...South Willamette Valley.
* WHEN...For the Dense Fog Advisory, until 1 PM PST this afternoon.
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. With temperatures at or just below freezing, fog
droplets may freeze on contact with surfaces, with slick spots on
roadways possible early Friday morning.
* ADDITIONAL DETAILS...Fog will reform and increase across the south
Willamette Valley this evening. Overall, temperatures will hold at
or just above freezing overnight. But, a few spots will drop back
below freezing. As such, motorists should be prepared for
potentially icy or slick spots, especially on less-traveled rural
roadways and bridges.
Dense freezing fog has formed again along Interstate 84 east of
Pendleton, on Cabbage Hill. In the LaGrande area, patchy dense
freezing fog was also occurring, along with very cold
temperatures. Visibilities of less than one half mile were
occurring in these areas.
Motorists are urged to use caution when traveling on Interstate
84 east of Pendleton through the morning hours due to low
visibilities and patches of ice.
* 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...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. For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog.
* WHERE...South Willamette Valley.
* WHEN...For the Air Stagnation Advisory, until 4 AM PST Saturday.
For the Dense Fog Advisory, until 11 AM PST this morning.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems. Low visibility could make driving conditions
hazardous. With temperatures at or just below freezing, fog
droplets may freeze on contact with surfaces, with slick spots on
roadways possible early Friday morning.
* WHAT...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. For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog.
* WHERE...South Willamette Valley.
* WHEN...For the Air Stagnation Advisory, until 4 AM PST Saturday.
For the Dense Fog Advisory, until 11 AM PST this morning.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems. Low visibility could make driving conditions
hazardous. With temperatures at or just below freezing, fog
droplets may freeze on contact with surfaces, with slick spots on
roadways possible early Friday morning.
* WHAT...Visibility one quarter of a mile or less in freezing fog.
* WHERE...John Day Basin.
* WHEN...Until 11 AM PST this morning.
* IMPACTS...Low visibility and slick roads could make driving
conditions hazardous.
* WHAT...Visibility one quarter of a mile or less in freezing fog.
* WHERE...Foothills of the Southern Blue Mountains of Oregon and
North Central Oregon.
* WHEN...Until 11 AM PST this morning.
* IMPACTS...Low visibility and slick roads could make driving
conditions hazardous.
* WHAT...Visibility one quarter of a mile or less in freezing fog.
* WHERE...Central Oregon.
* WHEN...Until 11 AM PST this morning.
* IMPACTS...Low visibility could make driving conditions hazardous.
Dense freezing fog has formed again along Interstate 84 east of
Pendleton, on Cabbage Hill. Visibilities of less than one quarter
mile were occurring in this area. Motorists are urged to use
caution when traveling on this stretch of interstate through the
morning hours due to low visibilities and patches of ice.
* 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/ Saturday.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems.
* WHAT...For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog. 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.
* WHERE...Treasure Valley Zones and the Weiser Basin.
* WHEN...For the Dense Fog Advisory, until 11 AM MST Saturday. For
the Air Stagnation Advisory, until 5 PM MST Saturday.
* IMPACTS...Low visibility could make driving conditions hazardous.
Poor air quality may cause issues for people with respiratory
problems.
* ADDITIONAL DETAILS...Fog could produce patchy black ice and slick
roads.
* WHAT...For the Dense Fog Advisory, visibility one quarter mile or
less in dense fog. 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.
* WHERE...Treasure Valley Zones and the Weiser Basin.
* WHEN...For the Dense Fog Advisory, until 11 AM MST Saturday. For
the Air Stagnation Advisory, until 5 PM MST Saturday.
* IMPACTS...Low visibility could make driving conditions hazardous.
Poor air quality may cause issues for people with respiratory
problems.
* ADDITIONAL DETAILS...Fog could produce patchy black ice and slick
roads.
* WHAT...Visibility one quarter of a mile or less in freezing fog.
* WHERE...John Day Basin.
* WHEN...Until 11 AM PST Friday.
* IMPACTS...Low visibility and slick roads could make driving
conditions hazardous.
* WHAT...Visibility one quarter of a mile or less in freezing fog.
* WHERE...Central Oregon.
* WHEN...Until 11 AM PST Friday.
* IMPACTS...Low visibility and slick roads could make driving
conditions hazardous.
* WHAT...Visibility one quarter of a mile or less in freezing fog.
* WHERE...Foothills of the Southern Blue Mountains of Oregon and
North Central Oregon.
* WHEN...Until 11 AM PST Friday.
* IMPACTS...Low visibility and slick roads 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...Poor air quality may cause issues for people with
respiratory problems.
* WHAT...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. For the Dense Fog Advisory, visibility frequently below one
quarter mile in dense fog and areas of freezing fog.
* WHERE...South Willamette Valley.
* WHEN...For the Air Stagnation Advisory, until 4 AM PST Saturday.
For the Dense Fog Advisory, until 11 AM PST Friday.
* IMPACTS...Poor air quality may cause issues for people with
respiratory problems. Low visibility could make driving conditions
hazardous.
* ADDITIONAL DETAILS...Fog will reform and increase across the south
Willamette Valley this evening. Overall, temperatures will hold at
or just above freezing overnight. But, a few spots will drop back
below freezing. As such, motorists should be prepared for
potentially icy or slick spots, especially on less-traveled rural
roadways and bridges.
