Updated 0900 MDT Friday,
July 18, 2014
Valid through Noon MDT Monday,
July 21, 2014
Smoke Outlook
Garden Valley continues to see impacts from the Whiskey
Complex. Overnight values were
consistent with what has been observed the past 2 nights in Garden Valley with
slightly lower readings in Idaho City. The Boise area was elevated overnight compared to previous nights. Idaho City was in the Unhealthy category yesterday while Garden Valley and Boise were both in the Unhealthy for Sensitive Groups
yesterday. North Idaho from St. Maries
north experienced moderate level impacts from the fires in Washington; however,
by mid-morning, the entire state was experiencing impacts to a varying degree
except for the region south of a line running from Twin Falls-Driggs. Afternoon heating allowed the smoke to rise and disperse.
The weather will be similar to yesterday with
west-northwest winds aloft and warm and dry conditions across the state. There is a slight chance for thunder along
the Nevada-Idaho border this afternoon. Expect
locally breezy winds this afternoon with gusts from 15-25 mph across the Snake
River Plain and 10-17 mph north of the Clearwater. A red flag warning for the Middle and Upper
Snake River Plain has been issued for this afternoon. Mixing heights will range from 4,000-9,000ft
AGL with lower heights in the northern portion of the state.
Late Sunday, the upper level wind pattern shifts to a southwest
flow, which will move smoke north of the Snake River Plain and allow monsoon
moisture back into southern Idaho. Warm
conditions will persist through Sunday with a chance for showers late
Sunday/early Monday in southern Idaho.
In north Idaho, this weekend will start with higher
humidity levels as subtropical moisture is transported into the area ahead of a
Saturday cold front. This front will create
dry conditions for Sunday with a chance for an upper level shortwave to impact
on Monday; however, this system is tracking along the border and is trending to
move northeast rather than east.
Smoke impacts today will be high near fires in the
Central Mountains. Transport of smoke
from fires burning in Oregon and Washington will be the primary contributors
today. A very consistent pattern has
developed over the last 18 hours in the models indicating clear zonal advection
of smoke. Expect all areas of Idaho to
be hazy except a swath running along a line from McCall-Bannock Pass and Lewiston-Lolo
Pass. The Whiskey Complex is planning a
burnout if weather and fireline work is conducive.
This
weekend may see a slight reprieve in northern Idaho as wetter conditions may
limit fire activity in Washington. The
wind shift to southwest on Sunday will likely introduce smoke from the Oregon
fires into the Clearwater while fire in the Boise National Forest will advect
smoke towards the Salmon-Challis region.
The timing of this wind shift will determine the strength of these
impacts as an afternoon wind shift will keep the smoke aloft while an evening
or nighttime shift may bring the smoke overhead just as heights lower and
temperatures drop.
Smoke
forecasts are dependent on predicted fire growth and weather. If
conditions change unexpectedly, impacts could occur. When visibility
starts to go below 5 miles, sensitive groups should minimize outdoor
activities. Everyone else should minimize prolonged or physical activity
outdoors. Refer to the Smoke and Health Tab on the Idaho Smoke Information Blog for additional
health information.
Your
eyes are your best tools to determine if it’s safe to be outside. Even if you smell
smoke, the air quality may still be good.
AQI
Category
|
Visibility
(miles)
|
Good
|
11+
|
Moderate
|
6-10
|
Unhealthy for Sensitive Groups
|
3-5
|
Unhealthy
|
1½ -2¾
|
Very Unhealthy
|
1-1¼
|
Hazardous
|
Less than 1
|