SMOKE MANAGEMENT
FORECAST AND INSTRUCTIONS
SALEM FORESTRY
WEATHER CENTER
OREGON DEPARTMENT
OF FORESTRY
ISSUED: Monday,
April 27, 2026 2:30 PM Gary Votaw
1. DISCUSSION AND FORECAST FOR THE WESTERN
OREGON AREA FORECAST ZONES 601-623 and 639
SHORT-TERM
DISCUSSION
A strong upper-level
ridge is sitting offshore which will cause dry conditions under periods of
clouds. Temperatures will be seasonal. Mixing heights look very good in the Cascades
but somewhat lower for the Coast Range, winds very light and ranging from W-N.
EXTENDED DISCUSSION
The
ridge remains on Wednesday and Thursday but slowly weakening. Look for sunny skies and temperatures above
normal. Little change is expected in
burning potential, mixing heights best in the Cascades. Winds again will be very light from NW-NE.
An
upper trough arrives on Friday, but no precipitation is expected under partly
sunny skies. Mixing will be good with
very light NW winds.
2. DISPERSION
TUESDAY
Zone 601, 602,
603 and 612 (North Coast Range):
MORNING
Mixing height
2200 - 3200 ft.
Transport wind W
to NW at 4 - 8 mph.
Surface wind
light and variable and controlled by local terrain.
AFTERNOON
Mixing height
3000 - 4000 ft.
Transport wind
similar to morning.
Surface wind
similar to morning.
EVENING
Mixing height
1000 - 1700 ft.
Transport wind NW
to N at 6 - 12 mph.
Surface wind
similar to afternoon.
Zone 605-611 and
639 (North Cascades):
MORNING
Mixing height below
1000 ft early rising to 2200 - 3200 ft.
Transport wind SW
to W at 6 - 12 mph.
Surface wind
light and variable and controlled by local terrain.
AFTERNOON
Mixing height
rising to 4300 - 5000 ft.
Transport wind
similar to morning.
Surface wind
increases to SW to WNW at 4 - 8 mph.
EVENING
Mixing height
1000 - 2000 ft.
Transport wind
similar to afternoon.
Surface wind
becomes light and variable and controlled by local terrain.
Zone 615-620
(South Coast Range):
MORNING
Mixing height below
1000 ft early rising to 2000 - 3000 ft.
Transport wind
light and variable and controlled by local terrain.
Surface wind
light and variable and controlled by local terrain.
AFTERNOON
Mixing height
rising to 3300 - 4300 ft.
Transport wind
increases to NW to N at 5 - 9 mph.
Surface wind
increases to WNW to NNW at 5 - 9 mph.
EVENING
Mixing height
lowers below 1000 ft.
Transport wind
similar to afternoon.
Surface wind
similar to afternoon.
Zone 616-623
(South Cascades):
MORNING
Mixing height below
1000 ft early rising to 2600 - 3600 ft.
Transport wind SW
to WNW at 4 - 8 mph.
Surface wind
light and variable and controlled by local terrain.
AFTERNOON
Mixing height
rising above 5000 ft.
Transport wind W
to NW at 4 - 8 mph.
Surface wind
similar to morning.
EVENING
Mixing height
1500 - 2500 ft.
Transport wind
similar to afternoon.
Surface wind
similar to afternoon.
OUTLOOK:
WEDNESDAY
Mixing height
below 1000 ft early rising to 2800 to 3800 ft by late morning rising to 4200 to
5000 ft during the afternoon. Transport
wind NW to NE at 4 - 8 mph. Surface wind
light and variable.
THURSDAY
Mixing height
below 1000 ft early rising to 1400 to 2400 ft by late morning rising to 3600 to
4600 ft during the afternoon. Transport
wind light and variable during the morning becoming NNW to NNE at 6 - 10 mph
during the afternoon. Surface wind light
and variable during the morning becoming NW to N at 4 - 8 mph during the
afternoon.
FRIDAY
In the north
mixing height below 1000 ft early rising to 2600 to 3600 ft by late morning
rising to 3800 to 4800 ft during the afternoon.
In the south mixing height below 1000 ft early rising to 1600 to 2600 ft
by late morning rising to 3500 to 4500 ft during the afternoon. Transport wind WNW to NNW at 4 - 8 mph. Surface wind light and variable during the
morning becoming WNW to NNW at 5 - 9 mph during the afternoon.
3. BURNING INSTRUCTIONS FOR ALL ZONES IN THE
WESTERN OREGON AREA
- Valid for burning done Tuesday, April 28,
2026.
=================================================================
Coast Range
Zone 601, 612,
and 616 east of R9W
Units should be
1000 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs. Restrict units in or near corridors to 500
tons or less. Restrict units to 500 tons
or less south of T30S in Zone 616.
Zone 602 and 603
Units should be
400 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs. Limit burning in or near corridors. Higher tonnage is possible south of the
Siuslaw River in Zone 603. Call the
forecaster.
Zone 615, 618,
and 619
Use standard
guidance matrix. (See section 5 below.)
Avoid burning directly upwind of the North Bend/Coos Bay SSRA.
Zone 616 west of
R8W
Units should be
1500 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.
Zone 620
Units should be
300 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs. Higher tonnage is possible south of the Rogue
River. Call the forecaster.
Cascades
Zone 605, 606,
607, 608, 639, 616, 617, and 623
Use standard
guidance matrix - see section 5 below.
Ensure adequate distance from downwind SSRAs for smoke to
dissipate. From T15S through T20S in
Zone 608 units should be 1200 tons or less, spaced 6 miles apart.
Zone 610
Units should be
1200 tons or less, spaced 6 miles apart, and 8 miles from downwind SSRAs.
Zone 611
Units should be
1500 tons or less, spaced 6 miles apart, and 8 miles from downwind SSRAs.
Zone 620
Units should be
750 tons or less, spaced 3 miles apart, and 5 miles from downwind SSRAs.
Zone 622
Units should be
1200 tons or less, spaced 3 miles apart, and 5 miles from downwind SSRAs. East of R2W, use standard guidance matrix -
see section 5 below.
Siskiyous
Use standard
guidance matrix - see section 5 below. Ensure adequate distance from downwind
SSRAs for smoke to dissipate.
==============================================================
4. SPECIAL NOTES:
The ODF forecast smoke zones differ from
the NWS fire zones and
are available at:
https://www.oregon.gov/odf/fire/documents/smoke-forecast-zone-map.pdf
Call the smoke management duty forecaster
at (503) 945-7401 to
discuss burning. Please do not call
individual's numbers to
discuss daily burning. If the forecaster is
not available,
leave a message and they will return your
call as soon as possible.
Avoid calling between 1:30 to 2:45 p.m.
The forecast is available on the Internet
at:
http://www.odf.state.or.us/DIVISIONS/protection/fire_protection/
Daily/smi.htm
Please ensure your units have been planned
and accomplished by
checking:
http://www.oregon.gov/ODF/Fire/Pages/Burn.aspx
A map of planned and/or accomplished burns
is located at:
http://geo.maps.arcgis.com/apps/webappviewer/index.html
?id=a7e321dc8fc444b7a33fbc67bc673a3b
The forecast/instruction telephone
recording is: (503) 945-7400.
To subscribe to or unsubscribe from the
email list for this
product, please go to the link:
http://weather.smkmgt.com/mailman/listinfo/
5. STANDARD GUIDANCE MATRIX:
* Greater than 5000 ft mixing height: Limit
to 150 tons per mile
from downwind SSRAs. Example: 75 tons
allowed if burned a half
mile from a downwind SSRA.
* 3000 - 5000 ft mixing height: Limit to 50
tons per mile if burning
within 5 miles of downwind SSRAs. Limit to
100 tons per mile if
burning 5 miles or beyond downwind SSRAs.
Example #1: 200 tons allowed if burned 4
miles from a downwind SSRA.
Example #2: 500 tons allowed if burned 5
miles from a downwind SSRA.
* Less than 3000 ft mixing height: No burning
within 5 miles of
downwind SSRAs. Limit to 60 tons per mile
from downwind SSRAs.
Example: 300 tons allowed if burned 5 miles
from a downwind SSRA.
* Ensure adequate spacing between units when
burning near downwind
SSRAs.
* Use of polyethylene (PE) sheeting on
greater than 75 percent of
piles in a unit with 60 percent coverage
per pile will allow a
50 percent increase in tonnage over the
existing instruction tonnage
for that zone.
* All exceptions must be coordinated with the
duty forecaster
prior to ignition.
6. BURN MONITORING:
Burns over 2000 tons must be monitored (OAR
629-048-0230(3) -
7/1/14). Monitoring of all burns is highly
recommended for both
smoke management purposes and wildfire
potential.