SMOKE MANAGEMENT
FORECAST AND INSTRUCTIONS
SALEM FORESTRY
WEATHER CENTER
OREGON DEPARTMENT
OF FORESTRY
ISSUED: Tuesday,
April 28, 2026
2:30 PM Gary Votaw
1. DISCUSSION AND
FORECAST FOR THE WESTERN OREGON AREA FORECAST ZONES 601-623 and 639
SHORT-TERM
DISCUSSION
An
upper-level ridge is just offshore and causing N flow aloft. Wednesday
will be generally sunny and unseasonably warm, especially in the north. Burning potential is good, mixing heights
best in the Cascades during afternoon with NW-NE winds.
EXTENDED DISCUSSION
The
ridge will be overhead on Thursday, slowly weakening and moving east. Look for sunny skies and temperatures well above
normal. Little change is expected for
burning potential, mixing heights best in the Cascades. Winds will be very light from NW-NE.
An
upper trough nears the coast on Friday when clouds increase but no
precipitation is expected. Mixing will
be good with light NW winds.
The
trough will be centered just offshore on Saturday and will draw some moisture
northward for a chance of showers, mainly in the Cascades. Otherwise, very warm conditions continue
under partly to mostly cloudy skies. Burning
conditions look to be good with NNW-NE winds.
2. DISPERSION
WEDNESDAY
Zone 601, 602,
603 and 612 (North Coast Range):
MORNING
Mixing height below
1000 ft early rising to 2800 - 3800 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 4000 - 5000 ft.
Transport wind
increases to NNW to NE at 4 - 8 mph.
Surface wind similar to morning.
EVENING
Mixing height
1000 - 1700 ft.
Transport wind
NNW to NNE at 8 - 12 mph.
Surface wind similar to afternoon.
Zone 605-611 and
639 (North Cascades):
MORNING
Mixing height below
1000 ft early rising to 3000 - 4000 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 above 5000 ft.
Transport wind
increases to NE to E at 4 - 8 mph.
Surface wind similar to morning.
EVENING
Mixing height
1200 - 2200 ft.
Transport wind
increases to N to NE at 9 - 15 mph.
Surface wind
increases to NNW to NNE at 4 - 8 mph.
Zone 615-620
(South Coast Range):
MORNING
Mixing height below
1000 ft early rising to 3000 - 4000 ft.
Transport wind N
to NE at 5 - 9 mph.
Surface wind
light and variable and controlled by local terrain.
AFTERNOON
Mixing height
3800 - 4800 ft.
Transport wind
NNW to NNE at 5 - 9 mph.
Surface wind
increases to N to NE at 5 - 9 mph.
EVENING
Mixing height
1000 - 1700 ft.
Transport wind NW
to NNE at 6 - 10 mph.
Surface wind
shifts to NW to N at 5 - 9 mph.
Zone 616-623
(South Cascades):
MORNING
Mixing height below
1000 ft early rising to 2600 - 3600 ft.
Transport wind
WNW to NNW at 4 - 8 mph.
Surface wind
light and variable and controlled by local terrain.
AFTERNOON
Mixing height
rising above 5000 ft.
Transport wind similar to morning.
Surface wind similar to morning.
EVENING
Mixing height
2100 - 3100 ft.
Transport wind
NNW to NNE at 6 - 10 mph.
Surface wind
increases to NW to N at 5 - 9 mph.
OUTLOOK:
THURSDAY
In the Coast Range mixing height below 1000 ft early rising to 2000 to
3000 ft by late morning rising to 3400 to 4400 ft during the afternoon. In the Cascades mixing height below 1000 ft
early rising to 3400 to 4400 ft by late morning rising above 5000 ft during the
afternoon. Transport wind N to E at 6 - 10 mph.
Surface wind light and variable.
FRIDAY
In the Coast
Range mixing height below 1000 ft early rising to 1000 to 2000 ft by late
morning rising to 2500 to 3500 ft during the afternoon. In the Cascades mixing height below 1000 ft
early rising to 2400 to 3400 ft by late morning rising above 5000 ft during the
afternoon. Transport wind WNW to NNW at
5 - 9 mph. Surface wind light and
variable during the morning becoming WNW to NNW at 4 - 8 mph during the
afternoon.
SATURDAY
Mixing height
below 1000 ft early rising to 1400 to 2400 ft by late morning rising to 3800 to
4800 ft during the afternoon. Transport
wind NNW to NE at 5 - 9 mph. Surface
wind light and variable.
3. BURNING
INSTRUCTIONS FOR ALL ZONES IN THE WESTERN OREGON AREA
- Valid for burning done Wednesday, April
29, 2026.
=================================================================
Coast Range
Zone 601, 602,
603, 612, 615, 618, and 619
Use standard
guidance matrix. (See section 5 below.)
Avoid burning directly upwind of coastal SSRAs. Limit tonnage north of Forest Grove/Hillsboro
or Sheridan/Willamina in Zone 602.
Higher tonnage is possible south of T17S in Zone 603. Call the forecaster.
Zone 616 west of
R8W
Units should be
1500 tons or less, spaced 6 miles apart, and 8 miles from downwind SSRAs.
Zone 616 east of
R9W
Units should be
1000 tons or less, spaced 6 miles apart, and 8 miles from downwind SSRAs. Restrict units to 500 tons or less south of
T30S.
Zone 620
Units should be
600 tons or less, spaced 6 miles apart, and 8 miles from downwind SSRAs. Higher tonnage is possible south of the Rogue
River. Call the forecaster.
Cascades
Zone 605, 606,
620, and 622
Units should be
750 tons or less, spaced 3 miles apart, and 5 miles from downwind SSRAs. Higher tonnage is possible south of T20S in
Zone 606 - call the forecaster. East of
R2W in Zone 622, use standard guidance matrix - see section 5 below.
Zone 607 and 608
Units should be
1500 tons or less, spaced 3 miles apart, and 5 miles from downwind SSRAs.
Zone 639, 610,
611, 616, 617, and 623
Use standard
guidance matrix - see section 5 below.
Ensure adequate distance from downwind SSRAs for smoke to
dissipate. South of T30S in Zone 616
units should be 1000 tons or less, spaced 3 miles apart.
Siskiyous
Use standard
guidance matrix - see section 5 below.
==============================================================
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.