SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Tuesday, April 21, 2026       2:30 PM      Sherri Pugh

 

1.  DISCUSSION AND FORECAST FOR THE WESTERN OREGON AREA FORECAST ZONES 601-623 and 639

 

SHORT-TERM DISCUSSION

 

Rain and mountain snow will bring up to 0.25” rainfall totals on Wednesday.  Flow aloft will turn from N with an upper-level trough shifting east and ridging far offshore.  Winds will be brisk from SW-W.  Temperatures sink further below average while freezing levels will be on the rise toward 5000 feet.  Mixing heights will be fair to good.

 

EXTENDED DISCUSSION

 

A few showers early will turn to dry weather on Thursday.  Temperatures will rise to near seasonable.  Mixing heights will be fair to good.  Light winds will be from SW-NW at the surface and mostly onshore for transport winds.

 

Friday will be dry with light N flow aloft.  Light winds will come from N in general.  Temperatures will climb above average.  Mixing heights will lower, especially for coastal zones.

 

While Saturday starts dry, a few showers will arrive late.  Flow aloft will be from N and temperatures will continue above average.  Light winds will be from NW-NE.  Mixing heights will be fair to good.

 

2.  DISPERSION

 

WEDNESDAY

 

Zone 601, 602, 603 and 612 (North Coast Range):

 

MORNING

Mixing height below 2000 ft early rising to 2300 - 3300 ft by late morning.

Transport wind WSW at 22 - 38 mph.

Surface wind SSW to WSW at 6 - 10 mph.

 

AFTERNOON

Mixing height 2300 - 3300 ft.

Transport wind similar to morning.

Surface wind SW to W at 8 - 12 mph.

 

EVENING

Mixing height 1500 - 2500 ft.

Transport wind decreases to SSW to WSW at 12 - 24 mph.

Surface wind SSW to WSW at 4 - 8 mph.

 

Zone 605-611 and 639 (North Cascades):

 

MORNING

Mixing height below 1500 ft early rising to 2500 - 3500 ft by late morning.

Transport wind WSW at 22 - 38 mph.

Surface wind SW to W at 6 - 10 mph.

 

AFTERNOON

Mixing height 3000 - 4000 ft.

Transport wind W at 22 - 38 mph.

Surface wind similar to morning.

 

EVENING

Mixing height 1000 - 2000 ft.

Transport wind decreases to WSW to WNW at 15 - 25 mph.

Surface wind similar to afternoon.

 

Zone 615-620 (South Coast Range):

 

MORNING

Mixing height below 2000 ft early rising to 2500 - 3500 ft by late morning.

Transport wind SSW to WSW at 9 - 15 mph.

Surface wind S to SW at 4 - 8 mph.

 

AFTERNOON

Mixing height 2700 - 3700 ft.

Transport wind similar to morning.

Surface wind SW to W at 6 - 10 mph.

 

EVENING

Mixing height 1000 - 2000 ft.

Transport wind WSW to WNW at 8 - 12 mph.

Surface wind WSW to WNW at 4 - 8 mph.

 

Zone 616-623 (South Cascades):

 

MORNING

Mixing height below 1500 ft early rising to 3000 - 4000 ft by late morning.

Transport wind SW to W at 8 - 12 mph.

Surface wind SSW to WSW at 4 - 8 mph.

 

AFTERNOON

Mixing height 3500 - 4500 ft.

Transport wind increases to WSW to WNW at 10 - 22 mph.

Surface wind WSW to WNW at 6 - 10 mph.

 

EVENING

Mixing height 1000 - 2000 ft.

Transport wind decreases to W to NW at 8 - 12 mph.

Surface wind similar to afternoon.

 

OUTLOOK:

 

THURSDAY

In the north mixing height below 1000 ft early rising to 1400 to 2400 ft by late morning rising to 3000 to 4000 ft during the afternoon.  In the south mixing height below 1000 ft early rising to 2200 to 3200 ft by late morning rising to 2800 to 3800 ft during the afternoon.  Transport wind SW to WNW at 4 - 8 mph during the morning becoming WNW to NNW at 4 - 8 mph during the afternoon.  Surface wind light and variable during the morning becoming W to NW at 4 - 8 mph during the afternoon.

 

FRIDAY

Mixing height below 1000 ft early rising to 1800 to 2800 ft by late morning rising to 2400 to 3400 ft during the afternoon.  Transport wind NE to E at 4 - 8 mph during the morning becoming N to NE at 4 - 8 mph during the afternoon.  Surface wind light and variable.

 

SATURDAY

Mixing height below 1000 ft early rising to 2000 to 3000 ft by late morning rising to 4200 to 5000 ft during the afternoon.  Transport wind NNW to NNE at 4 - 8 mph.  Surface wind light and variable during the morning becoming NNW to NE at 4 - 8 mph during the afternoon.

 

3.  BURNING INSTRUCTIONS FOR ALL ZONES IN THE WESTERN OREGON AREA

    - Valid for burning done Wednesday, April 22, 2026.

=================================================================

 

Coast Range

 

Zone 601

Units should be 500 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.  North of Tillamook, use standard guidance matrix. (See section 5 below.)

 

Zone 602 and 603

No burning allowed.  North of T3N in Zone 602, use standard guidance matrix. (See section 5 below.)  Limit burning in or near corridors.  Units may be 500 tons or less, spaced 12 miles apart, south of the Siuslaw River in Zone 603.

 

Zone 615, 616 west of R8W, and 620

Units should be 1200 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.  Higher tonnage is possible south of T29S in Zone 616.  Call the forecaster.  Higher tonnage is possible south of T35S in Zone 620.  Call the forecaster.

 

Zone 616 east of R9W

Units should be 750 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.  Higher tonnage is possible south of T29S.  Call the forecaster.

 

Zone 618 and 619

Use standard guidance matrix. (See section 5 below.)

 

 

Cascades

 

All zones except Zone 610 and 611

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 900 tons or less, spaced 8 miles apart.

 

Zone 610 and 611

Units should be 900 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.

 

 

Siskiyous

 

Units should be 1200 tons or less, spaced 6 miles apart, and 8 miles from downwind SSRAs.

 

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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.