SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Wednesday, December 3, 2025       2:30 PM      Sherri Pugh

 

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* Special Protection Zone (SPZ) provisions apply from November 15 through February 15.  Prescribed burning is not allowed in an SPZ from December 1 through February 15 on days when the daily woodstove “Ordinance” is either “Red,” “Exempt Wood Burning Device,” or “No Burning Period.”  Burning is allowed inside of SPZs all other days, but please use extra precautions and limit forestland burning to units that will not worsen air quality within nearby SSRAs. *

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

 

SHORT-TERM DISCUSSION

 

A gradual pattern change starts Thursday as upper-level ridging flattens with NW flow aloft.  Showers will increase from north to south with less than 0.10” rain totals in the valley and 0.25” or more in higher elevations.  Light surface winds will come from S-SW in northern zones and be variable in southern zones.  Transport winds are expected from SW-NW.  Temperatures will be near to above seasonable.  Mixing heights will be poor and burning near SSRAs will be limited.

 

EXTENDED DISCUSSION

 

More rain arrives for Friday with 0.10” in the valley and higher amounts for the coast and Cascades.  Flow aloft will increase from NW with the flattening upper-level ridge.  Temperatures will rise well above average and mixing heights will begin to improve.  Surface winds will be from SW-W, lighter in southern zones.  Onshore transport winds will be stronger to the north.

 

Showers and mountain snow last into Saturday with freezing levels near 5000 feet north and 6000 feet south.  Strong flow aloft will be from WNW.  Temperatures stay well above average.  Winds will come from SW-W, lighter in southern zones.  Mixing heights will be good.

 

More rain is likely Sunday, mostly north.  Flow aloft will be from W.  Winds will come from SSW-SW with well above seasonable temperatures.  Mixing heights will rise high.  Substantial rain is expected in the week ahead.

 

2.  DISPERSION

 

THURSDAY

 

Zone 601-612 and 639 (North Coast Range and Cascades):

 

MORNING

Mixing height below 500 ft early rising to 1000 - 1900 ft by late morning.

Transport wind S to SW at 4 - 8 mph.

Surface wind light and variable but favors S-SW and controlled by local terrain.

 

AFTERNOON

Mixing height 1100 - 2100 ft.

Transport wind SSW to WSW at 8 - 12 mph.

Surface wind similar to morning.

 

EVENING

Mixing height lowers below 1000 ft.

Transport wind similar to afternoon.

Surface wind increases to S to SW at 4 - 8 mph.

 

Zone 615-620 (South Coast Range):

 

MORNING

Mixing height below 1000 ft.

Transport wind light and variable and controlled by local terrain.

Surface wind light and variable and controlled by local terrain.

 

AFTERNOON

Mixing height 1000 - 1700 ft.

Transport wind increases to WNW to NNW at 4 - 8 mph.

Surface wind similar to morning.

 

EVENING

Mixing height lowers below 1000 ft.

Transport wind becomes light and variable and controlled by local terrain.

Surface wind similar to afternoon.

 

Zone 616-623 (South Cascades):

 

MORNING

Mixing height below 1000 ft.

Transport wind light and variable and controlled by local terrain.

Surface wind light and variable and controlled by local terrain.

 

AFTERNOON

Mixing height 1000 - 2000 ft.

Transport wind similar to morning.

Surface wind similar to morning.

 

EVENING

Mixing height lowers below 1000 ft.

Transport wind similar to afternoon.

Surface wind similar to afternoon.

 

OUTLOOK:

 

FRIDAY

Mixing height below 1000 ft early rising to 1600 to 2600 ft by late morning rising to 2300 to 3300 ft during the afternoon.  Transport wind SW to WSW at 9 - 15 mph during the morning becoming SW to W at 12 - 24 mph during the afternoon.  Surface wind SSW to WSW at 4 - 8 mph.

 

SATURDAY

In the Coast Range mixing height below 1000 ft early rising to 1900 to 2900 ft by late morning and through the afternoon.  In the Cascades mixing height below 1000 ft early rising to 2600 to 3600 ft by late morning and through the afternoon.  Transport wind SW to W at 8 - 14 mph.  Surface wind SW to W at 4 - 8 mph.

 

SUNDAY

Mixing height below 1000 ft early rising to 2700 to 3700 ft by late morning rising to 3800 to 4800 ft during the afternoon.  Transport wind SSW to SW at 14 - 24 mph during the morning becoming SSW to WSW at 18 - 30 mph during the afternoon.  Surface wind S to SW at 6 - 10 mph.

 

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

    - Valid for burning done Thursday, December 4, 2025.

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Coast Range

 

***Avoid ignitions before 10 a.m. in all zones.  Complete ignitions by 2:30 p.m. in all zones.***

 

Zone 601

Units should be 1000 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

Units should be 300 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.  North of T3N in Zone 602, use standard guidance matrix - see section 5 below.  Units may be 900 tons or less, spaced 12 miles apart, south of the Siuslaw River in Zone 603.

 

Zone 612 and 616 east of R9W

Units should be 900 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.

 

Zone 615 and 616 west of R8W

Units should be 1200 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.

 

Zone 618 and 619

Use standard guidance matrix - see section 5 below.

 

Zone 620

Units should be 600 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.  Higher tonnage is possible south of T35S - call the forecaster.

 

 

Cascades

 

***Avoid ignitions before 10 a.m. in all zones.  Complete ignitions by 2:30 p.m. in all zones.***

 

Zone 605, 606, 607, 608, 639, 610, 617, and 623

Use standard guidance matrix - see section 5 below.  Ensure adequate distance from downwind SSRAs for smoke to dissipate.

 

Zone 611

Units should be 900 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.

 

Zone 616

Units should be 600 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.

 

Zone 620 and 622

Units should be 300 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.

 

 

Siskiyous

 

***Avoid ignitions before 10 a.m. Complete ignitions by 2:30 p.m.***

 

Units should be 900 tons or less, spaced 12 miles apart, and 12 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.