SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Thursday, December 4, 2025       2:30 PM      Pete Parsons

 

*********************************************************************

* 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. *

*********************************************************************

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

 

SHORT-TERM DISCUSSION

A warm front is bringing light rain to the northern zones this afternoon, with clouds extending into the southern zones, while mostly sunny skies hold on near the California border.  Surface temperatures are near average, but freezing levels are above 8000 feet, which is creating poor mixing with generally light winds.

The upper-level ridge flattens enough on Friday to allow a cold front to sag southward over the region and spread rain across all zones, especially north.  Snow levels only drop to about 6000 feet north and stay above 7000 feet south.  Rainfall over .25” is likely north with around .10” south.  Slight cooling aloft and increasing SW winds will improve mixing.

EXTENDED DISCUSSION

Very little change in the weather pattern is projected for Saturday and Sunday, as a flat upper-level ridge maintains a relatively mild NW flow aloft and keeps a moist frontal system over the region.  Expect light rain at times north and a chance of rain south.  Additional rainfall will be generally around .25” north and .10” south.  Snow levels only drop to 5-6000 feet north and 6-7000 feet south, which would support at least fair mixing with SW winds.

A stronger weather system will bring increasing rain and SW wind on Monday afternoon, especially north.  Ahead of this system, snow levels should rise slightly but expect at least fair daytime mixing.  Rain may become heavy across the north by Monday night and spread south all the way to the California border.

2.  DISPERSION

 

FRIDAY

 

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

 

MORNING

Mixing height below 1000 ft early rising to 1500 - 2500 ft by late morning.

Transport wind SSW to SW at 15 - 25 mph.

Surface wind SSW to SW at 8 - 12 mph.

 

AFTERNOON

Mixing height 2400 - 3400 ft.

Transport wind SW at 18 - 32 mph.

Surface wind SSW to SW at 10 - 18 mph.

 

EVENING

Mixing height 2000 - 3000 ft.

Transport wind SW to W at 15 - 29 mph.

Surface wind SSW to WSW at 9 - 15 mph.

 

Zone 615-620 (South Coast Range):

 

MORNING

Mixing height below 1000 ft early rising to 1000 - 2000 ft by late morning.

Transport wind SSW to SW at 12 - 24 mph.

Surface wind S to SW at 6 - 10 mph.

 

AFTERNOON

Mixing height rising to 2200 - 3200 ft.

Transport wind similar to morning.

Surface wind similar to morning.

 

EVENING

Mixing height 1500 - 2500 ft.

Transport wind SW to W at 10 - 20 mph.

Surface wind SSW to WSW at 6 - 12 mph.

 

Zone 616-623 (South Cascades):

 

MORNING

Mixing height below 1000 ft early rising to 1000 - 1700 ft by late morning.

Transport wind S to SW at 6 - 10 mph.

Surface wind SSE to SW at 4 - 8 mph.

 

AFTERNOON

Mixing height rising to 2000 - 3000 ft.

Transport wind S to SW at 9 - 15 mph.

Surface wind similar to morning.

 

EVENING

Mixing height 1500 - 2500 ft.

Transport wind SW to WSW at 8 - 14 mph.

Surface wind SSW to WSW at 4 - 8 mph.

 

OUTLOOK:

 

SATURDAY

Mixing height 1400 to 2400 ft throughout the day.  Transport wind SW to W at 10 - 16 mph.  Surface wind SSW to WSW at 6 - 10 mph.

 

SUNDAY

Mixing height below 1000 ft early rising to 1400 to 2400 ft by late morning rising to 2200 to 3200 ft during the afternoon.  Transport wind SSW to SW at 10 - 20 mph.  Surface wind SSE to SW at 6 - 10 mph.

 

MONDAY

Mixing height below 1000 ft early rising to 1700 to 2700 ft by late morning rising to 2400 to 3400 ft during the afternoon.  Transport wind SSW to SW at 10 - 20 mph during the morning becoming SSW to SW at 15 - 25 mph during the afternoon.  Surface wind SSE to SW at 6 - 12 mph.

 

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

    - Valid for burning done Friday, December 5, 2025.

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

 

Coast Range

 

***Avoid ignitions before 10 a.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.  Higher tonnage is possible south of T29S in Zone 616 - call the forecaster.

 

Zone 615, 616 west of R8W, 618, 619, and 620

Use standard guidance matrix - see section 5 below.  Avoid burning directly upwind of the North Bend/Coos Bay SSRA.

 

 

Cascades

 

***Avoid ignitions before 10 a.m. in all zones.***

 

All zones except zone 611

Use standard guidance matrix - see section 5 below.  Ensure adequate distance from downwind SSRAs for smoke to dissipate.  Avoid ignitions north of T24S in Zone 616.

 

Zone 611

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

 

 

Siskiyous

 

***Avoid ignitions before 10 a.m.***

 

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

 

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

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.