SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Friday, December 26, 2025       2:30 PM      Gary Votaw

 

1.  DISCUSSION AND FORECAST FOR NORTHEAST FORECAST AREA ZONES 637-646

 

SHORT-TERM DISCUSSION

 

Northwest flow aloft will push well mixed air across the region Saturday.  Snow tapers off while skies remain mostly cloudy and cold.  Additional moisture may reach .10” to .25” in mountains.  Mixing conditions are good with NW winds.

 

An upper ridge centered offshore begins to dominate by Sunday as burning potential quickly becomes poor with light and variable winds. Mostly sunny skies will help little as temperatures remain below seasonal levels.

 

EXTENDED DISCUSSION

 

Sunny skies persist and temperatures rise above average for Monday and Tuesday.  However, the ridge maintains its grip on the region to cause very poor burning conditions with very light winds, favoring SE-S on both days. 

 

2.  DISPERSION

 

SATURDAY

 

Zone 640, 642, and 644 West of R35E:

Mixing height 4200 - 5000 ft during the morning.  Mixing height rises to above 5000 ft during the afternoon then lowers to 1400 - 2400 ft during the evening.

 

Transport wind NW to NNW at 16 - 30 mph during the morning and afternoon.  Transport wind decreases to WNW to NW at 10 - 20 mph during the evening.

 

Surface wind W to NW at 12 - 24 mph during the morning and afternoon.  Surface wind becomes light and variable and controlled by local terrain during the evening.

 

Zone 637, 643, 645, 646, and 644 East of R34E:

Mixing height 4400 - 5000 ft during the morning.  Afternoon mixing lowers to 4100 - 5000 ft and lowers to 2000 - 3000 ft during the evening.

 

Transport wind WNW to NW at 19 - 33 mph during the morning and afternoon.  Transport wind decreases to W to NW at 10 - 18 mph during the evening.

 

Surface wind W to NW at 10 - 20 mph during the morning and afternoon.  Surface wind decreases to W to NW at 5 - 9 mph during the evening.

 

OUTLOOK:

 

SUNDAY

Mixing height below 1000 ft during the morning rising to 1000 to 2000 ft during the afternoon.  Transport wind light and variable.  Surface wind light and variable.

 

MONDAY

Mixing height below 1000 ft during the morning rising to 1000 to 1800 ft during the afternoon.  Transport wind ESE to S at 6 - 10 mph.  Surface wind light and variable.

 

TUESDAY

Mixing height below 1000 ft throughout the day.  Transport wind ESE to S at 5 - 9 mph.  Surface wind light and variable.

 

3.  BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

    - Valid for burning done Saturday through Monday, December 27 through 29, 2025.

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For Saturday:

 

Zone 640, 642, and 644 West of R35E:

Follow standard guidance matrix - see section 5 below - for burning units to the WNW through NNW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles to the WNW through NNW in or near drainages leading to SSRAs.  Care needed in selecting units as smoke will likely fumigate along the ground in wind prone areas. No additional restrictions necessary. 

 

Zone 637, 643, 645, 646, and 644 East of R34E:

Follow standard guidance matrix - see section 5 below - for burning units to the W through NNW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 10 miles to the WSW through NNW in or near drainages leading to SSRAs.  No additional restrictions necessary. 

 

For Sunday:

 

Delay ignitions until 10 a.m.   Follow standard guidance matrix - see section 5 below - for burning units in all directions of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 30 miles in all directions of SSRAs.  Complete ignitions by 2:30 p.m.  No additional restrictions necessary. 

 

For Monday:

 

Delay ignitions until 10 a.m.   Follow standard guidance matrix - see section 5 below - for burning units to the ESE through S of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 30 miles to the ESE through S in or near drainages leading to SSRAs.  Complete ignitions by 2:30 p.m.  No additional restrictions necessary. 

 

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

4.  SPECIAL NOTE:

 

    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

 

    The smoke management forecaster is available at (503)-

    945-7401. Please call this number and not individual's

    numbers to discuss daily burning.  For large burns (over

    2000 tons) or burns extending over a considerable period,

    please request a special forecast.  Avoid calling

    between 1:30 to 2:45 p.m.

 

    http://www.odf.state.or.us/DIVISIONS/protection/fire_protection/

    Daily/neo.htm

 

    To subscribe to or unsubscribe from the email list for this

    product, please go to the link:

    http://weather.smkmgt.com/mailman/listinfo/

 

    Please ensure your units have been planned and accomplished by

    checking: http://oregon.gov/ODF/FIRE/SMP/dailysmoke.shtml

 

    A map of planned and/or accomplished burns is located at:

    http://geo.maps.arcgis.com/apps/webappviewer/index.html

    ?id=a7e321dc8fc444b7a33fbc67bc673a3b

 

 

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.

 

  * 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.