SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Wednesday, December 24, 2025       2:30 PM      Gary Votaw

 

********************** Christmas Schedule ***************************

The ODF forecast office will be closed on Christmas Day and reopen at 7 a.m. on December 26th.  This forecast includes burning instructions through Friday, December 26th (2 days).

For questions regarding prescribed burning planned for this period, please call the forecast office at 503-945-7401 prior to 5 p.m. today or after 7 a.m. on Friday, December 26th.

Have a Merry Christmas!

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

 

SHORT-TERM DISCUSSION

 

An upper-level trough is offshore and causing warm and moist SW flow, windy at the surface.  On Thursday light showers provide .10” or less of moisture, except possibly .25” in the Wallowas.  Snow levels will be 5500-6000 feet.  Look for very good mixing and strong S-SSW transport winds for the western zones.  The east will see mixing not as good with SE-S winds.

 

EXTENDED DISCUSSION

 

On Friday the trough is expected to weaken and finally move into Oregon, bringing colder air.  Light showers persist, .10” or less.  Surface temperatures fall close to average while snow levels fall to 3000-3500 feet.  Afternoon mixing looks good throughout the region with SSE-SSW winds.

 

The trough moves east of Oregon Saturday with NNW flow pushing well mixed air across the region.  Skies turn partly sunny and temperatures fall below seasonal levels.  Mixing conditions are good with W-NW winds.

 

An upper ridge arrives Saturday night and will cause partly sunny skies with poor mixing potential and Sunday and early next week.  Mixing will be fair for a few hours in the afternoon with light and variable winds.

 

2.  DISPERSION

 

THURSDAY

 

Zone 640, 642, and 644 West of R35E:

Mixing height below 1000 ft early rising to 3700 - 4700 ft during the morning.  Mixing height rises to above 5000 ft during the afternoon then lowers to 1500 - 2500 ft during the evening.

 

Transport wind SSE to S at 25 - 45 mph during the morning.  Transport wind increases to S to SSW at 34 - 54 mph during the afternoon then decreases to S to SSW at 20 - 36 mph during the evening.

 

Surface wind SE to S at 10 - 16 mph during the morning and afternoon.  Surface wind decreases to SSE to SSW at 8 - 14 mph during the evening.

 

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

Mixing height below 1000 ft early rising to 1100 - 2100 ft during the morning.  Afternoon mixing height rises to 2500 - 3500 ft then lowers to 1500 - 2500 ft during the evening.

 

Transport wind ESE to SSE at 12 - 22 mph during the morning.  Transport wind increases to SE to S at 14 - 28 mph during the afternoon and evening.

 

Surface wind ESE to SE at 8 - 12 mph during the morning.  Surface wind increases to ESE to SSE at 10 - 18 mph during the afternoon and evening.

 

OUTLOOK:

 

FRIDAY

Mixing height 3100 to 4100 ft during the morning rising to 4200 to 5000 ft during the afternoon.  Transport wind S to SSW at 16 - 30 mph.  Surface wind SSE to SSW at 8 - 14 mph.

 

SATURDAY

Mixing height 3400 to 4400 ft during the morning rising to 4000 to 5000 ft during the afternoon.  Transport wind WNW to NNW at 12 - 24 mph.  Surface wind WSW to WNW at 8 - 14 mph.

 

SUNDAY

Mixing height 1800 to 2800 ft throughout the day.  Transport wind N to NE at 4 - 8 mph during the morning becoming light and variable during the afternoon.  Surface wind light and variable.

 

3.  BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

    - Valid for burning done Thursday and Friday, December 25 and 26, 2025.

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For Thursday:

 

Zone 640, 642, and 644 West of R35E:

Delay ignitions until 10 a.m.   Follow standard guidance matrix - see section 5 below - for burning units to the SSE through SSW of 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:

Delay ignitions until 10 a.m.   Follow standard guidance matrix - see section 5 below - for burning units to the ESE through SSW of SSRAs.  No additional restrictions necessary. 

 

For Friday:

 

Follow standard guidance matrix - see section 5 below - for burning units to the SSW through WSW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 8 miles to the SSW through WNW 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. 

 

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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.