SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Tuesday, December 16, 2025       2:30 PM      Sherri Pugh

 

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

 

SHORT-TERM DISCUSSION

 

Rain and mountain snow arrive on Wednesday with freezing levels under 4000 feet.  Rainfall amounts could reach 0.25” with strong onshore flow aloft.  Mixing heights will be excellent with temperatures near or above average.  Surface winds will be brisk from W while strong transport winds will come from W-WNW.

 

EXTENDED DISCUSSION

 

Freezing levels will rise higher on Thursday with continued rainfall and strong onshore flow aloft.  Temperatures will climb well above seasonable.  Mixing heights will be suppressed with less burning close to SSRAs.  Surface winds will be from SSE-SSW and strong transport winds will come from S-SW.

 

A cold front will lower freezing levels again for Friday, reaching under 4000 feet.  Rain and mountain snow are likely.  Mixing heights will improve and temperatures will be above average.  Winds will come from WSW-W with strong transport winds. 

 

Saturday turns mostly dry with onshore but weaker winds aloft.  Warmer air aloft will decrease mixing heights.  Light surface winds will be from S-SSW.  Transport winds are expected from SSW-SW.  Temperatures will be near or above average.  Showers increase again for Sunday.

 

 

2.  DISPERSION

 

WEDNESDAY

 

Zone 640, 642, and 644 West of R35E:

Mixing height below 1000 ft early rising to 3000 - 4000 ft by late morning.  Afternoon mixing height rises to 3700 - 4700 ft then lowers to 1000 - 2000 ft during the evening.

 

Transport wind WSW to WNW at 22 - 38 mph throughout the morning and afternoon.  Transport wind shifts to SW to W and decreases to 9 - 15 mph during the evening.

 

Surface wind SW to W at 9 - 15 mph throughout the morning and afternoon.  Surface wind shifts to SSW to WSW and decreases to 4 - 8 mph during the evening.

 

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

Mixing height below 800 ft early rising to 3500 - 4500 ft by late morning.  Afternoon mixing height rises to 3700 - 4700 ft then lowers below 1000 ft during the evening.

 

Transport wind WNW to NW at 26 - 46 mph during the morning and afternoon.  Transport wind decreases to WSW to WNW at 8 - 12 mph during the evening.

 

Surface wind WSW to WNW at 9 - 15 mph throughout the morning and afternoon.  Surface wind shifts to SW to W and decreases to 4 - 8 mph during the evening.

 

OUTLOOK:

 

THURSDAY

Mixing height below 1000 ft early rising to 1500 to 2500 ft by late morning and through the afternoon.  Transport wind SSE to SSW at 8 - 14 mph during the morning becoming SSW to SW at 12 - 24 mph during the afternoon.  Surface wind SE to S at 4 - 8 mph.

 

FRIDAY

Mixing height below 1000 ft early rising to 2500 to 3500 ft by late morning rising to 3500 to 4500 ft during the afternoon.  Transport wind WSW to WNW at 15 - 25 mph during the morning becoming WSW to WNW at 20 - 36 mph during the afternoon.  Surface wind SW to W at 6 - 10 mph.

 

SATURDAY

Mixing height below 1000 ft early rising to 1500 to 2500 ft by late morning rising to 2300 to 3300 ft during the afternoon.  Transport wind S to SW at 6 - 10 mph.  Surface wind SSE to SSW at 4 - 8 mph.

 

3.  BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

    - Valid for burning done Wednesday, December 17, 2025.

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

 

Zone 640, 642, and 644 West of R35E:

Follow standard guidance matrix - see section 5 below - for burning units to the SW through NW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 25 miles to the SSE through NW in or near drainages leading to SSRAs.  Watch for shifting transport winds. 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 WSW through NW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles to the SE through NW in or near drainages leading to SSRAs.  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.