SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Thursday, November 6, 2025       2:30 PM      Gary Votaw

 

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

 

SHORT-TERM DISCUSSION

 

A weakening cold front sweeps across East Oregon tonight, then the upper-level trough passes very early on Friday.  Flow aloft becomes WNW in afternoon.  Showers taper off during the morning, becoming mostly sunny by afternoon and snow levels may drop to 5000 feet before snow ends.  Mixing potential is very good with winds turning W-NW.

 

EXTENDED DISCUSSION

 

A strong upper-level ridge will be over the area throughout the weekend.  Morning low clouds and fog will turn to sunny skies in the afternoons with temperatures above seasonal normals, reaching 10-15oF above average by Sunday afternoon.  Warm air aloft significantly suppresses mixing on both days.  Transport winds will generally be light and variable, except to favor SE-S for western zones on Saturday.

The ridge weakens somewhat by Monday with flow aloft becoming W, but conditions change little.  Skies will be mostly sunny but with poor mixing and light and variable wind, favoring SW-WNW in the afternoon.

2.  DISPERSION

 

FRIDAY

 

Zone 640, 642, and 644 West of R35E:

Mixing height 3700 - 4700 ft during the morning.  Afternoon mixing height rises to 4000 - 5000 ft then lowers to 1000 - 2000 ft during the evening.

 

Transport wind W to WNW at 12 - 24 mph during the morning and afternoon.  Transport wind decreases to WNW to NNW at 4 - 8 mph during the evening.

 

Surface wind SW to WNW at 4 - 8 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 4000 - 5000 ft during the morning.  Mixing height rises to above 5000 ft during the afternoon then lowers to 1000 - 2000 ft during the evening.

 

Transport wind WNW to NW at 12 - 24 mph during the morning.  Transport wind decreases to WNW to NW at 9 - 15 mph during the afternoon and decreases to NW to N at 5 - 9 mph during the evening.

 

Surface wind WNW to NNW at 6 - 12 mph during the morning and afternoon.  Surface wind becomes light and variable and controlled by local terrain during the evening.

 

OUTLOOK:

 

SATURDAY

Mixing height below 1000 ft early rising to 1200 to 2200 ft by late morning rising to 1900 to 2900 ft during the afternoon.  Transport wind SE to S at 6 - 10 mph.  Surface wind light and variable during the morning becoming ESE to SSE at 4 - 8 mph during the afternoon.

 

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 1700 ft during the afternoon.  Transport wind light and variable during the morning becoming SW to WNW at 4 - 8 mph during the afternoon.  Surface wind light and variable.

 

3.  BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

    - Valid for burning done Friday, November 7, 2025.

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

 

Zone 640, 642, and 644 West of R35E:

Follow standard guidance matrix - see section 5 below - for burning units to the WSW through NNW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles in all directions of SSRAs.  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 N of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles in all directions of 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.