SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Friday, April 18, 2025       2:30 PM      Sherri Pugh

 

1.  DISCUSSION AND FORECAST FOR SOUTH CENTRAL OREGON ZONES 624 AND 625

 

SHORT-TERM DISCUSSION

 

A weak front will move through early on Saturday with morning clouds and then clearing.  Flow aloft will come from NW with an upper-level trough moving through.  Temperatures will continue above average and mixing heights will rise high.  Surface winds will come from WNW-NW.  Transport winds will be from NW.

 

Sunday will have mostly cloudy skies and dry weather.  Broad upper-level troughing will have W flow aloft.  Temperatures will sink to near seasonable.  Mixing heights will be excellent with cooler air aloft.  Winds are expected from WNW-NW.

 

EXTENDED DISCUSSION

 

Monday stays dry with mostly sunny skies for the region.  Temperatures continue near average and mixing heights will stay good.  Winds will come from W-WNW.

 

Tuesday will have a few high clouds and dry weather.  Flow aloft will be light from W with weak upper-level ridging.  Surface winds will be light and variable, favoring NW.  Light transport winds will come from WNW-NW.  Temperatures will be above seasonable and mixing heights will be good.

 

2.  DISPERSION

 

SATURDAY

 

Mixing height below 300 ft early rising to 2000 - 3000 ft by late morning.  Afternoon mixing height rises above 5000 ft then lowers below 1000 ft during the evening.

 

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

 

Surface wind light and variable and controlled by local terrain during the morning.  Surface wind increases to W to NW at 4 - 8 mph during the afternoon and evening.

 

OUTLOOK:

 

SUNDAY

Mixing height below 1000 ft early rising to 2500 - 3500 ft by late morning rising above 5000 ft during the afternoon.  Transport wind W to NW at 5 - 9 mph during the morning becoming W to NW at 10 - 18 mph during the afternoon.  Surface wind light and variable during the morning becoming W to NW at 6 - 10 mph during the afternoon.

 

MONDAY

Mixing height below 1000 ft early rising to 2300 - 3300 ft by late morning rising to 3500 - 4500 ft during the afternoon.  Transport wind WSW to WNW at 4 - 8 mph.  Surface wind light and variable during the morning becoming WSW to WNW at 4 - 8 mph during the afternoon.

 

TUESDAY

Mixing height below 1000 ft early rising to 2500 - 3500 ft by late morning rising to 4500 - 5000 ft during the afternoon.  Transport wind light and variable during the morning becoming W to NW at 4 - 8 mph during the afternoon.  Surface wind light and variable during the morning becoming WNW to NNW at 4 - 8 mph during the afternoon.

 

3.  BURNING INSTRUCTIONS FOR ZONES 624 AND 625 INCLUDING THE WALKER

    RANGE PORTION OF ZONE 624

    - Valid for burning done Saturday through Monday, April 19 through 21, 2025.

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For Saturday:

 

Delay ignitions until 11 a.m. 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 25 miles to the W through NNW in or near drainages leading to SSRAs.  Verify transport winds away from SSRAs if burning in any other direction. No additional restrictions necessary. 

 

For Sunday:

 

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 25 miles to the W through N in or near drainages leading to SSRAs.  No additional restrictions necessary. 

 

For Monday:

 

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 25 miles to the WSW through NNW in or near drainages leading to SSRAs.  Verify transport winds away from SSRAs if burning in any other direction. No additional restrictions necessary. 

 

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4.  SPECIAL NOTE:

 

    The smoke management forecaster is available at (503)

    945-7401.  The smoke management forecaster is available

    to discuss specific burns.  The duty forecaster phone

    number is (503) 945-7401. Please call this number and

    not individual's numbers to discuss daily burning. Please

    avoid calling between 1:30 to 2:45 p.m.

 

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

    Daily/lmt.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.