SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Friday, May 1, 2026       2:30 PM      Pete Parsons

 

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

 

SHORT-TERM DISCUSSION

The upper-level ridge that has been bringing dry and relatively warm weather weakens slightly and shifts eastward, to over Idaho, on Saturday.  An upper-level trough approaching the coast will increase the S-SW flow aloft, bringing a chance of afternoon thundershowers.  A surface thermal trough should remain over central Oregon but may progress slightly eastward.  Temperatures will remain above average with increasing mostly southerly winds.  Daytime mixing remains good.

On Sunday, an upper-level low drops southward along the California Coast, transporting more moisture and instability northward over Oregon.  Expect scattered afternoon showers and thundershowers. Daytime temperatures will remain about 10°F above average.  SE winds become more variable in the afternoon with continued good mixing.

EXTENDED DISCUSSION

An upper-level trough comes ashore over southern California on Monday with a moist and unstable circulation around bringing scattered showers and a chance of thundershowers to south-central Oregon.  Rainfall totals from late Sunday through Monday could locally exceed .25” near the southern border.  Temperatures remain above average with good daytime mixing.  Winds will be variable near showers but trend towards northerly.

A building upper-level ridge brings a dry and warmer N-NE flow aloft on Tuesday.  Expect mostly sunny skies and temperatures 10-15°F above average. Daytime mixing remains good with mostly NW-N winds.

2.  DISPERSION

 

SATURDAY

 

Mixing height below 1000 ft early rising to 2500 - 3500 ft by late morning.  Afternoon mixing height rises above 5000 ft then lowers to 2000 - 3000 ft during the evening.

 

Transport wind SSE to SSW at 10 - 18 mph.

 

Surface wind SE to SSW at 6 - 10 mph during the morning and afternoon.  Surface wind decreases to SE to SSW at 5 - 9 mph during the evening.

 

OUTLOOK:

 

SUNDAY

Mixing height below 1000 ft early rising to 2200 - 3200 ft by late morning rising above 5000 ft during the afternoon.  Transport wind ESE to S at 6 - 10 mph.  Surface wind light and variable during the morning becoming ENE to ESE at 4 - 8 mph during the afternoon.

 

MONDAY

Mixing height below 1000 ft early rising to 2000 - 3000 ft by late morning rising above 5000 ft during the afternoon.  Transport wind NNW to NNE at 6 - 10 mph during the morning becoming NNW to NNE at 10 - 18 mph during the afternoon.  Surface wind NNW to NNE at 4 - 8 mph during the morning becoming NNW to NNE at 9 - 15 mph during the afternoon.

 

TUESDAY

Mixing height below 1000 ft early rising to 2000 - 3000 ft by late morning rising above 5000 ft during the afternoon.  Transport wind NNW to NNE at 10 - 18 mph.  Surface wind NNW to NNE at 6 - 10 mph.

 

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

    RANGE PORTION OF ZONE 624

    - Valid for burning done Saturday through Monday, May 2 through 4, 2026.

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For Saturday:

 

Follow standard guidance matrix - see section 5 below - for burning units to the SSE through SSW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles to the ESE through SSW in or near drainages leading to SSRAs.  No additional restrictions necessary. 

 

For Sunday:

 

Follow standard guidance matrix - see section 5 below - for burning units to the NE through S of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 10 miles in all directions of SSRAs.  Verify transport winds away from SSRAs if burning in any other direction. No additional restrictions necessary. 

 

For Monday:

 

Follow standard guidance matrix - see section 5 below - for burning units to the NNW through NNE of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles to the NW through NNE in or near drainages leading to SSRAs.  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.