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 NORTHEAST FORECAST AREA ZONES 637-646

 

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 more clouds.  A surface thermal trough should remain over central Oregon or progress slightly eastward.  Expect mostly cloudy skies, continued above-average temperatures, and mostly SE winds.  Daytime mixing should remain good.

On Sunday, an upper-level low drops southward along the California Coast, transporting more moisture and instability northward over Oregon.  There is a risk of a late-day shower or thundershower, mainly over the mountains. Daytime temperatures will be about 10-15°F above average.  Light SE winds become variable and possibly northerly in the afternoon with continued good mixing.

EXTENDED DISCUSSION

An upper-level trough comes ashore over southern California on Monday with a drier and more stable NE flow aloft bringing clearing.  Temperatures warm to about 15°F above average with increasing northerly winds and continued good daytime mixing.

A building upper-level ridge brings a dry and warmer N-NE flow aloft on Tuesday.  Expect sunshine with temperatures about 15°F above average. Daytime mixing remains good with mostly northerly 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 SE to S at 8 - 12 mph.

 

Surface wind E to SE at 4 - 8 mph.

 

OUTLOOK:

 

SUNDAY

Mixing height below 1000 ft early rising to 3000 to 4000 ft by late morning rising above 5000 ft during the afternoon.  Transport wind light and variable.  Surface wind light and variable.

 

MONDAY

Mixing height below 1000 ft early rising to 3000 to 4000 ft by late morning rising above 5000 ft during the afternoon.  Transport wind NNW to NNE at 8 - 12 mph.  Surface wind NNW to NNE at 6 - 10 mph.

 

TUESDAY

Mixing height below 1000 ft early rising to 3000 to 4000 ft by late morning rising above 5000 ft during the afternoon.  Transport wind NNW to NNE at 10 - 16 mph.  Surface wind NNW to NNE at 6 - 10 mph.

 

3.  BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

    - 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 ESE through S of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles to the ESE through S 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 N through SE of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles to the NNW through SE in or near drainages leading to 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 NE of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles to the NNW through NE in or near drainages leading to SSRAs.  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.