SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Monday, May 12, 2025       2:30 PM      Gary Votaw

 

1.  DISCUSSION AND FORECAST FOR THE WESTERN OREGON AREA FORECAST ZONES 601-623 and 639

 

SHORT-TERM DISCUSSION

 

An upper-level trough moves east of Oregon on Tuesday leaving N flow aloft over the region.  Light showers are expected, mostly for the Cascades where about .10” is possible and a snow level at 5-6000 feet.  Skies will be partly sunny.  Cooler low level air arriving will make mixing potential moderate at best except remaining good in the South Cascades.  Transport winds will range from SW-NW.

EXTENDED DISCUSSION

NNW flow aloft persists on Wednesday and Thursday and pushes drier air across West Oregon, but skies remain partly sunny with a few very light showers possible.  Mixing potential is good as heights rise through both afternoons and transport winds will be W-NW.

A cold front will arrive late on Friday while its associated upper trough follows that night.  Afternoon showers are likely to develop in the NW corner of the state as the snow level rises over 7000 feet.  Potential mixing across the region is very good in the afternoon with very light winds, favoring NW.

2.  DISPERSION

 

TUESDAY

 

Zone 601, 602, 603 and 612 (North Coast Range):

 

MORNING

Mixing height 2000 - 3000 ft.

Transport wind WSW to WNW at 9 - 15 mph.

Surface wind light and variable and controlled by local terrain.

 

AFTERNOON

Mixing height 2700 - 3700 ft.

Transport wind WSW to WNW at 10 - 20 mph.

Surface wind increases to WSW to WNW at 8 - 12 mph.

 

EVENING

Mixing height 1900 - 2900 ft.

Transport wind W to NW at 10 - 20 mph.

Surface wind WSW to NW at 6 - 12 mph.

 

Zone 605-611 and 639 (North Cascades):

 

MORNING

Mixing height 2000 - 3000 ft.

Transport wind WSW to WNW at 10 - 18 mph.

Surface wind light and variable and controlled by local terrain.

 

AFTERNOON

Mixing height 2300 - 3300 ft.

Transport wind SW to W at 8 - 14 mph.

Surface wind increases to SW to W at 6 - 10 mph.

 

EVENING

Mixing height 1000 - 1900 ft.

Transport wind similar to afternoon.

Surface wind similar to afternoon.

 

Zone 615-620 (South Coast Range):

 

MORNING

Mixing height 2100 - 3100 ft.

Transport wind WSW to NW at 6 - 12 mph.

Surface wind WSW to NW at 4 - 8 mph.

 

AFTERNOON

Mixing height 2500 - 3500 ft.

Transport wind similar to morning.

Surface wind similar to morning.

 

EVENING

Mixing height 2000 - 3000 ft.

Transport wind W to NNW at 5 - 9 mph.

Surface wind W to NNW at 4 - 8 mph.

 

Zone 616-623 (South Cascades):

 

MORNING

Mixing height 2600 - 3600 ft.

Transport wind W to NW at 6 - 10 mph.

Surface wind light and variable and controlled by local terrain.

 

AFTERNOON

Mixing height rising to 4300 - 5000 ft.

Transport wind similar to morning.

Surface wind increases to W to NW at 5 - 9 mph.

 

EVENING

Mixing height 2800 - 3800 ft.

Transport wind similar to afternoon.

Surface wind similar to afternoon.

 

OUTLOOK:

 

WEDNESDAY

Mixing height 1000 to 2000 ft early rising to 1900 to 2900 ft by late morning then rising to 3900 to 4900 ft during the afternoon.  Transport wind WSW to WNW at 6 - 10 mph during the morning becoming WNW to NNW at 9 - 15 mph during the afternoon.  Surface wind light and variable during the morning becoming W to NW at 5 - 9 mph during the afternoon.

 

THURSDAY

Mixing height 1500 to 2500 ft during the morning rising above 5000 ft during the afternoon.  Transport wind WSW to WNW at 6 - 10 mph during the morning becoming WNW to NNW at 9 - 15 mph during the afternoon.  Surface wind light and variable during the morning becoming WSW to NW at 4 - 8 mph during the afternoon.

 

FRIDAY

Mixing height below 1000 ft early rising to 2300 to 3300 ft by late morning rising above 5000 ft during the afternoon.  Transport wind light and variable during the morning becoming WNW to NNW 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 ALL ZONES IN THE WESTERN OREGON AREA

    - Valid for burning done Tuesday, May 13, 2025.

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Coast Range

 

Zone 601 and 612

Units should be 1000 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.  Restrict units in or near corridors to 500 tons or less.  North of Tillamook in Zone 601, use standard guidance matrix. (See section 5 below.)

 

Zone 602 and 603

Units should be 400 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.  North of T3N in Zone 602, use standard guidance matrix. (See section 5 below.)  Limit burning in or near corridors.  Units may be 500 tons or less, spaced 8 miles apart, south of the Siuslaw River in Zone 603.

 

Zone 615 and 616 west of R8W

Units should be 1200 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.

 

Zone 616 east of R9W

Units should be 750 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.

 

Zone 618 and 619

Use standard guidance matrix. (See section 5 below.)

 

Zone 620

Units should be 300 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.

 

 

Cascades

 

Zone 605, 606, 607, 608, 639, 610, 616, 617, and 623

Use standard guidance matrix - see section 5 below.  Ensure adequate distance from downwind SSRAs for smoke to dissipate.  From T18S through T22S in Zone 608 units should be 900 tons or less, spaced 12 miles apart.

 

Zone 611

Units should be 900 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.

 

Zone 620

Units should be 750 tons or less, spaced 6 miles apart, and 8 miles from downwind SSRAs.

 

Zone 622

Units should be 1200 tons or less, spaced 6 miles apart, and 8 miles from downwind SSRAs.  East of R2W, use standard guidance matrix - see section 5 below.

 

 

Siskiyous

 

Use standard guidance matrix - see section 5 below. Ensure adequate distance from downwind SSRAs for smoke to dissipate.

 

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4.  SPECIAL NOTES:

 

    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

 

    Call the smoke management duty forecaster at (503) 945-7401 to

    discuss burning. Please do not call individual's numbers to

    discuss daily burning. If the forecaster is not available,

    leave a message and they will return your call as soon as possible.

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

 

    The forecast is available on the Internet at:

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

    Daily/smi.htm

 

    Please ensure your units have been planned and accomplished by

    checking: http://www.oregon.gov/ODF/Fire/Pages/Burn.aspx

 

    A map of planned and/or accomplished burns is located at:

    http://geo.maps.arcgis.com/apps/webappviewer/index.html

    ?id=a7e321dc8fc444b7a33fbc67bc673a3b

 

    The forecast/instruction telephone recording is: (503) 945-7400.

 

    To subscribe to or unsubscribe from the email list for this

    product, please go to the link:

    http://weather.smkmgt.com/mailman/listinfo/

 

 

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.

    Example: 300 tons allowed if burned 5 miles from a downwind SSRA.

 

  * 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.