SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Monday, May 11, 2026       2:30 PM      Gary Votaw

 

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

 

SHORT-TERM DISCUSSION

 

An upper-level ridge will be centered just east of Oregon Tuesday with SW flow over the state.  Mostly sunny skies push temperatures 20oF or more above seasonal but very dry.  Mixing conditions will be excellent with S-SSW winds during the afternoon.

 

EXTENDED DISCUSSION

 

A cold front arrives Wednesday morning followed by a strong upper trough late in the day.  Showers are likely while thunderstorms are possible by afternoon and into Wednesday evening.  Potential rainfall is .10” to .25”, or more in storms.  Mixing will still be excellent with SW winds becoming W in the afternoon. 

 

Thursday will be much cooler but near seasonal levels, with a chance of showers in the morning.  Skies become mostly sunny and burning potential excellent with W winds.

 

Sunny and otherwise seasonal conditions are expected Friday under W flow aloft.  Mixing improves through the day with winds becoming W-NW.

 

2.  DISPERSION

 

TUESDAY

 

Zone 640, 642, and 644 West of R35E:

Mixing height below 1000 ft early rising above 5000 ft during the morning and through the afternoon.  Mixing height lowers below 1000 ft during the evening.

 

Transport wind SSE to SSW at 15 - 25 mph during the morning.  Transport wind increases to S to SSW at 18 - 30 mph during the afternoon then decreases to SSW to WSW at 8 - 12 mph during the evening.

 

Surface wind SE to SSW at 6 - 10 mph throughout the morning and afternoon.  Surface wind shifts to WSW to WNW and decreases to 4 - 8 mph during the evening.

 

Zone 637, 643, 645, 646, and 644 East of R34E:

Mixing height below 1000 ft early rising to 2500 - 3500 ft during the morning.  Mixing height rises above 5000 ft during the afternoon then lowers below 1000 ft during the evening.

 

Transport wind SE to SSW at 9 - 15 mph during the morning.  Transport wind increases to S to SSW at 15 - 25 mph during the afternoon then decreases to ESE to SSE at 8 - 12 mph during the evening.

 

Surface wind SE to S at 5 - 9 mph during the morning.  Surface wind increases to ESE to SSE at 9 - 15 mph during the afternoon and evening.

 

OUTLOOK:

 

WEDNESDAY

Mixing height below 1000 ft early rising to 3800 to 4800 ft by late morning rising above 5000 ft during the afternoon.  Transport wind SSW to SW at 9 - 21 mph during the morning becoming W to WNW at 18 - 32 mph during the afternoon.  In the west surface wind light and variable during the morning becoming WSW to WNW at 10 - 20 mph during the afternoon.  In the east surface wind SSW to WSW at 6 - 12 mph during the morning becoming WNW to NNW at 10 - 18 mph during the afternoon.

 

THURSDAY

Mixing height 2200 to 3200 ft during the morning rising above 5000 ft during the afternoon.  Transport wind WSW to WNW at 10 - 18 mph.  Surface wind WSW to WNW at 8 - 12 mph.

 

FRIDAY

Mixing height below 1000 ft early rising to 3200 to 4200 ft during the morning rising above 5000 ft during the afternoon.  Transport wind SSW to WSW at 6 - 12 mph during the morning becoming W to NW at 13 - 25 mph during the afternoon.  Surface wind SW to W at 6 - 10 mph during the morning becoming W to WNW at 10 - 22 mph during the afternoon.

 

3.  BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

    - Valid for burning done Tuesday, May 12, 2026.

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

 

Zone 640, 642, and 644 West of R35E:

Follow standard guidance matrix - see section 5 below - for burning units to the SSE through WSW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 30 miles to the SSE through WSW in or near drainages leading to 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 ESE through SW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 25 miles to the ESE through WSW in or near drainages leading to 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.