SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Thursday, April 16, 2026       2:30 PM      Gary Votaw

 

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

 

SHORT-TERM DISCUSSION

 

NW flow aloft decreases on Friday with a ridge arriving late.  Sunny skies warm the area but remaining cooler than seasonal.  Burning potential is very good with variable winds trending NE-E towards late afternoon and evening.

                                          

EXTENDED DISCUSSION

 

The ridge will be overhead on Saturday, and temperatures return to normal levels under sunny skies.  Afternoon mixing will be very good with light SE-S winds.

 

The ridge progresses into Idaho while flow aloft becomes weakly SW for Sunday and Monday.  Partly sunny skies are expected both days with temperatures well above normal.  Mixing heights improve nicely into the afternoons with very light SE winds.

 

2.  DISPERSION

 

FRIDAY

 

Zone 640, 642, and 644 West of R35E:

Mixing height below 1000 ft early rising to 3300 - 4300 ft during the morning.  Mixing height rises above 5000 ft during the afternoon then lowers below 1000 ft during the evening.

 

Transport wind SSW to WSW at 6 - 10 mph during the morning.  Transport wind becomes light and variable and controlled by local terrain during the afternoon then increases to NE to E at 6 - 10 mph during the evening.

 

Surface wind light and variable and controlled by local terrain.

 

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

Mixing height 1000 – 2000 ft early rising to 4200 - 5000 ft during the morning.  Mixing height rises above 5000 ft during the afternoon then lowers below 1000 ft during the evening.

 

Transport wind light and variable and controlled by local terrain during the morning.  Transport wind increases to NE to E at 5 - 9 mph during the afternoon then becomes light and variable during the evening.

 

Surface wind light and variable and controlled by local terrain during the morning.  Surface wind increases to NE to E at 5 - 9 mph during the afternoon then becomes light and variable during the evening.

 

OUTLOOK:

 

SATURDAY

Mixing height below 1000 ft early rising to 3300 to 4300 ft by late morning rising above 5000 ft during the afternoon.  Transport wind SE to S at 10 - 20 mph.  Surface wind light and variable during the morning becoming SE to S at 6 - 10 mph during the afternoon.

 

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 ESE to SSE at 6 - 10 mph.  Surface wind ESE to SSE at 4 - 8 mph.

 

MONDAY

Mixing height below 1000 ft early rising to 1500 to 2500 ft by late morning rising above 5000 ft during the afternoon.  Transport wind ESE to SSE at 4 - 8 mph.  Surface wind light and variable during the morning becoming SE to S at 5 - 9 mph during the afternoon.

 

3.  BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

    - Valid for burning done Friday, April 17, 2026.

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

 

Zone 640, 642, and 644 West of R35E:

Follow standard guidance matrix - see section 5 below - for burning units in all directions of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 25 miles in all directions of 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 in all directions of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles in all directions of 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.