SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Wednesday, April 15, 2026       2:30 PM      Gary Votaw

 

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

 

SHORT-TERM DISCUSSION

 

An upper-level trough moves eastward into Idaho Thursday causing N flow aloft.  There is a chance of lingering very light snow, but clouds decrease through the day, temperatures remaining 15oF below seasonal levels.  Colder air aloft helps mixing conditions to be excellent in NW winds.

                                          

EXTENDED DISCUSSION

 

Decreasing NW flow aloft on Friday allows for sunny and warmer conditions, but still cooler than normal.  Burning potential is very good with W winds becoming weak by afternoon.

 

A ridge keeps Saturday mostly sunny while the warming trend continues.  Afternoon mixing will be very good with S-SW transport winds.

 

By Sunday flow aloft becomes SW well ahead of an offshore system.  There is a slight chance of rain or high mountain snow under partly sunny skies, temperatures above normal.  Mixing heights improves through the day with very light SE-S winds.

 

2.  DISPERSION

 

THURSDAY

 

Zone 640, 642, and 644 West of R35E:

Mixing height above 5000 ft throughout the day.

 

Transport wind NW to NNW at 15 - 29 mph during the morning and afternoon.  Transport wind decreases to WNW to NNW at 10 - 18 mph during the evening.

 

Surface wind WNW to NNW at 9 - 15 mph during the morning and afternoon.  Surface wind decreases to W to NW at 6 - 10 mph during the evening.

 

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

Mixing height above 5000 ft throughout the day.

 

Transport wind WNW to NW at 14 - 28 mph during the morning and afternoon.  Transport wind decreases to WNW to NW at 10 - 16 mph during the evening.

 

Surface wind WNW to NW at 8 - 14 mph during the morning and afternoon.  Surface wind decreases to W to NW at 4 - 8 mph during the evening.

 

OUTLOOK:

 

FRIDAY

In the west mixing height 2700 to 3700 ft during the morning rising above 5000 ft during the afternoon.  In the east mixing height below 1000 ft early rising above 5000 ft by late morning and through the afternoon.  In the west transport wind WSW to WNW at 10 - 16 mph during the morning becoming SW to WNW at 4 - 8 mph during the afternoon.  In the east transport wind WSW to WNW at 4 - 8 mph during the morning becoming WNW to NNW at 4 - 8 mph during the afternoon.  Surface wind light and variable.

 

SATURDAY

Mixing height below 1000 ft early rising to 3000 to 4000 ft by late morning rising above 5000 ft during the afternoon.  Transport wind S to SW at 10 - 20 mph.  Surface wind SE to S at 4 - 8 mph.

 

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 SE to S at 4 - 8 mph.  Surface wind SE to S at 4 - 8 mph.

 

3.  BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

    - Valid for burning done Thursday, April 16, 2026.

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

 

Zone 640, 642, and 644 West of R35E:

Follow standard guidance matrix - see section 5 below - for burning units to the WNW through NNW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 10 miles to the W through NNW 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 WNW through NNW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 10 miles to the SW through NNW 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.