SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Thursday, April 30, 2026       2:30 PM      Sherri Pugh

 

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

 

SHORT-TERM DISCUSSION

 

Friday will have mostly dry weather with a few thunderstorms developing on the Cascades.  Flow aloft will increase from S as upper-level ridging moves east and a trough will be to the west.  Winds will turn to come from SE-S.  Temperatures will rise well above seasonable.  Mixing heights will be excellent.

 

EXTENDED DISCUSSION

 

Saturday will be mostly dry with a few showers and thunderstorms possible along with S flow aloft as an upper-level low sits offshore.  Winds will be from SE-S, though more from N near the Washington/Oregon border.  Temperatures will stay well above average and mixing heights will be high.

 

A dry start on Sunday could turn to scattered showers and thunderstorms late.  Flow aloft will be light from E as the upper-level low will be offshore of California and a high will be to the northwest.  Winds will be from NE-E with even warmer temperatures.  Mixing heights will be good.

 

Monday will be mostly dry with flow aloft light from NE as the upper-level low weakens and ridging will be offshore of Canada.  Winds will be from N.  Mixing heights will be excellent.  Upper-level ridging will build into midweek.

 

 

2.  DISPERSION

 

FRIDAY

 

Zone 640, 642, and 644 West of R35E:

Mixing height below 500 ft early rising above 5000 ft by late morning.  Mixing height lowers to 1000 - 2000 ft during the evening.

 

Transport wind SSE to SSW at 10 - 18 mph throughout the morning and afternoon.  Transport wind shifts to ESE to SSE and decreases to 6 - 10 mph during the evening.

 

Surface wind ESE to S at 6 - 10 mph during the morning and afternoon.  Surface wind becomes light and variable and controlled by local terrain during the evening.

 

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

Mixing height below 500 ft early rising above 5000 ft by late morning.  Mixing height lowers below 1000 ft during the evening.

 

Transport wind SSE to SSW at 8 - 12 mph during the morning and afternoon.  Transport wind decreases to ESE to SSE at 4 - 8 mph during the evening.

 

Surface wind ESE to S at 4 - 8 mph during the morning and afternoon.  Surface wind becomes light and variable and controlled by local terrain during the evening.

 

OUTLOOK:

 

SATURDAY

Mixing height below 1000 ft early rising to 2800 to 3800 ft by late morning rising above 5000 ft during the afternoon.  Transport wind light and variable during the morning becoming ESE to SSE at 8 - 12 mph during the afternoon.  Surface wind light and variable during the morning becoming ESE to SSE at 4 - 8 mph during the afternoon.

 

SUNDAY

Mixing height below 1000 ft early rising to 2300 to 3300 ft by late morning rising above 5000 ft during the afternoon.  Transport wind ENE to ESE at 4 - 8 mph.  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 N to NE at 6 - 10 mph.  Surface wind NNW to NNE at 4 - 8 mph.

 

3.  BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

    - Valid for burning done Friday, May 1, 2026.

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

 

Zone 640, 642, and 644 West of R35E:

Follow standard guidance matrix - see section 5 below - for burning units to the ESE through SSW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles to the ESE through SSW 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 E through SSW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles to the E through SSW 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.