SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Monday, May 12, 2025       2:30 PM      Sherri Pugh

 

******************** Instruction Zones Update ***********************

The National Weather Service recently changed borders and numbering of their fire zones.  ODF will use the previous zone boundaries for smoke management and not change with these updates.

A link to ODF’s smoke forecast zones is at the bottom of the instructions in the Special Notes section. (https://www.oregon.gov/odf/fire/documents/smoke-forecast-zone-map.pdf)

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

 

SHORT-TERM DISCUSSION

 

Tuesday will have fewer showers than Monday with totals barely to 0.05”.  An isolated chance of thunderstorms continue for the afternoon but mostly for northeastern zones.  An upper-level trough will be east of the state with N flow aloft.  Winds will come from WNW-NW and temperatures will drop below average.  Mixing heights will be good with freezing levels near 5000 feet.

 

EXTENDED DISCUSSION

 

Wednesday will be mostly dry with some risk of isolated showers.  A weaker trough will move through with NNW flow aloft.  Mixing heights stay good though a little lower.  Winds will be from W-NW.  Temperatures stay below seasonable.

 

Dry weather is expected Thursday other than in far northeastern zones.  Flow aloft will be light from NW with flat upper-level ridging.  Mixing heights will be excellent with seasonable temperatures.  Winds will be from WNW-NW, lighter in the northeast.

 

Friday will be the last dry day for most, other than a few showers in the northeast, before a system arrives overnight into Saturday with rain.  Flow aloft will be from NW with broad upper-level ridging, followed by a weak trough late.  Light winds will be from WSW-WNW.  Temperatures stay seasonable.  Mixing heights will be good though decreased.

 

2.  DISPERSION

 

TUESDAY

 

Zone 640, 642, and 644 West of R35E:

Mixing height below 2000 ft early rising to 3500 - 4500 ft by late morning.  Afternoon mixing height 3500 - 4500 ft then lowers to 1500 - 2500 ft during the evening.

 

Transport wind WNW to NNW at 10 - 18 mph.

 

Surface wind W to NW at 6 - 10 mph throughout the day.

 

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

Mixing height below 1000 ft early rising to 3500 - 4500 ft by late morning.  Afternoon mixing height rises above 5000 ft then lowers to 2000 - 3000 ft during the evening.

 

Transport wind WNW to NNW at 6 - 10 mph throughout the day.

 

Surface wind light and variable and controlled by local terrain during the morning.  Surface wind increases to WNW to NNW at 4 - 8 mph during the afternoon and evening.

 

OUTLOOK:

 

WEDNESDAY

Mixing height below 1000 ft early rising to 3500 to 4500 ft by late morning and through the afternoon.  In the west transport wind W to NW at 9 - 15 mph during the morning becoming WNW to NW at 12 - 24 mph during the afternoon.  In the east transport wind WNW to NNW at 5 - 9 mph.  Surface wind light and variable during the morning becoming W to NW at 5 - 9 mph during the afternoon.

 

THURSDAY

Mixing height below 1000 ft early rising to 2500 to 3500 ft by late morning rising to 4000 to 5000 ft during the afternoon.  Transport wind WNW to NNW at 6 - 10 mph.  Surface wind W to NW at 4 - 8 mph.

 

FRIDAY

Mixing height below 1000 ft early rising to 2300 to 3300 ft by late morning rising to 3300 to 4300 ft during the afternoon.  Transport wind WSW to WNW at 4 - 8 mph.  Surface wind light and variable.

 

3.  BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

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

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

 

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 15 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 W 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.