SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Friday, December 19, 2025       2:30 PM      Pete Parsons

 

*********************************************************************

* Special Protection Zone (SPZ) provisions apply from November 15 through February 15.  Prescribed burning is not allowed in an SPZ from December 1 through February 15 on days when the daily woodstove “Ordinance” is either “Red,” “Exempt Wood Burning Device,” or “No Burning Period.”  Burning is allowed inside of SPZs all other days, but please use extra precautions and limit forestland burning to units that will not worsen air quality within nearby SSRAs. *

*********************************************************************

1.  DISCUSSION AND FORECAST FOR THE WESTERN OREGON AREA FORECAST ZONES 601-623 and 639

 

SHORT-TERM DISCUSSION

The strong atmospheric river that dumped substantial rain across all zones over the past 24 hours is weakening and shifting south of the state this afternoon.  It is being replaced by a cooler and showery air mass, which will lower snow levels to about 2500 feet north and 3500 feet south tonight.  Most of the shower activity will be focused across the northern zones overnight with areas of dense fog possible in the southern valleys.

Scattered showers will continue across the north on Saturday with just a chance of showers south, after areas of morning valley fog.  Snow levels will rise to 3000 feet north and 4500 feet south.  Mixing will be good in the north but just fair in the south with S-SW winds.

A strong SW flow aloft will bring another weather system onshore Saturday night and Sunday for increasing areas of rain and mountain snow across all zones.  Expect precipitation totals mostly between .25” and .50”.  Snow levels will be 3-4000 feet north and 4-5000 feet south.  Mixing should be good with mostly SW transport winds.

EXTENDED DISCUSSION

Another weather comes ashore on Monday for continued areas of rain and mountain snow.  Snow levels drop to near 3000 feet north and 4000 feet south.  Precipitation totals should be slightly lower with this storm, but mixing will be excellent with mostly SW transport winds.

The flow aloft is projected to turn more southerly on Tuesday, which will continue to feed moisture across the region with slightly higher snow levels.  Warming aloft will begin to suppress mixing with transport winds becoming SE-S.  

2.  DISPERSION

 

SATURDAY

 

Zone 601-612 and 639 (North Coast Range and Cascades):

 

MORNING

Mixing height 2500 - 3500 ft.

Transport wind S to SW at 10 - 20 mph.

Surface wind SSE to SSW at 8 - 12 mph.

 

AFTERNOON

Mixing height rising above 5000 ft.

Transport wind SSW to SW at 15 - 25 mph.

Surface wind similar to morning.

 

EVENING

Mixing height 2000 - 3000 ft.

Transport wind SSE to SSW at 10 - 20 mph.

Surface wind SSE to SSW at 5 - 9 mph.

 

Zone 615-620 (South Coast Range):

 

MORNING

Mixing height below 1500 ft early rising to 1800 - 2800 ft by late morning.

Transport wind SSE to SSW at 6 - 10 mph.

Surface wind SE to S at 4 - 8 mph.

 

AFTERNOON

Mixing height rising to 3500 - 4500 ft.

Transport wind S to SW at 8 - 12 mph.

Surface wind SSE to SW at 5 - 9 mph.

 

EVENING

Mixing height 2000 - 3000 ft.

Transport wind SSE to SSW at 8 - 12 mph.

Surface wind SE to SSW at 4 - 8 mph.

 

Zone 616-623 (South Cascades):

 

MORNING

Mixing height below 1500 ft early rising to 1500 - 2500 ft by late morning.

Transport wind SE to SSW at 4 - 8 mph.

Surface wind light and variable but favors SE to S and controlled by local terrain.

 

AFTERNOON

Mixing height 2500 - 3500 ft.

Transport wind SSE to SW at 6 - 10 mph.

Surface wind increases to SSE to SW at 4 - 8 mph.

 

EVENING

Mixing height 2000 - 3000 ft.

Transport wind similar to afternoon.

Surface wind similar to afternoon.

 

OUTLOOK:

 

SUNDAY

Mixing height 2000 to 3000 ft during the morning rising to 3900 to 4900 ft during the afternoon.  Transport wind SSE to SSW at 8 - 14 mph during the morning becoming SSW to SW at 12 - 22 mph during the afternoon.  Surface wind SE to SSW at 6 - 10 mph.

 

MONDAY

Mixing height 3000 to 4000 ft during the morning rising above 5000 ft during the afternoon.  Transport wind S to SW at 14 - 28 mph.  Surface wind SSE to SSW at 9 - 15 mph.

 

TUESDAY

Mixing height 1400 to 2400 ft during the morning rising to 2800 to 3800 ft during the afternoon.  Transport wind SSE to SSW at 8 - 12 mph.  Surface wind SE to S at 5 - 9 mph.

 

3.  BURNING INSTRUCTIONS FOR ALL ZONES IN THE WESTERN OREGON AREA

    - Valid for burning done Saturday through Monday, December 20 through 22, 2025.

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

 

For Saturday:

 

Coast Range

 

***Avoid ignitions before 10 a.m. in Zone 615, 616, 618, 619 and 620.***

 

All Zones

Use standard guidance matrix - see section 5 below.  Ensure adequate distance from downwind SSRAs for smoke to dissipate.

 

 

Cascades

 

***Avoid ignitions before 10 a.m. in Zone 616, 617, 620, 622 and 623.***

 

Zone 605, 606, 607, 608, 639, 610, 617, 620, 622, and 623

Use standard guidance matrix - see section 5 below.  Ensure adequate distance from downwind SSRAs for smoke to dissipate.

 

Zone 611

Units should be 1500 tons or less, spaced 3 miles apart, and 5 miles from downwind SSRAs.

 

Zone 616

Units should be 1000 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.  Avoid ignitions north of T24S.  South of T29S higher tonnage is possible - call the forecaster.

 

 

Siskiyous

 

***Avoid ignitions before 10 a.m.***

 

Units should be 900 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.

 

For Sunday:

 

Coast Range

 

All Zones

Use standard guidance matrix - see section 5 below.  Ensure adequate distance from downwind SSRAs for smoke to dissipate.

 

 

Cascades

 

All zones except zone 611

Use standard guidance matrix - see section 5 below.  Ensure adequate distance from downwind SSRAs for smoke to dissipate.  Avoid ignitions north of T24S in Zone 616.

 

Zone 611

Units should be 1500 tons or less, spaced 6 miles apart, and 8 miles from downwind SSRAs.

 

 

Siskiyous

 

Units should be 900 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.

 

For Monday:

 

Coast Range

 

All Zones

Use standard guidance matrix - see section 5 below.  Ensure adequate distance from downwind SSRAs for smoke to dissipate.

 

 

Cascades

 

All zones except zone 611

Use standard guidance matrix - see section 5 below.  Ensure adequate distance from downwind SSRAs for smoke to dissipate.  Avoid ignitions north of T24S in Zone 616.

 

Zone 611

Units should be 1500 tons or less, spaced 3 miles apart, and 5 miles from downwind SSRAs.

 

 

Siskiyous

 

Units should be 1500 tons or less, spaced 3 miles apart, and 5 miles from downwind SSRAs.

 

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

4.  SPECIAL NOTES:

 

    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

 

    Call the smoke management duty forecaster at (503) 945-7401 to

    discuss burning. Please do not call individual's numbers to

    discuss daily burning. If the forecaster is not available,

    leave a message and they will return your call as soon as possible.

    Avoid calling between 1:30 to 2:45 p.m.

 

    The forecast is available on the Internet at:

    http://www.odf.state.or.us/DIVISIONS/protection/fire_protection/

    Daily/smi.htm

 

    Please ensure your units have been planned and accomplished by

    checking: http://www.oregon.gov/ODF/Fire/Pages/Burn.aspx

 

    A map of planned and/or accomplished burns is located at:

    http://geo.maps.arcgis.com/apps/webappviewer/index.html

    ?id=a7e321dc8fc444b7a33fbc67bc673a3b

 

    The forecast/instruction telephone recording is: (503) 945-7400.

 

    To subscribe to or unsubscribe from the email list for this

    product, please go to the link:

    http://weather.smkmgt.com/mailman/listinfo/

 

 

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.

    Example: 300 tons allowed if burned 5 miles from a downwind SSRA.

 

  * 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.