SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Thursday, December 5, 2024       2:30 PM      Pete Parsons

 

**************** Air Stagnation Advisory Information ****************

An Air Stagnation Advisory may be in effect for your area (consult the link below for the latest information). Please use extra precautions and limit forestland burning to units that will not worsen air quality within nearby SSRAs.

* Current Air Stagnation Advisories: https://www.weather.gov/wrh/. *

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* Special Protection Zone (SPZ) provisions apply from November 15 through February 15.  Prescribed burning is not allowed on Red woodstove days in an SPZ from December 1 through February 15. Burning is allowed inside of SPZs on green and yellow woodstove days, but please use extra precautions and limit forestland burning to units that will not worsen air quality within nearby SSRAs. *

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

 

SHORT-TERM DISCUSSION

A very weak weather system fell apart as it moved through a strong upper-level ridge over the region today.  It produced little-to-no precipitation and didn’t improve ventilation.  Stagnant conditions will continue through Friday with widespread valley fog/frost giving way to partly sunny skies in the afternoon.  Mixing will remain poor with light, mostly SE-S, winds.  Air stagnation advisories are in effect for most valley locations through 4 a.m. PST Saturday.

EXTENDED DISCUSSION

On Saturday, the next weather system will be stronger than its predecessor.  Clouds will keep early-morning temperatures warmer than they have been the past few mornings.  Some light rain is likely in the afternoon with inversions breaking and temperatures jumping to above average. Rainfall totals may hit .50” north and .25” south.  Light S-SW winds should increase and turn SW-W in the afternoon.

A cool upper-level trough will maintain a few showers and provide good mixing on Sunday with snow levels dropping to 3000 feet north and 4000 feet south.  SW winds in the morning will turn W-NW in the afternoon with surface temperatures dropping back to near average.

High pressure building offshore will stabilize the air mass, bringing a dry and cool northerly flow aloft on Monday.  Skies should turn sunny, but temperatures will struggle to reach average. Cool surface temperatures will keep mixing suppressed with N-NE transport winds.

2.  DISPERSION

 

FRIDAY

 

Zone 601, 602, 603 and 612 (North Coast Range):

 

MORNING

Mixing height below 1000 ft.

Transport wind light and variable but favors SE and controlled by local terrain.

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

 

AFTERNOON

Mixing height remains below 1000 ft.

Transport wind increases to SE to S at 4 - 8 mph.

Surface wind similar to morning.

 

EVENING

Mixing height remains below 1000 ft.

Transport wind SE to SSW at 4 - 8 mph.

Surface wind similar to afternoon.

 

Zone 605-611 and 639 (North Cascades):

 

MORNING

Mixing height below 1000 ft.

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 near 1000 ft.

Transport wind similar to morning.

Surface wind similar to morning.

 

EVENING

Mixing height lowers below 1000 ft.

Transport wind similar to afternoon.

Surface wind similar to afternoon.

 

Zone 615-620 (South Coast Range):

 

MORNING

Mixing height below 1000 ft.

Transport wind SE to S at 4 - 8 mph.

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

 

AFTERNOON

Mixing height remains below 1000 ft.

Transport wind SSE to SSW at 4 - 8 mph.

Surface wind similar to morning.

 

EVENING

Mixing height remains below 1000 ft.

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

Surface wind similar to afternoon.

 

Zone 616-623 (South Cascades):

 

MORNING

Mixing height below 1000 ft.

Transport wind light and variable but favors SE and controlled by local terrain.

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

 

AFTERNOON

Mixing height remains below 1000 ft.

Transport wind similar to morning.

Surface wind similar to morning.

 

EVENING

Mixing height remains below 1000 ft.

Transport wind increases to ESE to SSE at 4 - 8 mph.

Surface wind similar to afternoon.

 

OUTLOOK:

 

SATURDAY

Mixing height below 1000 ft early rising to 1400 to 2400 ft by late morning rising to 2300 to 3300 ft during the afternoon.  Transport wind SSW to SW at 8 - 12 mph during the morning becoming WSW to WNW at 10 - 16 mph during the afternoon.  Surface wind S to SW at 4 - 8 mph during the morning becoming WSW to WNW at 5 - 9 mph during the afternoon.

 

SUNDAY

Mixing height below 1000 ft early rising to 1400 to 2400 ft by late morning rising to 4000 to 5000 ft during the afternoon.  Transport wind SSW to SW at 8 - 12 mph during the morning becoming WSW to WNW at 10 - 18 mph during the afternoon.  Surface wind SW to W at 4 - 8 mph.

 

MONDAY

Mixing height below 1000 ft early rising to 1000 to 1800 ft by late morning and through the afternoon.  Transport wind light and variable during the morning becoming N to ENE at 4 - 8 mph during the afternoon.  Surface wind light and variable.

 

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

    - Valid for burning done Friday, December 6, 2024.

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Coast Range

 

***Avoid ignitions before 11 a.m. in all zones.  Complete ignitions by 2:30 p.m. in all zones.***

 

Zone 601, 602, 603, 612, 615, 616 west of R8W, 618, 619, and 620

Use standard guidance matrix - see section 5 below.  Avoid burning directly upwind of coastal SSRAs.  Higher tonnage is possible south of T29S in Zone 616 - call the forecaster.

 

Zone 616 east of R9W

Units should be 900 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.  Higher tonnage is possible south of T29S - call the forecaster.

 

 

Cascades

 

***Avoid ignitions before 11 a.m. in all zones.  Complete ignitions by 2:30 p.m. in all zones.***

 

Zone 605, 606, and 616

Units should be 600 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.  In zone 616 avoid ignitions north of T24S.  South of T29S higher tonnage is possible - call the forecaster.

 

Zone 607, 608, 639, 610, and 623

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

 

Zone 611 and 617

Units should be 900 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.

 

Zone 620 and 622

Units should be 300 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.

 

 

Siskiyous

 

***Avoid ignitions before 11 a.m. Complete ignitions by 2:30 p.m.***

 

Units should be 900 tons or less, spaced 12 miles apart, and 12 miles from downwind SSRAs.

 

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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.