SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Friday, December 19, 2025 2:30 PM Sherri Pugh

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

SHORT-TERM DISCUSSION

Saturday will be dry with W flow aloft. Winds will turn from SSE-SSW at the surface and SSW-SW for transport winds. Temperatures will be near or above average. Snow levels decrease to 3-4000 feet. Mixing heights will be mostly good.

Showers and mountain snow on Sunday will bring 0.10” rainfall to the region. Flow aloft comes from SW with a trough offshore moving inland overnight. Light surface winds will come from S-SSW and brisk transport winds will be from S-SW. Temperatures will be above seasonable. Snow levels will rise to 4-5000 feet and mixing heights will be good in central zones while fair in northeastern zones.

EXTENDED DISCUSSION

Monday will be mostly dry with SW flow aloft. Surface winds will be from SSE-SSW and transport winds are expected from SSW. Above average temperatures come with freezing levels near 4000 feet. Mixing heights will be good.

Showers increase late on Tuesday from south to north. Winds will be from SSE-S with above average temperatures. Freezing levels will be from 4-5000 feet. Mixing heights will decrease some.

2. DISPERSION

SATURDAY

Zone 640, 642, and 644 West of R35E:

Mixing height below 800 ft early rising to 2100 - 3100 ft by late morning. Afternoon mixing height rises to 2500 - 3500 ft then lowers below 1000 ft during the evening.

Transport wind S to SW at 9 - 15 mph during the morning and afternoon. Transport wind decreases to S to SW at 4 - 8 mph during the evening.

Surface wind S to SW at 4 - 8 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 to 2300 - 3300 ft by late morning. Afternoon mixing height rises to 2500 - 3500 ft then lowers below 1000 ft during the evening.

Transport wind S to SW at 6 - 10 mph throughout the morning and afternoon. Transport wind shifts to ESE to S and decreases to 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:

SUNDAY

Mixing height below 1000 ft early rising to 1200 to 2200 ft by late morning rising to 2400 to 3400 ft during the afternoon. Transport wind SSE to SSW at 6 - 10 mph. Surface wind light and variable.

MONDAY

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 S to SW at 8 - 12 mph. Surface wind SSE to SSW at 4 - 8 mph.

TUESDAY

Mixing height below 1000 ft early rising to 1500 to 2500 ft by late morning rising to 2100 to 3100 ft during the afternoon. Transport wind SSE to SSW at 8 - 12 mph. Surface wind light and variable during the morning becoming ESE to S at 4 - 8 mph during the afternoon.

3. BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

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

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For Saturday:

Zone 640, 642, and 644 West of R35E:

Follow standard guidance matrix - see section 5 below - for burning units to the S through WSW of SSRAs. For units that will smolder significantly through the night avoid burning within at least 25 miles to the S through WSW 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 ESE through SW of SSRAs. For units that will smolder significantly through the night avoid burning within at least 25 miles to the ESE through SW in or near drainages leading to SSRAs. Watch for shifting transport winds. No additional restrictions necessary.

For Sunday:

Follow standard guidance matrix - see section 5 below - for burning units to the SSE through WSW of SSRAs. For units that will smolder significantly through the night avoid burning within at least 30 miles to the SSE through WSW in or near drainages leading to SSRAs. No additional restrictions necessary.

For Monday:

Follow standard guidance matrix - see section 5 below - for burning units to the S through SW of SSRAs. For units that will smolder significantly through the night avoid burning within at least 25 miles to the SSE through SW in or near drainages leading to SSRAs. No additional restrictions necessary.

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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.