SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Thursday, April 9, 2026 2:30 PM Sherri Pugh

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

The risk of showers increases Friday afternoon and evening. There is some risk for isolated thunderstorms. Flow aloft will be from S with a weakening upper-level low moving into California. Surface winds will be variable while transport winds will come from SE-S. Mixing heights will be high with well above average temperatures.

EXTENDED DISCUSSION

Scattered showers continue Saturday with some risk for thunderstorms. Another upper-level low will be offshore California with S flow aloft for Oregon. Temperatures stay above average with excellent mixing heights. Winds will be from SSW.

Rounds of rain are expected Sunday as the weakening upper-level low moves south of the region. Temperatures will sink below average though freezing levels will stay high. Winds will be from NW-N. Mixing heights will be good.

Rain and mountain snow on Monday will end late. Flow aloft will come from N as broad upper-level ridging builds. Snow levels will be near 5-6000 feet. Temperatures will sink below average and mixing heights will be good but lower. Winds will come from W-WNW.

2. DISPERSION

FRIDAY

Zone 640, 642, and 644 West of R35E:

Mixing height below 500 ft early rising to 2300 - 3300 ft by late morning. Afternoon mixing height rises to 4000 - 5000 ft then lowers to 1000 - 2000 ft during the evening.

Transport wind SSE to SSW at 4 - 8 mph during the morning and afternoon. Transport wind becomes light and variable and controlled by local terrain during the evening.

Surface wind light and variable and controlled by local terrain.

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

Mixing height below 300 ft early rising to 1900 - 2900 ft by late morning. Afternoon mixing height rises above 5000 ft then lowers below 1000 ft during the evening.

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

Surface wind light and variable and controlled by local terrain.

OUTLOOK:

SATURDAY

Mixing height below 1000 ft early rising to 3200 to 4200 ft by late morning rising above 5000 ft during the afternoon. Transport wind S to SW at 6 - 12 mph. Surface wind light and variable during the morning becoming S to SW at 4 - 8 mph during the afternoon.

SUNDAY

Mixing height below 1000 ft early rising to 2500 to 3500 ft by late morning rising above 5000 ft during the afternoon. Transport wind NNW to NNE at 4 - 8 mph during the morning becoming NW to N at 9 - 15 mph during the afternoon. Surface wind light and variable during the morning becoming NW to N at 4 - 8 mph during the afternoon.

MONDAY

Mixing height below 1000 ft early rising to 3000 to 4000 ft by late morning and through the afternoon. Transport wind WSW to WNW at 9 - 15 mph. Surface wind W to NW at 4 - 8 mph.

3. BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

- Valid for burning done Friday, April 10, 2026.

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Zone 640, 642, and 644 West of R35E:

Follow standard guidance matrix - see section 5 below - for burning units in all directions of SSRAs. For units that will smolder significantly through the night avoid burning within at least 25 miles in all directions of SSRAs. No additional restrictions necessary.

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

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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.