SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Monday, April 27, 2026 2:30 PM Sherri Pugh

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

Tuesday will become dry with a few showers possible in far northeastern zones. Flow aloft will be from NW with upper-level troughing in the region and a ridge far offshore. Surface winds will come from WSW-WNW in central zones and SSW but more variable in northeastern zones. Transport winds will be from SW-W. Temperatures will rise to near average. Mixing heights will be excellent.

EXTENDED DISCUSSION

Dry weather continues Wednesday other than a few showers possible in the northeast. Flow aloft will be from N with an upper-level trough east and ridging west. Light winds will come from NNW-NNE with temperatures rising above seasonable. Mixing heights will be high.

Light flow aloft will come with upper-level ridging and dry conditions on Thursday. Winds will be from NNW and variable at times. Temperatures will climb well above average. Mixing heights will be good.

On Friday, an upper-level low will approach from northwest with increase SW flow aloft. Shower potential will increase. Winds will turn to be from SSW-SW, eventually turning NW late, with well above seasonable temperatures. Mixing heights will be good.

2. DISPERSION

TUESDAY

Zone 640, 642, and 644 West of R35E:

Mixing height below 800 ft early rising to 3000 - 4000 ft by late morning. Afternoon mixing height rises above 5000 ft then lowers to 2500 - 3500 ft during the evening.

Transport wind SW to W at 4 - 8 mph throughout the morning and afternoon. Transport wind shifts to WNW to NNW at 4 - 8 mph during the evening.

Surface wind light and variable and controlled by local terrain during the morning. Surface wind increases to W to NW at 4 - 8 mph during the afternoon then becomes light and variable during the evening.

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

Mixing height below 500 ft early rising to 3500 - 4500 ft by late morning. Afternoon mixing height rises above 5000 ft then lowers to 2500 - 3500 ft during the evening.

Transport wind SSW to WSW 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.

OUTLOOK:

WEDNESDAY

Mixing height below 1000 ft early rising to 2300 to 3300 ft by late morning rising to 4000 to 5000 ft during the afternoon. Transport wind light and variable during the morning becoming N to NE at 4 - 8 mph during the afternoon. Surface wind light and variable.

THURSDAY

Mixing height below 1000 ft early rising to 2300 to 3300 ft by late morning rising to 4500 to 5000 ft during the afternoon. Transport wind light and variable. Surface wind light and variable.

FRIDAY

Mixing height below 1000 ft early rising to 2500 to 3500 ft by late morning rising to 3500 to 4500 ft during the afternoon. Transport wind S to SW at 4 - 8 mph. Surface wind light and variable.

3. BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

- Valid for burning done Tuesday, April 28, 2026.

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Zone 640, 642, and 644 West of R35E:

Follow standard guidance matrix - see section 5 below - for burning units to the SW through NNW of SSRAs. For units that will smolder significantly through the night avoid burning within at least 15 miles to the SW through NNW in or near drainages leading to SSRAs. Verify transport winds away from SSRAs if burning in any other direction. 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 in all directions of SSRAs. For units that will smolder significantly through the night avoid burning within at least 10 miles in all directions of 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.