SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Thursday, April 23, 2026 2:30 PM Gary Votaw

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

SHORT-TERM DISCUSSION

NW flow aloft brings partly sunny skies on both Friday and Saturday with a chance of light showers, mainly in mountains. Temperatures remain 5-15^oF below seasonal levels. Burning potential is excellent on both days by late morning and afternoon, with light NW-NE winds.

EXTENDED DISCUSSION

Very little change occurs on Sunday and Monday though NW flow gradually weakens. Skies will be partly to mostly sunny with a very slow warming trend, still on the cool side by Monday. Mixing becomes excellent by the late mornings with light NW-N winds, trending W by Monday afternoon.

2. DISPERSION

FRIDAY

Zone 640, 642, and 644 West of R35E:

Mixing height below 1000 ft early rising to above 5000 ft by late morning and through the afternoon. Mixing height lowers to 3500 - 4500 ft during the evening.

Transport wind NNW to NNE at 10 - 18 mph.

Surface wind NNW to NE at 4 - 8 mph throughout the day.

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

Mixing height below 1000 ft early rising to above 5000 ft by late morning and through the afternoon.

Transport wind N to NE at 9 - 15 mph during the morning. Transport wind decreases to NNW to NE at 5 - 9 mph during the afternoon then increases to NW to N at 10 - 16 mph during the evening.

Surface wind NNE to ENE at 6 - 10 mph during the morning. Surface wind shifts to NW to NNE at 4 - 8 mph during the afternoon and evening.

OUTLOOK:

SATURDAY

Mixing height below 1000 ft early rising above 5000 ft by late morning and through the afternoon. Transport wind light and variable during the morning becoming NW to N at 6 - 10 mph during the afternoon. Surface wind light and variable during the morning becoming NNW to NNE at 4 - 8 mph during the afternoon.

SUNDAY

Mixing height below 1000 ft early rising above 5000 ft by late morning and through the afternoon. Transport wind NNW to NNE at 8 - 12 mph. Surface wind NW to N at 4 - 8 mph.

MONDAY

Mixing height below 1000 ft early rising above 5000 ft by late morning and through the afternoon. Transport wind WNW to NNW at 6 - 10 mph during the morning becoming WSW to WNW at 10 - 16 mph during the afternoon. Surface wind W to NW at 4 - 8 mph.

3. BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

- Valid for burning done Friday, April 24, 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 NNW through NE of SSRAs. For units that will smolder significantly through the night avoid burning within at least 10 miles to the NNW through E 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 NW through NE of SSRAs. For units that will smolder significantly through the night avoid burning within at least 10 miles to the WNW through NE in or near drainages leading to SSRAs. Verify transport winds away from SSRAs if burning in any other direction. 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.