SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Wednesday, May 20, 2026 2:30 PM Gary Votaw

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

SHORT-TERM DISCUSSION

On Thursday NW flow aloft weakens. Expect sunny skies with temperatures moving slightly above normal. Mixing conditions remain excellent with very light winds, favoring NW-NE.

EXTENDED DISCUSSION

Little change will occur on Friday, sunny and warm, temperatures 5-10^oF above seasonal. Mixing conditions will be excellent with very light NW winds in the afternoon.

Flow aloft turns W on Saturday and Sunday. The warming trend continues as temperatures reach 10-15^oF above normal under sunny skies. Burning potential is still very good on both afternoons with mainly W transport winds.

2. DISPERSION

THURSDAY

Zone 640, 642, and 644 West of R35E:

Mixing height below 1000 ft early rising to 4400 - 5000 ft during the morning. Mixing height rises to above 5000 ft during the afternoon then lowers to 2500 - 3500 ft during the evening.

Transport wind NW to N at 4 - 8 mph during the morning and afternoon. Transport wind increases to NNW to NNE at 10 - 16 mph during the evening.

Surface wind light and variable and controlled by local terrain. Surface wind increases to NW to NNE at 6 - 12 mph during the evening.

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

Mixing height below 1000 ft early rising above 5000 ft by late morning and throughout the afternoon. Mixing height lowers to 3700 - 4700 ft during the evening.

Transport wind N to NE at 6 - 10 mph throughout the day.

Surface wind light and variable and controlled by local terrain during the morning. Surface wind increases to NW to N at 6 - 10 mph during the afternoon and evening.

OUTLOOK:

FRIDAY

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

SATURDAY

Mixing height below 1000 ft early rising above 5000 ft by late morning and through the afternoon. Transport wind WSW to WNW at 6 - 12 mph. Surface wind light and variable during the morning becoming WSW to NW 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 WSW to WNW at 6 - 12 mph during the morning becoming WSW to WNW at 10 - 18 mph during the afternoon. Surface wind WSW to WNW at 4 - 8 mph.

3. BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

- Valid for burning done Thursday, May 21, 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 WNW through NNE 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.

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 NW through NE 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.