SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Monday, May 18, 2026 2:30 PM Gary Votaw

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

SHORT-TERM DISCUSSION

Flow aloft is NW on Tuesday causing mostly sunny and seasonal conditions. Burning opportunities are excellent with light winds, mostly NW.

EXTENDED DISCUSSION

Little change will be noted on Wednesday and Thursday though the flow aloft weakens. Skies remain mostly sunny which allows a slow warming trend. Mixing conditions improve through each day with very light NW-N winds.

A very weak ridge will be over the region on Friday, sunny and warm with temperatures reaching 5-10^oF above normal. Burning potential is still very good though winds will be light and variable.

2. DISPERSION

TUESDAY

Zone 640, 642, and 644 West of R35E:

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

Transport wind WSW to WNW at 6 - 10 mph during the morning and afternoon. Transport wind increases to NW to NNW at 10 - 16 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 shifts to NW to N at 4 - 8 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.

Transport wind light and variable and controlled by local terrain during the morning. Transport wind increases to WSW to NW at 5 - 9 mph during the afternoon then shifts to NW to N at 8 - 12 mph during the evening.

Surface wind light and variable and controlled by local terrain. Surface wind increases to NW to N at 5 - 9 mph during the evening.

OUTLOOK:

WEDNESDAY

Mixing height below 1000 ft early rising to 3700 to 4700 ft by late morning rising above 5000 ft during the afternoon. Transport wind NW to N at 5 - 9 mph. Surface wind light and variable during the morning becoming NW to NNE at 5 - 9 mph during the afternoon.

THURSDAY

Mixing height below 1000 ft early rising to 4500 to 5000 ft by late morning rising above 5000 ft during the afternoon. Transport wind light and variable during the morning becoming NW to N at 5 - 9 mph during the afternoon. Surface wind light and variable during the morning becoming NW to N at 5 - 9 mph during the afternoon.

FRIDAY

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

3. BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

- Valid for burning done Tuesday, May 19, 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 WSW through N of SSRAs. For units that will smolder significantly through the night avoid burning within at least 10 miles to the WSW through NNE 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 WSW through NNE of SSRAs. For units that will smolder significantly through the night avoid burning within at least 10 miles to the WSW through NNE 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.