SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Tuesday, May 12, 2026 2:30 PM Gary Votaw

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

SHORT-TERM DISCUSSION

A cold front arrives Wednesday morning followed by a strong upper trough, causing breezy conditions and temperatures falling to seasonal levels. Showers are likely all day with thunderstorms possible in the afternoon. Potential rainfall is .10” to .25”, or more in storms. Mixing conditions will be excellent with mainly SW-W winds.

EXTENDED DISCUSSION

W flow aloft provides sunny and dry conditions on Thursday and Friday, temperatures near normal. Burning potential is excellent on both days with W transport winds.

Partly sunny and cool weather will occur on Saturday under a broad upper trough but with only a slight chance of showers. Temperatures look to be about 10^oF below seasonal. Mixing will still be excellent with W-NW winds.

2. DISPERSION

WEDNESDAY

Zone 640, 642, and 644 West of R35E:

Mixing height below 1000 ft early but rising to 4000 to 5000 late morning then above 5000 ft in the afternoon. Mixing height lowers to 2900 - 3900 ft during the evening.

Transport wind WSW to WNW at 20 - 36 mph during the morning and afternoon. Transport wind decreases to W to WNW at 12 - 24 mph during the evening.

Surface wind WSW to WNW at 10 - 16 mph throughout the day.

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

Mixing height below 1000 ft early but rising to 4000 to 5000 late morning then above 5000 ft in the afternoon. Mixing height lowers to 3700 - 4700 ft during the evening.

Transport wind SW to W at 16 - 30 mph during the morning. Transport wind increases to W to WNW at 20 - 36 mph during the afternoon and increases to W to NW at 24 - 42 mph during the evening.

Surface wind WSW to WNW at 12 - 24 mph.

OUTLOOK:

THURSDAY

In the west mixing height 2500 to 3500 ft during the morning rising above 5000 ft during the afternoon. In the east mixing height 3500 to 4500 ft in the morning rising above 5000 ft during the afternoon. Transport wind WSW to WNW at 6 - 10 mph during the morning becoming WSW to WNW at 10 - 22 mph during the afternoon. Surface wind light and variable during the morning becoming WNW to NNW at 5 - 9 mph during the afternoon.

FRIDAY

Mixing height below 1000 ft early rising 3500 to 4500 ft during the morning and above 5000 ft during the afternoon. Transport wind WSW to WNW at 8 - 12 mph. Surface wind WSW to WNW at 5 - 9 mph.

SATURDAY

Mixing height 2500 to 3500 ft during the morning rising above 5000 ft during the afternoon. Transport wind WNW to NNW at 9 - 15 mph. Surface wind W to NW at 5 - 9 mph.

3. BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

- Valid for burning done Wednesday, May 13, 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 WNW of 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 WNW of SSRAs. For units that will smolder significantly through the night avoid burning within at least 10 miles to the WSW through NNW in or near drainages leading to SSRAs. Care needed in selecting units as smoke will likely fumigate along the ground in wind prone areas. 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.