SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Wednesday, April 22, 2026 2:30 PM Gary Votaw

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

SHORT-TERM DISCUSSION

Showers linger on Thursday, mainly in mountains, as an upper-level trough from the north brushes by the area. Snow will be above 4500-5000 feet. Conditions will be partly sunny yet chilly, 5-10^oF below seasonal. Mixing potential is very good with NW-N winds.

EXTENDED DISCUSSION

NW flow aloft brings partly to mostly sunny skies on both Friday and Saturday but temperatures 5-15^oF below normal. There is also the chance of a light shower in mountains. Burning potential is excellent on both days with NW-NE winds.

An upper trough remains over the region on Sunday. Little change is expected in weather conditions, still cool with a chance of light showers in mountains. Mixing will be excellent with NW-N winds.

2. DISPERSION

THURSDAY

Zone 640, 642, and 644 West of R35E:

Mixing height 2000 – 3000 ft early rising to 3300 - 4300 ft during the morning. Mixing height rises above 5000 ft during the afternoon and evening.

Transport wind NW to N at 9 - 15 mph.

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

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

Mixing height 2000 – 3000 ft early rising to 4000 - 5000 ft during the morning. Mixing height rises above 5000 ft during the afternoon and evening.

Transport wind WNW to NW at 18 - 32 mph throughout the day.

Surface wind WNW to NW at 8 - 14 mph during the morning and afternoon. Surface wind decreases to WNW to NNW at 5 - 9 mph during the evening.

OUTLOOK:

FRIDAY

Mixing height below 1000 ft early rising above 5000 ft by late morning and through the afternoon. Transport wind NW to N at 10 - 16 mph. Surface wind light and variable during the morning becoming NNW to NNE at 5 - 9 mph during the afternoon.

SATURDAY

Mixing height below 1000 ft early rising above 5000 ft by late morning and through the afternoon. Transport wind N to NE at 4 - 8 mph. Surface wind N to NE at 4 - 8 mph during the morning becoming NW 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 NW to N at 8 - 14 mph. Surface wind NW to N at 4 - 8 mph.

3. BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

- Valid for burning done Thursday, April 23, 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. 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 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. 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.