SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Friday, April 24, 2026 2:30 PM Gary Votaw

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

SHORT-TERM DISCUSSION

An upper-level trough and NW flow brings partly to mostly sunny skies on Saturday. There is a slight chance of a shower in mountains, but temperatures remain 5-10^oF below the seasonal level. Burning potential is excellent by late morning and afternoon, with light NW-NE winds.

Very little change occurs on Sunday as the trough remains, but NW flow weakens. Conditions are partly sunny and still cool with a slight chance of showers. Mixing becomes excellent by late morning with light NW-N winds.

EXTENDED DISCUSSION

The trough begins to move east on Monday but not before giving a chance of a light shower or even a thundershower. The snow level will be around 5000 feet. Mixing conditions remain excellent with light NW-N transport winds.

Weak NW flow aloft returns on Tuesday, keeping skies partly sunny, drier and temperatures a little below normal. Mixing is again excellent as SW winds become W-WNW in afternoon.

2. DISPERSION

SATURDAY

Zone 640, 642, and 644 West of R35E:

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

Transport wind N to NE at 6 - 10 mph.

Surface wind light and variable and controlled by local terrain during the morning. Surface wind increases to NNW to NNE at 4 - 8 mph during the afternoon and 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 through the afternoon. Mixing height lowers to 3000 - 4000 ft during the evening.

Transport wind NE to E at 4 - 8 mph during the morning. Transport wind shifts to WNW to NNW at 5 - 9 mph during the afternoon and shifts to N to ENE at 6 - 12 mph during the evening.

Surface wind light and variable and controlled by local terrain during the morning. Surface wind increases to WNW to NNW at 4 - 8 mph during the afternoon then shifts to N to NE at 4 - 8 mph during the evening.

OUTLOOK:

SUNDAY

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

MONDAY

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

TUESDAY

Mixing height below 1000 ft early rising above 5000 ft by late morning and through the afternoon. Transport wind SSW to WSW at 8 - 12 mph during the morning becoming W to NNW at 5 - 9 mph during the afternoon. Surface wind SW to W at 4 - 8 mph during the morning becoming light and variable during the afternoon.

3. BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

- Valid for burning done Saturday through Monday, April 25 through 27, 2026.

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For Saturday:

Zone 640, 642, and 644 West of R35E:

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.

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 E of SSRAs. For units that will smolder significantly through the night avoid burning within at least 10 miles to the WNW through E in or near drainages leading to SSRAs. Verify transport winds away from SSRAs if burning in any other direction. Watch for shifting transport winds. No additional restrictions necessary.

For Sunday:

Follow standard guidance matrix - see section 5 below - for burning units to the WNW through N of SSRAs. For units that will smolder significantly through the night avoid burning within at least 10 miles to the W through N in or near drainages leading to SSRAs. No additional restrictions necessary.

For Monday:

Follow standard guidance matrix - see section 5 below - for burning units to the WNW through N of SSRAs. For units that will smolder significantly through the night avoid burning within at least 10 miles to the WNW through NNE 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.