SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Friday, April 17, 2026 2:30 PM Gary Votaw

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

SHORT-TERM DISCUSSION

A broad upper-level ridge will be overhead on Saturday, and temperatures return near seasonal under sunny skies. Burning potential is very good with light SE-S winds.

EXTENDED DISCUSSION

On Sunday and Monday, the ridge progresses into Idaho while flow aloft becomes weakly SW. Skies will be partly sunny on both days as temperatures reach 10-15^oF above normal. Mixing heights improve into the afternoon with SE-S winds.

An upper trough off the northern California coast will begin to move inland on Tuesday to increase moisture in S flow aloft. Chances of rain increase late in the day while snow levels are over 8000 feet. Amounts will be less than .10” though they increase overnight and into Wednesday. Mixing conditions on Tuesday will become very good SE-SW winds.

2. DISPERSION

SATURDAY

Zone 640, 642, and 644 West of R35E:

Mixing height below 1000 ft early rising to 2600 - 3600 ft during the morning. Mixing height rises above 5000 ft during the afternoon then lowers below 1000 ft during the evening.

Transport wind SSE to SSW at 12 - 24 mph.

Surface wind SE to S at 4 - 8 mph throughout the day.

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

Mixing height below 1000 ft early rising to 3200 - 4200 ft during the morning. Mixing height rises above 5000 ft during the afternoon then lowers below 1000 ft during the evening.

Transport wind SSE to S at 15 - 25 mph during the morning and afternoon. Transport wind decreases to SSE to SSW at 10 - 20 mph during the evening.

Surface wind ESE to SSE at 6 - 10 mph.

OUTLOOK:

SUNDAY

Mixing height below 1000 ft early rising to 2600 to 3600 ft by late morning rising to 4000 to 5000 ft during the afternoon. In the west transport wind SE to SSE at 10 - 22 mph. In the east transport wind ESE to S at 6 - 12 mph. Surface wind light and variable during the morning becoming SE to S at 6 - 10 mph during the afternoon.

MONDAY

Mixing height below 1000 ft early rising to 2500 to 3500 ft by late morning rising to 4500 to 5000 ft during the afternoon. Transport wind light and variable during the morning becoming SSE to SSW at 9 - 15 mph during the afternoon. Surface wind light and variable during the morning becoming SE to SSW at 5 - 9 mph during the afternoon.

TUESDAY

Mixing height below 1000 ft early rising to 3500 to 4500 ft by late morning rising to 4500 to 5000 ft during the afternoon. Transport wind SE to SSW at 6 - 12 mph during the morning becoming S to SW at 10 - 22 mph during the afternoon. Surface wind ESE to SSE at 4 - 8 mph.

3. BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

- Valid for burning done Saturday through Monday, April 18 through 20, 2026.

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For Saturday:

Delay ignitions until 10 a.m. Zone 640, 642, and 644 West of R35E:

Follow standard guidance matrix - see section 5 below - for burning units to the SE through SSW of SSRAs. For units that will smolder significantly through the night avoid burning within at least 25 miles to the ESE through SSW in or near drainages leading to SSRAs. No additional restrictions necessary.

Delay ignitions until 10 a.m. Zone 637, 643, 645, 646, and 644 East of R34E:

For Sunday:

Delay ignitions until 10 a.m. Follow standard guidance matrix - see section 5 below - for burning units to the E through S of SSRAs. For units that will smolder significantly through the night avoid burning within at least 25 miles to the E through S 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 SE through SSW of SSRAs. For units that will smolder significantly through the night avoid burning within at least 25 miles in all directions of 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.