SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Friday, May 2, 2025 2:30 PM Gary Votaw

1. DISCUSSION AND FORECAST FOR SOUTH CENTRAL OREGON ZONES 624 AND 625

SHORT-TERM DISCUSSION

A cold front passes through the region tonight, bringing much colder conditions for Saturday and temperatures around 10^oF below average. South flow aloft will bring moist and unstable air for widespread showers and a possible thundershower. Moisture will be typically .10” to .25” while snow levels continue very high. The colder air at low levels should only allow mixing to reach moderate levels while winds become NW-N in the afternoon.

The upper trough will still be over the region on Sunday but bringing drier and still cool air into the area. Skies will be mostly sunny. Very good afternoon mixing is expected with N-NNE transport winds.

EXTENDED DISCUSSION

On Monday N flow aloft will be ahead of a ridge approaching the coast. Look for sunny and warmer conditions, and temperatures returning near seasonal. Mixing will again be very good in the afternoon with N-NE transport winds.

The ridge will be just to the NW of the area with NE flow aloft. Sunny skies allow the warming trend to continue with temperatures reaching 5-10^oF above average. Very good mixing is expected by afternoon with N-NE winds.

2. DISPERSION

SATURDAY

Mixing height 2900 - 3900 ft during the morning. Afternoon mixing height rises to 3300 - 4300 ft then lowers to 1500 - 2500 ft during the evening.

Transport wind SW to NW at 6 - 10 mph in the morning becoming NW to N at 8 - 15 mph in afternoon. Transport wind increases to NW to N at 10 - 20 mph during the evening.

Surface wind WSW to NW at 4 - 8 mph increasing to NW to N at 8 – 15 mph in afternoon and evening.

OUTLOOK:

SUNDAY

Mixing height 2300 - 3300 ft during the morning rising above 5000 ft during the afternoon. Transport wind N to NNE at 10 - 22 mph. Surface wind NNW to NNE at 8 - 12 mph.

MONDAY

Mixing height below 1000 ft early rising to 4500 - 5000 ft by late morning rising above 5000 ft during the afternoon. Transport wind NNE to NE at 23 - 41 mph during the morning becoming N to NE at 20 - 34 mph during the afternoon. Surface wind N to NE at 15 - 29 mph.

TUESDAY

Mixing height below 1000 ft early rising to 3500 - 4500 ft by late morning rising above 5000 ft during the afternoon. Transport wind N to NE at 15 - 25 mph during the morning becoming N to NE at 10 - 20 mph during the afternoon. Surface wind N to NE at 10 - 22 mph during the morning becoming NNE to ENE at 8 - 12 mph during the afternoon.

3. BURNING INSTRUCTIONS FOR ZONES 624 AND 625 INCLUDING THE WALKER

RANGE PORTION OF ZONE 624

- Valid for burning done Saturday through Monday, May 3 through 5, 2025.

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For Saturday:

Follow standard guidance matrix - see section 5 below - for burning units to the SW through N of SSRAs. For units that will smolder significantly through the night avoid burning within at least 25 miles to the SW through NNE in or near drainages leading to SSRAs. Watch for shifting transport winds. No additional restrictions necessary.

For Sunday:

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

For Monday:

Delay ignitions until 10 a.m. Follow standard guidance matrix - see section 5 below - for burning units to the NNE through NE of SSRAs. For units that will smolder significantly through the night avoid burning within at least 10 miles to the N through NE 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 smoke management forecaster is available at (503)

945-7401. The smoke management forecaster is available

to discuss specific burns. The duty forecaster phone

number is (503) 945-7401. Please call this number and

not individual's numbers to discuss daily burning. Please

avoid calling between 1:30 to 2:45 p.m.

http://www.odf.state.or.us/DIVISIONS/protection/fire_protection/

Daily/lmt.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.