SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Friday, May 26, 2023 2:30 PM Gary Votaw

************************* Holiday Schedule **************************

The ODF forecast office will be closed over Memorial Weekend (May 27th – 29th). Today’s forecast includes burning instructions for Saturday, May 27th through Tuesday, May 30th (4 days).

A forecaster is available at 503-945-7401 until 5 p.m. today (Friday), to handle questions regarding weekend burning. The office will reopen at 7 a.m. on Tuesday, May 30th.

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

SHORT-TERM DISCUSSION

A weakening trough will be over Oregon on Saturday but with enough instability for showers and thunderstorms to develop by the afternoon and into evening. Conditions will otherwise be partly sunny with seasonal temperatures. Mixing will be very good by late morning through afternoon with NW-N transport winds, possibly stronger and variable near storms.

The trough on Sunday will weaken further over Oregon with the stronger part moving to northern California, and to remain there on Monday. There is a persistent chance of a shower or thunderstorm both Sunday and Monday under otherwise mostly sunny skies. Monday will be the warmest day of the weekend, 5-10^oF above average. Mixing heights for both days will be good late in the mornings through the afternoons. Transport winds will be light, NW-N on Sunday then W-NW for Monday. Winds may be stronger and variable near storms.

EXTENDED DISCUSSION

The area will be under weak SW flow aloft on Tuesday on the fringe of a large upper trough in the Gulf of Alaska. Conditions will change little, mostly sunny and warm with a chance of showers and thunderstorms in the area. Mixing heights will be slower to rise but will be good in the afternoon with light NW transport winds.

2. DISPERSION

SATURDAY

Zone 640, 642, and 644 West of R35E:

Mixing height below 1000 ft early then above 5000 ft by late morning through the afternoon. Mixing height lowers to 1000 - 1900 ft during the evening.

Transport wind NW to N at 8 - 12 mph.

Surface wind WNW to NNW at 5 - 9 mph throughout the day.

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

Mixing height below 1000 ft early then above 5000 ft by late morning through the afternoon. Mixing height lowers below 1000 ft during the evening.

Transport wind NW to NNE at 6 - 10 mph during the morning. Transport wind increases to NW to N at 9 - 15 mph during the afternoon then decreases to NW to N at 5 - 9 mph during the evening.

Surface wind NW to NNE at 5 - 9 mph during the morning. Surface wind increases to WNW to NNW at 9 - 15 mph during the afternoon then decreases to WNW to NNW at 5 - 9 mph during the evening.

OUTLOOK:

SUNDAY

Mixing height below 1000 ft early rising to 4100 to 5000 ft by late morning rising above 5000 ft during the afternoon. Transport wind NW to N at 5 - 9 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 to 4500 to 5000 ft by late morning rising above 5000 ft during the afternoon. Transport wind light and variable during the morning becoming W to NW at 6 - 10 mph during the afternoon. Surface wind WSW to WNW at 4 - 8 mph.

TUESDAY

Mixing height below 1000 ft early rising to 1500 to 2500 ft by late morning rising above 5000 ft during the afternoon. Transport wind WNW to NNW at 4 - 8 mph. Surface wind light and variable during the morning becoming WNW to NNW at 6 - 12 mph during the afternoon.

3. BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

- Valid for burning done Saturday, Sunday, Monday and Tuesday, May 27 - 30, 2023.

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For Saturday:

***Avoid ignitions before 10 a.m. in all zones.***

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 15 miles to the WNW through NNE in or near drainages leading to SSRAs. No additional restrictions necessary.

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

For Sunday:

***Avoid ignitions before 10 a.m. in all zones.***

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 WSW through NNE in or near drainages leading to SSRAs. Verify transport winds away from SSRAs if burning in any other direction. No additional restrictions necessary.

For Monday:

***Avoid ignitions before 10 a.m. in all zones.***

Zone 640, 642, and 644 West of R35E:

Follow standard guidance matrix - see section 5 below - for burning units to the WSW through NNW of SSRAs. For units that will smolder significantly through the night avoid burning within at least 15 miles to the WSW through N in or near drainages leading to SSRAs. No additional restrictions necessary.

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

For Tuesday:

***Avoid ignitions before 10 a.m. in all zones.***

Follow standard guidance matrix - see section 5 below - for burning units to the W through NNW 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. Verify transport winds away from SSRAs if burning in any other direction. No additional restrictions necessary.

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4. SPECIAL NOTE:

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.