SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Friday, December 19, 2014       2:40 PM      Tom Jenkins

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ODF Weather has transitioned back to operating Monday through Friday, and will not be open this weekend. The final Smoke Management Instruction for the fall prescribed burning season will be issued on Monday afternoon, and will be valid for Tuesday the 23rd and Wednesday the 24th.

For smoke management guidance and burning clearance, call the forecaster Mondays through Fridays 7:30am-5:00pm. The smoke management instruction will resume when burning operations increase in Spring 2015 or sooner as required.

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

 

SHORT-TERM DISCUSSION

The atmosphere will remain unstable as an upper level trough slowly passes over northern Oregon Friday night and early Saturday morning. A surface frontal boundary will have stalled out early Saturday morning over the region, and will be re-energized as a mid-level trough follows it. This will mark the beginning of pronounced rainfall associated with an atmospheric river from the Pacific Ocean. Onshore flow will persist over southern Oregon throughout Saturday, building as the mid-level trough approaches Saturday evening. Mixing conditions will be fairly good in the vicinity of the stationary boundary and its associated rainfall.

EXTENDED DISCUSSION

The atmospheric river will remain active with an unstable atmosphere over northern Oregon. An upper level ridge will begin to build offshore Sunday, shifting the boundary further north before sunrise. Rainfall will taper off. Mixing conditions will start out poor with limited improvement by Sunday afternoon. The upper level ridge will strengthen and move onshore overnight, forming a surface ridge over southern Oregon. Winds will be light & variable Monday morning, influenced primarily by terrain. Mixing will start out poor, with very little improvement by Monday afternoon. The atmosphere will continue to stabilize as the upper ridge becomes nearly stationary over the Cascades. Light & variable winds with poor mixing conditions will persist throughout Monday evening and into Tuesday. This will help dry the atmosphere out, enhancing overall stability even further by Tuesday evening.

2.  DISPERSION

 

SATURDAY

 

Mixing height above 5000 ft throughout the day.  Mixing height lowers to 3500 - 4500 ft during the evening.

 

Transport wind SSW to SW at 26 - 46 mph during the morning.  Transport wind decreases to SW to WSW at 22 - 38 mph during the afternoon and evening.

 

Surface wind SSW to SW at 14 - 28 mph during the morning.  Surface wind decreases to SW to WSW at 10 - 20 mph during the afternoon and evening.

 

OUTLOOK:

 

SUNDAY

Mixing height 2500 - 3500 ft during the morning rising to 3500 - 4500 ft during the afternoon.  Transport wind WSW to W at 25 - 45 mph.  Surface wind WSW to W at 12 - 22 mph during the morning becoming WSW to WNW at 8 - 12 mph during the afternoon.

 

MONDAY

Mixing height 1000 - 1800 ft during the morning rising to 2000 - 3000 ft during the afternoon.  Transport wind WNW to NW at 8 - 12 mph.  Surface wind WSW to WNW at 5 - 9 mph.

 

TUESDAY

Mixing height below 1000 ft early rising to 1000 - 1700 ft by late morning and through the afternoon.  Transport wind E to ESE at 8 - 12 mph.  Surface wind NE to ESE at 5 - 9 mph.

 

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

    RANGE PORTION OF ZONE 624

This instruction is valid for burning conducted on Saturday and Sunday, December 20 and 21, 2014.

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For Saturday:

 

Avoid ignitions within 10 miles to the SSW through WSW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 10 miles to the SSW through W 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. 

 

For Sunday:

 

Avoid ignitions within 12 miles to the WSW through WNW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 20 miles to the WSW through WNW in or near drainages leading to SSRAs.  Care needed in selecting units as smoke will likely fumigate along the ground in wind prone areas. 

 

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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 before 8 a.m. and between 2 to 3 p.m.

 

    This forecast is available on the Internet at:

      http://oregon.gov/ODF/FIRE/fire.shtml/#Smoke_Management_Information

 

    Please ensure your units have been planned and accomplished by checking:

      http://oregon.gov/ODF/FIRE/SMP/dailysmoke.shtml