SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Friday, December 19, 2014       2:35 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 NORTHEAST FORECAST AREA ZONES 637-646

 

SHORT-TERM DISCUSSION

The atmosphere will remain unstable as an upper level trough slowly passes over northern Oregon Saturday. A surface frontal boundary will have stalled out earlier 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 be enhanced ahead of this feature. 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 northeastern Oregon. An upper level ridge will begin to build offshore Sunday, shifting the boundary further north. Rainfall will taper off slowly from the south to the north, but higher elevations in northern zones can expect heavier precipitation as the remaining moisture moves northward. Mixing conditions will remain fair near the boundary, but southern zones will see mixing heights begin to fall Sunday evening. The upper level ridge will strengthen and move onshore overnight, forming a surface ridge over southern Oregon. Onshore flow will weaken Monday morning. Mixing will start out poor, with only limited improvement by Monday afternoon. The atmosphere will continue to stabilize as the upper ridge becomes nearly stationary over the Cascades. Mixing conditions will deteriorate rapidly Monday evening. The atmosphere will become more stable as the surface ridge strengthens Tuesday morning. Winds will shift to weak offshore flow as a result. Mixing conditions will start out poor and remain marginal throughout Tuesday afternoon.

2.  DISPERSION

 

SATURDAY

 

Zone 640, 642, and 644 West of R35E:

Mixing height below 2500 ft early rising to 3000 - 4000 ft by late morning.  Afternoon mixing height rises to 4000 - 5000 ft then lowers to 3500 - 4500 ft during the evening.

 

Transport wind SW to WSW at 25 - 45 mph during the morning and afternoon.  Transport wind decreases to SW to W at 8 - 12 mph during the evening.

 

Surface wind S to SW at 12 - 22 mph throughout the morning and afternoon.  Surface wind shifts to SSE to SSW and decreases to 8 - 12 mph during the evening.

 

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

Mixing height below 2000 ft early rising to 2500 - 3500 ft by late morning.  Afternoon mixing height rises to 3500 - 4500 ft then lowers to 3000 - 4000 ft during the evening.

 

Transport wind S to SSW at 18 - 32 mph during the morning and afternoon.  Transport wind decreases to SW to WSW at 15 - 25 mph during the evening.

 

Surface wind SE to SSW at 9 - 15 mph during the morning and afternoon.  Surface wind decreases to SE to SSW at 8 - 12 mph during the evening.

 

OUTLOOK:

 

SUNDAY

Mixing height 2000 to 3000 ft during the morning rising to 3000 to 4000 ft during the afternoon.  Transport wind WSW to W at 15 - 29 mph during the morning becoming W to WNW at 18 - 32 mph during the afternoon.  Surface wind S to SW at 8 - 14 mph during the morning becoming WSW to WNW at 10 - 18 mph during the afternoon.

 

MONDAY

Mixing height 1200 to 2200 ft during the morning rising to 2500 to 3500 ft during the afternoon.  Transport wind WSW to WNW at 10 - 20 mph during the morning becoming WSW to WNW at 8 - 12 mph during the afternoon.  Surface wind WSW to WNW at 8 - 12 mph.

 

TUESDAY

Mixing height below 1000 ft early rising to 1000 to 2000 ft by late morning and through the afternoon.  Transport wind SSE to SSW at 10 - 18 mph.  Surface wind ESE to S at 5 - 9 mph.

 

3.  BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 637-646

    The following considerations should be adhered to in addition to

    the requirements of the Oregon Smoke Management Plan. These

    Instructions are valid for burning conducted on Saturday and Sunday, December 20 and 21, 2014.

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For Saturday:

 

Zone 640, 642, and 644 West of R35E:

Avoid ignitions within 10 miles to the SW through WSW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles to the SW through WSW in or near drainages leading to SSRAs.  Care needed in selecting units as smoke will likely fumigate along the ground in wind prone areas. 

 

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

Avoid ignitions within 12 miles to the S through WSW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 20 miles to the SE through WSW in or near drainages leading to SSRAs. 

 

For Sunday:

 

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

 

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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 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