SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

 

ISSUED: Wednesday, November 26, 2014       2:35 PM      Tom Jenkins
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ODF Weather will be closed on Thursday, November 27th to observe Thanksgiving. We will re-open on Friday, November 28th to provide smoke management prescriptions for the remainder of the holiday weekend.

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

 

SHORT-TERM DISCUSSION

The atmosphere will become unstable overnight, as an upper level trough deepens offshore Oregon. A surface frontal system will swing its cold front onshore Thursday morning, increasing mixing as winds build up. Precipitation will be scattered across northern zones, falling as rain. The frontal boundary will weaken as it enters the Cascades after sunset, and stall out overnight.

EXTENDED DISCUSSION

An active weather pattern develops for the holiday weekend. A secondary upper level trough will dive south from the Canadian coast, re-energizing the stalled out cold frontal boundary Friday morning. This will keep the atmosphere unstable, with great mixing conditions and onshore flow. Rainfall will be widespread and persistent, as the trough deepens and the cold frontal boundary at the surface slowly pushes south overnight into Saturday. Mixing will remain favorable due to instability near the boundary. The upper level trough will finally pass early Sunday, allowing the atmosphere to become more stable in northern zones. Offshore flow will begin to develop in northern Oregon, as a weak surface ridge forms east of the Cascades. Mixing will be fair, with breezy winds near the Columbia Gorge.

2.  DISPERSION

 

THURSDAY

 

Zone 640, 642, and 644 West of R35E:

Mixing height above 5000 ft throughout the day.  Mixing height lowers to 3000 - 4000 ft during the evening.

 

Transport wind SSW to SW at 21 - 37 mph during the morning.  Transport wind decreases to S to SW at 18 - 32 mph during the afternoon and evening.

 

Surface wind SSE to SSW at 10 - 20 mph throughout the day.

 

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

Mixing height below 1000 ft early rising above 5000 ft by late morning.  Mixing height lowers to 3500 - 4500 ft during the evening.

 

Transport wind SW to WSW at 15 - 25 mph throughout the day.

 

Surface wind SSW to SW at 8 - 12 mph during the morning.  Surface wind increases to SSE to SSW at 10 - 20 mph during the afternoon and evening.

 

OUTLOOK:

 

FRIDAY

Mixing height 2400 to 3400 ft during the morning rising above 5000 ft during the afternoon.  Transport wind SW to WSW at 16 - 30 mph.  Surface wind SSW to SW at 10 - 22 mph.

 

SATURDAY

Mixing height 4500 to 5000 ft during the morning rising above 5000 ft during the afternoon.  Transport wind WSW to WNW at 15 - 25 mph during the morning becoming W to NW at 10 - 20 mph during the afternoon.  Surface wind WNW to NNW at 10 - 16 mph.

 

SUNDAY

Mixing height below 1000 ft early rising to 1000 to 2000 ft by late morning rising to 2500 to 3500 ft during the afternoon.  Transport wind E to SE at 8 - 12 mph during the morning becoming ESE to SE at 10 - 20 mph during the afternoon.  Surface wind light and variable.

 

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 Thursday and Friday, November 27 and 28, 2014.

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For Thursday:

 

Zone 640, 642, and 644 West of R35E:

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 15 miles to the SSW through WSW in or near drainages leading to SSRAs. 

 

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

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 15 miles to the SSW through WSW in or near drainages leading to SSRAs. 

 

For Friday:

 

Avoid ignitions within 12 miles to the SSW through W of SSRAs. For units that will smolder significantly through the night avoid burning within at least 12 miles to the SSW 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. Complete ignitions by 3 p.m. for units east of R30E. 

 

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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