SMI South Central (Smoke Management Instructions) South Central Oregon Smoke Management Instructions

[ODF Smoke Management Instructions]

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS
SALEM FORESTRY WEATHER CENTER
OREGON DEPARTMENT OF FORESTRY

ISSUED: Monday, December 7, 2009       2:40 PM      Jim Little

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

Cold weather will continue.  Upper flow over the Pacific Northwest is essentially northerly.  A weak upper trough will drop down on the northerly flow.  Satellite pictures show some clouds with this feature but computer models indicate very limited moisture.  There could be a scattered snow shower or two late tomorrow but I expect no significant accumulation. Mixing heights will generally be around 3500 feet for fair smoke dispersal conditions.

    OUTLOOK (WEDNESDAY-FRIDAY)

A dry upper flow continues over the northwest Wednesday, however following the passage of Tuesday's weak upper trough the flow turns a little more north-northwest.  The air mass stabilizes for less favorable smoke dispersal conditions. Northwesterly flow aloft continues in the north on Thursday but westerly flow aloft begins to push into northern California and SW Oregon for improving smoke dispersal conditions.  A weak upper disturbance moves over southern Oregon and northern California Friday as the cold weather pattern slowly breaks for continued improvement in smoke dispersal conditions.

2.  DISPERSION

TUESDAY
Mixing height 1200 - 2200 ft during the morning.  Afternoon and evening mixing rises to 3000 - 4000 ft.

Transport wind SW to W at 8 - 12 mph during the morning.  Transport wind increases to WSW to WNW at 10 - 20 mph during the afternoon and evening.

Surface wind light and variable and controlled by local terrain during the morning.  Surface wind increases to WSW to WNW at 6 - 10 mph during the afternoon and evening.

OUTLOOK:

WEDNESDAY
Mixing height below 1000 ft early rising to 1200 - 2200 ft by late morning and through the afternoon.  Transport wind WSW to W at 12 - 24 mph.  Surface wind SSW to W at 6 - 10 mph.

THURSDAY
Mixing height below 1000 ft early rising to 1500 - 2500 ft by late morning rising to 2500 - 3500 ft during the afternoon.  Transport wind light and variable.  Surface wind light and variable.

FRIDAY
Mixing height below 1000 ft early rising to 1500 - 2500 ft by late morning rising to 3500 - 4500 ft during the afternoon.  Transport wind light and variable.  Surface wind light and variable.

3.  BURNING INSTRUCTIONS FOR ZONES 624 AND 625 INCLUDING THE WALKER
    RANGE PORTION OF ZONE 624
This instruction is valid for burning conducted on Tuesday, December 8, 2009.
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Delay ignitions until 10:00am.  Avoid ignitions within 15 miles to the SW through NW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 30 miles to the SW through NW in or near drainages leading to SSRAs.  Recommend against burning units that will smolder significantly overnight.

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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

    Please ensure your units have been planned and accomplished by checking:
      http://oregon.gov/ODF/FIRE/SMP/dailysmoke.shtml


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