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: Tuesday, April 21, 2009       2:40 PM      Jim Little

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

An upper level trough extending southwestward from a low in northern Alberta begins to move into the northwest Washington during the day on Wednesday.  Temperatures aloft will be cooling dramatically, destabilizing the atmosphere and providing good smoke dispersal conditions.  There will be limited moisture with this trough but some isolated showers are possible.  Expect transport winds to be generally southwesterly most areas.

    OUTLOOK (THURSDAY - SATURDAY):

The upper level trough sweeps through the region on Thursday further destabilizing the atmosphere over the Pacific Northwest.  Again, limited moisture, but showers are possible especially over mountainous areas.  Transport winds shift to northerly.  The trough remains over the region on Friday for a continued chance of scattered showers but also good smoke dispersal conditions with high mixing heights.  Saturday will see the upper trough well to the east, over the northern Rockies with surface high pressure centered several hundred miles west of Oregon.  A minor upper disturbance dropping south-southeast will cause some instability for a continued slight chance of a shower but also continued good smoke dispersal conditions.  By Saturday transport winds should be back to westerly.

2.  DISPERSION

WEDNESDAY
Mixing height 3500 - 4500 ft during the morning.  Mixing height rises to above 5000 ft during the afternoon then lowers to 2100 - 3100 ft during the evening.

Transport wind WSW to WNW at 6 - 10 mph during the morning.  Transport wind increases to WSW to WNW at 16 - 30 mph during the afternoon and evening.

Surface wind WSW to WNW at 4 - 8 mph during the morning.  Surface wind increases to WSW to WNW at 12 - 24 mph during the afternoon then decreases to WNW to NW at 10 - 16 mph during the evening.

OUTLOOK:

THURSDAY
Mixing height below 1000 ft early rising above 5000 ft by late morning and through the afternoon.  Transport wind NW to N at 10 - 16 mph.  Surface wind W to NW at 6 - 10 mph during the morning becoming WNW to NW at 10 - 22 mph during the afternoon.

FRIDAY
Mixing height above 5000 ft throughout the day.  Transport wind WNW to NNW at 10 - 18 mph during the morning becoming NW to NNW at 13 - 25 mph during the afternoon.  Surface wind WNW to NNW at 10 - 16 mph during the morning becoming NW to NNW at 12 - 24 mph during the afternoon.

SATURDAY
Mixing height 2800 - 3800 ft during the morning rising above 5000 ft during the afternoon.  Transport wind light and variable during the morning becoming WSW to NW at 5 - 9 mph during the afternoon.  Surface wind light and variable during the morning becoming WSW to NW at 6 - 10 mph during the afternoon.

3.  BURNING INSTRUCTIONS FOR ZONES 624 AND 625 INCLUDING THE WALKER
    RANGE PORTION OF ZONE 624
This instruction is valid for burning conducted on Wednesday, April 22, 2009.
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Avoid ignitions within 12 miles to the WSW through NW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 20 miles to the WSW through N 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

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


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