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: Wednesday, April 21, 2010       2:40 PM      Jim Little

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


An upper level low pressure area, centered over southern Nevada, is maintaining a very cool air mass over Oregon and continuing to circulate enough moisture over the region for widely scattered showers.  The flow aloft will dry out and turn northerly, tonight and Thursday, as the upper level trough slides southeastward to over Utah.  Showers should end by Thursday afternoon with northerly transport winds.  Mixing heights should climb to around 3500 feet Thursday afternoon.

    OUTLOOK (FRIDAY-SUNDAY)

A weak weather system will push into southern British Columbia on Friday, with transport winds turning westerly by late in the day.  Mixing heights should climb to around 5000 feet Thursday afternoon with good ventilation conditions.  An upper level trough is forecast to slide across eastern Washington and northern Idaho on Saturday with the flow aloft turning northwesterly. This system will likely bring only partly cloudy skies to the region with continued west-northwesterly transport winds. A weak upper-level ridge is forecast to move over western Oregon Sunday for dry and warmer weather.  Mixing heights should climb to around 5000 feet but with lighter transport winds.


2.  DISPERSION

THURSDAY
Mixing height 2000 - 3000 ft during the morning.  Afternoon mixing height rises to 3000 - 4000 ft then lowers to 2500 - 3500 ft during the evening.

Transport wind N to NNE at 18 - 32 mph during the morning.  Transport wind increases to N to NNE at 22 - 38 mph during the afternoon and evening.

Surface wind NNW to NNE at 12 - 22 mph during the morning.  Surface wind increases to N to NNE at 14 - 28 mph during the afternoon then decreases to NNW to NNE at 10 - 18 mph during the evening.

OUTLOOK:

FRIDAY
Mixing height below 1000 ft early rising to 1800 - 2800 ft by late morning rising above 5000 ft during the afternoon.  Transport wind NNW to NNE at 5 - 9 mph during the morning becoming W to WNW at 12 - 22 mph during the afternoon.  Surface wind light and variable during the morning becoming W to NW at 9 - 15 mph during the afternoon.

SATURDAY
Mixing height below 1000 ft early rising to 2500 - 3500 ft by late morning rising above 5000 ft during the afternoon.  Transport wind light and variable during the morning becoming W to NW at 5 - 9 mph during the afternoon.  Surface wind light and variable during the morning becoming W to NW at 5 - 9 mph during the afternoon.

SUNDAY
Mixing height below 1000 ft early rising to 3000 - 4000 ft by late morning rising above 5000 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 Thursday, April 22, 2010.
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Avoid ignitions within 12 miles to the N through NNE of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 20 miles to the N through NNE 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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