SMI South Central (Smoke Management Instructions) South Central Oregon Smoke Management Forecast and Instruction

[ODF Smoke Management Instructions]

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

ISSUED: Friday, April 30, 2010       2:40 PM      Pete Parsons

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

    SATURDAY

A strong northwesterly flow aloft will direct another cool weather system across Washington and Oregon. A few mountain showers are possible with continued cool temperatures.  Smoke dispersal will remain good with strong onshore flow.

    OUTLOOK (SUNDAY-TUESDAY)

The main jet stream will finally lift north and east, on Sunday, with a weak and transitory upper-level ridge moving over the region.  Dry weather is expected with transport winds becoming more northerly.  Stabilizing of the air mass may lead to lower early morning mixing heights, but afternoon smoke dispersion will remain good with surface temperatures recovering closer to normal.  A cold front is forecast bring increasing clouds and onshore flow on Monday.  Showers are likely by Monday evening with the snow level rapidly dropping below 4000 feet Monday night.  Tuesday looks very cool and unstable with numerous showers and a chance of afternoon thunderstorms.  Smoke dispersal should be good both days, but temperatures will be unseasonably cool with brisk northwesterly winds.  The snow level could drop below 3000 feet on Tuesday.

2.  DISPERSION

SATURDAY
Mixing height 3500 - 4500 ft during the morning.  Mixing height rises to above 5000 ft during the afternoon then lowers to 2500 - 3500 ft during the evening.

Transport wind WNW to NW at 13 - 25 mph during the morning.  Transport wind increases to NW to NNW at 22 - 38 mph during the afternoon then decreases to NW to NNW at 18 - 32 mph during the evening.

Surface wind WNW to NNW at 10 - 20 mph during the morning.  Surface wind increases to NW to NNW at 16 - 30 mph during the afternoon and evening.

OUTLOOK:

SUNDAY
Mixing height below 1000 ft early rising to 3500 - 4500 ft by late morning rising above 5000 ft during the afternoon.  Transport wind NNW to NE at 6 - 10 mph during the morning becoming WNW to NNW at 10 - 18 mph during the afternoon.  Surface wind NNW to NNE at 6 - 10 mph during the morning becoming NW to NNW at 10 - 16 mph during the afternoon.

MONDAY
Mixing height below 1000 ft early rising to 3500 - 4500 ft by late morning rising above 5000 ft during the afternoon.  Transport wind WSW to WNW at 12 - 24 mph during the morning becoming WNW to NW at 20 - 34 mph during the afternoon.  Surface wind W to NW at 9 - 15 mph during the morning becoming WNW to NW at 12 - 22 mph during the afternoon.

TUESDAY
Mixing height 2800 - 3800 ft during the morning rising above 5000 ft during the afternoon.  Transport wind NW to N at 6 - 10 mph during the morning becoming NW to NNW at 12 - 22 mph during the afternoon.  Surface wind NW to N at 5 - 9 mph during the morning becoming NW to N at 9 - 15 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 Saturday, May 1, 2010.
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Avoid ignitions within 10 miles to the WNW through NNW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 15 miles to the WNW 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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