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: Sunday, April 18, 2010       2:40 PM      Jim Little

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

Upper air charts show a major trough in the eastern Pacific on Monday.  Flow aloft over the region is southerly ahead of a slow moving Pacific cold front.  Any rain from this system will hold off until Tuesday.  Mixing heights support very good smoke dispersal conditions.

    OUTLOOK (TUESDAY-THURSDAY)

On Tuesday the upper trough slowly moves through the region, eventually splitting with the southern portion becoming a closed upper low over California.  Showers move in during the morning hours and continue throughout the day.  Transport winds will be variable becoming northwesterly during the day.  Expect good smoke dispersal conditions.  On Wednesday the upper low drifts across southern Nevada.  Flow aloft will be light and variable but brisk northwesterly transport winds are likely closer to the ground.  On Thursday weak ridging develops over the eastern Pacific Ocean.  Flow aloft will be from the north or northwest, and while there will still be a few showers around expect a drying trend during the day.  Smoke dispersal conditions should be good.


2.  DISPERSION

MONDAY
Mixing height 2300 - 3300 ft during the morning.  Mixing height rises to above 5000 ft during the afternoon then lowers to 3300 - 4300 ft during the evening.

Transport wind S to SW at 10 - 16 mph during the morning.  Transport wind increases to SSW to SW at 12 - 24 mph during the afternoon and evening.

Surface wind S to SW at 8 - 12 mph during the morning.  Surface wind increases to SSW to SW at 10 - 18 mph during the afternoon then decreases to SW to WSW at 8 - 12 mph during the evening.

OUTLOOK:

TUESDAY
Mixing height 2900 - 3900 ft during the morning rising to 3500 - 4500 ft during the afternoon.  Transport wind SSW to SW at 15 - 29 mph during the morning becoming W to WNW at 13 - 25 mph during the afternoon.  Surface wind S to SW at 10 - 16 mph during the morning becoming WSW to WNW at 10 - 20 mph during the afternoon.

WEDNESDAY
Mixing height 1200 - 2200 ft during the morning rising to 4500 - 5000 ft during the afternoon.  Transport wind light and variable.  Surface wind light and variable.

THURSDAY
Mixing height 2500 - 3500 ft during the morning rising to 4500 - 5000 ft during the afternoon.  Transport wind WNW to NNW at 4 - 8 mph.  Surface wind light and variable during the morning becoming WNW to NNW at 4 - 8 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 Monday, April 19, 2010.
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Avoid ignitions within 12 miles to the S through WSW of SSRAs.  No additional restrictions necessary.

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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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