SMI West (Smoke Management Instructions) Western Oregon Smoke Management Instructions

Fri Apr 29 14:33:11 PDT 2011

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Friday, April 29, 2011       2:30 PM      Pete Parsons

1.  DISCUSSION AND FORECAST FOR THE WESTERN OREGON AREA FORECAST ZONES 601-623

SATURDAY

An upper-level ridge is forecast to build about 500 miles offshore with a drier and more stable northwesterly flow aloft over Oregon.  Slow warming aloft should stabilize the atmosphere, but the snow level will only rise to 3500 feet north and 4500 feet south.  After a chilly morning, afternoon temperatures will moderate slightly but remain below normal.  Daytime heating could still trigger an isolated light shower or two, mainly north and over higher terrain. Mixing should be good with mostly northerly transport winds.

OUTLOOK (SUNDAY-TUESDAY)
A progressive upper-level ridge is forecast to move onshore Sunday, with continued warming and drying of the air mass over Oregon.  Warming aloft will stabilize the air mass, with the freezing level jumping to 9000 feet north and 10,000 feet south.  That will help afternoon temperatures recover to above normal, after a locally frosty early morning. A surface thermal trough is forecast to build northward, into southwestern Oregon, and turn transport winds offshore with fair to good afternoon mixing.

The upper-level ridge will push east of the state Monday with an increasing westerly flow aloft bringing a weak cold front onshore by the afternoon.  Transport winds will likely turn onshore in the early morning, which would limit burning opportunities in the coast range.  The cold front is forecast to bring light rain to the northern zones, with the southern zones likely staying dry, for a change.  Cold air aloft will not penetrate as far south, with this system, so snow levels will only drop to around 4000 feet north and 6500 feet south late.  Cooling aloft should maintain fair to good mixing with increasing onshore transport winds.  Surface temperatures will drop back to slightly below normal north but likely remain just above normal south.

A weak upper-level trough will push east of the state Tuesday, with a return to a dry northwesterly flow aloft.  Skies should be partly cloudy.  The freezing level will rise above 7000 feet north and 10,000 feet south, which may suppress afternoon mixing heights slightly.  Mixing should still be fair to good, with locally brisk northerly winds keeping temperatures near normal.

2.  DISPERSION

Zone 601-612 (North Coast Range and Cascades):

MORNING

Mixing height below 2000 ft early rising to 3500 - 4500 ft by late morning.

Transport wind NW to NNE at 6 - 10 mph.

Surface wind NW to N at 4 - 8 mph.

AFTERNOON

Mixing height rising above 5000 ft.

Transport wind NNW to NNE at 9 - 15 mph.

Surface wind NW to NNE at 6 - 12 mph.

EVENING

Mixing height 1500 - 2500 ft.

Transport wind similar to afternoon.

Surface wind NW to NNE at 4 - 8 mph.

Zone 615-623 (South Coast Range and Cascades):

MORNING

Mixing height below 1500 ft early rising to 3500 - 4500 ft by late morning.

Transport wind NNE to NE at 9 - 15 mph.

Surface wind N to NE at 8 - 12 mph.

AFTERNOON

Mixing height rising above 5000 ft.

Transport wind increases to NNE to NE at 12 - 24 mph.

Surface wind NNW to NNE at 9 - 15 mph.

EVENING

Mixing height 1500 - 2500 ft.

Transport wind N to NE at 10 - 20 mph.

Surface wind similar to afternoon.

OUTLOOK:

SUNDAY

In the north mixing height below 1000 ft early rising to 2500 to 3500 ft by late morning rising to 4000 to 5000 ft during the afternoon.  In the south mixing height below 1000 ft early rising to 1700 to 2700 ft by late morning rising above 5000 ft during the afternoon.  Transport wind ENE to ESE at 6 - 10 mph during the morning becoming ESE to SSE at 6 - 10 mph during the afternoon.  Surface wind light and variable.

MONDAY

Mixing height below 1000 ft early rising to 3000 to 4000 ft by late morning rising to 4100 to 5000 ft during the afternoon.  Transport wind SSW to WSW at 10 - 18 mph during the morning becoming W to NW at 10 - 18 mph during the afternoon.  Surface wind light and variable during the morning becoming W to NW at 6 - 12 mph during the afternoon.

TUESDAY

Mixing height below 1000 ft early rising to 2500 to 3500 ft by late morning rising to 4000 to 5000 ft during the afternoon.  Transport wind NNW to NNE at 6 - 12 mph.  Surface wind NNW to NNE at 4 - 8 mph.

3.  BURNING INSTRUCTIONS FOR ALL ZONES IN THE WESTERN OREGON AREA

These instructions are valid for burning conducted on Saturday, April 30, 2011.

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Coast Range

Zone 601 and 612

Units should be 2000 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.  Higher tonnage is possible south of Waldport in Zone 612.  Call the forecaster.

Zone 602 and 603

Units should be 750 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.  Avoid ignitions north of Forest Grove/Hillsboro or Sheridan/Willamina in Zone 602.  Higher tonnage is possible south of T17S in Zone 603.  Call the forecaster.

Zone 615, 616, 618, 619, and 620

Use standard guidance matrix. (See section 5 below.)  Avoid burning directly upwind of the North Bend/Coos Bay SSRA.

Cascades

Zone 605 and 606

Units should be 1200 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.  Verify transport winds away from SSRA if burning within 10 miles of the SSRA.  Higher tonnage is possible south of T20S in Zone 606.  Call the forecaster.

Zone 607, 608, 609, and 611

Use standard guidance matrix. (See section 5 below.)  Ensure adequate distance from downwind SSRAs for smoke to dissipate.

Zone 610 and 616

Units should be 1000 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.  South of T30S in Zone 616 units should be 500 tons or less, spaced 5 miles apart.

Zone 617

Units should be 2000 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.  South of T30S units should be 750 tons or less, spaced 5 miles apart.

Zone 620 and 622

Units should be 500 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.

Zone 623

Units should be 1500 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.  South of T36S, use standard guidance matrix. (See section 5 below.)

Siskiyous

Use standard guidance matrix. (See section 5 below.)

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4.  SPECIAL NOTE:

    Call the smoke management duty forecaster at (503) 945-7401 to

    discuss burning.  Please do not call individual's numbers to

    discuss daily burning.  If the forecaster is not available,

    leave a message and he will return your call as soon as possible.

    Avoid calling between 2 to 2:30 p.m.

    The 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

5.  STANDARD GUIDANCE MATRIX:

  * Greater than 5000 ft mixing height:  No burning within 5 miles of

    downwind SSRA.  Maximum 100 tons per mile from downwind SSRA.

    Example:  500 ton maximum allowed if burned 5 miles from downwind SSRA.

  * 3000 - 5000 ft mixing height:  No burning within 10 miles of

    downwind SSRA.  Maximum 75 tons per mile from downwind SSRA.

    Example:  750 ton maximum allowed if burned 10 miles from downwind SSRA.

  * Less than 3000 ft mixing height:  No burning within 15 miles of

    downwind SSRA.  Maximum 50 tons per mile from downwind SSRA.

    Example:  750 ton maximum allowed if burned 15 miles from downwind SSRA.

  * All exceptions must be coordinated with the duty forecaster

    prior to ignition.

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