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

Sat May 14 14:33:20 PDT 2011

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Saturday, May 14, 2011       2:30 PM      Pete Parsons

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

SUNDAY

An upper-level low-pressure system is forecast to finally come onshore just south of the Oregon/California border.  Southeasterly flow aloft will continue, with a substantial increase in the amount of moisture circulating into Oregon.  Look for widespread showers and/or areas of steady rain and mountain snow.  There is also a chance of a thunderstorm, mainly over the southern Cascades and Siskiyous.

The snow level will lower to 3-4000 feet.  Significant precipitation is forecast, but it difficult to predict where the greatest totals will be.  Amounts should range from .25" to over .50".  Maximum temperatures should be 10-15 degrees below mid-May normals.  Although southeasterly flow aloft tends to suppress mixing heights, cooling aloft will combine with what little daytime heating there will be to improve afternoon smoke dispersal conditions, especially south.  Look for increasing onshore transport winds in the afternoon.

OUTLOOK (MONDAY-WEDNESDAY)

On Monday, the upper-level low-pressure system is forecast to open into a general trough, with its axis along the coast.  The flow aloft will veer from southeasterly to southwesterly, which is a more stable but still fairly moist pattern.  Expect mostly cloudy skies and scattered showers.  The snow level will remain at 3-4000 feet, with surface temperatures about 10 degrees below normal. Maximum mixing heights should climb above 5000 feet with weakening onshore transport winds veering to northwesterly.

Another weather system is forecast to feed into the general trough over the Pacific Northwest, on Tuesday, with the main energy directed into Northern California and southern Oregon.  Skies may start out partly sunny, but clouds will increase in the afternoon with showers likely, mainly south. The snow level will only rise to 4-5000 feet, with surface temperatures 5-10 degrees below normal.  Cool air aloft and increasing onshore flow will provide fair to good smoke dispersal conditions.

The upper-level trough appears as if it will finally weaken and shift eastward on Wednesday.  A drier northwesterly flow aloft will taper off the shower activity with some afternoon clearing.  The snow level will rise to 5-6000 feet with surface temperatures recovering to near normal.  Afternoon mixing heights should rise above 5000 feet with light north-northwesterly transport winds.

2.  DISPERSION

Zone 601, 602, 603 and 612 (North Coast Range):

MORNING

Mixing height below 1200 ft early rising to 2000 - 3000 ft by late morning.

Transport wind SW to W at 8 - 12 mph.

Surface wind S to SW at 4 - 8 mph.

AFTERNOON

Mixing height rising to 4000 - 5000 ft.

Transport wind similar to morning.

Surface wind SSW to WSW at 4 - 8 mph.

EVENING

Mixing height 2500 - 3500 ft.

Transport wind similar to afternoon.

Surface wind similar to afternoon.

Zone 605-611 (North Cascades):

MORNING

Mixing height below 1000 ft early rising to 1700 - 2700 ft by late morning.

Transport wind WSW to WNW at 8 - 12 mph.

Surface wind SW to W at 5 - 9 mph.

AFTERNOON

Mixing height rising to 3000 - 4000 ft.

Transport wind similar to morning.

Surface wind similar to morning.

EVENING

Mixing height 2000 - 3000 ft.

Transport wind similar to afternoon.

Surface wind similar to afternoon.

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

MORNING

Mixing height below 1500 ft early rising to 2500 - 3500 ft by late morning.

Transport wind WSW to WNW at 4 - 8 mph.

Surface wind light and variable but favors W and controlled by local terrain.

AFTERNOON

Mixing height rising above 5000 ft.

Transport wind WSW to WNW at 6 - 12 mph.

Surface wind increases to WSW to WNW at 4 - 8 mph.

EVENING

Mixing height 2500 - 3500 ft.

Transport wind similar to afternoon.

Surface wind SW to W at 4 - 8 mph.

OUTLOOK:

MONDAY

Mixing height 2500 to 3500 ft during the morning rising above 5000 ft during the afternoon.  In the north transport wind SSW to SW at 8 - 12 mph during the morning becoming W to NW at 4 - 8 mph during the afternoon.  In the south transport wind light and variable.  Surface wind light and variable during the morning becoming WNW to NNW at 4 - 8 mph during the afternoon.

TUESDAY

Mixing height below 1000 ft early rising to 2300 to 3300 ft by late morning rising above 5000 ft during the afternoon.  Transport wind light and variable during the morning becoming W to NW at 4 - 8 mph during the afternoon.  Surface wind light and variable during the morning becoming W to NW at 4 - 8 mph during the afternoon.

WEDNESDAY

Mixing height below 1000 ft early rising to 2800 to 3800 ft by late morning rising above 5000 ft during the afternoon.  Transport wind light and variable during the morning becoming NW to N at 6 - 10 mph during the afternoon.  Surface wind light and variable during the morning becoming NW to N at 5 - 9 mph during the afternoon.

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

These instructions are valid for burning conducted on Sunday, May 15, 2011.

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Coast Range

Zone 601 and 612

Units should be 750 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.  Restrict units in or near corridors to 500 tons or less.  North of Tillamook in Zone 601, use standard guidance matrix. (See section 5 below.)

Zone 602 and 603

Units should be 300 tons or less, spaced 8 miles apart, and 10 miles from downwind SSRAs.  North of T3N in Zone 602, use standard guidance matrix. (See section 5 below.)  Avoid burning in or near corridors.  Units may be 500 tons or less, spaced 8 miles apart, south of the Siuslaw River in Zone 603.

Zone 615

Units should be 1500 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.

Zone 616 west of R8W

Units should be 1200 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.  Higher tonnage is possible south of T29S.  Call the forecaster.

Zone 616 east of R9W

Units should be 750 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.  Higher tonnage is possible south of T29S.  Call the forecaster.

Zone 618

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

Zone 619

Units should be 2000 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.

Zone 620

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

Cascades

All zones except Zone 610 and 611

Use standard guidance matrix. (See section 5 below.)  Ensure adequate distance from downwind SSRAs for smoke to dissipate.  From T15S through T20S in Zone 608 units should be 750 tons or less, spaced 10 miles apart.

Zone 610 and 611

Units should be 750 tons or less, spaced 10 miles apart, and 12 miles from downwind SSRAs.

Siskiyous

Units should be 1000 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.

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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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