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

Fri Nov 12 14:32:00 PST 2010

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Friday, November 12, 2010       2:30 PM      Pete Parsons

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

SATURDAY

A broad upper-level ridge will continue to amplify offshore.  A warm front will track along a strong jet stream, on the north side of the ridge, and drop into the Pacific Northwest.  That will bring cloudy skies and some light rain to northern and western zones, with mostly cloudy skies and a chance of light rain to the southeastern zones. There may also be areas of morning valley fog, mainly south.

Rainfall totals should range from up to one-half inch in the northern coastal mountains to less than one-tenth of an inch in the southern Cascades. The snow level will rise above 8000 feet.  Warming aloft will suppress mixing heights.  Transport winds will turn southerly across the northern zones and become light over southern zones with generally marginal to poor smoke dispersal conditions.

OUTLOOK (SUNDAY-TUESDAY)

The warm front is forecast to dissipate over Oregon on Sunday, as the offshore upper-level ridge continues to build.  The flow aloft will turn from northwesterly to more northerly and begin to dry out. Skies should remain mostly cloudy with areas of light rain tapering off in the afternoon.  Look for rainfall totals to be less than one-tenth of an inch.  The snow level will rise to near 10,000 feet.  Warm air aloft will keep mixing heights suppressed with light winds making for generally poor smoke dispersal conditions.

The offshore ridge will begin to flatten on Monday, allowing a weak weather system to slide down the southern British Columbia coastline.  That will bring back a chance of rain to northern zones with the snow level dropping to about 8000 feet.  Southern zones will likely stay dry but with considerable clouds and areas of morning valley fog.  Ventilation conditions should improve to marginal.

Strong northwesterly flow aloft is forecast for Tuesday with a weak and transitory ridge limiting shower activity.  Snow levels will continue to drop to around 5000 feet north and 7000 feet south.  Smoke dispersal conditions will likely remain marginal.

2.  DISPERSION

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

MORNING

Mixing height below 800 ft early rising to 1000 - 1700 ft by late morning.

Transport wind SSE to SSW at 6 - 10 mph.

Surface wind light and variable but favors SE to S and controlled by local terrain.

AFTERNOON

Mixing height 1700 - 2700 ft.

Transport wind similar to morning.

Surface wind increases to SE to SSW at 4 - 8 mph.

EVENING

Mixing height 1000 - 1500 ft.

Transport wind becomes light and variable but favors S and controlled by local terrain.

Surface wind becomes light and variable but favors SE to S and controlled by local terrain.

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

MORNING

Mixing height below 500 ft early rising to 1000 - 1500 ft by late morning.

Transport wind light and variable and controlled by local terrain.

Surface wind light and variable and controlled by local terrain.

AFTERNOON

Mixing height 1300 - 2300 ft.

Transport wind similar to morning.

Surface wind similar to morning.

EVENING

Mixing height lowers below 1000 ft.

Transport wind similar to afternoon.

Surface wind similar to afternoon.

OUTLOOK:

SUNDAY

Mixing height below 1000 ft early rising to 1000 to 1800 ft by late morning and through the afternoon.  Transport wind light and variable during the morning becoming NW to N at 4 - 8 mph during the afternoon.  Surface wind light and variable.

MONDAY

Mixing height below 1000 ft early rising to 1000 to 1900 ft by late morning rising to 1800 to 2800 ft during the afternoon.  Transport wind W to NW at 4 - 8 mph.  Surface wind light and variable during the morning becoming W to NW at 4 - 8 mph during the afternoon.

TUESDAY

Mixing height below 1000 ft early rising to 1100 to 2100 ft by late morning rising to 2100 to 3100 ft during the afternoon.  Transport wind W to NW at 4 - 8 mph during the morning becoming light and variable during the afternoon.  Surface wind light and variable.

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

These instructions are valid for burning conducted on Saturday, November 13, 2010.

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Coast Range

***Complete ignitions by 2:30 p.m. in all zones.***

Zone 601, 612, 615, 616 west of and R8W

Units should be 1000 tons or less, spaced 15 miles apart, and 15 miles from downwind SSRAs.  North of Tillamook in Zone 601, use standard guidance matrix. (See section 5 below.)  Higher tonnage is possible south of T29S in Zone 616.  Call the forecaster.

Zone 602 and 603

No burning allowed.  North of T3N in Zone 602, use standard guidance matrix. (See section 5 below.)  Units may be 750 tons or less, spaced 15 miles apart, south of the Siuslaw River in Zone 603.

Zone 616 east of R9W

Units should be 750 tons or less, spaced 15 miles apart, and 15 miles from downwind SSRAs.  Higher tonnage is possible south of T29S.  Call the forecaster.

Zone 618 and 619

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

Zone 620

Units should be 500 tons or less, spaced 15 miles apart, and 15 miles from downwind SSRAs.

Cascades

***Complete ignitions by 2:30 p.m. in all zones.***

Zone 605, 606, and 616

Units should be 500 tons or less, spaced 15 miles apart, and 15 miles from downwind SSRAs.

Zone 607, 608, 609, 610, 617, and 623

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

Zone 611

Units should be 750 tons or less, spaced 15 miles apart, and 15 miles from downwind SSRAs.

Zone 620 and 622

No burning allowed.

Siskiyous

Units should be 1000 tons or less, spaced 15 miles apart, and 15 miles from downwind SSRAs.

==============================================================

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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