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

Wed Dec 8 15:12:10 PST 2010

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

...Corrected Siskiyous Instructions and Extended Mixing Heights Forecasts...

ISSUED: Wednesday, December 8, 2010       2:30 PM      Pete Parsons

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

THURSDAY

An embedded upper-air disturbance, in a strong westerly flow aloft, will increase the shower activity across western Oregon in the afternoon and evening.  Precipitation totals will range from around one-quarter of an inch, in the southern valleys, to more than an inch over the northern mountains.  Accumulating snow is likely above 4000 feet north and 5000 feet south.  Ventilation conditions should be fair to good with south to southwesterly transport winds.

OUTLOOK (FRIDAY-SUNDAY)

The air mass will begin to stabilize by late Friday, as the flow aloft veers to northwesterly. Showers will begin to decrease in the afternoon.  Transport winds will veer to more westerly.  Smoke dispersal conditions should remain fair to good through Friday afternoon, but mixing heights will drop sharply in the evening.

A strong warm front will spread significant rainfall back across western Oregon Saturday, mainly north, with the snow level rising to 6000 feet north and 8000 feet south. The combination of possibly heavy rainfall and rising snow levels may lead to areas of flooding north.  Increasing southeasterly to southerly transport winds will turn southerly south of the warm front, across the southern zones, in the afternoon.  North of the warm front, smoke dispersal conditions will likely be marginal to poor, due to warm air aloft.  However, south of the warm front, balmy southerly winds will help to warm surface temperatures and improve ventilation conditions to fair.

The strong warm front should push north of the region by Sunday morning, with the rainfall tapering off.  Southerly surface and transport winds will also taper off but make for unseasonably mild conditions.  The freezing level will rise to above 7000 north and to near 9000 feet south.  Warm air aloft will suppress mixing heights, with marginal to poor ventilation conditions.

2.  DISPERSION

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

MORNING

Mixing height 2900 - 3900 ft.

Transport wind SSW to SW at 14 - 28 mph.

Surface wind SSE to SSW at 9 - 15 mph.

AFTERNOON

Mixing height 3000 - 4000 ft.

Transport wind similar to morning.

Surface wind similar to morning.

EVENING

Mixing height 3000 - 4000 ft.

Transport wind SW at 18 - 32 mph.

Surface wind similar to afternoon.

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

MORNING

Mixing height below 3000 ft early rising to 2800 - 3800 ft by late morning.

Transport wind SSW to SW at 10 - 22 mph.

Surface wind SSE to SSW at 8 - 12 mph.

AFTERNOON

Mixing height 3000 - 4000 ft.

Transport wind similar to morning.

Surface wind similar to morning.

EVENING

Mixing height 3000 - 4000 ft.

Transport wind SSW to SW at 15 - 29 mph.

Surface wind similar to afternoon.

OUTLOOK:

FRIDAY

Mixing height 3200 to 4200 ft during the day, then dropping below 1500 feet in the early evening.  Transport wind SW to W at 16 - 26 mph during the morning becoming WSW to WNW at 10 - 18 mph during the afternoon.  Surface wind SSW to WSW at 8 - 14 mph during the morning becoming SSW to WSW at 4 - 8 mph during the afternoon.

SATURDAY

Mixing height below 1000 ft early rising to 2200 to 2800 ft north and 2500 to 3500 ft south during the late morning and afternoon.  Transport wind SSE to SSW at 10 - 22 mph during the morning becoming S to SW at 16 - 30 mph during the afternoon.  Surface wind SE to S at 6 - 10 mph during the morning becoming SSE to SSW at 6 - 12 mph during the afternoon.

SUNDAY

Mixing height below 1000 ft early rising to 1500 to 2500 ft north and 1000 to 2000 ft south by late morning through the afternoon.  Transport wind SSE to SSW at 8 - 12 mph.  Surface wind SE to SSW at 4 - 8 mph.

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

These instructions are valid for burning conducted on Thursday, December 9, 2010.

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Coast Range

Zone 601, 612, and 616 east of R9W

Units should be 750 tons or less, spaced 10 miles apart, and 12 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

Units should be 300 tons or less, spaced 10 miles apart, and 12 miles from downwind SSRAs.  North of T3N in Zone 602, use standard guidance matrix. (See section 5 below.)  Units may be 750 tons or less, spaced 10 miles apart, south of the Siuslaw River in Zone 603.

Zone 615 and 616 west of R8W

Units should be 1500 tons or less, spaced 10 miles apart, and 12 miles from downwind SSRAs.  Higher tonnage is possible south of T29S in Zone 616.  Call the forecaster.

Zone 618, 619, and 620

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

Cascades

All zones except zone 611

Use standard guidance matrix. (See section 5 below.)  Ensure adequate distance from downwind SSRAs for smoke to dissipate.  Avoid ignitions north of T24S in Zone 616.

Zone 611

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

Siskiyous

Units should be 750 tons or less, spaced 10 miles apart, and 12 miles from downwind SSRAs.  Higher tonnage may locally be possible. Call the forecaster.

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

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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