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

Thu Feb 3 14:23:37 PST 2011

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Thursday, February 3, 2011       2:30 PM      Pete Parsons

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

The National Weather Service has issued an Air Stagnation Advisory for the southwestern valleys and for south-central Oregon through 10 am Monday.
FRIDAY
A persistent upper-level ridge of high pressure, which has been over the region for several days, will get flattened slightly by a weather system riding over the top of it and into southern British Columbia. Forecast models show rain moving across western Washington with a chance of light rain spreading as far south as about Newport, along the coast, and across the northern Cascades.  Elsewhere, expect just increased cloudiness.
Low level flow should turn mostly onshore with southwesterly transport winds across the northern zones and very light north to northwesterly flow over the southern zones.  Mixing heights should improve slightly, mainly over the northern zones, where smoke dispersal conditions may improve to marginal.
OUTLOOK (SATURDAY-MONDAY)
On Saturday the upper-level ridge is forecast to retreat just far enough offshore to allow a chance of rain to extend southward across most of Oregon, in an increasing northwesterly flow aloft.  Rainfall amounts should be mostly less than one-tenth of an inch with little to no rain forecast for most southwestern zones.  The snow level will drop to about 6000 feet north and to about 7000 feet south.  Slightly cooler air aloft will nudge mixing heights up just a bit with marginal smoke dispersal conditions for most areas.  Northern zones should have west to southwest transport winds with northwest transport winds across southern zones.
Northwesterly flow aloft will continue on Sunday, with minimal change in low-level transport winds, as the upper-level ridge slowly builds back over the state.  Skies should remain mostly cloudy with a continued chance of light rain and high elevation snow.  Precipitation totals should be less than one-tenth of an inch, with the best chance of rain or snow over the northern Cascades.  Mixing heights will likely lower slightly with a return to mostly poor smoke dispersal conditions.
On Monday, the upper-level ridge is forecast to back away from the coastline, with another upper-level disturbance dropping southeastward across eastern Washington and northeastern Oregon.  That will renew the threat of showers across mainly the northern and eastern zones with the snow level dropping to 4000 feet north and 5000 feet south.  Colder air aloft will lift mixing heights with improving smoke dispersal conditions in the afternoon.  Transport winds will be mostly southwest to west across the northern zones and northwest to north across the southern zones.

2.  DISPERSION

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

MORNING

Mixing height below 1000 ft early rising to 1000 - 2000 ft by late morning.

Transport wind SSW to WSW at 8 - 12 mph.

Surface wind S to SW at 5 - 9 mph.

AFTERNOON

Mixing height 1600 - 2600 ft.

Transport wind SW to W at 8 - 12 mph.

Surface wind similar to morning.

EVENING

Mixing height 1000 - 1700 ft.

Transport wind SW to WNW at 4 - 8 mph.

Surface wind becomes light and variable and controlled by local terrain.

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

MORNING

Mixing height below 500 ft early rising to 1000 - 1600 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 1500 - 2500 ft.

Transport wind shifts to NNW to NNE at 4 - 8 mph.

Surface wind similar to morning.

EVENING

Mixing height lowers below 1000 ft.

Transport wind becomes light and variable and controlled by local terrain.

Surface wind similar to afternoon.

OUTLOOK:

SATURDAY

Mixing height below 1000 ft early rising to 1200 to 2200 ft by late morning rising to 1800 to 2800 ft during the afternoon.  Transport wind light and variable during the morning becoming SW to W at 6 - 12 mph during the afternoon.  Surface wind light and variable during the morning becoming SW to W at 4 - 8 mph during the afternoon.

SUNDAY

Mixing height below 1000 ft early rising to 1000 to 1900 ft by late morning and through the afternoon.  Transport wind WSW to WNW at 4 - 8 mph.  Surface wind light and variable.

MONDAY

Mixing height below 1000 ft early rising to 1000 to 1700 ft by late morning rising to 2400 to 3400 ft during the afternoon.  Transport wind WSW to WNW at 5 - 9 mph during the morning becoming WNW to NW at 8 - 12 mph during the afternoon.  Surface wind light and variable during the morning becoming W to NW 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 Friday, February 4, 2011.

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Coast Range

Zone 601, 612, and 616 east of R9W

Units should be 500 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.)

Zone 602, 603, and 620

No burning allowed.  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 15 miles apart, south of the Siuslaw River in Zone 603.  Some burning allowed south of the Rogue River in Zone 620.  Call the forecaster.

Zone 615

Units should be 1500 tons or less, spaced 15 miles apart, and 15 miles from downwind SSRAs.

Zone 616 west of R8W

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

Zone 618 and 619

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

Cascades

Zone 605, 606, 607, 608, 609, 616, 617, and 623

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 15 miles apart.  South of T30S in Zone 616 units should be 500 tons or less, spaced 15 miles apart.  South of T30S in Zone 617 units should be 500 tons or less, spaced 15 miles apart.

Zone 610 and 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

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

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

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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