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

Thu Apr 28 14:34:43 PDT 2011

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

ISSUED: Thursday, April 28, 2011       2:30 PM      Pete Parsons

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

FRIDAY

The axis of an unseasonably cold upper-level trough is forecast to slowly push east of the state with a continued cool and somewhat unstable northwesterly flow aloft. Scattered showers are likely, mainly north and over higher terrain south, with a slight chance of afternoon thunderstorms and small hail.  The snow level will start out near 1500 feet north and 2500 feet south, before rising to 3000 feet north and 4000 feet south in the afternoon.  Afternoon temperatures will be well below normal, with good mixing and northwesterly transport winds.

OUTLOOK (SATURDAY-MONDAY)
An upper-level ridge is forecast to build offshore Saturday with a drier and more stable northwesterly flow aloft over Oregon.  Look for partly cloudy skies.  The snow level will only rise to 3500 feet north and 4500 feet south.  The air aloft will remain cold enough for daytime heating to possibly trigger a few showers, mainly north and over higher terrain. After a chilly morning, afternoon temperatures will moderate slightly but remain below normal.  Mixing should be good with transport winds veering from northwesterly to northerly.

A weak upper-level ridge axis is forecast to move onshore Sunday, with generally sunny skies expected.  Temperatures should rebound to above normal with a surface thermal trough building northward, into southwestern Oregon, and turning transport winds offshore.  The freezing level will jump to 9000 feet north and 10,000 feet south.  Warming aloft will stabilize the air mass, with fair to good afternoon mixing.

The transitory 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 only bring light rain to the northern zones, with the southern zones likely staying dry, for a change.  A lack of cold air aloft with this system will only drop snow levels to around 4000 feet north and 6000 feet south.  Surface temperatures will drop back below normal with good mixing and increasing onshore transport winds.

2.  DISPERSION

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

MORNING

Mixing height below 2500 ft early rising to 3000 - 4000 ft by late morning.

Transport wind WNW to NNW at 9 - 15 mph.

Surface wind W to NW at 4 - 8 mph.

AFTERNOON

Mixing height rising above 5000 ft.

Transport wind NW to NNW at 10 - 22 mph.

Surface wind WNW to NW at 8 - 12 mph.

EVENING

Mixing height 2500 - 3500 ft.

Transport wind WNW to NNW at 9 - 15 mph.

Surface wind similar to afternoon.

Zone 605-611 (North Cascades):

MORNING

Mixing height below 2500 ft early rising to 3000 - 4000 ft by late morning.

Transport wind WNW to NW at 9 - 15 mph.

Surface wind WSW to WNW at 4 - 8 mph.

AFTERNOON

Mixing height rising above 5000 ft.

Transport wind WNW to NW at 10 - 22 mph.

Surface wind similar to morning.

EVENING

Mixing height 2500 - 3500 ft.

Transport wind WNW to NW at 9 - 15 mph.

Surface wind similar to afternoon.

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

MORNING

Mixing height below 2500 ft early rising to 3000 - 4000 ft by late morning.

Transport wind WNW to NNW at 10 - 18 mph.

Surface wind W to NW at 6 - 10 mph.

AFTERNOON

Mixing height rising above 5000 ft.

Transport wind NW to NNW at 12 - 22 mph.

Surface wind NW to N at 8 - 12 mph.

EVENING

Mixing height 2000 - 3000 ft.

Transport wind decreases to NNW to NNE at 8 - 12 mph.

Surface wind NW to NNE at 5 - 9 mph.

OUTLOOK:

SATURDAY

Mixing height 2200 to 3200 ft during the morning rising above 5000 ft during the afternoon.  Transport wind NW to N at 6 - 10 mph during the morning becoming NNW to NNE at 10 - 16 mph during the afternoon.  Surface wind NW to N at 4 - 8 mph.

SUNDAY

Mixing height below 1000 ft early rising to 2000 to 3000 ft by late morning rising to 3800 to 4800 ft during the afternoon.  Transport wind E to SE at 6 - 10 mph during the morning becoming ESE to SSE at 4 - 8 mph during the afternoon.  Surface wind light and variable.

MONDAY

Mixing height below 1000 ft early rising to 2800 to 3800 ft by late morning rising above 5000 ft during the afternoon.  Transport wind SSW to WSW at 10 - 18 mph during the morning becoming WSW to WNW at 10 - 18 mph during the afternoon.  Surface wind light and variable during the morning becoming W to NW at 6 - 10 mph during the afternoon.

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

These instructions are valid for burning conducted on Friday, April 29, 2011.

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Coast Range

Zone 601 and 612

Units should be 1000 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.  Restrict units in or near corridors to 500 tons or less.  Higher tonnage is possible south of Waldport in Zone 612.  Call the forecaster.

Zone 602, 603, and 620

Units should be 500 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.  Avoid burning in or near corridors.  Higher tonnage is possible south of the Siuslaw River in Zone 603.  Call the forecaster.  Higher tonnage is possible south of the Rogue River in Zone 620.  Call the forecaster.

Zone 615, 618, and 619

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

Zone 616 west of R8W

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

Zone 616 east of R9W

Units should be 750 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.  Restrict units to 500 tons or less south of T30S.

Cascades

Zone 605, 606, 607, 608, 609, 611, 616, 617, and 623

Use standard guidance matrix. (See section 5 below.)  Ensure adequate distance from downwind SSRAs for smoke to dissipate.  From T12S through T17S in Zone 608 units should be 1000 tons or less, spaced 5 miles apart.  South of T30S in Zone 616 units should be 500 tons or less, spaced 5 miles apart.

Zone 610

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

Zone 620 and 622

Units should be 500 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.  East of R2W in Zone 622, use standard guidance matrix. (See section 5 below.)

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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