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

Wed Nov 10 15:37:25 PST 2010

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY

***Amended to add this statement regarding forecasted winds for Friday***

 - Computer models are showing a north to northeasterly wind-flow pattern developing across southwestern Oregon Friday and increasing slightly during the day.  Confidence is high that a northerly component to the wind will develop and increase during the afternoon, but the wind speeds will mostly be less than 10 mph.  Wind speeds will be strongest in the afternoon and across southern Coos, southwestern Douglas, Curry and western Josephine Counties.

ISSUED: Wednesday, November 10, 2010       3:30 PM      Pete Parsons

***Due to the Veterans Day holiday, there will be no smoke forecaster available on Thursday, November 11th and no forecasts will be issued.  Friday's burning instructions will be issued early Friday morning.

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

THURSDAY

A transitory upper-level ridge of high pressure will slide east of the region, around midday, with a weak cold front coming onshore in the late afternoon and evening.  Ahead of the front, transport winds will be mostly southerly with smoke dispersal conditions fair north and only marginal to fair south. Between one-tenth and one-quarter of an inch of rain is expected north, beginning late in the day, with generally one-tenth of an inch or less south.  Transport winds will turn more westerly late, with snow levels lowering to near 4000 feet.  Precipitation is forecast to turn showery and taper off overnight.

OUTLOOK (FRIDAY-SUNDAY)

A flat upper-level ridge, in the eastern Gulf of Alaska, will bring a drying and cool northwesterly flow aloft to the region on Friday.  There may still be a few residual morning showers, mainly north.  Transport winds will be variable across the north but will likely turn northerly over the southern zones.  The building upper-level ridge will act to suppress mixing heights somewhat, especially south, with marginal to fair smoke dispersal conditions.  A stabilizing air mass will quickly drop mixing heights in the evening.

A broad upper-level ridge will continue to amplify offshore, Saturday and Sunday, with a strong north-northwesterly flow aloft over Oregon.  Skies should stay mostly cloudy with a chance of light rain at times, mainly north.  There may also be areas of morning valley fog, mainly south.  Northern mountains could pick up as much as one-tenth of an inch of rain, over the weekend, while many southern locations stay dry.  The snow level will rise above 8000 feet.  Warming aloft will suppress mixing heights with marginal to poor smoke dispersion.

2.  DISPERSION

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

MORNING

Mixing height below 500 ft early rising to 1600 - 2600 ft by late morning.

Transport wind SSE to SSW at 8 - 12 mph.

Surface wind SE to SSW at 4 - 8 mph.

AFTERNOON

Mixing height rising to 3300 - 4300 ft.

Transport wind increases to SSW to WSW at 15 - 29 mph.

Surface wind increases to SSE to SSW at 9 - 15 mph.

EVENING

Mixing height 2000 - 3000 ft.

Transport wind WSW to WNW at 12 - 22 mph.

Surface wind shifts to SW to W and decreases to 4 - 8 mph.

Zone 605-611 (North Cascades):

MORNING

Mixing height below 500 ft early rising to 1500 - 2500 ft by late morning.

Transport wind SSE to SW at 4 - 8 mph.

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

AFTERNOON

Mixing height rising to 3300 - 4300 ft.

Transport wind increases to SSW to WSW at 12 - 24 mph.

Surface wind increases to S to SW at 6 - 12 mph.

EVENING

Mixing height 2000 - 3000 ft.

Transport wind SW to W at 12 - 24 mph.

Surface wind similar to afternoon.

Zone 615-620 (South Coast Range):

MORNING

Mixing height below 500 ft early rising to 1500 - 2500 ft by late morning.

Transport wind SSE to SSW at 5 - 9 mph.

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

AFTERNOON

Mixing height 2500 - 3500 ft.

Transport wind SSW to WSW at 8 - 12 mph.

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

EVENING

Mixing height 1000 - 2000 ft.

Transport wind similar to afternoon.

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

Zone 616-623 (South Cascades):

MORNING

Mixing height below 500 ft early rising to 1000 - 1700 ft by late morning.

Transport wind SSE to SSW at 4 - 8 mph.

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

AFTERNOON

Mixing height rising to 1900 - 2900 ft.

Transport wind shifts to SSW to WSW at 4 - 8 mph.

Surface wind similar to morning.

EVENING

Mixing height 1300 - 2300 ft.

Transport wind SW to W at 4 - 8 mph.

Surface wind similar to afternoon.

OUTLOOK:

FRIDAY

Mixing height below 1000 ft early rising to 1100 to 2100 ft by late morning rising to 2400 to 3400 ft during the afternoon.  Transport wind light and variable during the morning becoming NNW to NE at 6 - 10 mph during the afternoon.  Surface wind light and variable during the morning becoming NNW to NNE at 4 - 8 mph during the afternoon.

SATURDAY

Mixing height below 1000 ft early rising to 1000 to 1600 ft by late morning rising to 1600 to 2600 ft during the afternoon.  Transport wind light and variable during the morning becoming SSW to WSW at 4 - 8 mph during the afternoon.  Surface wind light and variable.

SUNDAY

Mixing height below 1000 ft during the morning rising to 1400 to 2400 ft during the afternoon.  Transport wind light and variable during the morning becoming WNW to NNW at 4 - 8 mph 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 Thursday, November 11, 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, 616 west of R8W, 619, and 620

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.  South of T35S in Zone 620 units should be 500 tons or less, spaced 10 miles apart, and 12 miles from downwind SSRAs.

Zone 618

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

Cascades

All zones except zone 611

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 10 miles apart, and 12 miles from downwind SSRAs.

Siskiyous

Units should be 750 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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