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

Wed Nov 4 15:28:50 PST 2009

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS
SALEM FORESTRY WEATHER CENTER
OREGON DEPARTMENT OF FORESTRY

ISSUED: Wednesday, November 4, 2009       2:30 PM      Jim Little

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

A very deep upper level low will sit in the northern Gulf of Alaska on Thursday.  This will support a very deep surface low in the same location.  The surface low to the north will give the Pacific Northwest a strong south-to-north pressure gradient for strong south winds through much of Oregon.  Strongest winds will be along the northern Oregon Coast where wind gusts to above 50mph are possible.  A Pacific cold front will spread some light rain to the coast early.  The rain will spread eastward, covering all of western Oregon by early evening.  Rainfall amounts in the northern coast range could top two inches, with lesser amounts elsewhere.  Cooler air aloft will destabilize the atmosphere and mixing heights will top 5000 feet throughout the day.  That, combined with the brisk southerly winds will make for good smoke dispersal conditions all areas.

    OUTLOOK (FRIDAY-SUNDAY)

The upper low remains in the northern Gulf of Alaska and a strong upper level jet (120mph) swings around the bottom of the low and into the Pacific Northwest.  Expect periods of rain Friday, then an increase in the rain Friday night as another Pacific cold front moves through.  This will be followed by another system Saturday evening.  Showers will continue Sunday.  Snow levels Saturday and Sunday will be in the 3500 to 4500 foot range.  High mixing heights and occasional windy conditions mean good smoke dispersal conditions throughout the outlook period.

2.  DISPERSION

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

MORNING
Mixing height above 5000 ft.
Transport wind SSW at 22 - 38 mph.
Surface wind S to SW at 12 - 22 mph.

AFTERNOON
Mixing height above 5000 ft.
Transport wind SSW at 26 - 46 mph.
Surface wind SSW to SW at 15 - 29 mph.

EVENING
Mixing height 3500 - 4500 ft.
Transport wind SSW at 26 - 46 mph.
Surface wind SSW to SW at 15 - 29 mph.

Zone 605-611 (North Cascades):

MORNING
Mixing height above 5000 ft.
Transport wind SSW to SW at 15 - 25 mph.
Surface wind SSW to SW at 12 - 24 mph.

AFTERNOON
Mixing height above 5000 ft.
Transport wind SSW to SW at 15 - 25 mph.
Surface wind SSW to SW at 12 - 24 mph.

EVENING
Mixing height 4100 - 5000 ft.
Transport wind SSW to SW at 16 - 30 mph.
Surface wind SSW to SW at 15 - 29 mph.

Zone 615-620 (South Coast Range):

MORNING
Mixing height above 5000 ft.
Transport wind SSW at 18 - 32 mph.
Surface wind S to SSW at 13 - 25 mph.

AFTERNOON
Mixing height above 5000 ft.
Transport wind SSW at 22 - 38 mph.
Surface wind SSW to SW at 16 - 30 mph.

EVENING
Mixing height 4000 - 5000 ft.
Transport wind SW at 18 - 32 mph.
Surface wind SSW to SW at 15 - 25 mph.

Zone 616-623 (South Cascades):

MORNING
Mixing height 3900 - 4900 ft.
Transport wind S to SW at 15 - 25 mph.
Surface wind S to SW at 10 - 22 mph.

AFTERNOON
Mixing height above 5000 ft.
Transport wind SSW to SW at 18 - 30 mph.
Surface wind SSW to SW at 15 - 25 mph.

EVENING
Mixing height 3700 - 4700 ft.
Transport wind similar to afternoon.
Surface wind S to SW at 12 - 22 mph.

OUTLOOK:

FRIDAY
Mixing height 3400 to 4400 ft during the morning rising to 4300 to 5000 ft during the afternoon.  Transport wind SW to WSW at 14 - 28 mph.  Surface wind SW to WSW at 10 - 22 mph.

SATURDAY
Mixing height 2200 to 3200 ft during the morning rising above 5000 ft during the afternoon.  Transport wind SSW to WSW at 9 - 15 mph during the morning becoming WSW to WNW at 10 - 16 mph during the afternoon.  Surface wind light and variable.

SUNDAY
Mixing height 2000 to 3000 ft during the morning rising to 3500 to 4500 ft during the afternoon.  Transport wind light and variable during the morning becoming SSE to SSW 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 5, 2009.
=================================================================

Coast Range

All Zones
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 1000 tons or less, spaced 5 miles apart, and 10 miles from downwind SSRAs.

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

==============================================================
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.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://omls.oregon.gov/pipermail/smi_west/attachments/20091104/b94c50bb/attachment.html>