SMI South Central (Smoke Management Instructions) South Central Smoke Management Instructions

[ODF Smoke Management Instructions]

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY



ISSUED: Friday, November 19, 2010       2:40 PM      Pete Parsons



1.  DISCUSSION AND FORECAST FOR SOUTH CENTRAL OREGON ZONES 624 AND 625



SATURDAY



A cold upper-level trough will remain anchored over the region with the trough axis staying just offshore. A fairly strong upper-air disturbance will drop southward, into the parent trough, with a corresponding surface low-pressure center developing off the Washington coast and drifting southeastward during the day.



A moist southwesterly flow aloft will maintain mostly cloudy skies with snow showers.  Transport winds should turn mostly southerly with good smoke dispersal conditions.  Look for snow to increase late, with accumulations likely, as the surface low-pressure area comes onshore.


OUTLOOK (SUNDAY-TUESDAY)

A cold upper-level trough will remain over the region, on Sunday.  One disturbance will rotate inland, across northern California, with accumulating snow likely across most of the region.  Expect good smoke dispersal conditions with westerly transport winds. Snow may taper off in the afternoon, but another upper-level disturbance is forecast to drop southward, from British Columbia, to just off the Washington and northern Oregon coast, by late in the day.  That system should bring a renewed threat of snow to the region by Sunday night, along with even colder air.



By Monday, the flow aloft is forecast to turn northwesterly, with an even colder upper-level system dropping southward, from British Columbia, into the region.  This system will be accompanied by a surface Arctic cold front, which will usher the coldest air of the season into the region.  The track of this system is still uncertain, but it will likely bring accumulating snow to the entire region by late in the day.  Smoke dispersal conditions should remain good with brisk westerly transport winds.



On Tuesday, a very cold and drier northerly flow is forecast, with sub-freezing temperatures and snow-covered ground likely.  Skies will stay partly to mostly cloudy with a chance of light snow showers.  Cold low-level air will stabilize the air mass, with light winds and only marginal to fair smoke dispersal conditions.



2.  DISPERSION



SATURDAY

Mixing height below 2500 ft early rising to 3000 - 4000 ft by late morning.  Afternoon mixing height rises above 5000 ft then lowers to 1500 - 2500 ft during the evening.



Transport wind SSW to SW at 18 - 32 mph during the morning.  Transport wind decreases to S to SSW at 13 - 25 mph during the afternoon and evening.



Surface wind SSE to SSW at 8 - 12 mph.



OUTLOOK:



SUNDAY

Mixing height below 1000 ft early rising to 2000 - 3000 ft by late morning rising above 5000 ft during the afternoon.  Transport wind WNW to NNW at 6 - 12 mph during the morning becoming WSW to WNW at 15 - 25 mph during the afternoon.  Surface wind light and variable during the morning becoming WSW to WNW at 8 - 12 mph during the afternoon.



MONDAY

Mixing height 2500 - 3500 ft during the morning rising above 5000 ft during the afternoon.  Transport wind WSW to WNW at 15 - 29 mph during the morning becoming WNW to NW at 22 - 38 mph during the afternoon.  Surface wind WSW to WNW at 9 - 15 mph.



TUESDAY

Mixing height below 1000 ft early rising to 1800 - 2800 ft by late morning rising to 3300 - 4300 ft during the afternoon.  Transport wind WNW to NW at 8 - 12 mph.  Surface wind light and variable.



3.  BURNING INSTRUCTIONS FOR ZONES 624 AND 625 INCLUDING THE WALKER

    RANGE PORTION OF ZONE 624

This instruction is valid for burning conducted on Saturday, November 20, 2010.

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Avoid ignitions within 15 miles to the SSE through SW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 30 miles in all directions of SSRAs.  Recommend against burning units that will smolder significantly overnight.  Complete ignitions by 2:30 p.m.



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

4.  SPECIAL NOTE:



    The smoke management forecaster is available at (503)

    945-7401.  The smoke management forecaster is available

    to discuss specific burns.  The duty forecaster phone

    number is (503) 945-7401. Please call this number and

    not individual's numbers to discuss daily burning. Please

    avoid calling before 8 a.m. and between 2 to 3 p.m.



    This 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

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