SMI Northeast (Smoke Management Instructions) Northeast Oregon Smoke Management Instructions

[ODF Smoke Management Instructions]

SMOKE MANAGEMENT FORECAST AND INSTRUCTIONS

SALEM FORESTRY WEATHER CENTER

OREGON DEPARTMENT OF FORESTRY



ISSUED: Friday, October 8, 2010       2:35 PM      Pete Parsons



1.  DISCUSSION AND FORECAST FOR NORTHEAST FORECAST AREA ZONES 630-638



SATURDAY



The jet stream is transitioning to a more autumn-like pattern.  A developing westerly flow aloft helped to eject the upper-level low pressure system that has been bringing showers to much of the region eastward into the northern Rockies on Friday.  It also pushed a very weak cold front into north-central Oregon by Friday afternoon.  That system was causing an increase in the southwesterly transport winds, with improving ventilation conditions.  Radar showed some light showers, associated with the decaying front, pushing across north-central Oregon Friday afternoon.



A stronger system, with some entrained tropical moisture, will approach the coastline early Saturday.  The bulk of the moisture from this system is forecast to stay north and west of the region.  The cold front is forecast to stall and push north, as a warm front, Saturday afternoon and evening. Southerly transport winds will continue to improve ventilation conditions, but warming aloft and cloud-cover will keep afternoon mixing heights somewhat suppressed.  Smoke dispersal conditions will be fair.


OUTLOOK (SUNDAY-TUESDAY)


Rain will increase, from west to east, across the entire region Sunday, as a strong cold front comes onshore and sweeps across the state.  Increasing southwesterly transport winds will greatly improve ventilation conditions.  Winds will veer to westerly, in the wake of the cold front, Sunday evening.  There will not be much post-frontal shower activity, because the air aloft will stay fairly mild.  The snow level should stay above 7000 feet.



The flow aloft is forecast to dry out and turn northwesterly on Monday.  There will likely still be enough mixing and instability for a few mountain showers, mainly in the morning.  Transport winds will turn more northerly, and begin to weaken, in the afternoon.  Even with some afternoon sunshine, mixing heights will be suppressed by subsidence aloft, associated with the building ridge of high pressure.  Smoke dispersal conditions will be only fair.



As the upper-level ridge continues to build over the region, strong surface-based inversions are likely by Tuesday morning.  Areas of morning valley fog are possible, especially for areas that get appreciable rain on Sunday.  Mostly sunny skies are expected by the afternoon, but low mixing heights and light transport winds will likely make for marginal to poor ventilation conditions.



2.  DISPERSION



SATURDAY



Zone 630 and 632:

Mixing height below 1000 ft early rising to 2000 - 3000 ft by late morning.  Afternoon mixing height rises to 3500 - 4500 ft then lowers to 1000 - 2000 ft during the evening.



Transport wind SSW to SW at 10 - 18 mph during the morning and afternoon.  Transport wind decreases to SW to WNW at 4 - 8 mph during the evening.



Surface wind SSE to SSW at 4 - 8 mph during the morning and afternoon.  Surface wind becomes light and variable and controlled by local terrain during the evening.



Zone 633 - 638:

Mixing height below 1000 ft early rising to 2000 - 3000 ft by late morning.  Afternoon mixing height rises to 3500 - 4500 ft then lowers to 1000 - 2000 ft during the evening.



Transport wind SSE to SW at 6 - 10 mph during the morning and afternoon.  Transport wind becomes light and variable and controlled by local terrain during the evening.



Surface wind SE to SSW at 4 - 8 mph during the morning.  Surface wind becomes light and variable and controlled by local terrain during the afternoon and evening.



OUTLOOK:



SUNDAY

Mixing height below 1000 ft early rising to 2500 to 3500 ft by late morning rising to 4000 to 5000 ft during the afternoon.  Transport wind light and variable 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 - 12 mph during the afternoon.



MONDAY

Mixing height 1500 to 2500 ft during the morning rising to 2700 to 3700 ft during the afternoon.  Transport wind NW to NNE at 4 - 8 mph.  Surface wind light and variable.



TUESDAY

Mixing height below 1000 ft early rising to 1000 to 2000 ft by late morning rising to 2500 to 3500 ft during the afternoon.  Transport wind light and variable.  Surface wind light and variable.



3.  BURNING INSTRUCTIONS FOR NORTHEAST OREGON ZONES 630-638

    The following considerations should be adhered to in addition to

    the requirements of the Oregon Smoke Management Plan. These

    Instructions are valid for burning conducted on Saturday, October 9, 2010.

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



Zone 630 and 632:

Avoid ignitions within 15 miles to the S through WNW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 30 miles to the S through WNW in or near drainages leading to SSRAs.  Recommend against burning units that will smolder significantly overnight.  Complete ignitions by 4 p.m.



Zone 633 - 638:

Avoid ignitions within 15 miles to the SE through WSW of SSRAs.  For units that will smolder significantly through the night avoid burning within at least 30 miles to the SE through WSW in or near drainages leading to SSRAs.  Recommend against burning units that will smolder significantly overnight.  Complete ignitions by 4 p.m.



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

4.  SPECIAL NOTE:



    The smoke management forecaster is available at (503)-

    945-7401. Please call this number and not individual's

    numbers to discuss daily burning.  For large burns (over

    2000 tons) or burns extending over a considerable period,

    please request a special forecast.  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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